Author: "Donskov, S." - Searchworks@Jio Institute Digital Library Search Results

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945 results on '"Donskov, S."'

51. Longitudinal double-spin asymmetry $A_1^{\rm p}$ and spin-dependent structure function $g_1^{\rm p}$ of the proton at small values of $x$ and $Q^2$

Author: Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Antoshkin, A., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Bressan, A., Buechele, M., Burtsev, V. E., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chumakov, A. G., Chung, S. -U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duennweber, W., Dusaev, R. R., Dziewiecki, M., Efremov, A., Eversheim, P. D., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grasso, A., Gridin, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Kerbizi, A., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kral, Z., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Kuznetsov, I. I., Kveton, A., Lednev, A. A., Levchenko, E. A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Lyubovitskij, V. E., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Mamon, S. A., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Moretti, A., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peskova, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rogacheva, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Tasevsky, M., Tessaro, S., Tessarotto, F., Thiel, A., Tomsa, J., Tosello, F., Tskhay, V., Uhl, S., Vasilishin, B. I., Vauth, A., Veloso, J., Vidon, A., Virius, M., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Experiment
Abstract: We present a precise measurement of the proton longitudinal double-spin asymmetry $A_1^{\rm p}$ and the proton spin-dependent structure function $g_1^{\rm p}$ at photon virtualities $0.006~({\rm GeV}/c)^2
Published: 2017
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52. Search for vector mediator of Dark Matter production in invisible decay mode

Author: NA64 Collaboration, Banerjee, D., Burtsev, V. E., Chumakov, A. G., Cooke, D., Crivelli, P., Depero, E., Dermenev, A. V., Donskov, S. V., Dubinin, F., Dusaev, R. R., Emmenegger, S., Fabich, A., Frolov, V. N., Gardikiotis, A., Gerassimov, S. G., Gninenko, S. N., Hosgen, M., Karneyeu, A. E., Ketzer, B., Kirpichnikov, D. V., Kirsanov, M. M., Konorov, I. V., Kovalenko, S. G., Kramarenko, V. A., Kravchuk, L. V., Krasnikov, N. V., Kuleshov, S. V., Lyubovitskij, V. E., Lysan, V., Matveev, V. A., Mikhailov, Yu. V., Peshekhonov, D. V., Polyakov, V. A., Radics, B., Rubbia, A., Samoylenko, V. D., Tikhomirov, V. O., Tlisov, D. A., Toropin, A. N., Trifonov, A. Yu., Vasilishin, B. I., Arenas, G. Vasquez, and Ulloa, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: A search is performed for a new sub-GeV vector boson ($A'$) mediated production of Dark Matter ($\chi$) in the fixed-target experiment, NA64, at the CERN SPS. The $A'$, called dark photon, could be generated in the reaction $ e^- Z \to e^- Z A'$ of 100 GeV electrons dumped against an active target which is followed by the prompt invisible decay $A' \to \chi \overline{\chi}$. The experimental signature of this process would be an event with an isolated electron and large missing energy in the detector. From the analysis of the data sample collected in 2016 corresponding to $4.3\times10^{10}$ electrons on target no evidence of such a process has been found. New stringent constraints on the $A'$ mixing strength with photons, $10^{-5}\lesssim \epsilon \lesssim 10^{-2}$, for the $A'$ mass range $m_{A'} \lesssim 1$ GeV are derived. For models considering scalar and fermionic thermal Dark Matter interacting with the visible sector through the vector portal the 90% C.L. limits $10^{-11}\lesssim y \lesssim 10^{-6}$ on the dark-matter parameter $y = \epsilon^2 \alpha_D (\frac{m_\chi}{m_{A'}})^4 $ are obtained for the dark coupling constant $\alpha_D = 0.5$ and dark-matter masses $0.001 \lesssim m_\chi \lesssim 0.5 $ GeV. The lower limits $\alpha_D \gtrsim 10^{-3} $ for pseudo-Dirac Dark Matter in the mass region $m_\chi \lesssim 0.05 $ GeV are more stringent than the corresponding bounds from beam dump experiments. The results are obtained by using tree level, exact calculations of the $A'$ production cross-sections, which turn out to be significantly smaller compared to the one obtained in the Weizs\"{a}cker-Williams approximation for the mass region $m_{A'} \gtrsim 0.1$ GeV., Comment: 22 pages, 17 figures, version accepted for publication in PRD
Published: 2017
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53. Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

Author: Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Antoshkin, A., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Bressan, A., Buechele, M., Burtsev, V. E., Capozza, L., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chumakov, A. G., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duennweber, W., Dusaev, R. R., Dziewiecki, M., Efremov, A., Eversheim, P. D., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grasso, A., Gridin, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Kerbizi, A., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kral, Z., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Kuznetsov, I. I., Kveton, A., Lednev, A. A., Levchenko, E. A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Lyubovitskij, V. E., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Mamon, S. A., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Moretti, A., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peskova, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rogacheva, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Tasevsky, M., Tessaro, S., Tessarotto, F., Thiel, A., Tomsa, J., Tosello, F., Tskhay, V., Uhl, S., Vasilishin, B. I., Vauth, A., Veloso, J., Vidon, A., Virius, M., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality $Q^{2}>1$ (GeV/$c$)$^2$, invariant mass of the hadronic system $W > 5$ GeV/$c^2$, Bjorken scaling variable in the range $0.003 < x < 0.4$, fraction of the virtual photon energy carried by the hadron in the range $0.2 < z < 0.8$, square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/$c)^2 < P_{\rm{hT}}^{2} < 3$ (GeV/$c$)$^2$. The multiplicities are presented as a function of $P_{\rm{hT}}^{2}$ in three-dimensional bins of $x$, $Q^2$, $z$ and compared to previous semi-inclusive measurements. We explore the small-$P_{\rm{hT}}^{2}$ region, i.e. $P_{\rm{hT}}^{2} < 1$ (GeV/$c$)$^2$, where hadron transverse momenta are expected to arise from non-perturbative effects, and also the domain of larger $P_{\rm{hT}}^{2}$, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small $P_{\rm{hT}}^{2}$ to study the dependence of the average transverse momentum $\langle P_{\rm{hT}}^{2}\rangle$ on $x$, $Q^2$ and $z$. The power-law behaviour of the multiplicities at large $P_{\rm{hT}}^{2}$ is investigated using various functional forms. The fits describe the data reasonably well over the full measured range., Comment: 28 pages, 20 figures
Published: 2017
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54. Search for heavy neutrino in $K^{+} \to \mu^{+} \nu_{H}$ decay

Author: Sadovsky, A. S., Kurshetsov, V. F., Filin, A. P., Akimenko, S. A., Artamonov, A. V., Blik, A. M., Brekhovskikh, V. V., Burtovoy, V. S., Donskov, S. V., Inyakin, A. V., Gorin, A. M., Khaustov, G. V., Kholodenko, S. A., Kolosov, V. N., Konstantinov, A. S., Leontiev, V. M., Lishin, V. A., Medynsky, M. V., Mikhailov, Yu. V., Obraztsov, V. F., Polyakov, V. A., Popov, A. V., Romanovsky, V. I., Rykalin, V. I., Samoilenko, V. D., Semenov, V. K., Stenyakin, O. V., Tchikilev, O. G., Uvarov, V. A., Yushchenko, O. P., Duk, V. A., Filippov, S. N., Gushchin, E. N., Khudyakov, A. A., Kravtsov, V. I., Kudenko, Yu. G., Polyarush, A. Yu., Bychkov, V. N., Kekelidze, G. D., Lysan, V. M., and Zalikhanov, B. Zh.
Subjects: High Energy Physics - Experiment
Abstract: A high statistics data sample of the $K^{+}\to\mu^{+}\nu_{\mu}$ decay was accumulated by the OKA experiment in 2012. The missing mass analysis was performed to search for the decay channel $K^{+}\to\mu^{+}\nu_{H}$ with a hypothetic stable heavy neutrino in the final state. The obtained missing mass spectrum does not show peaks which could be attributed to existence of stable heavy neutrinos in the mass range (220 $< m_{\nu_{H}} <$ 375) MeV$/c^{2}$. As a result, we obtain upper limits on the branching ratio and on the value of the mixing element $|U_{\mu H}|^{2}$., Comment: 11 pages, 10 figures
Published: 2017
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55. $K_{e3}$ decay studies in OKA experiment

Author: Yushchenko, O. P., Kurshetsov, V. F., Filin, A. P., Akimenko, S. A., Artamonov, A. V., Blik, A. M., Brekhovskikh, V. V., Burtovoy, V. S., Donskov, S. V., Inyakin, A. V., Gorin, A. M., Khaustov, G. V., Kholodenko, S. A., Kolosov, V. N., Konstantinov, A. S., Leontiev, V. M., Lishin, V. A., Medynsky, M. V., Mikhailov, Yu. V., Obraztsov, V. F., Polyakov, V. A., Popov, A. V., Romanovsky, V. I., Rykalin, V. I., Sadovsky, A. S., Samoilenko, V. D., Semenov, V. K., Stenyakin, O. V., Tchikilev, O. G., Uvarov, V. A., Duk, V. A., Filippov, S. N., Guschin, E. V., Kudenko, Yu. G., Khudyakov, A. A., Kravtsov, V. I., Polyarush, A. Yu., Bychkov, V. N., Kekelidze, G. D., Lysan, V. M., and Zalikhanov, B. Zh.
Subjects: High Energy Physics - Experiment
Abstract: Recent results from OKA setup concerning form factor studies in $K_{e3}$ decay are presented. About 5.25M events are selected for the analysis. The linear and quadratic slopes for the decay formfactor $f_{+}(t)$ are measured: $\lambda'_{+}=(26.1 \pm 0.35 \pm 0.28 )\times 10^{-3}$, $\lambda"_{+}=(1.91 \pm 0.19 \pm 0.14)\times 10^{-3}$. The scalar and tensor contributions are compatible with zero. Several alternative parametrizations are tried: the Pole fit parameter is found to be $M_V = 891 \pm 2.0$ MeV ; the parameter of the Dispersive parametrization is measured to be $\Lambda_+ =(24.58 \pm 0.18) \times 10^{-3}$. The presented results are considered as preliminary.
Published: 2017
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56. Performance of Multiplexed XY Resistive Micromegas detectors in a high intensity beam

Author: Banerjee, D., Burtsev, V., Chumakov, A., Cooke, D., Depero, E., Dermenev, A. V., Donskov, S. V., Dubinin, F., Dusaev, R. R., Emmenegger, S., Fabich, A., Frolov, V. N., Gardikiotis, A., Gninenko, S. N., Hösgen, M., Karneyeu, A. E., Ketzer, B., Kirsanov, M. M., Konorov, I. V., Kramarenko, V. A., Kuleshov, S. V., Levchenko, E., Lyubovitskij, V. E., Lysan, V., Mamon, S., Matveev, V. A., Mikhailov, Yu. V., Myalkovskiy, V. V., Peshekhonov, V. D., Peshekhonov, D. V., Polyakov, V. A., Radics, B., Rubbia, A., Samoylenko, V. D., Tikhomirov, V. O., Tlisov, D. A., Toropin, A. N., Vasilishin, B., Arenas, G. Vasquez, Ulloa, P., and Crivelli, P.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: We present the performance of multiplexed XY resistive Micromegas detectors tested in the CERN SPS 100 GeV/c electron beam at intensities up to 3.3 $\times$ 10$^5$ e$^- $/(s$\cdot$cm$^2$). So far, all studies with multiplexed Micromegas have only been reported for tests with radioactive sources and cosmic rays. The use of multiplexed modules in high intensity environments was not explored due to the effect of ambiguities in the reconstruction of the hit point caused by the multiplexing feature. At the beam intensities analysed in this work and with a multiplexing factor of 5, more than 50% level of ambiguity is introduced. Our results prove that by using the additional information of cluster size and integrated charge from the signal clusters induced on the XY strips, the ambiguities can be reduced to a level below 2%. The tested detectors are used in the CERN NA64 experiment for tracking the incoming particles bending in a magnetic field in order to reconstruct their momentum. The average hit detection efficiency of each module was found to be $\sim$ 96% at the highest beam intensities. By using four modules a tracking resolution of 1.1% was obtained with $\sim$ 85% combined tracking efficiency.
Published: 2017
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57. New analysis of $\eta\pi$ tensor resonances measured at the COMPASS experiment

Author: Jackura, A., Fernandez-Ramirez, C., Mikhasenko, M., Pilloni, A., Mathieu, V., Nys, J., Pauk, V., Szczepaniak, A. P., Fox, G., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Antoshkin, A., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Bressan, A., Buechele, M., Burtsev, V. E., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chumakov, A. G., Chung, S. -U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duennweber, W., Dusaev, R. R., Dziewiecki, M., Efremov, A., Eversheim, P. D., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Kerbizi, A., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kral, Z., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Kuznetsov, I. I., Kveton, A., Lednev, A. A., Levchenko, E. A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Lyubovitskij, V. E., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Mamon, S. A., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peskova, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rogacheva, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schluter, T., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Tasevsky, M., Tessaro, S., Tessarotto, F., Thiel, A., Tomsa, J., Tosello, F., Tskhay, V., Uhl, S., Vasilishin, B. I., Vauth, A., Veloso, J., Vidon, A., Virius, M., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Phenomenology, High Energy Physics - Experiment
Abstract: We present a new amplitude analysis of the $\eta\pi$ $D$-wave in $\pi^- p\to \eta\pi^- p$ measured by COMPASS. Employing an analytical model based on the principles of the relativistic $S$-matrix, we find two resonances that can be identified with the $a_2(1320)$ and the excited $a_2^\prime(1700)$, and perform a comprehensive analysis of their pole positions. For the mass and width of the $a_2$ we find $M=(1307 \pm 1 \pm 6)$~MeV and $\Gamma=(112 \pm 1 \pm 8)$~MeV, and for the excited state $a_2^\prime$ we obtain $M=(1720 \pm 10 \pm 60)$~MeV and $\Gamma=(280\pm 10 \pm 70)$~MeV, respectively., Comment: 15 pages, 6 figures
Published: 2017
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58. Search for muoproduction of $X(3872)$ at COMPASS and indication of a new state $\widetilde{X}(3872)$

Author: Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Antoshkin, A., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Bressan, A., Buechele, M., Burtsev, V. E., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chumakov, A. G., Chung, S. -U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duennweber, W., Dusaev, R. R., Dziewiecki, M., Efremov, A., Eversheim, P. D., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grasso, A., Gridin, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Kerbizi, A., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kral, Z., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Kuznetsov, I. I., Kveton, A., Lednev, A. A., Levchenko, E. A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Lyubovitskij, V. E., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Mamon, S. A., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peskova, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rogacheva, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Tasevsky, M., Tessaro, S., Tessarotto, F., Thiel, A., Tomsa, J., Tosello, F., Tskhay, V., Uhl, S., Vasilishin, B. I., Vauth, A., Veloso, J., Vidon, A., Virius, M., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Experiment
Abstract: We have searched for exclusive production of exotic charmonia in the reaction $\mu^+~N \rightarrow \mu^+ (J\!/\!\psi\pi^+\pi^-)\pi^{\pm}~N'$ using COMPASS data collected with incoming muons of 160 GeV/$c$ and 200 GeV/$c$ momentum. In the $J\!/\!\psi\pi^+\pi^-$ mass distribution we observe a signal with a statistical significance of 4.1 $\sigma$. Its mass and width are consistent with those of the $X(3872)$. The shape of the $\pi^+\pi^-$ mass distribution from the observed decay into $J\!/\!\psi\pi^+\pi^-$ shows disagreement with previous observations for $X(3872)$. The observed signal may be interpreted as a possible evidence of a new charmonium state. It could be associated with a neutral partner of $X(3872)$ with $C = -1$ predicted by a tetraquark model. The product of cross section and branching fraction of the decay of the observed state into $J\!/\!\psi\pi^+\pi^-$ is determined to be 71$\pm$28(stat)$\pm$39(syst) pb., Comment: 12 pages, 6 figures
Published: 2017
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59. First measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process

Author: Aghasyan, Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Antoshkin, A., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Kerbizi, A., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kral, Z., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Kveton, A., Lednev, A. A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rogacheva, N. S., Roskot, M., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Tasevsky, M., Tessaro, S., Tessarotto, F., Thiel, A., Tomsa, J., Tosello, F., Tskhay, V., Uhl, S., Vauth, A., Veloso, J., Virius, M., Vondra, J., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190 GeV/$c$, $\pi^{-}$ beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3 GeV/$c^2$ and 8.5 GeV/$c^2$. The observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of Quantum Chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. These DY results are obtained at a hard scale comparable to that of a recent COMPASS SIDIS measurement and hence allow unique tests of fundamental QCD universality predictions., Comment: 11 pages, 6 figures
Published: 2017
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60. High purity 100 GeV electron identification with synchrotron radiation

Author: Depero, E., Banerjee, D., Burtsev, V., Chumakov, A., Cooke, D., Dermenev, A. V., Donskov, S. V., Dubinin, F., Dusaev, R. R., Emmenegger, S., Fabich, A., Frolov, V. N., Gardikiotis, A., Gninenko, S. N., Hösgen, M., Karneyeu, A. E., Ketzer, B., Kirsanov, M. M., Konorov, I. V., Kramarenko, V. A., Kuleshov, S. V., Lyubovitskij, V. E., Lysan, V., Matveev, V. A., Mikhailov, Yu. V., Myalkovskiy, V. V., Peshekhonov, V. D., Peshekhonov, D. V., Polyakov, V. A., Radics, B., Rubbia, A., Samoylenko, V. D., Tikhomirov, V. O., Tlisov, D. A., Toropin, A. N., Vasilishin, B., Arenas, G. Vasquez, Ulloa, P., and Crivelli, P.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: In high energy experiments such as active beam dump searches for rare decays and missing energy events, the beam purity is a crucial parameter. In this paper we present a technique to reject heavy charged particle contamination in the 100 GeV electron beam of the H4 beam line at CERN SPS. The method is based on the detection with BGO scintillators of the synchrotron radiation emitted by the electrons passing through a bending dipole magnet. A 100 GeV $\pi^-$ beam is used to test the method in the NA64 experiment resulting in a suppression factor of $10^{-5}$ while the efficiency for electron detection is $\sim$95%. The spectra and the rejection factors are in very good agreement with the Monte Carlo simulation. The reported suppression factors are significantly better than previously achieved., Comment: 10 pages, 6 figures
Published: 2017
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61. The active muon shield in the SHiP experiment

Author: SHiP collaboration, Akmete, A., Alexandrov, A., Anokhina, A., Aoki, S., Atkin, E., Azorskiy, N., Back, J. J., Bagulya, A., Baranov, A., Barker, G. J., Bay, A., Bayliss, V., Bencivenni, G., Berdnikov, A. Y., Berdnikov, Y. A., Bertani, M., Betancourt, C., Bezshyiko, I., Bezshyyko, O., Bick, D., Bieschke, S., Blanco, A., Boehm, J., Bogomilov, M., Bondarenko, K., Bonivento, W. M., Boyarsky, A., Brenner, R., Breton, D., Brundler, R., Bruschi, M., Büscher, V., Buonaura, A., Buontempo, S., Cadeddu, S., Calcaterra, A., Campanelli, M., Chauveau, J., Chepurnov, A., Chernyavsky, M., Choi, K. -Y., Chumakov, A., Ciambrone, P., Dallavalle, G. M., D'Ambrosio, N., D'Appollonio, G., De Lellis, G., De Roeck, A., De Serio, M., Dedenko, L., Di Crescenzo, A., Di Marco, N., Dib, C., Dijkstra, H., Dmitrenko, V., Domenici, D., Donskov, S., Dubreuil, A., Ebert, J., Enik, T., Etenko, A., Fabbri, F., Fabbri, L., Fedin, O., Fedorova, G., Felici, G., Ferro-Luzzi, M., Fini, R. A., Fonte, P., Franco, C., Fukuda, T., Galati, G., Gavrilov, G., Gerlach, S., Golinka-Bezshyyko, L., Golubkov, D., Golutvin, A., Gorbunov, D., Gorbunov, S., Gorkavenko, V., Gornushkin, Y., Gorshenkov, M., Grachev, V., Graverini, E., Grichine, V., Guler, A. M., Guz, Yu., Hagner, C., Hakobyan, H., van Herwijnen, E., Hollnagel, A., Hosseini, B., Hushchyn, M., Iaselli, G., Iuliano, A., Jacobsson, R., Jonker, M., Kadenko, I., Kamiscioglu, C., Kamiscioglu, M., Khabibullin, M., Khaustov, G., Khotyantsev, A., Kim, S. H., Kim, V., Kim, Y. G., Kitagawa, N., Ko, J. -W., Kodama, K., Kolesnikov, A., Kolev, D. I., Kolosov, V., Komatsu, M., Konovalova, N., Korkmaz, M. A., Korol, I., Korol'ko, I., Korzenev, A., Kovalenko, S., Krasilnikova, I., Krivova, K., Kudenko, Y., Kurochka, V., Kuznetsova, E., Lacker, H. M., Lai, A., Lanfranchi, G., Lantwin, O., Lauria, A., Lebbolo, H., Lee, K. Y., Lévy, J. -M., Likacheva, V., Lopes, L., Lyubovitskij, V., Maalmi, J., Magnan, A., Maleev, V., Malinin, A., Mefodev, A., Mermod, P., Mikado, S., Mikhaylov, Yu., Milstead, D. A., Mineev, O., Montanari, A., Montesi, M. C., Morishima, K., Movchan, S., Naganawa, N., Nakamura, M., Nakano, T., Novikov, A., Obinyakov, B., Ogawa, S., Okateva, N., Owen, P. H., Paoloni, A., Park, B. D., Paparella, L., Pastore, A., Patel, M., Pereyma, D., Petrenko, D., Petridis, K., Podgrudkov, D., Poliakov, V., Polukhina, N., Prokudin, M., Prota, A., Rademakers, A., Ratnikov, F., Rawlings, T., Razeti, M., Redi, F., Ricciardi, S., Roganova, T., Rogozhnikov, A., Rokujo, H., Rosa, G., Rovelli, T., Ruchayskiy, O., Ruf, T., Samoylenko, V., Saputi, A., Sato, O., Savchenko, E. S., Schmidt-Parzefall, W., Serra, N., Shakin, A., Shaposhnikov, M., Shatalov, P., Shchedrina, T., Shchutska, L., Shevchenko, V., Shibuya, H., Shustov, A., Silverstein, S. B., Simone, S., Skorokhvatov, M., Smirnov, S., Sohn, J. Y., Sokolenko, A., Starkov, N., Storaci, B., Strolin, P., Takahashi, S., Timiryasov, I., Tioukov, V., Tosi, N., Treille, D., Tsenov, R., Ulin, S., Ustyuzhanin, A., Uteshev, Z., Vankova-Kirilova, G., Vannucci, F., Venkova, P., Vilchinski, S., Villa, M., Vlasik, K., Volkov, A., Voronkov, R., Wanke, R., Woo, J. -K., Wurm, M., Xella, S., Yilmaz, D., Yilmazer, A. U., Yoon, C. S., and Zaytsev, Yu.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: The SHiP experiment is designed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. An essential task for the experiment is to keep the Standard Model background level to less than 0.1 event after $2\times 10^{20}$ protons on target. In the beam dump, around $10^{11}$ muons will be produced per second. The muon rate in the spectrometer has to be reduced by at least four orders of magnitude to avoid muon-induced combinatorial background. A novel active muon shield is used to magnetically deflect the muons out of the acceptance of the spectrometer. This paper describes the basic principle of such a shield, its optimization and its performance., Comment: 8 pages, 5 figures; added clarifications to the penalty function and emphasized that we care about neutrino interactions in the air
Published: 2017
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62. First Results in the Search for Dark Sectors at NA64 with the CERN SPS High Energy Muon Beam

Author: Andreev, Yu. M., primary, Banerjee, D., additional, Banto Oberhauser, B., additional, Bernhard, J., additional, Bisio, P., additional, Charitonidis, N., additional, Crivelli, P., additional, Depero, E., additional, Dermenev, A. V., additional, Donskov, S. V., additional, Dusaev, R. R., additional, Enik, T., additional, Frolov, V. N., additional, Gardikiotis, A., additional, Gertsenberger, S. V., additional, Girod, S., additional, Gninenko, S. N., additional, Hösgen, M., additional, Joosten, R., additional, Kachanov, V. A., additional, Kambar, Y., additional, Karneyeu, A. E., additional, Kasianova, E. A., additional, Kekelidze, G., additional, Ketzer, B., additional, Kirpichnikov, D. V., additional, Kirsanov, M. M., additional, Kolosov, V. N., additional, Kramarenko, V. A., additional, Kravchuk, L. V., additional, Krasnikov, N. V., additional, Kuleshov, S. V., additional, Lyubovitskij, V. E., additional, Lysan, V., additional, Matveev, V. A., additional, Mena Fredes, R., additional, Mena Yanssen, R. G., additional, Molina Bueno, L., additional, Mongillo, M., additional, Peshekhonov, D. V., additional, Polyakov, V. A., additional, Radics, B., additional, Salamatin, K. M., additional, Samoylenko, V. D., additional, Shchukin, D. A., additional, Soto, O., additional, Sieber, H., additional, Tikhomirov, V. O., additional, Tlisova, I. V., additional, Toropin, A. N., additional, Tuzi, M., additional, Veit, M. B., additional, Volkov, P. V., additional, Volkov, V. Yu., additional, Voronchikhin, I. V., additional, Zamora-Saá, J., additional, and Zhevlakov, A. S., additional
Published: 2024
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63. First measurement of the Sivers asymmetry for gluons from SIDIS data

Author: Adolph, C., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Antoshkin, A., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Kerbizi, A., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rogacheva, N. S., Roskot, M., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Thiel, A., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The Sivers function describes the correlation between the transverse spin of a nucleon and the transverse motion of its partons. It was extracted from measurements of the azimuthal asymmetry of hadrons produced in semi-inclusive deep inelastic scattering of leptons off transversely polarised nucleon targets, and it turned out to be non-zero for quarks. In this letter the evaluation of the Sivers asymmetry for gluons in the same process is presented. The analysis method is based on a Monte Carlo simulation that includes three hard processes: photon-gluon fusion, QCD Compton scattering and leading-order virtual-photon absorption process. The Sivers asymmetries of the three processes are simultaneously extracted using the LEPTO event generator and a neural network approach. The method is applied to samples of events containing at least two hadrons with large transverse momentum from the COMPASS data taken with a 160 GeV/$c$ muon beam scattered off transversely polarised deuterons and protons. With a significance of more than two standard deviations a negative value is obtained for the gluon Sivers asymmetry. The result of a similar analysis for a Collins-like asymmetry for gluons is consistent with zero., Comment: 18 pages, 8 figures
Published: 2017
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64. Final COMPASS results on the deuteron spin-dependent structure function $g_1^{\rm d}$ and the Bjorken sum rule

Author: Adolph, C., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Kerbizi, A., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Roskot, M., Rossiyskaya, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Thiel, A., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Wallner, S., Weisrock, T., Wilfert, M., Windmolders, R., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment
Abstract: Final results are presented from the inclusive measurement of deep-inelastic polarised-muon scattering on longitudinally polarised deuterons using a $^6$LiD target. The data were taken at $160~{\rm GeV}$ beam energy and the results are shown for the kinematic range $1~({\rm GeV}/c)^2 < Q^2 < 100~({\rm GeV}/c)^2$ in photon virtuality, $0.004 4~{\rm GeV}/c^2$ in the mass of the hadronic final state. The deuteron double-spin asymmetry $A_1^{\rm d}$ and the deuteron longitudinal-spin structure function $g_1^{\rm d}$ are presented in bins of $x$ and $Q^2$. Towards lowest accessible values of $x$, $g_1^{\rm d}$ decreases and becomes consistent with zero within uncertainties. The presented final $g_1^{\rm d}$ values together with the recently published final $g_1^{\rm p}$ values of COMPASS are used to again evaluate the Bjorken sum rule and perform the QCD fit to the $g_1$ world data at next-to-leading order of the strong coupling constant. In both cases, changes in central values of the resulting numbers are well within statistical uncertainties. The flavour-singlet axial charge $a_0$, {which is identified in the $\overline{\rm MS}$ renormalisation scheme with the total contribution of quark helicities to the nucleon spin}, is extracted from only the COMPASS deuteron data with negligible extrapolation uncertainty: $a_0 (Q^2 = 3~({\rm GeV}/c)^2) = 0.32 \pm 0.02_{\rm stat} \pm0.04_{\rm syst} \pm 0.05_{\rm evol}$. Together with the recent results on the proton spin structure function $g_1^{\rm p}$, the results on $g_1^{\rm d}$ constitute the COMPASS legacy on the measurements of $g_1$ through inclusive spin-dependent deep inelastic scattering., Comment: 16 pages, 6 figures
Published: 2016
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65. Search for invisible decays of sub-GeV dark photons in missing-energy events at the CERN SPS

Author: NA64 Collaboration, Banerjee, D., Burtsev, V., Cooke, D., Crivelli, P., Depero, E., Dermenev, A. V., Donskov, S. V., Dubinin, F., Dusaev, R. R., Emmenegger, S., Fabich, A., Frolov, V. N., Gardikiotis, A., Gninenko, S. N., Hosgen, M., Kachanov, V. A., Karneyeu, A. E., Ketzer, B., Kirpichnikov, D. V., Kirsanov, M. M., Kovalenko, S. G., Kramarenko, V. A., Kravchuk, L. V., Krasnikov, N. V., Kuleshov, S. V., Lyubovitskij, V. E., Lysan, V., Matveev, V. A., Mikhailov, Yu. V., Myalkovskiy, V. V., Peshekhonov, V. D., Peshekhonov, D. V., Petuhov, O., Polyakov, V. A., Radics, B., Rubbia, A., Samoylenko, V. D., Tikhomirov, V. O., Tlisov, D. A., Toropin, A. N., Trifonov, A. Yu., Vasilishin, B., Arenas, G. Vasquez, Ulloa, P., Zhukov, K., and Zioutas, K.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: We report on a direct search for sub-GeV dark photons (A') which might be produced in the reaction e^- Z \to e^- Z A' via kinetic mixing with photons by 100 GeV electrons incident on an active target in the NA64 experiment at the CERN SPS. The A's would decay invisibly into dark matter particles resulting in events with large missing energy. No evidence for such decays was found with 2.75\cdot 10^{9} electrons on target. We set new limits on the \gamma-A' mixing strength and exclude the invisible A' with a mass < 100 MeV as an explanation of the muon g_\mu-2 anomaly., Comment: 6 pages, 3 figures; Typos corrected, references added
Published: 2016
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66. Sivers asymmetry extracted in SIDIS at the hard scale of the Drell-Yan process at COMPASS

Author: Adolph, C., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Roskot, M., Rossiyskaya, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Sozzi, F., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Thiel, A., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Proton transverse-spin azimuthal asymmetries are extracted from the COMPASS 2010 semi-inclusive hadron measurements in deep inelastic muon-nucleon scattering in those four regions of the photon virtuality $Q^2$, which correspond to the four regions of the di-muon mass $\sqrt{Q^2}$ used in the ongoing analysis of the COMPASS Drell-Yan measurements. This allows for a future direct comparison of the nucleon transverse-momentum-dependent parton distribution functions extracted from these two alternative measurements. Various two-dimensional kinematic dependences are presented for the azimuthal asymmetries induced by the Sivers transverse-momentum-dependent parton distribution function. The integrated Sivers asymmetries are found to be positive with an accuracy that appears to be sufficient to test the sign change of the Sivers function predicted by Quantum Chromodynamics., Comment: 13 pages, 6 figures
Published: 2016
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67. Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons

Author: Adolph, C., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Roskot, M., Rossiyskaya, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Thiel, A., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Single hadron azimuthal asymmetries of positive and negative hadrons produced in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also combined all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle $\phi$ is obtained by means of a five-parameter fitting function that besides a $\phi$-independent term includes four modulations predicted by theory: $\sin\phi$, $\sin 2 \phi$, $\sin 3\phi$ and $\cos\phi$. The amplitudes of the five terms have been extracted, first, for the hadrons in the whole available kinematic region. In further fits, performed for hadrons from a restricted kinematic region, the $\phi$-dependence is determined as a function of one of three variables (Bjorken-$x$, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the others. Except the $\phi$-independent term, all the modulation amplitudes are very small, and no clear kinematic dependence could be observed within experimental uncertainties., Comment: 15 pages, 5 figures
Published: 2016
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68. Multiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target

Author: Adolph, C., Agarwala, J., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Augsten, K., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bodlak, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Capozza, L., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., Hamar, G., von Harrach, D., Heinsius, F. H., Heitz, R., Herrmann, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jary, V., Joosten, R., Joeorg, P., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Nagaytsev, A., Nerling, F., Neyret, D., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Roskot, M., Rossiyskaya, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Srnka, A., Steffen, D., Stolarski, M., Subrt, O., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Thiel, A., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Wallner, S., Weisrock, T., Wilfert, M., Windmolders, R., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Precise measurements of charged-kaon multiplicities in deep inelastic scattering were performed. The results are presented in three-dimensional bins of the Bjorken scaling variable x, the relative virtual-photon energy y, and the fraction z of the virtual-photon energy carried by the produced hadron. The data were obtained by the COMPASS Collaboration by scattering 160 GeV muons off an isoscalar 6 LiD target. They cover the kinematic domain 1 (GeV/c)2 < Q2 < 60 (GeV/c)^2 in the photon virtuality, 0.004 < x < 0.4, 0.1 < y < 0.7, 0.20 < z < 0.85, and W > 5 GeV/c^2 in the invariant mass of the hadronic system. The results from the sum of the z-integrated K+ and K- multiplicities at high x point to a value of the non-strange quark fragmentation function larger than obtained by the earlier DSS fit., Comment: 10 pages, 9 figures
Published: 2016
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69. Exclusive $\omega$ meson muoproduction on transversely polarised protons

Author: Adolph, C., Agarwala, J., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Heitz, R., Herrmann, F., Hinterberger, F., Horikawa, N., dHose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lian, Y. -S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, M., Meyer, W., Michigami, T., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Montuenga, P., Nagaytsev, A., Nerling, F., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Pierre, N., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Roskot, M., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Seder, E., Selyunin, A., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Sozzi, F., Srnka, A., Steffen, D., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Wallner, S., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Exclusive production of $\omega$ mesons was studied at the COMPASS experiment by scattering $160~\mathrm{GeV}/\mathit{c}$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality $1~(\mathrm{GeV}/\mathit{c})^2 < Q^2 < 10~(\mathrm{GeV}/\mathit{c})^2$, Bjorken scaling variable $0.003 < x_{\mathit{Bj}} < 0.3$ and transverse momentum squared of the $\omega$ meson $0.05~(\mathrm{GeV}/\mathit{c})^2 < p_{T}^{2} < 0.5~(\mathrm{GeV}/\mathit{c})^2$. The measured asymmetries are sensitive to the nucleon helicity-flip Generalised Parton Distributions (GPD) $E$ that are related to the orbital angular momentum of quarks, the chiral-odd GPDs $H_{T}$ that are related to the transversity Parton Distribution Functions, and the sign of the $\pi\omega$ transition form factor. The results are compared to recent calculations of a GPD-based model., Comment: 23 pages, 9 figures
Published: 2016
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70. Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target

Author: Adolph, C., Agarwala, J., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Capozza, L., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Heitz, R., Herrmann, F., Hinterberger, F., Horikawa, N., dHose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kuhn, R., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, W., Michigami, T., Mikhailov, Yu. V., Mikhasenko, M., Mitrofanov, E., Mitrofanov, N., Miyachi, Y., Montuenga, P., Nagaytsev, A., Nerling, F., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Roskot, M., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Seder, E., Selyunin, A., Shevchenko, O. Yu., Steffen, D., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Sozzi, F., Srnka, A., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Weisrock, T., Wilfert, M., Windmolders, R., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Multiplicities of charged pions and unidentified hadrons produced in deep-inelastic scattering were measured in bins of the Bjorken scaling variable $x$, the relative virtual-photon energy $y$ and the relative hadron energy $z$. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and an isoscalar target ($^6$LiD). They cover the kinematic domain in the photon virtuality $Q^2$ > 1(GeV/c$)^2$, $0.004 < x < 0.4$, $0.2 < z < 0.85$ and $0.1 < y < 0.7$. In addition, a leading-order pQCD analysis was performed using the pion multiplicity results to extract quark fragmentation functions.
Published: 2016
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71. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

Author: Adolph, C., Aghasyan, M., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anfimov, N. V., Anosov, V., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Chang, W. -C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Heitz, R., Herrmann, F., Hinterberger, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Joosten, R., Joerg, P., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kulinich, Y., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G. V., Meyer, W., Michigami, T., Mikhailov, Yu. V., Mikhasenko, M., Miyachi, Y., Montuenga, P., Nagaytsev, A., Nerling, F., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Roskot, M., Rossiyskaya, N. S., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Seder, E., Selyunin, A., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Smolik, J., Sozzi, F., Srnka, A., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tasevsky, M., Tessaro, S., Tessarotto, F., Thibaud, F., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Vondra, J., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_{\rm T}$, the different $p_{\rm T}$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\mu^2= \langle Q^2 \rangle = 3 ({\rm GeV}/c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_{\rm g}$, covering the range $0.04 \!<\! x_{ \rm g}\! <\! 0.28$~ and does not exhibit a significant dependence on $x_{\rm g}$. The average over the three intervals, $\langle \Delta g/g \rangle = 0.113 \pm 0.038_{\rm (stat.)}\pm 0.036_{\rm (syst.)}$ at $\langle x_{\rm g} \rangle \approx 0.10$, suggests that the gluon polarisation is positive in the measured $x_{\rm g}$ range., Comment: 14 pages, 6 figures
Published: 2015

72. Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high $p_T$

Author: COMPASS Collaboration, Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badełek, B., Balestra, F., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Büchele, M., Burtin, E., Chang, W. -C., Chiosso, M., Choi, I., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Dünnweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmüller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Joosten, R., Jörg, P., Kabuß, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Königsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Krämer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kuchinski, N., Kuhn, R., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Marianski, B., Martin, A., Marzec, J., Matoušek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Montuenga, P., Nagaytsev, A., Nerling, F., Neyret, D., Nikolaenko, V. I., Nový, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pešek, M., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schönning, K., Schopferer, S., Selyunin, A., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sozzi, F., Srnka, A., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tessaro, S., Tessarotto, F., Thibaud, F., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: We measured the longitudinal double spin asymmetries $A_{LL}$ for single hadron muo-production off protons and deuterons at photon virtuality $Q^2$ < 1(GeV/$\it c$)$^2$ for transverse hadron momenta $p_T$ in the range 0.7 GeV/$\it c$ to 4 GeV/$\it c$ . They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/$\it c$ or 200 GeV/$\it c$ impinging on polarised $\mathrm{{}^6LiD}$ or $\mathrm{NH_3}$ targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation $\Delta G$ inside the nucleon in the range of the nucleon momentum fraction carried by gluons $0.05 < x_g < 0.2$.
Published: 2015

73. Resonance Production and $\pi\pi$ S-wave in $\pi^- + p \rightarrow \pi^- \pi^- \pi^+ + p_{recoil}$ at 190 GeV/c

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badełek, B., Balestra, F., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Büchele, M., Burtin, E., Chang, W. -C., Chiosso, M., Choi, I., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Dünnweber, W., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmüller, S., Grasso, A., Perdekamp, M. Grosse, Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Horikawa, N., d'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Joosten, R., Jörg, P., Kabuß, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Königsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Krämer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Marianski, B., Martin, A., Marzec, J., Matoušek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Montuenga, P., Nagaytsev, A., Nerling, F., Neyret, D., Nikolaenko, V. I., Nový, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pešek, M., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schlüter, T., Schmidt, K., Schmieden, H., Schönning, K., Schopferer, S., Selyunin, A., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sozzi, F., Srnka, A., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., Tessaro, S., Tessarotto, F., Thibaud, F., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Weisrock, T., Wilfert, M., ter Wolbeek, J., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The COMPASS collaboration has collected the currently largest data set on diffractively produced $\pi^-\pi^-\pi^+$ final states using a negative pion beam of 190 GeV/c momentum impinging on a stationary proton target. This data set allows for a systematic partial-wave analysis in 100 bins of three-pion mass, $0.5 < m_{3\pi} < 2.5$ GeV/c$^2$ , and in 11 bins of the reduced four-momentum transfer squared, $0.1 < t < 1.0$ (GeV/c)$^2$ . This two-dimensional analysis offers sensitivity to genuine one-step resonance production, i.e. the production of a state followed by its decay, as well as to more complex dynamical effects in nonresonant $3\pi$ production. In this paper, we present detailed studies on selected $3\pi$ partial waves with $J^{PC} = 0^{-+}$, $1^{++}$, $2^{-+}$, $2^{++}$, and $4^{++}$. In these waves, we observe the well-known ground-state mesons as well as a new narrow axial-vector meson $a_1(1420)$ decaying into $f_0(980) \pi$. In addition, we present the results of a novel method to extract the amplitude of the $\pi^-\pi^+$ subsystem with $I^{G}J^{PC} = 0^+ 0^{++}$ in various partial waves from the $\pi^-\pi^-\pi^+$ data. Evidence is found for correlation of the $f_0(980)$ and $f_0(1500)$ appearing as intermediate $\pi^- \pi^+$ isobars in the decay of the known $\pi(1800)$ and $\pi_2(1880)$., Comment: 96 pages
Published: 2015
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74. Interplay among transversity induced asymmetries in hadron leptoproduction

Author: Compass Collaboration, Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Augustyniak, W., Austregesilo, A., Azevedo, C. D. R., Badelek, B., Balestra, F., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Büchele, M., Burtin, E., Chang, W. -C., Chiosso, M., Choi, I., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., d'Hose, N., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmüller, S., Grasso, A., Grosse-Perdekamp, M., Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Horikawa, N., Hsieh, C. -Yu, Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jörg, P., Joosten, R., Kabuß, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Königsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Krämer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Marianski, B., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Montuenga, P., Nagaytsev, A., Nerling, F., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nukazuka, G., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesaro, G., Pesek, M., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schönning, K., Schopferer, S., Selyunin, A., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sozzi, F., Srnka, A., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Weisrock, T., Wilfert, M., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: In the fragmentation of a transversely polarized quark several left-right asymmetries are possible for the hadrons in the jet. When only one unpolarized hadron is selected, it exhibits an azimuthal modulation known as Collins effect. When a pair of oppositely charged hadrons is observed, three asymmetries can be considered, a di-hadron asymmetry and two single hadron asymmetries. In lepton deep inelastic scattering on transversely polarized nucleons all these asymmetries are coupled with the transversity distribution. From the high statistics COMPASS data on oppositely charged hadron-pair production we have investigated for the first time the dependence of these three asymmetries on the difference of the azimuthal angles of the two hadrons. The similarity of transversity induced single and di-hadron asymmetries is discussed. A new analysis of the data allows to establish quantitative relationships among them, providing for the first time strong experimental indication that the underlying fragmentation mechanisms are all driven by a common physical process., Comment: 6 figures
Published: 2015
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75. A facility to Search for Hidden Particles (SHiP) at the CERN SPS

Author: SHiP Collaboration, Anelli, M., Aoki, S., Arduini, G., Back, J. J., Bagulya, A., Baldini, W., Baranov, A., Barker, G. J., Barsuk, S., Battistin, M., Bauche, J., Bay, A., Bayliss, V., Bellagamba, L., Bencivenni, G., Bertani, M., Bezshyyko, O., Bick, D., Bingefors, N., Blondel, A., Bogomilov, M., Boyarsky, A., Bonacorsi, D., Bondarenko, D., Bonivento, W., Borburgh, J., Bradshaw, T., Brenner, R., Breton, D., Brook, N., Bruschi, M., Buonaura, A., Buontempo, S., Cadeddu, S., Calcaterra, A., Calviani, M., Campanelli, M., Capoccia, C., Cecchetti, A., Chatterjee, A., Chauveau, J., Chepurnov, A., Chernyavskiy, M., Ciambrone, P., Cicalo, C., Conti, G., Cornelis, K., Courthold, M., Dallavalle, M. G., D'Ambrosio, N., De Lellis, G., De Serio, M., Dedenko, L., Di Crescenzo, A., Di Marco, N., Dib, C., Dietrich, J., Dijkstra, H., Domenici, D., Donskov, S., Druzhkin, D., Ebert, J., Egede, U., Egorov, A., Egorychev, V., Alaoui, M. A. El, Enik, T., Etenko, A., Fabbri, F., Fabbri, L., Fedorova, G., Felici, G., Ferro-Luzzi, M., Fini, R. A., Franke, M., Fraser, M., Galati, G., Giacobbe, B., Goddard, B., Golinka-Bezshyyko, L., Golubkov, D., Golutvin, A., Gorbunov, D., Graverini, E., Grenard, J-L, Guler, A. M., Hagner, C., Hakobyan, H., Helo, J. C., van Herwijnen, E., Horvath, D., Iacovacci, M., Iaselli, G., Jacobsson, R., Kadenko, I., Kamiscioglu, M., Kamiscioglu, C., Khaustov, G., Khotjansev, A., Kilminster, B., Kim, V., Kitagawa, N., Kodama, K., Kolesnikov, A., Kolev, D., Komatsu, M., Konovalova, N., Koretskiy, S., Korolko, I., Korzenev, A., Kovalenko, S., Kudenko, Y., Kuznetsova, E., Lacker, H., Lai, A., Lanfranchi, G., Lauria, A., Lebbolo, H., Levy, J. -M., Lista, L., Loverre, P., Lukiashin, A., Lyubovitskij, V. E., Malinin, A., Manfredi, M., Perillo-Marcone, A., Marrone, A., Matev, R., Messomo, E. N., Mermod, P., Mikado, S., Mikhaylov, Yu., Miller, J., Milstead, D., Mineev, O., Mingazheva, R., Mitselmakher, G., Miyanishi, M., Monacelli, P., Montanari, A., Montesi, M. C., Morello, G., Morishima, K., Movtchan, S., Murzin, V., Naganawa, N., Naka, T., Nakamura, M., Nakano, T., Nurakhov, N., Obinyakov, B., Ocalan, K., Ogawa, S., Oreshkin, V., Orlov, A., Osborne, J., Pacholek, P., Panman, J., Paoloni, A., Paparella, L., Pastore, A., Patel, M., Petridis, K., Petrushin, M., Poli-Lener, M., Polukhina, N., Polyakov, V., Prokudin, M., Puddu, G., Pupilli, F., Rademakers, F., Rakai, A., Rawlings, T., Redi, F., Ricciardi, S., Rinaldesi, R., Roganova, T., Rogozhnikov, A., Rokujo, H., Romaniouk, A., Rosa, G., Rostovtseva, I., Rovelli, T., Ruchayskiy, O., Ruf, T., Saitta, G., Samoylenko, V., Samsonov, V., Ull, A. Sanz, Saputi, A., Sato, O., Schmidt-Parzefall, W., Serra, N., Sgobba, S., Shaposhnikov, M., Shatalov, P., Shaykhiev, A., Shchutska, L., Shevchenko, V., Shibuya, H., Shitov, Y., Silverstein, S., Simone, S., Skorokhvatov, M., Smirnov, S., Solodko, E., Sosnovtsev, V., Spighi, R., Spinetti, M., Starkov, N., Storaci, B., Strabel, C., Strolin, P., Takahashi, S., Teterin, P., Tioukov, V., Tommasini, D., Treille, D., Tsenov, R., Tshchedrina, T., Ustyuzhanin, A., Vannucci, F., Venturi, V., Villa, M., Vincke, Heinz, Vincke, Helmut, Vladymyrov, M., Xella, S., Yalvac, M., Yershov, N., Yilmaz, D., Yilmazer, A. U., Vankova-Kirilova, G., Zaitsev, Y., and Zoccoli, A.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: A new general purpose fixed target facility is proposed at the CERN SPS accelerator which is aimed at exploring the domain of hidden particles and make measurements with tau neutrinos. Hidden particles are predicted by a large number of models beyond the Standard Model. The high intensity of the SPS 400~GeV beam allows probing a wide variety of models containing light long-lived exotic particles with masses below ${\cal O}$(10)~GeV/c$^2$, including very weakly interacting low-energy SUSY states. The experimental programme of the proposed facility is capable of being extended in the future, e.g. to include direct searches for Dark Matter and Lepton Flavour Violation., Comment: Technical Proposal
Published: 2015

76. The Spin Structure Function $g_1^{\rm p}$ of the Proton and a Test of the Bjorken Sum Rule

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Azevedo, C., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, G. R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chang, W. -C., Chiosso, M., Choi, I., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giordano, F., Gnesi, I., Gorzellik, M., Grabmüller, S., Grasso, A., Grosse-Perdekamp, M., Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Horikawa, N., d'Hose, N., Hsieh, C. -Yu, Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jörg, P., Joosten, R., Kabuß, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Longo, R., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rocco, E., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Selyunin, A., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sozzi, F., Srnka, A., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Tosello, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Weisrock, T., Wilfert, M., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: New results for the double spin asymmetry $A_1^{\rm p}$ and the proton longitudinal spin structure function $g_1^{\rm p}$ are presented. They were obtained by the COMPASS collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH$_3$ target. The data were collected in 2011 and complement those recorded in 2007 at 160\,GeV, in particular at lower values of $x$. They improve the statistical precision of $g_1^{\rm p}(x)$ by about a factor of two in the region $x\lesssim 0.02$. A next-to-leading order QCD fit to the $g_1$ world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, $\Delta \Sigma$ ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of $g_1^{\rm p}$. The uncertainty of $\Delta \Sigma$ is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function $g_1^{\rm NS}(x,Q^2)$ yields as ratio of the axial and vector coupling constants $|g_{\rm A}/g_{\rm V}| = 1.22 \pm 0.05~({\rm stat.}) \pm 0.10~({\rm syst.})$, which validates the sum rule to an accuracy of about 9\%., Comment: 19 pages, 8 figures and tables
Published: 2015
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77. On detection of narrow angle e+e- pairs from dark photon decays

Author: Dermenev, A. V., Donskov, S. V., Gninenko, S. N., Kuleshov, S. B., Matveev, V. A., Myalkovskiy, V. V., Peshekhonov, V. D., Poliakov, V. A., Savenkov, A. A., Tikhomirov, V. O., and Zhukov, I. A.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: A class of models of dark sectors consider new very weak interaction between the ordinary and dark matter transmitted by U'(1) gauge bosons A' (dark photons) mixing with our photons. If such A's exist, they could be searched for in a light-shining-through-a-wall experiment with a high energy electron beam from the CERN SPS. The proposed search scheme suggests detection of the e+e- pairs produced in the A' -> e+e- decay with a very small opening angle. Coordinate chambers based on the thin-wall drift tubes with a minimal material budget and a two-hit resolution for e+ and e- tracks separated by more than 0.5 mm are considered as an option for detecting such pairs.
Published: 2015
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78. Upper Limit on the K+ → π0π0π0e+ν Decay.

Author: Artamonov, A. V., Bychkov, V. N., Donskov, S. V., Filin, A. P., Filippov, S. N., Gorin, A. M., Gushchin, E. N., Inyakin, A. V., Kekelidze, G. D., Khaustov, G. V., Kholodenko, S. A., Khudyakov, A. A., Kolosov, V. N., Konoplyannikov, A. K., Kravtsov, V. I., Kudenko, Yu. G., Kulik, A. V., Kurshetsov, V. F., Lishin, V. A., and Lysan, V. M.
Subjects: SIGNALS & signaling
Abstract: A search for the decay is performed by the OKA collaboration. The search is based on K+ decays. No signal is observed. The upper limit set is BR < 5.4 × 10–8 90% CL, 65 times lower than the one currently listed by PDG. [ABSTRACT FROM AUTHOR]
Published: 2024
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79. The SHiP experiment at the proposed CERN SPS Beam Dump Facility

Author: Ahdida, C., Akmete, A., Albanese, R., Alt, J., Alexandrov, A., Anokhina, A., Aoki, S., Arduini, G., Atkin, E., Azorskiy, N., Back, J. J., Bagulya, A., Baaltasar Dos Santos, F., Baranov, A., Bardou, F., Barker, G. J., Battistin, M., Bauche, J., Bay, A., Bayliss, V., Berdnikov, A. Y., Berdnikov, Y. A., Betancourt, C., Bezshyiko, I., Bezshyyko, O., Bick, D., Bieschke, S., Blanco, A., Boehm, J., Bogomilov, M., Boiarska, I., Bondarenko, K., Bonivento, W. M., Borburgh, J., Boyarsky, A., Brenner, R., Breton, D., Brignoli, A., Büscher, V., Buonaura, A., Buontempo, S., Cadeddu, S., Calviani, M., Campanelli, M., Casolino, M., Charitonidis, N., Chau, P., Chauveau, J., Chepurnov, A., Chernyavskiy, M., Choi, K.-Y., Chumakov, A., Climescu, M., Conaboy, A., Congedo, L., Cornelis, K., Cristinziani, M., Crupano, A., Dallavalle, G. M., Datwyler, A., D’Ambrosio, N., D’Appollonio, G., de Asmundis, R., De Carvalho Saraiva, J., De Lellis, G., de Magistris, M., De Roeck, A., De Serio, M., De Simone, D., Dedenko, L., Dergachev, P., Di Crescenzo, A., Di Giulio, L., Dib, C., Dijkstra, H., Dmitrenko, V., Dougherty, L. A., Dolmatov, A., Donskov, S., Drohan, V., Dubreuil, A., Durhan, O., Ehlert, M., Elikkaya, E., Enik, T., Etenko, A., Fedin, O., Fedotovs, F., Ferrillo, M., Ferro-Luzzi, M., Filippov, K., Fini, R. A., Fischer, H., Fonte, P., Franco, C., Fraser, M., Fresa, R., Froeschl, R., Fukuda, T., Galati, G., Gall, J., Gatignon, L., Gavrilov, G., Gentile, V., Goddard, B., Golinka-Bezshyyko, L., Golovatiuk, A., Golovtsov, V., Golubkov, D., Golutvin, A., Gorbounov, P., Gorbunov, D., Gorbunov, S., Gorkavenko, V., Gorshenkov, M., Grachev, V., Grandchamp, A. L., Graverini, E., Grenard, J.-L., Grenier, D., Grichine, V., Gruzinskii, N., Guler, A. M., Guz, Yu., Haefeli, G. J., Hagner, C., Hakobyan, H., Harris, I. W., van Herwijnen, E., Hessler, C., Hollnagel, A., Hosseini, B., Hushchyn, M., Iaselli, G., Iuliano, A., Jacobsson, R., Joković, D., Jonker, M., Kadenko, I., Kain, V., Kaiser, B., Kamiscioglu, C., Karpenkov, D., Kershaw, K., Khabibullin, M., Khalikov, E., Khaustov, G., Khoriauli, G., Khotyantsev, A., Kim, Y. G., Kim, V., Kitagawa, N., Ko, J.-W., Kodama, K., Kolesnikov, A., Kolev, D. I., Kolosov, V., Komatsu, M., Kono, A., Konovalova, N., Kormannshaus, S., Korol, I., Korol’ko, I., Korzenev, A., Koukovini Platia, E., Kovalenko, S., Krasilnikova, I., Kudenko, Y., Kurbatov, E., Kurbatov, P., Kurochka, V., Kuznetsova, E., Lacker, H. M., Lamont, M., Lantwin, O., Lauria, A., Lee, K. S., Lee, K. Y., Leonardo, N., Lévy, J.-M., Loschiavo, V. P., Lopes, L., Lopez Sola, E., Lyons, F., Lyubovitskij, V., Maalmi, J., Magnan, A.-M., Maleev, V., Malinin, A., Manabe, Y., Managadze, A. K., Manfredi, M., Marsh, S., Marshall, A. M., Mefodev, A., Mermod, P., Miano, A., Mikado, S., Mikhaylov, Yu., Mikulenko, A., Milstead, D. A., Mineev, O., Montesi, M. C., Morishima, K., Movchan, S., Muttoni, Y., Naganawa, N., Nakamura, M., Nakano, T., Nasybulin, S., Ninin, P., Nishio, A., Obinyakov, B., Ogawa, S., Okateva, N., Osborne, J., Ovchynnikov, M., Owtscharenko, N., Owen, P. H., Pacholek, P., Park, B. D., Pastore, A., Patel, M., Pereyma, D., Perillo-Marcone, A., Petkov, G. L., Petridis, K., Petrov, A., Podgrudkov, D., Poliakov, V., Polukhina, N., Prieto Prieto, J., Prokudin, M., Prota, A., Quercia, A., Rademakers, A., Rakai, A., Ratnikov, F., Rawlings, T., Redi, F., Reghunath, A., Ricciardi, S., Rinaldesi, M., Rodin, Volodymyr, Rodin, Viktor, Robbe, P., Rodrigues Cavalcante, A. B., Roganova, T., Rokujo, H., Rosa, G., Ruchayskiy, O., Ruf, T., Samoylenko, V., Samsonov, V., Sanchez Galan, F., Santos Diaz, P., Sanz Ull, A., Sato, O., Savchenko, E. S., Schliwinski, J. S., Schmidt-Parzefall, W., Schumann, M., Serra, N., Sgobba, S., Shadura, O., Shakin, A., Shaposhnikov, M., Shatalov, P., Shchedrina, T., Shchutska, L., Shevchenko, V., Shibuya, H., Shihora, L., Shirobokov, S., Shustov, A., Silverstein, S. B., Simone, S., Simoniello, R., Skorokhvatov, M., Smirnov, S., Soares, G., Sohn, J. Y., Sokolenko, A., Solodko, E., Starkov, N., Stoel, L., Stramaglia, M. E., Sukhonos, D., Suzuki, Y., Takahashi, S., Tastet, J. L., Teterin, P., Than Naing, S., Timiryasov, I., Tioukov, V., Tommasini, D., Torii, M., Treille, D., Tsenov, R., Ulin, S., Ursov, E., Ustyuzhanin, A., Uteshev, Z., Uvarov, L., Vankova-Kirilova, G., Vannucci, F., Venkova, P., Venturi, V., Vidulin, I., Vilchinski, S., Vincke, Heinz, Vincke, Helmut, Visone, C., Vlasik, K., Volkov, A., Voronkov, R., van Waasen, S., Wanke, R., Wertelaers, P., Williams, O., Woo, J.-K., Wurm, M., Xella, S., Yilmaz, D., Yilmazer, A. U., Yoon, C. S., Zaytsev, Yu., Zelenov, A., and Zimmerman, J.
Published: 2022
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80. Observation of a new narrow axial-vector meson $a_1(1420)$

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Azevedo, C., Badelek, B., Balestra, F., Barth, J., Beck, R., Bedfer, Y., Bernhard, J., Bicker, K., Bielert, E. R., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Chang, W. -C., Chiosso, M., Choi, I., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duennweber, W, Duic, V., Dziewiecki, M., Efremov, A., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Gnesi, I., Gorzellik, M., Grabmueller, S., Grasso, A., Grosse-Perdekamp, M., Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., Hahne, D., von Harrach, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Horikawa, N., d'Hose, N., Hsieh, C. -Yu, Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kremser, P., Krinner, F., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makins, N., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panzieri, D., Parsamyan, B., Paul, S., Peng, J. -C., Pereira, F., Pesek, M., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Riedl, C., Rocco, E., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Santos, C., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schlueter, T., Selyunin, A., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sozzi, F., Srnka, A., Stolarski, M., Sulc, M., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Tskhay, V., Uhl, S., Veloso, J., Virius, M., Wallner, S., Weisrock, T., Wilfert, M., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment
Abstract: The COMPASS collaboration at CERN has measured diffractive dissociation of 190 GeV/$c$ pions into the $\pi^-\pi^-\pi^+$ final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of $3\pi$ mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88 waves. A narrow $J^{PC} = 1^{++}$ signal is observed in the $f_0(980)\,\pi$ channel. We present a resonance-model study of a subset of the spin-density matrix selecting $3\pi$ states with $J^{PC} = 2^{++}$ and $4^{++}$ decaying into $\rho(770)\,\pi$ and with $J^{PC} = 1^{++}$ decaying into $f_0(980)\,\pi$. We identify a new $a_1$ meson with mass $(1414^{+15}_{-13})$ MeV/$c^2$ and width $(153^{+8}_{-23})$ MeV/$c^2$. Within the final states investigated in our analysis, we observe the new $a_1(1420)$ decaying only into $f_0(980)\,\pi$, suggesting its exotic nature., Comment: 8 pages, 1 figure
Published: 2015
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81. Observation of $$K^{+} \rightarrow \pi ^{+}\pi ^{0}\pi ^{0}\gamma $$ decay

Author: Artamonov, A. V., primary, Bychkov, V. N., additional, Donskov, S. V., additional, Filin, A. P., additional, Filippov, S. N., additional, Gorin, A. M., additional, Gushchin, E. N., additional, Inyakin, A. V., additional, Kekelidze, G. D., additional, Khaustov, G. V., additional, Kholodenko, S. A., additional, Khudyakov, A. A., additional, Kolosov, V. N., additional, Kravtsov, V. I., additional, Kudenko, Yu. G., additional, Kulik, A. V., additional, Kurshetsov, V. F., additional, Lishin, V. A., additional, Lysan, V. M., additional, Medynsky, M. V., additional, Obraztsov, V. F., additional, Okhotnikov, A. V., additional, Polyakov, V. A., additional, Polyarush, A. Yu., additional, Romanovsky, V. I., additional, Rykalin, V. I., additional, Sadovsky, A. S., additional, Samoylenko, V. D., additional, Shapkin, M. M., additional, Tiurin, I. S., additional, Uvarov, V. A., additional, Yushchenko, O. P., additional, and Zalikhanov, B. Zh., additional
Published: 2024
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82. Searches for the light invisible axion-like particle in $$K^{+} \rightarrow \pi ^{+}\pi ^{0} a$$ decay

Author: Sadovsky, A. S., primary, Filin, A. P., additional, Akimenko, S. A., additional, Artamonov, A. V., additional, Blik, A. M., additional, Bychkov, V. N., additional, Donskov, S. V., additional, Filippov, S. N., additional, Gorin, A. M., additional, Gushchin, E. N., additional, Inyakin, A. V., additional, Kekelidze, G. D., additional, Khaustov, G. V., additional, Kholodenko, S. A., additional, Khudyakov, A. A., additional, Kolosov, V. N., additional, Kravtsov, V. I., additional, Kudenko, Yu. G., additional, Kulik, A. V., additional, Kurshetsov, V. F., additional, Lishin, V. A., additional, Lysan, V. M., additional, Medynsky, M. V., additional, Obraztsov, V. F., additional, Okhotnikov, A. V., additional, Polyakov, V. A., additional, Polyarush, A. Yu., additional, Romanovsky, V. I., additional, Rykalin, V. I., additional, Samoylenko, V. D., additional, Tiurin, I. S., additional, Uvarov, V. A., additional, Yushchenko, O. P., additional, and Zalikhanov, B. Zh., additional
Published: 2024
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83. The COMPASS Setup for Physics with Hadron Beams

Author: Abbon, Ph., Adolph, C., Akhunzyanov, R., Alexandrov, Yu., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bicker, K., Bielert, E. R., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Ciliberti, P., Chiosso, M., Chung, S. U., Cicuttin, A., Colantoni, M., Cotte, D., Crespo, M. L., Curiel, Q., Dafni, T., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Desforge, D., Dinkelbach, A. M., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Durand, D., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Gatignon, L., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giganon, A., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Gregori, M., Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kuhn, R., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Marroncle, J., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Menon, G., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Moinester, M. A., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Pesaro, G., Pesaro, V., Peshekhonov, D. V., Pires, C., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Reymond, J-M., Rocco, E., Rossiyskaya, N. S., Rousse, J. -Y., Ryabchikov, D. I., Rychter, A., Samartsev, A., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Tskhay, V., Uhl, S., Uman, I., Virius, M., Wang, L., Weisrock, T., Weitzel, Q., Wilfert, M., Windmolders, R., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This article describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup., Comment: 91 pages, 101 figures and 7 tables
Published: 2014
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84. Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bicker, K., Bielert, E. R., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Rocco, E., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Virius, M., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment
Abstract: Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise., Comment: 15 pages, 13 figures and 1 table
Published: 2014
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85. Odd and Even Partial Waves of $\eta\pi^-$ and $\eta'\pi^-$ in $\pi^-p\to\eta^{(\prime)}\pi^-p$ at $191\,\textrm{GeV}/c$

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bicker, K., Bielert, E. R., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Rocco, E., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Virius, M., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Exclusive production of $\eta\pi^-$ and $\eta'\pi^-$ has been studied with a $191\,\textrm{GeV}/c$ $\pi^-$ beam impinging on a hydrogen target at COMPASS (CERN). Partial-wave analyses reveal different odd/even angular momentum ($L$) characteristics in the inspected invariant mass range up to $3\,\textrm{GeV}/c^2$. A striking similarity between the two systems is observed for the $L=2,4,6$ intensities (scaled by kinematical factors) and the relative phases. The known resonances $a_2(1320)$ and $a_4(2040)$ are in line with this similarity. In contrast, a strong enhancement of $\eta'\pi^-$ over $\eta\pi^-$ is found for the $L=1,3,5$ waves, which carry non-$q\bar q$ quantum numbers. The $L=1$ intensity peaks at $1.7\,\textrm{GeV}/c^2$ in $\eta'\pi^-$ and at $1.4\,\textrm{GeV}/c^2$ in $\eta\pi^-$, the corresponding phase motions with respect to $L=2$ are different., Comment: 16 pages, 5 figures and 1 table
Published: 2014
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86. Search for exclusive photoproduction of Z$_c^{\pm}$(3900) at COMPASS

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bicker, K., Bielert, E. R., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Grussenmeyer, T., Guskov, A., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Peshekhonov, D. V., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Rocco, E., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Virius, M., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment
Abstract: A search for the exclusive production of the $Z_c^{\pm}(3900)$ hadron by virtual photons has been performed in the channel $Z_c^{\pm}(3900)\rightarrow J/\psi \pi^{\pm}$. The data cover the range from 7 GeV to 19 GeV in the centre-of-mass energy of the photon-nucleon system. The full set of the COMPASS data set collected with a muon beam between 2002 and 2011 has been used. An upper limit for the ratio $BR(Z_c^{\pm}(3900)\rightarrow J/\psi \pi^{\pm} )\times \sigma_{ \gamma~N \rightarrow Z_c^{\pm}(3900)~ N} /\sigma_{\gamma~N \rightarrow J/\psi~ N}$ of $3.7\times10^{-3}$ has been established at the confidence level of 90%., Comment: 8 pages, 3 figures, 1 table
Published: 2014
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87. A search for decay $\eta' \rightarrow 4 \pi^{0}$ with GAMS-$4\pi$ Setup

Author: Donskov, S. V., Kolosov, V. N., Lednev, A. A., Mikhailov, Yu. V., Polyakov, V. A., Samoylenko, V. D., and Khaustov, G. V.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: A search for rare decay $\eta' \rightarrow 4 \pi^{0}$ has been performed with GAMS-4$\pi$ Setup. The new upper limit for decay was established $BR(\eta' \rightarrow 4 \pi^{0}) < 3.2 \cdot 10^{-4}$ at 90\% confidence level. The $\pi^{-} p$ charge-exchange reaction at 32.5 GeV/c was used as a source of $1.3\cdot 10^{6}$ $ \eta'$ mesons. Experiment carried out at the IHEP U-70 accelerator., Comment: 5 pages, 4 figures
Published: 2014
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88. Spin alignment and violation of the OZI rule in exclusive $\omega$ and $\phi$ production in pp collisions

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger, r. M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Grussenmeyer, T., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, h., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, u., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, u. A., Kisselev, u., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, u. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Peshekhonov, D., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Rocco, E., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Virius, M., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Exclusive production of the isoscalar vector mesons $\omega$ and $\phi$ is measured with a 190 GeV$/c$ proton beam impinging on a liquid hydrogen target. Cross section ratios are determined in three intervals of the Feynman variable $x_{F}$ of the fast proton. A significant violation of the OZI rule is found, confirming earlier findings. Its kinematic dependence on $x_{F}$ and on the invariant mass $M_{p\mathrm{V}}$ of the system formed by fast proton $p_\mathrm{fast}$ and vector meson $V$ is discussed in terms of diffractive production of $p_\mathrm{fast}V$ resonances in competition with central production. The measurement of the spin density matrix element $\rho_{00}$ of the vector mesons in different selected reference frames provides another handle to distinguish the contributions of these two major reaction types. Again, dependences of the alignment on $x_{F}$ and on $M_{p\mathrm{V}}$ are found. Most of the observations can be traced back to the existence of several excited baryon states contributing to $\omega$ production which are absent in the case of the $\phi$ meson. Removing the low-mass $M_{p\mathrm{V}}$ resonant region, the OZI rule is found to be violated by a factor of eight, independently of $x_\mathrm{F}$., Comment: 23 pages, 13 figures and 5 tables
Published: 2014
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89. Measurement of the charged-pion polarisability

Author: Adolph, C., Akhunzyanov, R., Alexeev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Colantoni, M., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dinkelbach, A. M., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger, M. jr., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Grussenmeyer, T., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kuhn, R., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levillain, M., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Moinester, M. A., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Orlov, I., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Peshekhonov, D., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Regali, C., Reicherz, G., Rocco, E., Rossiyskaya, N. S., Ryabchikov, D. I., Rychter, A., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Virius, M., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., and Zink, A.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: The COMPASS collaboration at CERN has investigated pion Compton scattering, $\pi^-\gamma\rightarrow \pi^-\gamma$, at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction $\pi^-\mathrm{Ni}\rightarrow\pi^-\gamma\;\mathrm{Ni}$, which is initiated by 190\,GeV pions impinging on a nickel target. The exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, $Q^2<0.0015$\,(GeV/$c$)$^2$. From a sample of 63\,000 events the pion electric polarisability is determined to be $\alpha_\pi\ =\ (\,2.0\ \pm\ 0.6_{\mbox{\scriptsize stat}}\ \pm\ 0.7_{\mbox{\scriptsize syst}}\,) \times 10^{-4}\,\mbox{fm}^3$ under the assumption $\alpha_\pi=-\beta_\pi$, which relates the electric and magnetic dipole polarisabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction, that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambigiously known, was performed for an independent estimate of the systematic uncertainty., Comment: Published version: 9 pages, 3 figures, 1 table
Published: 2014
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90. Measurement of radiative widths of $a_2(1320)$ and $\pi_2(1670)$

Author: Adolph, C., Akhunzyanov, R., Alekseev, M. G., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger~jr., M., Fischer, H., Franco, C., du~Fresne~von~Hohenesche, N., Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kral, Z., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Orlov, I., Olshevsky, A. G., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Pesek, M., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Reicherz, G., Rocco, E., Rychter, A., Rossiyskaya, N. S., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, A., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabelski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter~Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Vandenbroucke, M., Virius, M., Vondra, J., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., and Ziembicki., M.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The COMPASS Collaboration at CERN has investigated the reaction $\pi^- \gamma \rightarrow \pi^-\pi^-\pi^+$ embedded in the Primakoff reaction of $190~\textrm{GeV}$ pions scattering in the Coulomb field of a lead target, $\pi^- \text{Pb} \rightarrow \pi^-\pi^-\pi^+ \text{Pb}$. Exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at momentum transfer below $0.001~(\text{GeV}/c)^2$. Using a partial-wave analysis the amplitudes and relative phases of the $a_2(1320)$ and $\pi_2(1670)$ mesons have been extracted, and the Coulomb and the diffractive contributions have been disentangled. Measuring absolute production cross sections we have determined the radiative width of the $a_2(1320)$ to be $\Gamma_0(a_2(1320) \rightarrow \pi\gamma) = (358 \pm 6_{\textrm{stat}} \pm 42_{\textrm{syst}})~\textrm{keV}$. As the first measurement, $\Gamma_0(\pi_2(1670) \rightarrow \pi\gamma) = (181 \pm 11_{\textrm{stat}} \pm 27_{\textrm{syst}})~\textrm{keV} \cdot (\textrm{BR}^{\textrm{PDG}}_{f_2 \pi}/\textrm{BR}_{f_2 \pi})$ is obtained for the radiative width of the $\pi_2(1670)$, where in this analysis the branching ratio $\textrm{BR}^{\textrm{PDG}}_{f_2 \pi}=0.56$ has been used. We compare these values to previous measurements and theoretical predictions., Comment: 27 pages, 12 figures and 3 tables
Published: 2014
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91. Search for a light muon-philic $Z'$ with the NA64-$e$ experiment at CERN

Author: Andreev, Yu. M., Antonov, A., Banerjee, D., Oberhauser, B. Banto, Bernhard, J., Bisio, P., Celentano, A., Charitonidis, N., Cooke, D., Crivelli, P., Depero, E., Dermenev, A. V., Donskov, S. V., Dusaev, R. R., Enik, T., Frolov, V. N., Gardikiotis, A., Gninenko, S. N., Hösgen, M., Kachanov, V. A., Kambar, Y., Karneyeu, A. E., Kekelidze, G., Ketzer, B., Kirpichnikov, D. V., Kirsanov, M. M., Kolosov, V. N., Gertsenberger, S. V., Girod, S., Kasianova, E. A., Kramarenko, V. A., Kravchuk, L. V., Krasnikov, N. V., Kuleshov, S. V., Lyubovitskij, V. E., Lysan, V., Marini, A., Marsicano, L., Matveev, V. A., Fredes, R. Mena, Yanssen, R. Mena, Bueno, L. Molina, Mongillo, M., Peshekhonov, D. V., Polyakov, V. A., Radics, B., Salamatin, K., Samoylenko, V. D., Sieber, H., Shchukin, D., Soto, O., Tikhomirov, V. O., Tlisova, I., Toropin, A. N., Tuzi, M., Ulloa, P., Volkov, P. V., Volkov, V. Yu., Voronchikhin, I. V., Zamora-Saá, J., Zhevlako, A. S., Andreev, Yu. M., Antonov, A., Banerjee, D., Oberhauser, B. Banto, Bernhard, J., Bisio, P., Celentano, A., Charitonidis, N., Cooke, D., Crivelli, P., Depero, E., Dermenev, A. V., Donskov, S. V., Dusaev, R. R., Enik, T., Frolov, V. N., Gardikiotis, A., Gninenko, S. N., Hösgen, M., Kachanov, V. A., Kambar, Y., Karneyeu, A. E., Kekelidze, G., Ketzer, B., Kirpichnikov, D. V., Kirsanov, M. M., Kolosov, V. N., Gertsenberger, S. V., Girod, S., Kasianova, E. A., Kramarenko, V. A., Kravchuk, L. V., Krasnikov, N. V., Kuleshov, S. V., Lyubovitskij, V. E., Lysan, V., Marini, A., Marsicano, L., Matveev, V. A., Fredes, R. Mena, Yanssen, R. Mena, Bueno, L. Molina, Mongillo, M., Peshekhonov, D. V., Polyakov, V. A., Radics, B., Salamatin, K., Samoylenko, V. D., Sieber, H., Shchukin, D., Soto, O., Tikhomirov, V. O., Tlisova, I., Toropin, A. N., Tuzi, M., Ulloa, P., Volkov, P. V., Volkov, V. Yu., Voronchikhin, I. V., Zamora-Saá, J., and Zhevlako, A. S.
Abstract: The inclusion of an additional U(1) gauge $L_{\mu} - L_{\tau}$ symmetry would release the tension between the measured and the predicted value of the anomalous muon magnetic moment: this paradigm assumes the existence of a new, light $Z'$ vector boson, with dominant coupling to ${\mu}$ and ${\tau}$ and interacting with electrons via a loop mechanism. The $L_{\mu} - L_{\tau}$ model can also explain the Dark Matter relic abundance, by assuming that the $Z'$ boson acts as a "portal" to a new Dark Sector of particles in Nature, not charged under known interactions. In this work we present the results of the $Z'$ search performed by the NA64-$e$ experiment at CERN SPS, that collected $ \sim 9 \times 10^{11}$ 100-GeV electrons impinging on an active thick target. Despite the suppressed $Z'$ production yield with an electron beam, the limits sets by NA64-$e$ are competitive with other experimental searches, and partially exclude the $g-2$ preferred model parameter values for $Z'$ masses lighter than 2 MeV. This result proves the complementarity of this search with NA64-${\mu}$, the parallel effort of the NA64 collaboration with a muon beam., Comment: 7 pages, 4 figures
Published: 2024

92. A high-statistics measurement of transverse spin effects in dihadron production from muon-proton semi-inclusive deep-inelastic scattering

Author: Adolph, C., Akhunzyanov, R., Alekseev, M. G., Alexandrov, Yu., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bertini, R., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bravar, A., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, M., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kral, Z., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Orlov, I., Olshevsky, A. G., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Pesek, M., Peshekhonov, D., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Reicherz, G., Rocco, E., Rodionov, V., Rondio, E., Rychter, A., Rossiyskaya, N. S., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, A., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabeleski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Vandenbroucke, M., Virius, M., Vondra, J., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wislicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., and Ziembicki, M.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: A measurement of the azimuthal asymmetry in dihadron production in deep-inelastic scattering of muons on transversely polarised proton (NH$_{3}$) targets are presented. They provide independent access to the transversity distribution functions through the measurement of the Collins asymmetry in single hadron production. The data were taken in the year $2010$ with the COMPASS spectrometer using a $160\,\mbox{GeV}/c$ muon beam of the CERN SPS, increasing by a factor of about three the available statistics of the previously published data taken in the year $2007$. The measured sizeable asymmetry is in good agreement with the published data. An approximate equality of the Collins asymmetry and the dihadron asymmetry is observed, suggesting a common physical mechanism in the underlying fragmentation., Comment: 14 pages, 8 figures
Published: 2014
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93. Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons

Author: Adolph, C., Akhunzyanov, R., Alekseev, M. G., Alexandrov, Yu., Alexeev, G. D., Amoroso, A., Andrieux, V., Anosov, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Beck, R., Bedfer, Y., Berlin, A., Bernhard, J., Bertini, R., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Bodlak, M., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bravar, A., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Curiel, Q., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, M., Gnesi, I., Gobbo, B., Goertz, S., Gorzellik, M., Grabmueller, S., Grasso, A., Grube, B., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Hahne, D., Hashimoto, R., Heinsius, F. H., Herrmann, F., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, A., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joerg, P., Joosten, R., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kral, Z., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Orlov, I., Olshevsky, A. G., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Pesek, M., Peshekhonov, D., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Reicherz, G., Rocco, E., Rodionov, V., Rondio, E., Rychter, A., Rossiyskaya, N. S., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, A., Schmidt, K., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Szabeleski, A., Szameitat, T., Sznajder, P., Takekawa, S., ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Vandenbroucke, M., Virius, M., Vondra, J., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wislicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., and Ziembicki, M.
Subjects: High Energy Physics - Experiment
Abstract: Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS muon beam at $160$ GeV/c and a $^6$LiD target. The amplitudes of the three azimuthal modulations $\cos\phi_h$, $\cos2\phi_h$ and $\sin\phi_h$ were obtained binning the data separately in each of the relevant kinematic variables $x$, $z$ or $p_T^{\,h}$ and binning in a three-dimensional grid of these three variables. The amplitudes of the $\cos \phi_h$ and $\cos 2\phi_h$ modulations show strong kinematic dependencies both for positive and negative hadrons., Comment: 33 pages, 15 figures and 10 pages
Published: 2014
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94. The Coherent Production of the (K+π0) System by K+ Beam on Copper Nuclei at the OKA Setup

Author: Burtovoy, V. S., Akimenko, S. A., Artamonov, A. V., Blik, A. M., Brekhovskikh, V. V., Gorin, A. M., Donskov, S. V., Inyakin, A. V., Kolosov, V. N., Kurshetsov, V. F., Lishin, V. A., Medynsky, M. V., Mikhailov, Yu. V., Obraztsov, V. F., Polyakov, V. A., Romanovsky, V. I., Rykalin, V. I., Sadovsky, A. S., Samoilenko, V. D., Stenyakin, O. V., Uvarov, V. A., Filin, A. P., Khaustov, G. V., Kholodenko, S. A., Tchikilev, O. G., Yushchenko, O. P., Guschin, E. N., Duk, V. A., Kravtsov, V. I., Kudenko, Yu. G., Polyarush, A. Yu., Filippov, S. N., Khudyakov, A. A., Bychkov, V. N., Zalikhanov, B. Zh., Kekelidze, G. D., and Lysan, V. M.
Published: 2020
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95. Proposal for an Experiment to Search for Light Dark Matter at the SPS

Author: Andreas, S., Donskov, S. V., Crivelli, P., Gardikiotis, A., Gninenko, S. N., Golubev, N. A., Guber, F. F., Ivashkin, A. P., Kirsanov, M. M., Krasnikov, N. V., Matveev, V. A., Mikhailov, Yu. V., Musienko, Yu. V., Polyakov, V. A., Ringwald, A., Rubbia, A., Samoylenko, V. D., Semertzidis, Y. K., and Zioutas, K.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract: Several models of dark matter suggest the existence of dark sectors consisting of SU(3)_C x SU(2)_L x U(1)_Y singlet fields. These sectors of particles do not interact with the ordinary matter directly but could couple to it via gravity. In addition to gravity, there might be another very weak interaction between the ordinary and dark matter mediated by U'(1) gauge bosons A' (dark photons) mixing with our photons. In a class of models the corresponding dark gauge bosons could be light and have the $\gamma$-A' coupling strength laying in the experimentally accessible and theoretically interesting region. If such A' mediators exist, their di-electron decays A' -> e+e- could be searched for in a light-shining-through-a-wall experiment looking for an excess of events with the two-shower signature generated by a single high energy electron in the detector. A proposal to perform such an experiment aiming to probe the still unexplored area of the mixing strength 10^-5 < $\epsilon$ < 10^-3 and masses M_A' < 100 MeV by using 10-300 GeV electron beams from the CERN SPS is presented. The experiment can provide complementary coverage of the parameter space, which is intended to be probed by other searches. It has also a capability for a sensitive search for A's decaying invisibly to dark-sector particles, such as dark matter, which could cover a significant part of the still allowed parameter space. The full running time of the proposed measurements is requested to be up to several months, and it could be taken at different SPS secondary beams., Comment: 42 pages, 19 figures. This work is a continuation of work started in arXiv:1308.6521
Published: 2013

96. Transverse target spin asymmetries in exclusive $\rho^0$ muoproduction

Author: Adolph, C., Alekseev, M. G., Alexakhin, V. Yu., Alexandrov, Yu., Alexeev, G. D., Amoroso, A., Andrieux, V., Austregesilo, A., Badellek, B., Balestra, F., Barth, J., Baum, G., Bedfer, Y., Berlin, A., Bernhard, J., Bertini, R., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bravar, A., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, M., Gnesi, I., Gobbo, B., Goertz, S., Grabmueller, S., Grasso, A., Grube, B., Gushterski, R., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Hahne, D., Heinsius, F. H., Herrmann, F., Hess, C., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joosten, R., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Marchand, C., Martin, A., Marzec, J., Matousek, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Morreale, A., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Pesek, M., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Reicherz, G., Rocco, E., Rodionov, V., Rondio, E., Rossiyskaya, N. S., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Sapozhnikov, M. G., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, A., Schmidt, K., Schmitt, L., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Sznajder, P., Takekawa, S., Ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Vandenbroucke, M., Virius, M., Vondra, J., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wislicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Exclusive production of $\rho^0$ mesons was studied at the COMPASS experiment by scattering 160 GeV/$c$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured as a function of $Q^2$, $x_{Bj}$, or $p_{T}^{2}$. The $\sin \phi_S$ asymmetry is found to be $-0.019 \pm 0.008(stat.) \pm 0.003(syst.)$. All other asymmetries are also found to be of small magnitude and consistent with zero within experimental uncertainties. Very recent calculations using a GPD-based model agree well with the present results. The data is interpreted as evidence for the existence of chiral-odd, transverse generalized parton distributions., Comment: 14 pages, two tables, 5 figures, bibliography updated
Published: 2013
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97. Hadron Transverse Momentum Distributions in Muon Deep Inelastic Scattering at 160 GeV/$c$

Author: Adolph, C., Alekseev, M. G., Alexakhin, V. Yu., Alexandrov, Yu., Alexeev, G. D., Amoroso, A., Andrieux, V., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Bedfer, Y., Berlin, A., Bernhard, J., Bertini, R., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Boer, M., Bordalo, P., Bradamante, F., Braun, C., Bravar, A., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, M., Gnesi, I., Gobbo, B., Goertz, S., Grabmueller, S., Grasso, A., Grube, B., Gushterski, R., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Heinsius, F. H., Herrmann, F., Hess, C., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joosten, R., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Mann, A., Marchand, C., Martin, A., Marzec, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Morreale, A., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Rajotte, J. -F., Ramos, S., Reicherz, G., Rocco, E., Rodionov, V., Rondio, E., Rossiyskaya, N. S., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Sapozhnikov, M. G., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, A., Schmidt, K., Schmitt, L., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Sznajder, P., Takekawa, S., Ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Vandenbroucke, M., Virius, M., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wiślicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Multiplicities of charged hadrons produced in deep inelastic muon scattering off a $^6$LiD target have been measured as a function of the DIS variables $x_{Bj}$, $Q^2$, $W^2$ and the final state hadron variables $p_T$ and $z$. The $p_T^2$ distributions are fitted with a single exponential function at low values of $p_T^2$ to determine the dependence of $\langle p_T^2 \rangle$ on $x_{Bj}$, $Q^2$, $W^2$ and $z$. The $z$-dependence of $\langle p_T^2 \rangle$ is shown to be a potential tool to extract the average intrinsic transverse momentum squared of partons, $\langle k_{\perp}^2 \rangle$, as a function of $x_{Bj}$ and $Q^2$ in a leading order QCD parton model., Comment: 18 pages, 13 figures and 3 tables
Published: 2013
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98. Study of \Sigma(1385) and \Xi(1321) hyperon and antihyperon production in deep inelastic muon scattering

Author: Adolph, C., Alekseev, M., Alexakhin, V. Yu., Alexandrov, Yu., Alexeev, G. D., Amoroso, A., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Bedfer, Y., Berlin, A., Bernhard, J., Bertini, R., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, F., Braun, C., Bravar, A., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger jr., M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, M., Gnesi, I., Gobbo, B., Goertz, S., Grabmueller, S., Grasso, A., Grube, B., Gushterski, R., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Heinsius, F. H., Herrmann, F., Hess, C., Hinterberger, F., Hoeppner, Ch., Horikawa, N., d'Hose, N., Huber, S., Ishimoto, S., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joosten, R., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kuchinski, N., Kunne, F., Kurek, K., Kurjata, R. P., Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Mann, A., Marchand, C., Martin, A., Marzec, J., Matsuda, H., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Miyachi, Y., Morreale, A., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Novy, J., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Ostrick, M., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Ramos, S., Reicherz, G., Rocco, E., Rodionov, V., Rondio, E., Rossiyskaya, N. S., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Sapozhnikov, M. G., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, A., Schmidt, K., Schmitt, L., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sirtl, S., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Sznajder, P., Takekawa, S., Ter Wolbeek, J., Tessaro, S., Tessarotto, F., Thibaud, F., Uhl, S., Uman, I., Vandenbroucke, M., Virius, M., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wislicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Zhuravlev, N., and Ziembicki, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Large samples of \Lambda, \Sigma(1385) and \Xi(1321) hyperons produced in deep-inelastic muon scattering off a ^6LiD target were collected with the COMPASS experimental setup at CERN. The relative yields of \Sigma(1385)^+, \Sigma(1385)^-, \bar{\Sigma}(1385)^-, \bar{\Sigma}(1385)^+, \Xi(1321)^-, and \bar{\Xi}(1321)^+ hyperons decaying into \Lambda(\bar{\Lambda})\pi were measured. The heavy hyperon to \Lambda and heavy antihyperon to \bar{\Lambda} yield ratios were found to be in the range 3.8% to 5.6% with a relative uncertainty of about 10%. They were used to tune the parameters relevant for strange particle production of the LEPTO Monte Carlo generator., Comment: 13 pages, 4 figures and 3 tables, 1 Appendix with 3 figures. Version accepted by the Editor
Published: 2013
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99. Measurement of the $\eta$ -$\eta'$ mixing angle in $\pi^{-}$ and $K^{-}$ beams with GAMS-$4\pi$ Setup

Author: Donskov, S. V., Kolosov, V. N., Lednev, A. A., Mikhailov, Yu. V., Polyakov, V. A., Samoylenko, V. D., and Khaustov, G. V.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The results of mixing angle measurement for $\eta'$, $\eta$ mesons generated in charge exchange reactions with $\pi^{-}$ and $K^{-}$ beams are preseneted. When the $\eta'$, $\eta$ mesons are described in nonstrange(NS)--strange(S) quark basis the $\pi^{-}$ and $K^{-}$ beams allow to study $|\eta_{q}>$ and $|\eta_{s}>$ parts of the meson wave function. The cross section ratio at $t'=0$ (GeV/c)$^{2}$ in the $\pi^{-}$ beam is $R_{\pi}(\eta'/\eta)= 0.56 \pm 0.04$, results in mixing angle $\phi_{P} = (36.8 \pm 1.)^{o} $. For $K^{-}$ beam the ratio is $R_{K}(\eta'/\eta)= 1.30 \pm 0.16$. It was found that gluonium content in $\eta'$ is $\sin^{2}\psi_{G}= 0.15 \pm 0.06$. The experiment was carried out with GAMS-4$\pi$ Setup., Comment: 6 pages, 4 figures, 1 table, to be submitted in European physical journal C. Minor changes, the Bibliography extended
Published: 2013
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100. Leading and Next-to-Leading Order Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction

Author: Adolph, C., Alekseev, M. G., Alexakhin, V. Yu., Alexandrov, Yu., Alexeev, G. D., Amoroso, A., Antonov, A. A., Austregesilo, A., Badelek, B., Balestra, F., Barth, J., Baum, G., Bedfer, Y., Berlin, A., Bernhard, J., Bertini, R., Bettinelli, M., Bicker, K., Bieling, J., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, F., Braun, C., Bravar, A., Bressan, A., Buechele, M., Burtin, E., Capozza, L., Chiosso, M., Chung, S. U., Cicuttin, A., Crespo, M. L., Torre, S. Dalla, Das, S., Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Duic, V., Duennweber, W., Dziewiecki, M., Efremov, A., Elia, C., Eversheim, P. D., Eyrich, W., Faessler, M., Ferrero, A., Filin, A., Finger, M., Finger Jr, M., Fischer, H., Franco, C., von Hohenesche, N. du Fresne, Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, M., Gnesi, I., Gobbo, B., Goertz, S., Grabmueller, S., Grasso, A., Grube, B., Gushterski, R., Guskov, A., Guthoerl, T., Haas, F., von Harrach, D., Heinsius, F. H., Herrmann, F., Hess, C., Hinterberger, F., Horikawa, N., Hoeppner, Ch., d'Hose, N., Huber, S., Ishimoto, S., Ivanov, O., Ivanshin, Yu., Iwata, T., Jahn, R., Jary, V., Jasinski, P., Joosten, R., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koblitz, S., Koivuniemi, J. H., Kolosov, V. N., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Korzenev, A., Kotzinian, A. M., Kouznetsov, O., Kraemer, M., Kroumchtein, Z. V., Kunne, F., Kurek, K., Lauser, L., Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Liska, T., Maggiora, A., Magnon, A., Makke, N., Mallot, G. K., Mann, A., Marchand, C., Martin, A., Marzec, J., Matsuda, T., Meshcheryakov, G., Meyer, W., Michigami, T., Mikhailov, Yu. V., Morreale, A., Mutter, A., Nagaytsev, A., Nagel, T., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Nowak, W. -D., Nunes, A. S., Olshevsky, A. G., Ostrick, M., Padee, A., Panknin, R., Panzieri, D., Parsamyan, B., Paul, S., Perevalova, E., Pesaro, G., Peshekhonov, D. V., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Quaresma, M., Quintans, C., Rajotte, J. -F., Ramos, S., Rapatsky, V., Reicherz, G., Rocco, E., Rondio, E., Rossiyskaya, N. S., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Sapozhnikov, M. G., Sarkar, S., Savin, I. A., Sbrizzai, G., Schiavon, P., Schill, C., Schlueter, T., Schmidt, A., Schmidt, K., Schmitt, L., Schmieden, H., Schoenning, K., Schopferer, S., Schott, M., Shevchenko, O. Yu., Silva, L., Sinha, L., Sissakian, A. N., Slunecka, M., Smirnov, G. I., Sosio, S., Sozzi, F., Srnka, A., Steiger, L., Stolarski, M., Sulc, M., Sulej, R., Suzuki, H., Sznajder, P., Takekawa, S., Ter Wolbeek, J., Tessaro, S., Tessarotto, F., Tkatchev, L. G., Uhl, S., Uman, I., Vandenbroucke, M., Virius, M., Vlassov, N. V., Wang, L., Weisrock, T., Wilfert, M., Windmolders, R., Wislicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziembicki, M., Zhuravlev, N., and Zvyagin, A.
Subjects: High Energy Physics - Experiment
Abstract: The gluon polarisation in the nucleon was measured using open charm production by scattering 160 GeV/c polarised muons off longitudinally polarised protons or deuterons. The data were taken by the COMPASS collaboration between 2002 and 2007. A detailed account is given of the analysis method that includes the application of neural networks. Several decay channels of D^0 mesons are investigated. Longitudinal spin asymmetries of the D meson production cross-sections are extracted in bins of D^0 transverse momentum and energy. At leading order QCD accuracy the average gluon polarisation is determined as (Delta g/G)^LO=-0.06 +/- 0.21 (stat.) +/- 0.08 (syst.) at the scale ~13 (GeV/c)^2 and an average gluon momentum fraction ~ 0.11. For the first time, the average gluon polarisation is also obtained at next-to-leading order QCD accuracy as (Delta g/G)^NLO = -0.13 +/- 0.15 (stat.) +/- 0.15 (syst.) at the scale ~ 13 (\GeV/c)^2 and ~ 0.20., Comment: 35 pages, 13 figures and 13 tables
Published: 2012
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