Author: "L. Sinha" / Journal: physics letters b - Searchworks@Jio Institute Digital Library Search Results

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1. Transverse-spin-dependent azimuthal asymmetries of pion and kaon pairs produced in muon-proton and muon-deuteron semi-inclusive deep inelastic scattering

Author: G.D. Alexeev, M.G. Alexeev, C. Alice, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, C. Braun, A. Bressan, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, A.G. Chumakov, S.-U. Chung, A. Cicuttin, P.M.M. Correia, M.L. Crespo, D. D'Ago, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, F. Del Carro, I. Denisenko, O.Yu. Denisov, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, D. Ecker, A. Efremov, C. Elia, D. Eremeev, P. Faccioli, M. Faessler, M. Finger, M. Finger, jr., H. Fischer, K.J. Flöthner, W. Florian, J.M. Friedrich, V. Frolov, L.G. Garcia Ordòñez, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, D. Giordano, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, M. Grüner, A. Guskov, D. von Harrach, M. Hoffmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, M. Jandek, V. Jary, R. Joosten, E. Kabuß, F. Kaspar, A. Kerbizi, B. Ketzer, A. Khatun, G.V. Khaustov, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo Horikawa, I. Konorov, V.F. Konstantinov, A.M. Korzenev, A.M. Kotzinian, O.M. Kouznetsov, A. Koval, Z. Kral, F. Krinner, F. Kunne, K. Kurek, R.P. Kurjata, A. Kveton, K. Lavickova, S. Levorato, Y.-S. Lian, J. Lichtenstadt, P.-J. Lin, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, A. Maltsev, S.A. Mamon, A. Martin, J. Marzec, J. Matoušek, T. Matsuda, G. Mattson, C. Menezes Pires, F. Metzger, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, D. Miura, Y. Miyachi, R. Molina, A. Moretti, A. Nagaytsev, D. Neyret, M. Niemiec, J. Nový, W.-D. Nowak, G. Nukazuka, A.G. Olshevsky, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, H. Pekeler, J.-C. Peng, G. Pesaro, M. Pešek, D.V. Peshekhonov, M. Pešková, S. Platchkov, J. Pochodzalla, V.A. Polyakov, M. Quaresma, C. Quintans, G. Reicherz, C. Riedl, D.I. Ryabchikov, A. Rychter, A. Rymbekova, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, H. Schmieden, A. Selyunin, K. Sharko, L. Sinha, M. Slunecka, F. Sozzi, D. Spülbeck, A. Srnka, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, A. Townsend, T. Triloki, V. Tskhay, B. Valinoti, B.M. Veit, J.F.C.A. Veloso, B. Ventura, M. Virius, M. Wagner, S. Wallner, K. Zaremba, M. Zavertyaev, M. Zemko, E. Zemlyanichkina, and M. Ziembicki
Subjects: SIDIS, Di-hadron, Spin, Fragmentation, Transversity, Collins effect, Physics, QC1-999
Abstract: A set of measurements of azimuthal asymmetries in the production of pairs of identified hadrons in deep-inelastic scattering of muons on transversely polarised 6LiD (deuteron) and NH3 (proton) targets is presented. All available data collected in the years 2003–2004 and 2007/2010 with the COMPASS spectrometer using a muon beam of 160GeV/c at the CERN SPS were analysed. The asymmetries provide access to the transversity distribution functions via a fragmentation function that in principle may be independently obtained from e+e− annihilation data. Results are presented, discussed and compared to existing measurements as well as to model predictions. Asymmetries of π+π− pairs measured with the proton target as a function of the Bjorken scaling variable are sizeable in the range x>0.032, indicating non-vanishing transversity distribution and di-hadron interference fragmentation functions. As already pointed out by several authors, the small asymmetries of π+π− measured on the 6LiD target can be interpreted as indication for a cancellation of u and d-quark transversity distributions.
Published: 2023
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2. Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ρ0 mesons

Author: G.D. Alexeev, M.G. Alexeev, C. Alice, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badelek, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, A.G. Chumakov, S.-U. Chung, A. Cicuttin, P.M.M. Correia, M.L. Crespo, D. D'Ago, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, F. Del Carro, I. Denisenko, O.Yu. Denisov, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, D. Ecker, A. Efremov, C. Elia, D. Eremeev, P. Faccioli, M. Faessler, M. Finger, M. Finger, jr., H. Fischer, K.J. Flöthner, W. Florian, J.M. Friedrich, V. Frolov, L.G. Garcia Ordòñez, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, D. Giordano, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, M. Grüner, A. Guskov, D. von Harrach, M. Hoffmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, M. Jandek, V. Jary, R. Joosten, E. Kabuß, F. Kaspar, A. Kerbizi, B. Ketzer, A. Khatun, G.V. Khaustov, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo Horikawa, I. Konorov, V.F. Konstantinov, A.M. Korzenev, A.M. Kotzinian, O.M. Kouznetsov, A. Koval, Z. Kral, F. Krinner, F. Kunne, K. Kurek, R.P. Kurjata, A. Kveton, K. Lavickova, S. Levorato, Y.-S. Lian, J. Lichtenstadt, P.-J. Lin, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, A. Maltsev, S.A. Mamon, A. Martin, J. Marzec, J. Matoušek, T. Matsuda, G. Mattson, C. Menezes Pires, F. Metzger, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, D. Miura, Y. Miyachi, R. Molina, A. Moretti, A. Nagaytsev, C. Naim, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.G. Olshevsky, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, H. Pekeler, J.-C. Peng, M. Pešek, D.V. Peshekhonov, M. Pešková, S. Platchkov, J. Pochodzalla, V.A. Polyakov, M. Quaresma, C. Quintans, G. Reicherz, C. Riedl, T. Rudnicki, D.I. Ryabchikov, A. Rychter, A. Rymbekova, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, H. Schmieden, A. Selyunin, K. Sharko, L. Sinha, M. Slunecka, F. Sozzi, D. Spülbeck, A. Srnka, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, A. Townsend, T. Triloki, V. Tskhay, B. Valinoti, B.M. Veit, J.F.C.A. Veloso, B. Ventura, M. Virius, M. Wagner, S. Wallner, K. Zaremba, M. Zavertyaev, M. Zemko, E. Zemlyanichkina, and M. Ziembicki
Subjects: SIDIS, Spin, Fragmentation, Collins asymmetry, Sivers asymmetry, Physics, QC1-999
Abstract: The production of vector mesons in deep inelastic scattering is an interesting yet scarcely explored channel to study the transverse spin structure of the nucleon and the spin-dependence of fragmentation. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced ρ0 mesons. The analysis is based on the data set collected in deep inelastic scattering in 2010 using a 160GeV/c μ+ beam impinging on a transversely polarized NH3 target. The ρ0 mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-x variable, the transverse momentum of the pair and the fraction of the energy z carried by the pair. Indications for positive Collins and Sivers asymmetries are observed.
Published: 2023
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3. Double J/ψ production in pion-nucleon scattering at COMPASS

Author: G.D. Alexeev, M.G. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badełek, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, A.G. Chumakov, S.-U. Chung, A. Cicuttin, P.M.M. Correia, M.L. Crespo, D. D'Ago, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, I. Denisenko, O.Yu. Denisov, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, D. Ecker, A. Efremov, D. Eremeev, P.D. Eversheim, P. Faccioli, M. Faessler, M. Finger, M. Finger, jr., H. Fischer, K.J. Flöthner, W. Florian, C. Franco, J.M. Friedrich, V. Frolov, L.G. Garcia Ordòñez, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, D. Giordano, M. Gorzellik, A. Grasso, A. Gridin, S. Groote, M. Grosse Perdekamp, B. Grube, M. Grüner, A. Guskov, D. von Harrach, M. Hoffmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, M. Jandek, V. Jary, R. Joosten, E. Kabuß, F. Kaspar, A. Kerbizi, B. Ketzer, A. Khatun, G.V. Khaustov, Yu.A. Khokhlov, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo Horikawa, I. Konorov, V.F. Konstantinov, A.M. Korzenev, S. Koshkarev, A.M. Kotzinian, O.M. Kouznetsov, A. Koval, Z. Kral, F. Krinner, F. Kunne, K. Kurek, R.P. Kurjata, A. Kveton, K. Lavickova, S. Levorato, Y.-S. Lian, J. Lichtenstadt, P.-J. Lin, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, A. Maltsev, S.A. Mamon, A. Martin, J. Marzec, J. Matoušek, T. Matsuda, G. Mattson, C. Menezes Pires, F. Metzger, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, Y. Miyachi, R. Molina, A. Moretti, A. Nagaytsev, C. Naim, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.G. Olshevsky, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, H. Pekeler, J.-C. Peng, M. Pešek, D.V. Peshekhonov, M. Pešková, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, G. Reicherz, C. Riedl, T. Rudnicki, D.I. Ryabchikov, A. Rychter, A. Rymbekova, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, H. Schmieden, A. Selyunin, K. Sharko, L. Sinha, M. Slunecka, D. Spülbeck, A. Srnka, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, A. Townsend, T. Triloki, V. Tskhay, B. Valinoti, B.M. Veit, J.F.C.A. Veloso, B. Ventura, M. Virius, M. Wagner, S. Wallner, K. Zaremba, M. Zavertyaev, M. Zemko, E. Zemlyanichkina, and M. Ziembicki
Subjects: COMPASS, Charmonia production, Double J/ψ, Single parton scattering, Intrinsic charm, Physics, QC1-999
Abstract: We present the study of the production of double J/ψ mesons using COMPASS data collected with a 190 GeV/c π− beam scattering off NH3, Al and W targets. Kinematic distributions of the collected double J/ψ events are analysed, and the double J/ψ production cross section is estimated for each of the COMPASS targets. The NH3 results are compared to predictions from single- and double-parton scattering models as well as the pion intrinsic charm and the tetraquark exotic resonance hypotheses. It is demonstrated that the single parton scattering production mechanism gives the dominant contribution that is sufficient to describe the data. An upper limit on the double intrinsic charm content of the pion is evaluated. No significant signatures that could be associated with exotic tetraquarks are found in the double J/ψ mass spectrum.
Published: 2023
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4. Probing transversity by measuring Λ polarisation in SIDIS

Author: G.D. Alexeev, M.G. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, A.G. Chumakov, S.-U. Chung, A. Cicuttin, P.M.M. Correia, M.L. Crespo, D. D'Ago, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, I. Denisenko, O.Yu. Denisov, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, A. Efremov, C. Elia, D. Eremeev, P.D. Eversheim, P. Faccioli, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, K.J. Flöthner, C. Franco, J.M. Friedrich, V. Frolov, L.G. Garcia Ordòñez, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, D. Giordano, I. Gnesi, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, A. Guskov, D. von Harrach, R. Heitz, M. Hoffmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, M. Jandek, V. Jary, R. Joosten, E. Kabuß, D.-H. Kang, F. Kaspar, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo Horikawa, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, A. Koval, Z. Kral, F. Krinner, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A. Kveton, K. Lavickova, S. Levorato, Y.-S. Lian, J. Lichtenstadt, P.-J. Lin, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, A. Maltsev, S.A. Mamon, B. Marianski, A. Martin, J. Marzec, J. Matoušek, T. Matsuda, G. Mattson, G.V. Meshcheryakov, F. Metzger, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, Y. Miyachi, A. Moretti, A. Nagaytsev, C. Naim, T.S. Negrini, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, H. Pekeler, J.-C. Peng, M. Pešek, D.V. Peshekhonov, M. Pešková, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, G. Reicherz, C. Riedl, T. Rudnicki, D.I. Ryabchikov, A. Rychter, A. Rymbekova, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, H. Schmieden, A. Selyunin, K. Sharko, L. Sinha, M. Slunecka, J. Smolik, F. Sozzi, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, P. Sznajder, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, A. Townsend, V. Tskhay, S. Uhl, B.I. Vasilishin, A. Vauth, B.M. Veit, J. Veloso, B. Ventura, A. Vidon, M. Virius, M. Wagner, S. Wallner, K. Zaremba, P. Zavada, M. Zavertyaev, M. Zemko, E. Zemlyanichkina, Y. Zhao, and M. Ziembicki
Subjects: Quantum chromodynamics, Deep inelastic scattering, Lambda polarisation, Transversity, COMPASS, Physics, QC1-999
Abstract: Based on the observation of sizeable target-transverse-spin asymmetries in single-hadron and hadron-pair production in Semi-Inclusive measurements of Deep Inelastic Scattering (SIDIS), the chiral-odd transversity quark distribution functions h1q are nowadays well established. Several possible channels to access these functions were originally proposed. One candidate is the measurement of the polarisation of Λ hyperons produced in SIDIS off transversely polarised nucleons, where the transverse polarisation of the struck quark might be transferred to the final-state hyperon. In this article, we present the COMPASS results on the transversity-induced polarisation of Λ and Λ¯ hyperons produced in SIDIS off transversely polarised protons. Within the experimental uncertainties, no significant deviation from zero was observed. The results are discussed in the context of different models taking into account previous experimental results on h1u and h1d.
Published: 2022
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5. Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section

Author: R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, A. Bressan, M. Büchele, E. Burtin, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, A.G. Chumakov, S.-U. Chung, A. Cicuttin, M.L. Crespo, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, M. Dziewiecki, A. Efremov, P.D. Eversheim, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, I. Gnesi, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, D. Hahne, G. Hamar, D. von Harrach, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, V. Jary, R. Joosten, P. Jörg, K. Juraskova, E. Kabuß, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, Z. Kral, M. Krämer, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, I.I. Kuznetsov, A. Kveton, A.A. Lednev, E.A. Levchenko, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, S.A. Mamon, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Moretti, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, M. Pešková, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, N.S. Rogacheva, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, H. Schmieden, K. Schönning, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, M. Tasevsky, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, V. Tskhay, S. Uhl, B.I. Vasilishin, A. Vauth, B.M. Veit, J. Veloso, A. Vidon, M. Virius, S. Wallner, M. Wilfert, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, and M. Ziembicki
Subjects: Physics, QC1-999
Abstract: We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160GeV/c polarised μ+ and μ− beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ+ and μ− cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B=(4.3±0.6stat|sys−0.3+0.1)(GeV/c)−2. This result can be converted into a transverse extension of partons in the proton, 〈r⊥2〉=(0.58±0.04stat|sys−0.02+0.01±0.04model)fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q2〉=1.8(GeV/c)2 and the average value of the Bjorken variable is 〈xBj〉=0.056. Keywords: Quantum chromodynamics, Deep inelastic scattering, Exclusive reactions, Deeply virtual Compton scattering, Generalized Parton Distributions, Proton size, COMPASS
Published: 2019
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6. K− over K+ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

Author: R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, A. Bressan, M. Büchele, V.E. Burtsev, L. Capozza, W.-C. Chang, C. Chatterjee, M. Chiosso, A.G. Chumakov, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, M. Dziewiecki, A. Efremov, P.D. Eversheim, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, I. Gnesi, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, A. Guskov, D. Hahne, G. Hamar, D. von Harrach, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, V. Jary, R. Joosten, P. Jörg, E. Kabuß, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, Z. Kral, M. Krämer, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, I.I. Kuznetsov, A. Kveton, A.A. Lednev, E.A. Levchenko, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, S.A. Mamon, C. Marchand, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Moretti, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, G. Pesaro, M. Pešek, M. Pešková, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, H. Schmieden, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, F. Sozzi, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, M. Tasevsky, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, V. Tskhay, S. Uhl, B.I. Vasilishin, A. Vauth, B.M. Veit, J. Veloso, A. Vidon, M. Virius, S. Wallner, M. Wilfert, R. Windmolders, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, and M. Ziembicki
Subjects: Physics, QC1-999
Abstract: The K− over K+ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction z of the virtual-photon energy. The data were obtained by the COMPASS collaboration using a 160 GeV muon beam and an isoscalar 6LiD target. The regime of deep-inelastic scattering is ensured by requiring Q2>1(GeV/c)2 for the photon virtuality and W>5GeV/c2 for the invariant mass of the produced hadronic system. Kaons are identified in the momentum range from 12 GeV/c to 40 GeV/c, thereby restricting the range in Bjorken-x to 0.010.75. For very large values of z, i.e. z>0.8, we observe the kaon multiplicity ratio to fall below the lower limits expected from calculations based on leading and next-to-leading order perturbative quantum chromodynamics. Also, the kaon multiplicity ratio shows a strong dependence on the missing mass of the single-kaon production process. This suggests that within the perturbative quantum chromodynamics formalism an additional correction may be required, which takes into account the phase space available for hadronisation.
Published: 2018
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7. Corrigendum to 'Odd and even partial waves of ηπ− and η′π− in π−p → η(′)π−p at 191 GeV/c' [Phys. Lett. B 740 (2015) 303–311]

Author: C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Austregesilo, B. Badełek, F. Balestra, J. Barth, G. Baum, R. Beck, Y. Bedfer, A. Berlin, J. Bernhard, K. Bicker, E.R. Bielert, J. Bieling, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, E. Burtin, L. Capozza, M. Chiosso, S.U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, C. Elia, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, R. Geyer, I. Gnesi, B. Gobbo, S. Goertz, M. Gorzellik, S. Grabmüller, A. Grasso, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. von Harrach, D. Hahne, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, Ch. Höppner, N. Horikawa, N. d'Hose, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jasinski, P. Jörg, R. Joosten, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, M. Krämer, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, J. Lichtenstadt, A. Maggiora, A. Magnon, N. Makke, G.K. Mallot, C. Marchand, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, M. Mikhasenko, Y. Miyachi, A. Nagaytsev, T. Nagel, F. Nerling, S. Neubert, D. Neyret, J. Novy, W.-D. Nowak, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, D.V. Peshekhonov, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, E. Rocco, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rychter, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, M. Schott, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, S. Sosio, F. Sozzi, A. Srnka, L. Steiger, M. Stolarski, M. Sulc, R. Sulej, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, S. Uhl, I. Uman, M. Virius, L. Wang, T. Weisrock, M. Wilfert, R. Windmolders, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, and A. Zink
Subjects: Physics, QC1-999
Abstract: In Fig. 5 on p. 311 of our Phys. Lett. B 740 (2015) 303 an adjustment by 180∘ is required for the phases with respect to the L=2,M=1 wave, of the following waves: L=1,3,5 with M=1, and L=2 with M=2. After this correction (Fig. 5 (corrected) below), the extracted partial waves describe the angular distribution of the η(′) in the Gottfried-Jackson (GJ) frame, using Eq. (4) with implicit Condon-Shortley phase convention. The other results of our paper are not affected. The right-handed GJ coordinate system was defined by the z-axis pointing in the direction of the beam in the η(′)π− center-of-mass system and the y-axis pointing in the direction of precoilGJ×pbeamGJ.
Published: 2020
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8. Antiproton over proton and K− over K+ multiplicity ratios at high z in DIS

Author: G.D. Alexeev, M.G. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. Bressan, M. Büchele, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, A.G. Chumakov, S.-U. Chung, A. Cicuttin, P.M.M. Correia, M.L. Crespo, D. D'Ago, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, I. Denisenko, O.Yu. Denisov, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, A. Efremov, P.D. Eversheim, P. Faccioli, M. Faessler, M. Finger, M. Finger, jr., H. Fischer, C. Franco, J.M. Friedrich, V. Frolov, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, I. Gnesi, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, A. Guskov, D. von Harrach, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, M. Jandek, V. Jary, R. Joosten, P. Jörg, E. Kabuß, F. Kaspar, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo Horikawa, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, A. Koval, Z. Kral, F. Krinner, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A. Kveton, K. Lavičková, S. Levorato, Y.-S. Lian, J. Lichtenstadt, P.-J. Lin, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, A. Maltsev, S.A. Mamon, B. Marianski, A. Martin, J. Marzec, J. Matoušek, T. Matsuda, G. Mattson, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Moretti, A. Nagaytsev, C. Naim, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, H. Pekeler, J.-C. Peng, M. Pešek, D.V. Peshekhonov, M. Pešková, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, G. Reicherz, C. Riedl, T. Rudnicki, D.I. Ryabchikov, A. Rybnikov, A. Rychter, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, H. Schmieden, A. Selyunin, L. Sinha, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, P. Sznajder, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, A. Townsend, V. Tskhay, S. Uhl, B.I. Vasilishin, A. Vauth, B.M. Veit, J. Veloso, B. Ventura, A. Vidon, M. Virius, M. Wagner, S. Wallner, K. Zaremba, P. Zavada, M. Zavertyaev, M. Zemko, E. Zemlyanichkina, Y. Zhao, and M. Ziembicki
Subjects: Quantum chromodynamics, pQCD, Deep-inelastic scattering, Hadron multiplicities, COMPASS, Physics, QC1-999
Abstract: The antiparticle-over-particle multiplicity ratio is measured in deep-inelastic scattering for negatively and positively charged kaons and, for the first time, for antiprotons and protons. The data were obtained by the COMPASS Collaboration using a 160 GeV muon beam impinging on an isoscalar 6LiD target. The regime of deep-inelastic scattering is ensured by requiring Q2 > 1 (GeV/c)2 for the photon virtuality and W>5 GeV/c2 for the invariant mass of the produced hadronic system. Bjorken-x is restricted to the range 0.01 to 0.40. Protons and antiprotons are identified in the momentum range from 20 GeV/c to 60 GeV/c and required to carry a large fraction of the virtual-photon energy, z>0.5. In the whole studied z-region, the p¯ over p multiplicity ratio is found to be below the lower limit expected from calculations based on leading-order perturbative Quantum Chromodynamics (pQCD). Kaons were previously analysed in the momentum range 12 GeV/c to 40 GeV/c. In the present analysis this range is extended up to 55 GeV/c, whereby events with larger virtual-photon energies are included in the analysis and the observed K− over K+ ratio becomes closer to the expectation of next-to-leading order pQCD. The results of both analyses strengthen our earlier conclusion that at COMPASS energies the phase space available for single-hadron production in deep-inelastic scattering should be taken into account in the standard pQCD formalism.
Published: 2020
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9. Measurement of the cross section for hard exclusive π0 muoproduction on the proton

Author: M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, M. Bodlak, P. Bordalo, F. Bradamante, A. Bressan, M. Büchele, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, A.G. Chumakov, S.-U. Chung, A. Cicuttin, M.L. Crespo, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, A. Efremov, P.D. Eversheim, M. Faessler, A. Ferrero, M. Finger, M. Finger, Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, I. Gnesi, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, A. Guskov, D. Hahne, G. Hamar, D. von Harrach, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, M. Jandek, V. Jary, R. Joosten, P. Jörg, K. Juraskova, E. Kabuß, F. Kaspar, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo Horikawa, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, Z. Kral, M. Krämer, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A. Kveton, S. Levorato, Y.-S. Lian, J. Lichtenstadt, P.-J. Lin, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, S.A. Mamon, B. Marianski, A. Martin, J. Marzec, J. Matoušek, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Moretti, C. Naim, A. Nagaytsev, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, D.V. Peshekhonov, M. Pešková, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, D.I. Ryabchikov, A. Rybnikov, A. Rychter, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, H. Schmieden, A. Selyunin, L. Silva, L. Sinha, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, V. Tskhay, S. Uhl, B.I. Vasilishin, A. Vauth, B.M. Veit, J. Veloso, A. Vidon, M. Virius, M. Wagner, S. Wallner, M. Wilfert, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, Y. Zhao, and M. Ziembicki
Subjects: Quantum chromodynamics, Muoproduction, Hard exclusive meson production, Generalised Parton Distributions, COMPASS, Physics, QC1-999
Abstract: We report on a measurement of hard exclusive π0 muoproduction on the proton by COMPASS using 160GeV/c polarised μ+ and μ− beams of the CERN SPS impinging on a liquid hydrogen target. From the average of the measured μ+ and μ− cross sections, the virtual-photon proton cross section is determined as a function of the squared four-momentum transfer between initial and final proton in the range 0.08(GeV/c)2
Published: 2020
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10. Longitudinal double-spin asymmetry A1p and spin-dependent structure function g1p of the proton at small values of x and Q2

Author: M. Aghasyan, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, A. Bressan, M. Büchele, V.E. Burtsev, L. Capozza, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, A.G. Chumakov, S.-U. Chung, A. Cicuttin, M.L. Crespo, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, M. Dziewiecki, A. Efremov, P.D. Eversheim, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, F. Giordano, I. Gnesi, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, D. Hahne, G. Hamar, D. von Harrach, F.H. Heinsius, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, V. Jary, R. Joosten, P. Jörg, E. Kabuß, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, Z. Kral, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, I.I. Kuznetsov, A. Kveton, A.A. Lednev, E.A. Levchenko, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, S.A. Mamon, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Moretti, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, M. Pešková, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, N.S. Rogacheva, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, M. Tasevsky, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, V. Tskhay, S. Uhl, B.I. Vasilishin, A. Vauth, J. Veloso, A. Vidon, M. Virius, S. Wallner, T. Weisrock, M. Wilfert, R. Windmolders, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, and M. Ziembicki
Subjects: Physics, QC1-999
Abstract: We present a precise measurement of the proton longitudinal double-spin asymmetry A1p and the proton spin-dependent structure function g1p at photon virtualities 0.006(GeV/c)2
Published: 2018
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11. New analysis of ηπ tensor resonances measured at the COMPASS experiment

Author: A. Jackura, C. Fernández-Ramírez, M. Mikhasenko, A. Pilloni, V. Mathieu, J. Nys, V. Pauk, A.P. Szczepaniak, G. Fox, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, A. Bressan, M. Büchele, V.E. Burtsev, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, A.G. Chumakov, S.-U. Chung, A. Cicuttin, M.L. Crespo, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, W. Dünnweber, R.R. Dusaev, M. Dziewiecki, A. Efremov, P.D. Eversheim, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, F. Giordano, I. Gnesi, M. Gorzellik, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, D. Hahne, G. Hamar, D. von Harrach, F.H. Heinsius, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, V. Jary, R. Joosten, P. Jörg, E. Kabuß, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, Z. Kral, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, I.I. Kuznetsov, A. Kveton, A.A. Lednev, E.A. Levchenko, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, V.E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, S.A. Mamon, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, M. Pešková, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, N.S. Rogacheva, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, T. Schlüter, K. Schmidt, H. Schmieden, K. Schönning, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, M. Tasevsky, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, V. Tskhay, S. Uhl, B.I. Vasilishin, A. Vauth, J. Veloso, A. Vidon, M. Virius, S. Wallner, T. Weisrock, M. Wilfert, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, and M. Ziembicki
Subjects: Physics, QC1-999
Abstract: We present a new amplitude analysis of the ηπ D-wave in the reaction π−p→ηπ−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 a2(1320) and the excited a2′(1700), and perform a comprehensive analysis of their pole positions. For the mass and width of the a2 we find M=(1307±1±6) MeV and Γ=(112±1±8) MeV, and for the excited state a2′ we obtain M=(1720±10±60) MeV and Γ=(280±10±70) MeV, respectively.
Published: 2018
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12. First measurement of the Sivers asymmetry for gluons using SIDIS data

Author: C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, G. Hamar, D. von Harrach, F.H. Heinsius, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, V. Jary, R. Joosten, P. Jörg, E. Kabuß, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, M. Roskot, N.S. Rogacheva, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, M. Tasevsky, S. Tessaro, F. Tessarotto, F. Thibaud, A. Thiel, F. Tosello, V. Tskhay, S. Uhl, A. Vauth, J. Veloso, M. Virius, J. Vondra, S. Wallner, T. Weisrock, M. Wilfert, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, M. Ziembicki, and A. Zink
Subjects: Deep inelastic scattering, Gluon, Sivers, TMD, PDF, Physics, QC1-999
Abstract: The Sivers function describes the correlation between the transverse spin of a nucleon and the transverse motion of its partons. For quarks, it was studied in previous measurements of the azimuthal asymmetry of hadrons produced in semi-inclusive deep inelastic scattering of leptons off transversely polarised nucleon targets, and it was found to be non-zero. In this letter the evaluation of the Sivers asymmetry for gluons is presented. The contribution of the photon–gluon fusion subprocess is enhanced by requiring two high transverse-momentum hadrons. The analysis method is based on a Monte Carlo simulation that includes three hard processes: photon–gluon fusion, QCD Compton scattering and the 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 about 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.
Published: 2017
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13. Sivers asymmetry extracted in SIDIS at the hard scales of the Drell–Yan process at COMPASS

Author: C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger, Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, G. Hamar, D. von Harrach, F.H. Heinsius, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, V. Jary, R. Joosten, P. Jörg, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, M. Roskot, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, M. Tasevsky, S. Tessaro, F. Tessarotto, F. Thibaud, A. Thiel, F. Tosello, V. Tskhay, S. Uhl, J. Veloso, M. Virius, J. Vondra, S. Wallner, T. Weisrock, M. Wilfert, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, M. Ziembicki, and A. Zink
Subjects: SIDIS, Drell–Yan, Spin, Azimuthal asymmetries, Sivers, TMDs, Physics, QC1-999
Abstract: Eight proton transverse-spin-dependent azimuthal asymmetries are extracted in four regions of the photon virtuality Q2 from the COMPASS 2010 semi-inclusive hadron measurements in deep inelastic muon–nucleon scattering. These Q2 regions correspond to the four regions of the di-muon mass Q2 used in the ongoing analyses of the COMPASS Drell–Yan measurements, which allows for a future direct comparison of the nucleon transverse-momentum-dependent parton distribution functions extracted from these two alternative measurements. In addition, for the azimuthal asymmetries induced by the Sivers transverse-momentum-dependent parton distribution function various two-dimensional kinematic dependences are presented. 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.
Published: 2017
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14. Final COMPASS results on the deuteron spin-dependent structure function g1d and the Bjorken sum rule

Author: C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger, jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, J. Giarra, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, G. Hamar, D. von Harrach, F.H. Heinsius, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, V. Jary, R. Joosten, P. Jörg, E. Kabuß, A. Kerbizi, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, M. Roskot, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, M. Tasevsky, S. Tessaro, F. Tessarotto, F. Thibaud, A. Thiel, F. Tosello, V. Tskhay, S. Uhl, A. Vauth, J. Veloso, M. Virius, J. Vondra, S. Wallner, T. Weisrock, M. Wilfert, R. Windmolders, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, M. Ziembicki, and A. Zink
Subjects: COMPASS, Deep inelastic scattering, Spin, Structure function, Parton helicity distributions, Physics, QC1-999
Abstract: Final results are presented from the inclusive measurement of deep-inelastic polarised-muon scattering on longitudinally polarised deuterons using a 6LiD target. The data were taken at 160 GeV beam energy and the results are shown for the kinematic range 1(GeV/c)24GeV/c2 in the mass of the hadronic final state. The deuteron double-spin asymmetry A1d and the deuteron longitudinal-spin structure function g1d are presented in bins of x and Q2. Towards lowest accessible values of x, g1d decreases and becomes consistent with zero within uncertainties. The presented final g1d values together with the recently published final g1p values of COMPASS are used to again evaluate the Bjorken sum rule and perform the QCD fit to the g1 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 a0, which is identified in the MS‾ renormalisation scheme with the total contribution of quark helicities to the nucleon spin, is extracted at next-to-leading order accuracy from only the COMPASS deuteron data: a0(Q2=3(GeV/c)2)=0.32±0.02stat±0.04syst±0.05evol. Together with the recent results on the proton spin structure function g1p, the results on g1d constitute the COMPASS legacy on the measurements of g1 through inclusive spin-dependent deep inelastic scattering.
Published: 2017
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15. Multiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target

Author: C. Adolph, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, M. Bodlak, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, L. Capozza, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, Ch. Dreisbach, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger, Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, G. Hamar, D. von Harrach, F.H. Heinsius, R. Heitz, F. Herrmann, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, V. Jary, R. Joosten, P. Jörg, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Nagaytsev, F. Nerling, D. Neyret, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, M. Roskot, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, E. Seder, A. Selyunin, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, F. Sozzi, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, M. Tasevsky, S. Tessaro, F. Tessarotto, F. Thibaud, A. Thiel, F. Tosello, V. Tskhay, S. Uhl, J. Veloso, M. Virius, J. Vondra, S. Wallner, T. Weisrock, M. Wilfert, R. Windmolders, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, M. Ziembicki, and A. Zink
Subjects: Deep inelastic scattering, Kaon multiplicities, Quark fragmentation functions, Strange quark, Physics, QC1-999
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 6LiD target. They cover the kinematic domain 1(GeV/c)25 GeV/c2 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.
Published: 2017
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16. Multiplicities of charged pions and charged hadrons from deep-inelastic scattering of muons off an isoscalar target

Author: C. Adolph, M. Aghasyan, R. Akhunzyanov, G.D. Alexeev, M.G. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V. Anosov, K. Augsten, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, L. Capozza, W.-C. Chang, C. Chatterjee, M. Chiosso, I. Choi, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, D. von Harrach, R. Hashimoto, F.H. Heinsius, R. Heitz, F. Herrmann, F. Hinterberger, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, R. Joosten, P. Jörg, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O.M. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, R. Kuhn, Y. Kulinich, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, Y.-S. Lian, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, C. Marchand, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G.V. Meshcheryakov, M. Meyer, W. Meyer, T. Michigami, Yu.V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, P. Montuenga, A. Nagaytsev, F. Nerling, D. Neyret, V.I. Nikolaenko, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, D.V. Peshekhonov, N. Pierre, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, M. Roskot, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rybnikov, A. Rychter, R. Salac, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, T. Sawada, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, E. Seder, A. Selyunin, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, J. Smolik, F. Sozzi, A. Srnka, D. Steffen, M. Stolarski, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, M. Tasevsky, S. Tessaro, F. Tessarotto, F. Thibaud, F. Tosello, V. Tskhay, S. Uhl, J. Veloso, M. Virius, J. Vondra, T. Weisrock, M. Wilfert, R. Windmolders, J. ter Wolbeek, K. Zaremba, P. Zavada, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, M. Ziembicki, and A. Zink
Subjects: Deep inelastic scattering, Pion multiplicities, Fragmentation functions, Physics, QC1-999
Abstract: Multiplicities of charged pions and charged hadrons produced in deep-inelastic scattering were measured in three-dimensional 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 160GeV muon beam and an isoscalar target (6LiD). They cover the kinematic domain in the photon virtuality Q2>1(GeV/c)2, 0.004
Published: 2017
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17. Interplay among transversity induced asymmetries in hadron leptoproduction

Author: C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, E. Burtin, W.-C. Chang, M. Chiosso, I. Choi, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, N. d'Hose, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, V. Duic, M. Dziewiecki, A. Efremov, C. Elia, P.D. Eversheim, W. Eyrich, A. Ferrero, M. Finger, M. Finger Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, D. von Harrach, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, N. Horikawa, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jörg, R. Joosten, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, C. Marchand, B. Marianski, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, P. Montuenga, A. Nagaytsev, F. Nerling, D. Neyret, V.I. Nikolaenko, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, G. Pesaro, M. Pesek, D.V. Peshekhonov, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rychter, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, A. Selyunin, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, F. Sozzi, A. Srnka, M. Stolarski, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, F. Tosello, V. Tskhay, S. Uhl, J. Veloso, M. Virius, T. Weisrock, M. Wilfert, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, and A. Zink
Subjects: Physics, QC1-999
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 the 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 quantitative relationships to be established among them, providing for the first time strong experimental indication that the underlying fragmentation mechanisms are all driven by a common physical process.
Published: 2016
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18. The spin structure function g1p of the proton and a test of the Bjorken sum rule

Author: C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Austregesilo, C. Azevedo, B. Badełek, F. Balestra, J. Barth, G. Baum, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, E. Burtin, L. Capozza, W.-C. Chang, M. Chiosso, I. Choi, S.U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, V. Duic, M. Dziewiecki, A. Efremov, P.D. Eversheim, W. Eyrich, A. Ferrero, M. Finger, M. Finger jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse-Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, D. von Harrach, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, N. Horikawa, N. d'Hose, C. -Yu Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jörg, R. Joosten, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, C. Marchand, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, A. Nagaytsev, T. Nagel, F. Nerling, D. Neyret, V.I. Nikolaenko, J. Novy, W.-D. Nowak, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pesek, D.V. Peshekhonov, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, E. Rocco, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rychter, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, A. Selyunin, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, F. Sozzi, A. Srnka, M. Stolarski, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, F. Tosello, V. Tskhay, S. Uhl, J. Veloso, M. Virius, T. Weisrock, M. Wilfert, R. Windmolders, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, and A. Zink
Subjects: Physics, QC1-999
Abstract: New results for the double spin asymmetry A1p and the proton longitudinal spin structure function g1p are presented. They were obtained by the COMPASS Collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH3 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 g1p(x) by about a factor of two in the region x≲0.02. A next-to-leading order QCD fit to the g1 world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, ΔΣ, ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of g1p. The uncertainty of ΔΣ 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 g1NS(x,Q2) yields as ratio of the axial and vector coupling constants |gA/gV|=1.22±0.05 (stat.)±0.10 (syst.), which validates the sum rule to an accuracy of about 9%.
Published: 2016
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19. Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high pT

Author: C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, W. Augustyniak, A. Austregesilo, C.D.R. Azevedo, B. Badełek, F. Balestra, J. Barth, R. Beck, Y. Bedfer, J. Bernhard, K. Bicker, E.R. Bielert, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, E. Burtin, W.-C. Chang, M. Chiosso, I. Choi, S.-U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, L. Dhara, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, E. Fuchey, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, F. Giordano, I. Gnesi, M. Gorzellik, S. Grabmüller, A. Grasso, M. Grosse Perdekamp, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. Hahne, D. von Harrach, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, N. Horikawa, N. d'Hose, C.-Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, R. Joosten, P. Jörg, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, M. Krämer, P. Kremser, F. Krinner, Z.V. Kroumchtein, N. Kuchinski, R. Kuhn, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, J. Lichtenstadt, R. Longo, A. Maggiora, A. Magnon, N. Makins, N. Makke, G.K. Mallot, C. Marchand, B. Marianski, A. Martin, J. Marzec, J. Matoušek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, P. Montuenga, A. Nagaytsev, F. Nerling, D. Neyret, V.I. Nikolaenko, J. Nový, W.-D. Nowak, G. Nukazuka, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, J.-C. Peng, F. Pereira, M. Pešek, D.V. Peshekhonov, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, C. Riedl, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rychter, V.D. Samoylenko, A. Sandacz, C. Santos, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, A. Selyunin, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, F. Sozzi, A. Srnka, M. Stolarski, M. Sulc, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, S. Tessaro, F. Tessarotto, F. Thibaud, F. Tosello, V. Tskhay, S. Uhl, J. Veloso, M. Virius, T. Weisrock, M. Wilfert, J. ter Wolbeek, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, and A. Zink
Subjects: COMPASS, Deep inelastic scattering, Double spin asymmetry, High pT, ΔG, Physics, QC1-999
Abstract: We measured the longitudinal double spin asymmetries ALL for single hadron muoproduction off protons and deuterons at photon virtuality Q2
Published: 2016
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20. Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised protons

Author: C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Austregesilo, B. Badełek, F. Balestra, J. Barth, G. Baum, R. Beck, Y. Bedfer, A. Berlin, J. Bernhard, K. Bicker, E.R. Bielert, J. Bieling, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, E. Burtin, L. Capozza, M. Chiosso, S.U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, C. Elia, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger, Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, R. Geyer, I. Gnesi, B. Gobbo, S. Goertz, M. Gorzellik, S. Grabmüller, A. Grasso, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. von Harrach, D. Hahne, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, Ch. Höppner, N. Horikawa, N. d'Hose, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jasinski, P. Jörg, R. Joosten, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, M. Krämer, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, J. Lichtenstadt, A. Maggiora, A. Magnon, N. Makke, G.K. Mallot, C. Marchand, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, A. Nagaytsev, T. Nagel, F. Nerling, S. Neubert, D. Neyret, J. Novy, W.-D. Nowak, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, G. Pesaro, D.V. Peshekhonov, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, E. Rocco, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rychter, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, M. Schott, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, S. Sosio, F. Sozzi, A. Srnka, L. Steiger, M. Stolarski, M. Sulc, R. Sulej, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, S. Uhl, I. Uman, M. Virius, L. Wang, T. Weisrock, M. Wilfert, R. Windmolders, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, and A. Zink
Subjects: Physics, QC1-999
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.
Published: 2015
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21. Search for exclusive photoproduction of Zc±(3900) at COMPASS

Author: C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Austregesilo, B. Badełek, F. Balestra, J. Barth, G. Baum, R. Beck, Y. Bedfer, A. Berlin, J. Bernhard, K. Bicker, E.R. Bielert, J. Bieling, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, E. Burtin, L. Capozza, M. Chiosso, S.U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, C. Elia, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, A. Filin, M. Finger, M. Finger, Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, R. Geyer, I. Gnesi, B. Gobbo, S. Goertz, M. Gorzellik, S. Grabmüller, A. Grasso, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. von Harrach, D. Hahne, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, Ch. Höppner, N. Horikawa, N. d'Hose, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jasinski, P. Jörg, R. Joosten, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, M. Krämer, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, J. Lichtenstadt, A. Maggiora, A. Magnon, N. Makke, G.K. Mallot, C. Marchand, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, A. Nagaytsev, T. Nagel, F. Nerling, S. Neubert, D. Neyret, V.I. Nikolaenko, J. Novy, W.-D. Nowak, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, D.V. Peshekhonov, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, E. Rocco, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rychter, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, M. Schott, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, S. Sosio, F. Sozzi, A. Srnka, L. Steiger, M. Stolarski, M. Sulc, R. Sulej, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, S. Uhl, I. Uman, M. Virius, L. Wang, T. Weisrock, M. Wilfert, R. Windmolders, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, and A. Zink
Subjects: Physics, QC1-999
Abstract: A search for the exclusive production of the Zc±(3900) hadron by virtual photons has been performed in the channel Zc±(3900)→J/ψπ±. 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(Zc±(3900)→J/ψπ±)×σγN→Zc±(3900)N/σγN→J/ψN of 3.7×10−3 has been established at the confidence level of 90%. Keywords: COMPASS, Zc(3900), Photoproduction, Tetraquark
Published: 2015
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22. Odd and even partial waves of ηπ− and η′π− in π−p→η(′)π−p at 191 GeV/c

Author: C. Adolph, R. Akhunzyanov, M.G. Alexeev, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Austregesilo, B. Badełek, F. Balestra, J. Barth, G. Baum, R. Beck, Y. Bedfer, A. Berlin, J. Bernhard, K. Bicker, E.R. Bielert, J. Bieling, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bressan, M. Büchele, E. Burtin, L. Capozza, M. Chiosso, S.U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, C. Elia, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, M. Finger, M. Finger, Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, R. Geyer, I. Gnesi, B. Gobbo, S. Goertz, M. Gorzellik, S. Grabmüller, A. Grasso, B. Grube, T. Grussenmeyer, A. Guskov, F. Haas, D. von Harrach, D. Hahne, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, Ch. Höppner, N. Horikawa, N. d'Hose, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jasinski, P. Jörg, R. Joosten, E. Kabuß, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, M. Krämer, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, M. Levillain, S. Levorato, J. Lichtenstadt, A. Maggiora, A. Magnon, N. Makke, G.K. Mallot, C. Marchand, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, A. Nagaytsev, T. Nagel, F. Nerling, S. Neubert, D. Neyret, J. Novy, W.-D. Nowak, A.S. Nunes, A.G. Olshevsky, I. Orlov, M. Ostrick, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, D.V. Peshekhonov, S. Platchkov, J. Pochodzalla, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, C. Regali, G. Reicherz, E. Rocco, N.S. Rossiyskaya, D.I. Ryabchikov, A. Rychter, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, M. Schott, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, S. Sosio, F. Sozzi, A. Srnka, L. Steiger, M. Stolarski, M. Sulc, R. Sulej, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, S. Uhl, I. Uman, M. Virius, L. Wang, T. Weisrock, M. Wilfert, R. Windmolders, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, and A. Zink
Subjects: Physics, QC1-999
Abstract: Exclusive production of ηπ− and η′π− has been studied with a 191 GeV/c π− 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 GeV/c2. 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 a2(1320) and a4(2040) are in line with this similarity. In contrast, a strong enhancement of η′π− over ηπ− is found for the L=1,3,5 waves, which carry non-qq¯ quantum numbers. The L=1 intensity peaks at 1.7 GeV/c2 in η′π− and at 1.4 GeV/c2 in ηπ−, the corresponding phase motions with respect to L=2 are different.
Published: 2015
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23. A high-statistics measurement of transverse spin effects in dihadron production from muon–proton semi-inclusive deep-inelastic scattering

Author: C. Adolph, R. Akhunzyanov, M.G. Alekseev, Yu. Alexandrov, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Austregesilo, B. Badełek, F. Balestra, J. Barth, G. Baum, R. Beck, Y. Bedfer, A. Berlin, J. Bernhard, R. Bertini, K. Bicker, J. Bieling, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bravar, A. Bressan, M. Büchele, E. Burtin, L. Capozza, M. Chiosso, S.U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, C. Elia, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, A. Filin, M. Finger, M. Finger, Jr., H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, R. Garfagnini, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, R. Geyer, M. Giorgi, I. Gnesi, B. Gobbo, S. Goertz, M. Gorzellik, S. Grabmüller, A. Grasso, B. Grube, A. Guskov, T. Guthörl, F. Haas, D. von Harrach, D. Hahne, R. Hashimoto, F.H. Heinsius, F. Herrmann, F. Hinterberger, Ch. Höppner, N. Horikawa, N. d'Hose, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jasinski, P. Joerg, R. Joosten, E. Kabuß, D. Kang, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, Z. Kral, M. Krämer, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, S. Levorato, J. Lichtenstadt, A. Maggiora, A. Magnon, N. Makke, G.K. Mallot, C. Marchand, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, A. Nagaytsev, T. Nagel, F. Nerling, S. Neubert, D. Neyret, V.I. Nikolaenko, J. Novy, W.-D. Nowak, A.S. Nunes, I. Orlov, A.G. Olshevsky, M. Ostrick, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, M. Pesek, D. Peshekhonov, G. Piragino, S. Platchkov, J. Pochodzalla, J. Polak, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, G. Reicherz, E. Rocco, V. Rodionov, E. Rondio, A. Rychter, N.S. Rossiyskaya, D.I. Ryabchikov, V.D. Samoylenko, A. Sandacz, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, A. Schmidt, K. Schmidt, H. Schmieden, K. Schönning, S. Schopferer, M. Schott, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, S. Sosio, F. Sozzi, A. Srnka, L. Steiger, M. Stolarski, M. Sulc, R. Sulej, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, S. Uhl, I. Uman, M. Vandenbroucke, M. Virius, J. Vondra, L. Wang, T. Weisrock, M. Wilfert, R. Windmolders, W. Wiślicki, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, and M. Ziembicki
Subjects: Physics, QC1-999
Abstract: A measurement of the azimuthal asymmetry in dihadron production in deep-inelastic scattering of muons on transversely polarised proton (NH3) targets is 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 GeV/c muon beam of the CERN SPS, increasing by a factor of about four the overall statistics with respect to 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.
Published: 2014
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24. K− over K+ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

Author: S. Gerassimov, N. Horikawa, A. Srnka, A.G. Olshevsky, A. Rychter, F. Tosello, S. Tessaro, D. Hahne, R. Longo, M. Wilfert, V.N. Kolosov, L. Capozza, K. Kondo, F. Krinner, Yu.A. Khokhlov, Y.-S. Lian, C. Quintans, Alexandr Selyunin, Andrea Ferrero, I. Konorov, Y. Bedfer, K. Zaremba, C. Regali, C. Chatterjee, T. Sawada, Norihiro Doshita, V.A. Polyakov, Nour Makke, W. C. Chang, N. d'Hose, F. Kunne, Valery E. Lyubovitskij, C. Franco, R.R. Dusaev, V. Tskhay, Z.V. Kroumchtein, M. Chiosso, G. Sbrizzai, M. Quaresma, J. Barth, J. Smolik, E. Seder, J.F.C.A. Veloso, S.A. Mamon, O. Subrt, A. Amoroso, C.-Y. Hsieh, L. Dhara, B. Badełek, M. Ziembicki, Franco Bradamante, F. Pereira, N. du Fresne von Hohenesche, O.M. Kouznetsov, M. Stolarski, T. Szameitat, M. Grosse Perdekamp, B.M. Veit, A. Grasso, A. Gridin, A. Vidon, B. Marianski, Bakur Parsamyan, W. Augustyniak, S. Ramos, D.V. Peshekhonov, G. Pesaro, S. Platchkov, P. Zavada, Maria Liz Crespo, Miroslav Sulc, A. Kveton, Y. Miyachi, A.A. Lednev, P. Schiavon, M. A. Faessler, G.V. Khaustov, V. Frolov, B. Ketzer, Soumen Paul, R. Birsa, Jen-Chieh Peng, J. Lichtenstadt, P. Sznajder, J. Pochodzalla, V. Jary, Anne-Laure Martin, P. Jörg, S.S. Dasgupta, I. Gnesi, H. Schmieden, D. Steffen, Andrew Ivanov, S. Sarkar, Yu. Kisselev, O.P. Gavrichtchouk, Martin Bodlak, J.M. Friedrich, A. Sandacz, A. Vauth, H. Matsuda, R. Salac, M. Ostrick, S. Levorato, L. Sinha, T. Matsuda, D. Neyret, S. Dasgupta, A. Austregesilo, P. Bordalo, R. Akhunzyanov, Laura Silva, V.F. Konstantinov, Yakov Petrovich Kulinich, E.R. Bielert, D.I. Ryabchikov, A. Thiel, Q. Curiel, V.E. Burtsev, N. Mitrofanov, S. Huber, S. Wallner, E.A. Levchenko, S. Ishimoto, D. von Harrach, H. Fischer, E. M. Kabuß, E. Zemlyanichkina, Naomi C R Makins, G. D. Alexeev, R.P. Kurjata, Jan Tomsa, M. V. Zavertyaev, W. Dünnweber, K. Bicker, I.A. Savin, C. Marchand, M. Büchele, M.G. Alexeev, M. Krämer, S. Uhl, M. Finger, G. Hamar, J. Giarra, A.V. Efremov, Ilya Kuznetsov, J.H. Koivuniemi, Michal Dziewiecki, Andres Cicuttin, A. Moretti, I. Orlov, V.D. Samoylenko, Jan Matousek, G. Reicherz, Nikolay Anfimov, M. Pešková, M. Gorzellik, R. Heitz, M. Virius, J. Nový, R. Joosten, O.Yu. Denisov, Z. Kral, S. Dalla Torre, A. Antoshkin, P.D. Eversheim, F. Klein, Kamil Augsten, S.-U. Chung, G.V. Meshcheryakov, H. Suzuki, C.D.R. Azevedo, Yu. V. Mikhailov, R. Beck, A. Kerbizi, S. Sirtl, A. Maggiora, F. Tessarotto, Mikhail Mikhasenko, F. Nerling, François Herrmann, B. Grube, Johannes Bernhard, Ch. Dreisbach, S. V. Donskov, A. Guskov, M. Pešek, A.S. Nunes, Andrea Bressan, Markus Ball, D. Panzieri, Janusz Marzec, M. Tasevsky, E. Mitrofanov, G. Nukazuka, M. Slunecka, A. Magnon, Takahiro Iwata, Federica Sozzi, W. Meyer, K. Kurek, Gerhard K. Mallot, Aram Kotzinian, R. Windmolders, B.I. Vasilishin, M. Meyer, A.G. Chumakov, J. Pretz, Arseniy Rybnikov, W.-D. Nowak, V. Anosov, V. Andrieux, Adam Szabelski, A. Nagaytsev, F. Balestra, N. Pierre, F. Gautheron, C. Riedl, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, COMPASS, Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, 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., Badełek, 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., Büchele, M., Burtsev, V. E., Capozza, L., Chang, W. -C., Chatterjee, C., Chiosso, M., Chumakov, A. G., Chung, S. -U., Cicuttin, A., Crespo, M. L., Curiel, Q., Dalla Torre, S., Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Dünnweber, W., Dusaev, R. R., Dziewiecki, M., Efremov, A., Eversheim, P. D., Faessler, M., Ferrero, A., Finger, M., Fischer, H., Franco, C., du Fresne von Hohenesche, N., Friedrich, J. M., Frolov, V., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Gnesi, I., Gorzellik, M., Grasso, A., Gridin, A., Grosse Perdekamp, M., Grube, B., Guskov, A., Hahne, D., Hamar, G., von Harrach, D., Heitz, R., Herrmann, F., Horikawa, N., D'Hose, N., Hsieh, C. -Y., Huber, S., Ishimoto, S., Ivanov, A., Iwata, T., Jary, V., Joosten, R., Jörg, 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., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kral, Z., Krämer, M., 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., 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., Marchand, C., Marianski, B., Martin, A., Marzec, J., Matoušek, 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., 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., Pesaro, G., Pešek, M., Pešková, 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., Ryabchikov, D. I., Rybnikov, A., Rychter, A., Salac, R., Samoylenko, V. D., Sandacz, A., Sarkar, S., Savin, I. A., Sawada, T., Sbrizzai, G., Schiavon, P., Schmieden, H., Seder, E., Selyunin, A., Silva, L., Sinha, L., Sirtl, S., Slunecka, M., Sozzi, F., 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., Veit, B. M., Veloso, J., Vidon, A., Virius, M., Wallner, S., Wilfert, M., Windmolders, R., Zaremba, K., Zavada, P., Zavertyaev, M., Zemlyanichkina, E., and Ziembicki, M.
Subjects: Hadron, 0 [higher-order], target: isoscalar, 01 natural sciences, COMPASS, deep inelastic scattering [muon+ nucleon], High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), K: multiplicity, High Energy Physics - Phenomenology (hep-ph), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], isoscalar [target], Invariant mass, Nuclear Experiment, Boson, Physics, Quantum chromodynamics, quark: fragmentation function, higher-order: 0, photon, perturbation theory: higher-order, hep-ph, мюоны, lcsh:QC1-999, Bjorken [scaling], High Energy Physics - Phenomenology, beam [muon], рассеяние, factorization [cross section], multiplicity [pi], Particle Physics - Experiment, perturbation theory [quantum chromodynamics], Particle physics, Nuclear and High Energy Physics, Meson, FOS: Physical sciences, ratio [multiplicity], fragmentation function [quark], x-dependence, scaling: Bjorken, charged particle: multiplicity, phase space, multiplicity [charged particle], [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], виртуальные фотоны, 0103 physical sciences, ddc:530, universality, quantum chromodynamics: perturbation theory, 010306 general physics, Particle Physics - Phenomenology, muon+ nucleon: deep inelastic scattering, Muon, multiplicity: ratio, pi: multiplicity, 010308 nuclear & particles physics, hep-ex, muon: beam, Multiplicity (mathematics), cross section: factorization, CERN SPS, Deep inelastic scattering, higher-order [perturbation theory], [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], каоны, [ PHYS.HPHE ] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, multiplicity [K], hadronization, lcsh:Physics, experimental results
Abstract: The K$^{-}$ over K$^{+}$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction $z$ of the virtual-photon energy. The data were obtained by the COMPASS collaboration using a 160 GeV muon beam and an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2>1$ (GeV/$c)^2$ for the photon virtuality and $W>5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. Kaons are identified in the momentum range from 12 GeV/$c$ to 40 GeV/$c$, thereby restricting the range in Bjorken-$x$ to $0.010.75$. For very large values of $z$, $i.e.$ $z>0.8$, we observe the kaon multiplicity ratio to fall below the lower limits expected from calculations based on leading and next-to-leading order perturbative quantum chromodynamics. Also, the kaon multiplicity ratio shows a strong dependence on the missing mass of the single-kaon production process. This suggests that within the perturbative quantum chromodynamics formalism an additional correction may be required, which takes into account the phase space available for hadronisation., Comment: 16 pages, 7 figures
Published: 2018

25. Corrigendum to 'Odd and even partial waves of ηπ− and η′π− in π−p → η(′)π−p at 191 GeV/c' [Phys. Lett. B 740 (2015) 303–311]

Author: S. Takekawa, L. Steiger, E. M. Kabuß, R. Panknin, I.A. Savin, N.S. Rossiyskaya, A. Srnka, A. Grasso, Frank Klein, Yu. Kisselev, M. Ostrick, E.R. Bielert, M. Boer, S. Ramos, M. Wilfert, S.-U. Chung, F. Tessarotto, J. Pretz, S.S. Dasgupta, S. Neubert, V. Anosov, S. Gerassimov, D.V. Peshekhonov, C. Quintans, N. Horikawa, M. Büchele, P. Sznajder, H. Wollny, P. Jörg, M. V. Zavertyaev, François Herrmann, Yu. Ivanshin, O.Yu. Shevchenko, S. Levorato, C. Braun, Z.V. Kroumchtein, B. Badelek, M. Stolarski, J.H. Koivuniemi, T. Iwata, M. Krämer, T. Szameitat, Asher Berlin, Fabrice Gautheron, S. Tessaro, D. Hahne, C. Marchand, D.I. Ryabchikov, M. A. Faessler, M. Gorzellik, Ch. Höppner, T. Nagel, A. Lehmann, C. Regali, O. Kouznetsov, K. Königsmann, Miroslav Sulc, R. Joosten, F. Hinterberger, B. Ketzer, R. Sulej, Yu.A. Khokhlov, J. Novy, A. Rychter, M. Chiosso, Franco Bradamante, F. Haas, O.P. Gavrichtchouk, I. Gnesi, Martin Bodlak, R. Hashimoto, R.P. Kurjata, M. Slunecka, R. Akhunzyanov, Y. Miyachi, L. Sinha, K. Klimaszewski, T. Matsuda, R. Geyer, M. Ziembicki, M. Finger, S. Sarkar, Laura Silva, A. Maggiora, A. Zink, I. Konorov, B. Gobbo, G. D. Alexeev, Aram Kotzinian, W. Dünnweber, V.N. Kolosov, K. Schönning, A.A. Lednev, K. Kurek, W. Meyer, Maria Liz Crespo, Lei Wang, M. Virius, T. Michigami, V. Jary, F. H. Heinsius, Federica Sozzi, S. Schopferer, R. Windmolders, Andres Cicuttin, I. Orlov, V.D. Samoylenko, G. Reicherz, L. Capozza, K. Kondo, S. Goertz, P. Schiavon, Mikhail Mikhasenko, S. Grabmüller, K. Bicker, A.B. Ivanov, S. V. Donskov, A. Magnon, Y. Bedfer, S. Sosio, O.Yu. Denisov, F. Kunne, R. Jahn, S. Dalla Torre, V. Duic, A. Sandacz, Alessandro Bressan, D. von Harrach, A. Austregesilo, C. Elia, G.V. Khaustov, G. Baum, G.V. Meshcheryakov, A.S. Nunes, Bakur Parsamyan, P.D. Eversheim, W. Eyrich, P. Jasinski, D. Panzieri, Janusz Marzec, M.G. Alexeev, S. Uhl, R. Beck, B. Grube, H. Suzuki, Nour Makke, J. Bieling, H. Matsuda, T. Grussenmeyer, M. Quaresma, Michal Dziewiecki, S. Platchkov, Yu. V. Mikhailov, Christian Schill, J. ter Wolbeek, C. Franco, J. Pochodzalla, Jan Matousek, S. Sirtl, A.G. Olshevsky, Andrea Ferrero, F. Nerling, Q. Curiel, R. Birsa, J. Lichtenstadt, M. Levillain, D. Neyret, W.-D. Nowak, H. Schmieden, P. Bordalo, F. Thibaud, J. Barth, V. Frolov, Soumen Paul, J.M. Friedrich, N. Kuchinski, J. Bisplinghoff, Gerhard K. Mallot, K. Schmidt, Norihiro Doshita, S. Huber, Matthias Schott, Anne-Laure Martin, T. Weisrock, N. d'Hose, E. Zemlyanichkina, E. Burtin, V.F. Konstantinov, S. Ishimoto, H. Fischer, V. Andrieux, Adam Szabelski, A. Nagaytsev, F. Balestra, K. Zaremba, V.A. Polyakov, G. Sbrizzai, A. Amoroso, N. du Fresne von Hohenesche, T. Schlüter, E. Rocco, C. Adolph, Johannes Bernhard, A.V. Efremov, A. Guskov, and I. Uman
Subjects: Physics, Nuclear and High Energy Physics, Angular distribution, Recoil, Coordinate system, Phase (waves), Atomic physics, Beam (structure), lcsh:Physics, lcsh:QC1-999
Abstract: In Fig. 5 on p. 311 of our Phys. Lett. B 740 (2015) 303 an adjustment by 180 ∘ is required for the phases with respect to the L = 2 , M = 1 wave, of the following waves: L = 1 , 3 , 5 with M = 1 , and L = 2 with M = 2 . After this correction (Fig. 5 (corrected) below), the extracted partial waves describe the angular distribution of the η ( ′ ) in the Gottfried-Jackson (GJ) frame, using Eq. (4) with implicit Condon-Shortley phase convention. The other results of our paper are not affected. The right-handed GJ coordinate system was defined by the z-axis pointing in the direction of the beam in the η ( ′ ) π − center-of-mass system and the y-axis pointing in the direction of p recoil GJ × p beam GJ .
Published: 2020

26. Search for muoproduction of X(3872) at COMPASS and indication of a new state X˜(3872)

Author: L. Silva, S.S. Dasgupta, A.G. Chumakov, J. Nový, Y. Miyachi, P.D. Eversheim, P. Zavada, E. Zemlyanichkina, François Herrmann, S. Uhl, Y. Bedfer, A. Antoshkin, G. Sbrizzai, N.S. Rogacheva, A. Ferrero, G.V. Khaustov, A. Magnon, F. Pereira, I. Konorov, J. ter Wolbeek, Maria Liz Crespo, C. Regali, J. Marzec, A. Kveton, G.D. Alexeev, K. Schmidt, P. Kremser, O.Yu. Denisov, F. Gautheron, F. Nerling, Yu.A. Khokhlov, K. Kondo, N. C. R. Makins, M. Faessler, V.N. Kolosov, A. Amoroso, H. Matsuda, D. Neyret, C.D.R. Azevedo, V. Jary, V. Anosov, M. Grosse Perdekamp, S. Sarkar, Y.-S. Lian, R. Beck, A. Selyunin, B. Grube, M. Stolarski, M. Tasevsky, T. Sawada, N. Horikawa, M. Sulc, S. Tessaro, D. Hahne, V.D. Samoylenko, J. Giarra, N. d'Hose, W. Meyer, R. Joosten, Andres Cicuttin, O. Subrt, S. Wallner, S. Platchkov, R. Salac, Jen-Chieh Peng, V.A. Polyakov, J. Veloso, N. Zhuravlev, G.V. Meshcheryakov, A. Sandacz, M. Virius, F. H. Heinsius, S. Ishimoto, M. Aghasyan, A.M. Kotzinian, M. Zavertyaev, Jan Matousek, G. Reicherz, S. Dalla Torre, C. Quintans, M. Pešek, J. Barth, Alan D. Martin, M. Chiosso, N.V. Anfimov, Jan Tomsa, M. Ostrick, R.P. Kurjata, M. Finger, E. Kabuß, R.R. Dusaev, A.S. Nunes, T. Weisrock, R. Birsa, K. Augsten, V. Frolov, A. Maggiora, A. Vauth, A.A. Lednev, V.E. Lyubovitskij, C. Chatterjee, P. Jörg, Yakov Petrovich Kulinich, Gerhard K. Mallot, Andrey Ivanov, Frank Klein, P. Bordalo, A. Nagaytsev, Johannes Bernhard, Ch. Dreisbach, D. Panzieri, K. Zaremba, E.R. Bielert, Markus F. Krämer, J. Pochodzalla, K. Königsmann, M. Slunecka, A. Guskov, J.M. Friedrich, A. Srnka, H. Suzuki, S. Dasgupta, B. Marianski, T. Grussenmeyer, A. Rybnikov, Andrea Bressan, Anatoli Vasilievich Efremov, L. Dhara, T. Matsuda, M. Meyer, M. Dziewiecki, Markus Ball, M. Gorzellik, W.-D. Nowak, Yu. Kisselev, P. Schiavon, C. Santos, E. Mitrofanov, Bakur Parsamyan, W. Dünnweber, Martin Bodlak, Yu. Ivanshin, M.G. Alexeev, Ilya Kuznetsov, W. C. Chang, S.V. Donskov, D. Steffen, M. Wilfert, J. Smolik, K. Bicker, S. Ramos, L. Sinha, J. Pretz, E. Fuchey, S. Levorato, A. Austregesilo, A. Gridin, I. J. Choi, N. Mitrofanov, C. Franco, Stephan M. Paul, M. Levillain, A. Thiel, C. Riedl, V. Andrieux, Mikhail Mikhasenko, F. Krinner, I.A. Savin, O.P. Gavrichtchouk, N. Makke, I. Orlov, A. Szabelski, F. Giordano, E.A. Levchenko, N. du Fresne von Hohenesche, S. Gerassimov, N. Pierre, R. Longo, M. Quaresma, N. Doshita, B. Ketzer, A. Vidon, Yu.V. Mikhailov, I. Gnesi, G. Hamar, V.F. Konstantinov, P. Sznajder, Z. Kral, T. Iwata, B.I. Vasilishin, A. Grasso, V. Tskhay, H. Fischer, M. Ziembicki, M. Büchele, A. Rychter, S. Sirtl, Z.V. Kroumchtein, F. Balestra, S.-U. Chung, F. Tosello, T. Szameitat, D. von Harrach, K. Schönning, F. Tessarotto, J.H. Koivuniemi, Franco Bradamante, A. Kerbizi, J. Lichtenstadt, F. Kunne, M. Pešková, E. Seder, K. Kurek, G. Nukazuka, D.V. Peshekhonov, R. Heitz, O.M. Kouznetsov, V.E. Burtsev, R. Akhunzyanov, S.A. Mamon, H. Schmieden, C.-Y. Hsieh, B. Badełek, W. Augustyniak, D.I. Ryabchikov, A.G. Olshevsky, and S. Huber
Subjects: Physics, Nuclear and High Energy Physics, Muon, Mass distribution, 010308 nuclear & particles physics, Branching fraction, Hadron, State (functional analysis), 01 natural sciences, Momentum, 0103 physical sciences, Tetraquark, Atomic physics, 010306 general physics, X(3872)
Abstract: We have searched for exclusive production of exotic charmonia in the reaction μ + N → μ + ( J / ψ π + π − ) π ± N ′ using COMPASS data collected with incoming muons of 160 GeV/c and 200 GeV/c momentum. In the J / ψ π + π − mass distribution we observe a signal with a statistical significance of 4.1 σ. Its mass and width are consistent with those of the X ( 3872 ) . The shape of the π + π − mass distribution from the observed decay into J / ψ π + π − 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 / ψ π + π − is determined to be 71±28(stat)±39(syst) pb.
Published: 2018

27. Longitudinal double-spin asymmetry A1p and spin-dependent structure function g1p of the proton at small values of x and Q2

Author: P.D. Eversheim, H. Suzuki, C.D.R. Azevedo, Jen-Chieh Peng, V. Andrieux, Adam Szabelski, M. Wilfert, O.P. Gavrichtchouk, Martin Bodlak, L. Sinha, T. Matsuda, E.A. Levchenko, M.G. Alexeev, S. Uhl, J. Giarra, Michal Dziewiecki, R.P. Kurjata, Miroslav Sulc, Y.-S. Lian, V. Anosov, F. Tessarotto, M. Grosse Perdekamp, F. Giordano, Laura Gonzalez Silva, Johannes Bernhard, Ch. Dreisbach, E. M. Kabuß, A. Nagaytsev, F. Balestra, N. Pierre, A. Guskov, Andres Cicuttin, A. Moretti, Z.V. Kroumchtein, P. Jörg, A. Grasso, A. Srnka, C. Quintans, J.F.C.A. Veloso, Frank Klein, F. Kunne, G. D. Alexeev, I.A. Savin, M. Ziembicki, I. Orlov, S. Ramos, I. Konorov, W. Dünnweber, K. Königsmann, Valery E. Lyubovitskij, V.D. Samoylenko, Yakov Petrovich Kulinich, F. Gautheron, W.-D. Nowak, K. Schmidt, Andrea Ferrero, Norihiro Doshita, F. H. Heinsius, R. Heitz, K. Zaremba, O.M. Kouznetsov, L. Dhara, Markus Ball, G. Hamar, S. Levorato, V.E. Burtsev, N. Mitrofanov, B. Badelek, C. Regali, Yu. Kisselev, G.V. Khaustov, R. Salac, Nikolay Anfimov, N. d'Hose, O.Yu. Denisov, Z. Kral, Naomi C R Makins, V.A. Polyakov, A. Maggiora, S. Dalla Torre, S. Sarkar, B. Ketzer, A. Rychter, M. Ostrick, Arseniy Rybnikov, A. Vauth, J. Smolik, G.V. Meshcheryakov, G. Sbrizzai, R. Longo, E.R. Bielert, M. Büchele, V.N. Kolosov, R. Birsa, A. Amoroso, Yu. V. Mikhailov, K. Schönning, S. Sirtl, O. Subrt, M. Finger, W. Augustyniak, S. V. Donskov, M. Pešek, R. Joosten, N. du Fresne von Hohenesche, J. Lichtenstadt, R. Beck, J.H. Koivuniemi, Mikhail Mikhasenko, T. Iwata, E. Fuchey, A. Kerbizi, A.S. Nunes, S.S. Dasgupta, M. Quaresma, D.V. Peshekhonov, D. Panzieri, M. Gorzellik, L. Capozza, K. Kondo, F. Pereira, Y. Miyachi, A.A. Lednev, Janusz Marzec, E. Seder, D.I. Ryabchikov, K. Bicker, M. V. Zavertyaev, T. Grussenmeyer, M. Pešková, Jan Matousek, G. Reicherz, Celso Augusto Guimarães Santos, Franco Bradamante, Y. Bedfer, P. Sznajder, C. Riedl, J. Nový, D. Neyret, Jan Tomsa, H. Schmieden, C. Chatterjee, B. Grube, S.-U. Chung, J.M. Friedrich, A.V. Efremov, D. Steffen, A. Gridin, S. Huber, T. Szameitat, M. A. Faessler, A. Sandacz, M. Meyer, A.G. Chumakov, A. Thiel, C. Franco, François Herrmann, E. Zemlyanichkina, M. Krämer, P. Schiavon, M. Virius, P. Kremser, S.A. Mamon, Ilya Kuznetsov, M. Slunecka, A. Antoshkin, P. Bordalo, M. Aghasyan, H. Matsuda, J. Pochodzalla, F. Nerling, J. Pretz, A. Kveton, Kamil Augsten, S. Dasgupta, A. Austregesilo, T. Sawada, M. Stolarski, I. Gnesi, M. Chiosso, W. Meyer, K. Kurek, M. Tasevsky, E. Mitrofanov, Alexandr Selyunin, Nour Makke, W. C. Chang, Andrew Ivanov, Alessandro Bressan, D. von Harrach, S. Platchkov, P. Zavada, J. Barth, Maria Liz Crespo, Gerhard K. Mallot, V. Jary, T. Weisrock, S. Gerassimov, N. Horikawa, F. Tosello, S. Tessaro, D. Hahne, F. Krinner, Yu.A. Khokhlov, Aram Kotzinian, R. Windmolders, R.R. Dusaev, V. Tskhay, B.I. Vasilishin, J. ter Wolbeek, G. Nukazuka, A. Magnon, Anne-Laure Martin, V.F. Konstantinov, S. Wallner, S. Ishimoto, H. Fischer, N.S. Rogacheva, A. Vidon, B. Marianski, Bakur Parsamyan, A.G. Olshevsky, M. Levillain, C.-Y. Hsieh, V. Frolov, Soumen Paul, and I. J. Choi
Subjects: Physics, Nuclear and High Energy Physics, Muon, Proton, 010308 nuclear & particles physics, media_common.quotation_subject, Hadron, Elementary particle, 01 natural sciences, Asymmetry, Baryon, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, Lepton, media_common
Abstract: We present a precise measurement of the proton longitudinal double-spin asymmetry A 1 p and the proton spin-dependent structure function g 1 p at photon virtualities 0.006 ( GeV / c ) 2 Q 2 1 ( GeV / c ) 2 in the Bjorken x range of 4 × 10 − 5 x 4 × 10 − 2 . The results are based on data collected by the COMPASS Collaboration at CERN using muon beam energies of 160 GeV and 200 GeV . The statistical precision is more than tenfold better than that of the previous measurement in this region. In the whole range of x , the measured values of A 1 p and g 1 p are found to be positive. It is for the first time that spin effects are found at such low values of x .
Published: 2018

28. New analysis of ηπ tensor resonances measured at the COMPASS experiment

Author: L. Sinha, T. Matsuda, C. Quintans, A. Jackura, E.A. Levchenko, Andrew Ivanov, M.G. Alexeev, D. von Harrach, S. Uhl, J. Giarra, Michal Dziewiecki, Nikolay Anfimov, Franco Bradamante, M. Krämer, Jen-Chieh Peng, N. C. R. Makins, S.S. Dasgupta, W.-D. Nowak, Fabrice Gautheron, E. Fuchey, R. Joosten, P. Jörg, E. M. Kabuß, César Fernández-Ramírez, Jan Matousek, Aram Kotzinian, S.A. Mamon, M. A. Faessler, Adam P. Szczepaniak, M. Aghasyan, J. Pochodzalla, P. Bordalo, F. Kunne, A. Maggiora, A. Vauth, A. Antoshkin, M. Slunecka, Geoffrey C. Fox, R.R. Dusaev, V. Tskhay, W. Augustyniak, S. Ramos, S. Levorato, V.E. Burtsev, B.I. Vasilishin, V. Andrieux, Kamil Augsten, Adam Szabelski, N. I. Zhuravlev, M. Tasevsky, E. Mitrofanov, I.A. Savin, N. Mitrofanov, P. Sznajder, K. Kondo, P. Kremser, K. Schmidt, Andrea Ferrero, G.V. Meshcheryakov, J. Lichtenstadt, Sagari Sarkar, Yu. V. Mikhailov, O.Yu. Denisov, Z. Kral, P. Schiavon, M. Stolarski, D. Steffen, M. Gorzellik, Y. Bedfer, M. Büchele, J. ter Wolbeek, F. Giordano, C. Chatterjee, J. Nový, A. Kveton, S. Sirtl, S.-U. Chung, J.H. Koivuniemi, Jan Tomsa, A. Thiel, Norihiro Doshita, S. Platchkov, M. Grosse Perdekamp, E. Seder, P. Zavada, H. Matsuda, D. Neyret, R. Beck, A. Kerbizi, A. Nagaytsev, F. Balestra, N. Pierre, A. Grasso, A.V. Efremov, François Herrmann, Miroslav Sulc, Laura Silva, F. Tessarotto, M. Ziembicki, Celso Augusto Guimarães Santos, F. Pereira, G. Nukazuka, N. d'Hose, A. Magnon, J. Smolik, W. Meyer, Maria Liz Crespo, V. Jary, K. Zaremba, Yakov Petrovich Kulinich, S. Gerassimov, F. H. Heinsius, Andres Cicuttin, I. Orlov, V.D. Samoylenko, G. Reicherz, M. Pešková, Valery E. Lyubovitskij, S. V. Donskov, M. Pešek, R. Akhunzyanov, Takahiro Iwata, V.A. Polyakov, A.S. Nunes, M. Finger, S. Dalla Torre, N. Horikawa, D. Panzieri, Janusz Marzec, S. Dasgupta, A. Austregesilo, O. Subrt, G. Sbrizzai, G.V. Khaustov, F. Tosello, G. D. Alexeev, C. Riedl, T. Grussenmeyer, C. Regali, W. Dünnweber, I. Konorov, A. Amoroso, K. Bicker, V. Anosov, Yu. Kisselev, Johannes Bernhard, Ch. Dreisbach, A. Guskov, R. Salac, S. Tessaro, D. Hahne, P.D. Eversheim, N. du Fresne von Hohenesche, T. Schlüter, M. Ostrick, Andrea Bressan, T. Szameitat, Y. Miyachi, H. Suzuki, C.D.R. Azevedo, E.R. Bielert, A.G. Olshevsky, A.A. Lednev, R. Birsa, Jannes Nys, F. Krinner, R. Heitz, Yu.A. Khokhlov, M. Levillain, C.-Y. Hsieh, V. Frolov, J. Barth, Soumen Paul, Gerhard K. Mallot, A. Sandacz, T. Weisrock, I. J. Choi, Ilya Kuznetsov, F. Nerling, A. Srnka, K. Königsmann, M. V. Zavertyaev, H. Schmieden, J.M. Friedrich, S. Huber, E. Zemlyanichkina, Alessandro Pilloni, N.S. Rogacheva, Y.-S. Lian, A. Vidon, B. Marianski, Bakur Parsamyan, Z.V. Kroumchtein, L. Dhara, Anne-Laure Martin, G. Hamar, B. Badelek, V.F. Konstantinov, S. Wallner, S. Ishimoto, H. Fischer, B. Ketzer, A. Rychter, Frank Klein, R. Longo, V.N. Kolosov, K. Schönning, C. Franco, V. Pauk, Markus Ball, Yu. Ivanshin, D.I. Ryabchikov, J.F.C.A. Veloso, R.P. Kurjata, O.M. Kouznetsov, M. Virius, Mikhail Mikhasenko, B. Grube, Alexandr Selyunin, Nour Makke, W. C. Chang, M. Quaresma, D.V. Peshekhonov, I. Gnesi, M. Meyer, A.G. Chumakov, J. Pretz, T. Sawada, M. Chiosso, K. Kurek, Vincent Mathieu, Arseniy Rybnikov, M. Wilfert, O.P. Gavrichtchouk, Martin Bodlak, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, JPAC, COMPASS, Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Jackura, A., Fernández-Ramírez, 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., Badełek, 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., Büchele, M., Burtsev, V. E., Chang, W. -C., Chatterjee, C., Chiosso, M., Choi, I., Chumakov, A. G., Chung, S. -U., Cicuttin, A., Crespo, M. L., Dalla Torre, S., Dasgupta, S. S., Dasgupta, S., Denisov, O. Yu., Dhara, L., Donskov, S. V., Doshita, N., Dreisbach, Ch., Dünnweber, W., Dusaev, R. R., Dziewiecki, M., Efremov, A., Eversheim, P. D., Faessler, M., Ferrero, A., Finger, M., Fischer, H., Franco, C., du Fresne von Hohenesche, N., Friedrich, J. M., Frolov, V., Fuchey, E., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Giarra, J., Giordano, F., Gnesi, I., Gorzellik, M., Grasso, A., Grosse Perdekamp, M., 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., Jörg, 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., Königsmann, K., Konorov, I., Konstantinov, V. F., Kotzinian, A. M., Kouznetsov, O. M., Kral, Z., Krämer, 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., Matoušek, 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., 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., Pešková, 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., Schlüter, T., Schmidt, K., Schmieden, H., Schönning, 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: M012M3, 11.80.Et, COMPASS, 01 natural sciences, High Energy Physics - Experiment, UNITARITY, Subatomär fysik, Pomeron, Compass, excited state, Subatomic Physics, Nuclear and high energy physics, peripheral photoproduction, physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], COMPASS experiment, EXCHANGE, a2(1320), Nuclear Experiment, a2(1700), Quantum chromodynamics, Physics, Unitarity, PP INTERACTIONS, hep-ph, amplitude analysis, MESONS, lcsh:QC1-999, analytic properties, High Energy Physics - Phenomenology, Amplitude, S-matrix, Particle Physics - Experiment, AMPLITUDE ANALYSIS, Nuclear and High Energy Physics, Particle physics, Meson, CONNECTION, PHYSICS, 14.40.Be, [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], pomeron, 0103 physical sciences, ddc:530, Tensor, 010306 general physics, M012W3, Particle Physics - Phenomenology, POMERON, hep-ex, 010308 nuclear & particles physics, M162M, 11.55.Bq, 11.55.Fv, meson resonance, M162W, Physics and Astronomy, 450 GEV/C, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], [ PHYS.HPHE ] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, MATRIX, lcsh:Physics
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: 2018

29. Final COMPASS results on the deuteron spin-dependent structure functiong1dand the Bjorken sum rule

Author: K. Königsmann, Anne-Laure Martin, A. Maggiora, S. Takekawa, F. Pereira, T. Szameitat, R.P. Kurjata, M. Grosse Perdekamp, N.S. Rossiyskaya, F. Giordano, M. Roskot, Y. Miyachi, A.A. Lednev, Nikolay Anfimov, M. Meyer, Jen-Chieh Peng, A. Sandacz, V. Tskhay, Laura Silva, K. Zaremba, A. Vauth, V.A. Polyakov, M. Slunecka, V.F. Konstantinov, S. Wallner, A. Grasso, Yakov Petrovich Kulinich, R. Joosten, S. Gerassimov, Andrew Ivanov, N. Horikawa, M. Gorzellik, O.P. Gavrichtchouk, Martin Bodlak, S. Ishimoto, H. Fischer, N. I. Zhuravlev, K. Klimaszewski, D.V. Peshekhonov, G. Sbrizzai, P.D. Eversheim, F. Tosello, V. Anosov, S. Grabmüller, P. Jörg, K. Kondo, D. von Harrach, H. Suzuki, C.D.R. Azevedo, L. Sinha, T. Matsuda, J. Nový, S. Sarkar, V. Andrieux, A. Zink, Adam Szabelski, J. Pretz, A. Amoroso, S. Tessaro, A. Srnka, D. Hahne, S. Levorato, Y. Bedfer, Yu. Kisselev, R. Salac, S.-U. Chung, C. Chatterjee, F. Tessarotto, K. Bicker, B. Marianski, Andres Cicuttin, I. Orlov, N. Mitrofanov, M. Tasevsky, Bakur Parsamyan, F. Krinner, S. V. Donskov, M. Pešek, M. Aghasyan, V.D. Samoylenko, M. Ostrick, François Herrmann, I. Konorov, G. Reicherz, P. Kremser, E. Mitrofanov, I. Gnesi, J. Pochodzalla, A.S. Nunes, D.I. Ryabchikov, J. Vondra, E.R. Bielert, Yu.A. Khokhlov, D. Panzieri, Janusz Marzec, T. Sawada, P. Bordalo, S.S. Dasgupta, A.G. Olshevsky, T. Grussenmeyer, S. Dalla Torre, B. Badełek, C. Adolph, E. M. Kabuß, Naomi C R Makins, S. Platchkov, P. Zavada, A. Nagaytsev, F. Balestra, J.F.C.A. Veloso, M.G. Alexeev, M. Ziembicki, Markus Ball, M. Chiosso, S. Uhl, N. Pierre, M. V. Zavertyaev, I.A. Savin, Yu. Ivanshin, W. Meyer, Maria Liz Crespo, F. Thibaud, J. Giarra, Michal Dziewiecki, S. Dasgupta, A. Austregesilo, E. Fuchey, M. Finger, K. Kurek, F. H. Heinsius, W. Augustyniak, S. Ramos, Alexandr Selyunin, J. Barth, V. Jary, O.M. Kouznetsov, F. Haas, Jan Matousek, G. Nukazuka, G. Hamar, G.V. Khaustov, M. Büchele, Mikhail Mikhasenko, J.H. Koivuniemi, P. Sznajder, W.-D. Nowak, A. Magnon, W. Eyrich, Gerhard K. Mallot, Nour Makke, C. Riedl, V. Duic, Arseniy Rybnikov, D. Steffen, A.V. Efremov, B. Grube, M. Stolarski, W. C. Chang, A. Lehmann, Takahiro Iwata, M. Virius, A. Thiel, Q. Curiel, F. Klein, Miroslav Sulc, Johannes Bernhard, Ch. Dreisbach, A. Guskov, G.V. Meshcheryakov, M. Quaresma, Andrea Bressan, Yu. V. Mikhailov, S. Sirtl, M. Levillain, T. Weisrock, C.-Y. Hsieh, V. Frolov, Soumen Paul, Y.-S. Lian, I. J. Choi, Aram Kotzinian, R. Windmolders, Z.V. Kroumchtein, N. du Fresne von Hohenesche, J. ter Wolbeek, F. Kunne, C. Regali, E. Seder, Celso Augusto Guimarães Santos, Fabrice Gautheron, M. A. Faessler, A. Rychter, R. Longo, V.N. Kolosov, O.Yu. Denisov, K. Schönning, R. Beck, A. Kerbizi, R. Akhunzyanov, C. Franco, G. D. Alexeev, W. Dünnweber, H. Schmieden, J.M. Friedrich, R. Heitz, K. Schmidt, Andrea Ferrero, Norihiro Doshita, N. d'Hose, J. Smolik, O. Subrt, M. Krämer, S. Huber, F. Nerling, Kamil Augsten, J. Lichtenstadt, E. Zemlyanichkina, D. Neyret, M. Wilfert, L. Dhara, C. Braun, R. Birsa, C. Quintans, B. Ketzer, Franco Bradamante, P. Schiavon, and H. Matsuda
Subjects: Physics, Quark, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Hadron, Deep inelastic scattering, 01 natural sciences, Nuclear physics, Compass, 0103 physical sciences, Proton spin crisis, High Energy Physics::Experiment, Sum rule in quantum mechanics, 010306 general physics, Nucleon
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 GeV beam energy and the results are shown for the kinematic range 1(GeV/c)2 4GeV/c2 in the mass of the hadronic final state. The deuteron double-spin asymmetry A1d and the deuteron longitudinal-spin structure function g1d are presented in bins of x and Q2 . Towards lowest accessible values of x , g1d decreases and becomes consistent with zero within uncertainties. The presented final g1d values together with the recently published final g1p values of COMPASS are used to again evaluate the Bjorken sum rule and perform the QCD fit to the g1 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 a0 , which is identified in the MS‾ renormalisation scheme with the total contribution of quark helicities to the nucleon spin, is extracted at next-to-leading order accuracy from only the COMPASS deuteron data: a0(Q2=3(GeV/c)2)=0.32±0.02stat±0.04syst±0.05evol . Together with the recent results on the proton spin structure function g1p , the results on g1d constitute the COMPASS legacy on the measurements of g1 through inclusive spin-dependent deep inelastic scattering.
Published: 2017

30. The spin structure functiong1pof the proton and a test of the Bjorken sum rule

Author: N.S. Rossiyskaya, F. Giordano, F. Haas, A. Grasso, V. Anosov, A.G. Olshevsky, F. Tessarotto, Laura Silva, C. Riedl, S. Ramos, Fabrice Gautheron, Q. Curiel, D. Neyret, L. Capozza, K. Kondo, A. Srnka, P. Sznajder, R. Jahn, A. Lehmann, J. Pretz, V. Andrieux, K. Bicker, P.D. Eversheim, J. Lichtenstadt, Adam Szabelski, K. Klimaszewski, M. Büchele, Andres Cicuttin, H. Suzuki, I. Orlov, C.D.R. Azevedo, V.D. Samoylenko, G. Reicherz, S. Dalla Torre, O.Yu. Denisov, K. Zaremba, F. Kunne, J.H. Koivuniemi, W.-D. Nowak, P. Kremser, V.A. Polyakov, D.I. Ryabchikov, G. Sbrizzai, M. Levillain, E. M. Kabuß, A. Nagaytsev, Yu. Kisselev, V. Frolov, E. Burtin, A. Amoroso, V.F. Konstantinov, Takahiro Iwata, F. Balestra, M. Ostrick, Soumen Paul, R. Beck, S. Ishimoto, M. Stolarski, Jen-Chieh Peng, H. Fischer, E. Rocco, E.R. Bielert, R. Joosten, C. Adolph, R. Akhunzyanov, G. Baum, I.A. Savin, Andrea Ferrero, Miroslav Sulc, Bakur Parsamyan, F. Hinterberger, V. Tskhay, G. D. Alexeev, E. Fuchey, R.P. Kurjata, I. J. Choi, A.B. Ivanov, M. Boer, S. Dasgupta, A. Austregesilo, A.V. Efremov, O.P. Gavrichtchouk, F. Krinner, Martin Bodlak, M. Finger, L. Sinha, Aram Kotzinian, S. G. Gerassimov, T. Matsuda, Johannes Bernhard, Jan Matousek, A. Guskov, A. Zink, Frank Klein, Andrea Bressan, Alexandr Selyunin, R. Windmolders, M. Chiosso, A. Magnon, R. Birsa, M. Gorzellik, Yu. Ivanshin, M. Krämer, W. Meyer, Maria Liz Crespo, V.I. Nikolaenko, M.G. Alexeev, S. Uhl, S. Sarkar, G.V. Meshcheryakov, Michal Dziewiecki, K. Kurek, V. Jary, M. Ziembicki, Yu. V. Mikhailov, S. Sirtl, B. Grube, W. Eyrich, Nour Makke, F. H. Heinsius, W. C. Chang, Y. Bedfer, S.-U. Chung, D. von Harrach, S. V. Donskov, M. Pešek, A.S. Nunes, C.-Yu. Hsieh, François Herrmann, G.V. Khaustov, D. Panzieri, Janusz Marzec, I. Konorov, M. Quaresma, T. Grussenmeyer, D.V. Peshekhonov, M. Slunecka, T. Szameitat, Federica Sozzi, S. Schopferer, I. Gnesi, J. ter Wolbeek, Z.V. Kroumchtein, N. du Fresne von Hohenesche, F. Thibaud, J. Barth, Gerhard K. Mallot, T. Weisrock, N. Horikawa, F. Tosello, S. Tessaro, D. Hahne, P. Schiavon, Yu.A. Khokhlov, H. Matsuda, M. Wilfert, C. Quintans, O. Kouznetsov, Franco Bradamante, J.F.C.A. Veloso, V. Duic, Alan D. Martin, S.S. Dasgupta, M. V. Zavertyaev, H. Schmieden, R. Hashimoto, J.M. Friedrich, N. Kuchinski, J. Bisplinghoff, S. Huber, C. Marchand, E. Zemlyanichkina, C. Regali, A. Rychter, R. Longo, V.N. Kolosov, K. Schönning, K. Königsmann, S. Platchkov, F. Nerling, J. Novy, C. Franco, A. Maggiora, Celso Augusto Guimarães Santos, S. Grabmüller, K. Schmidt, Norihiro Doshita, N. d'Hose, J. Pochodzalla, P. Bordalo, T. Nagel, L. Dhara, C. Braun, Y. Miyachi, A.A. Lednev, T. Michigami, B. Badelek, A. Sandacz, B. Ketzer, S. Takekawa, F. Pereira, M. Virius, P. Jörg, O.Yu. Shevchenko, S. Levorato, M. Grosse-Perdekamp, and Naomi C R Makins
Subjects: Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, Muon, Proton, 010308 nuclear & particles physics, Deep inelastic scattering, 01 natural sciences, Helicity, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Sum rule in quantum mechanics, 010306 general physics, Nucleon, Spin-½
Abstract: New results for the double spin asymmetry A(1)(p) and the proton longitudinal spin structure function g(1)(p) are presented. They were obtained by the COMPASS Collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH3 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)(p)(x) by about a factor of two in the region x less than or similar to 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)(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)(NS) (x, Q(2)) yields as ratio of the axial and vector coupling constants vertical bar gA/gV vertical bar = 1.22 +/- 0.05 (stat.) +/- 0.10 (syst.), which validates the sum rule to an accuracy of about 9%.
Published: 2016

31. Search for exclusive photoproduction ofZc±(3900) at COMPASS

Author: F. Sozzi, T. Weisrock, S. Gerassimov, V.D. Samoylenko, E. Zemlyanichkina, Yu.A. Khokhlov, S. Tessaro, R. Windmolders, K. Kondo, P. Jasinski, J. ter Wolbeek, O.P. Gavrichtchouk, L. Sinha, S.S. Dasgupta, R. Sulej, M. Wilfert, Alan D. Martin, A. Maggiora, L. Silva, T. Matsuda, A. Zink, Adam Szabelski, Andres Cicuttin, A. Srnka, R. Joosten, H. Wollny, M. V. Zavertyaev, D.V. Peshekhonov, I. Orlov, N. Doshita, F. Kunne, W. Dünnweber, R. Geyer, M. Chiosso, M. Dziewiecki, D. Hahne, G. Sbrizzai, Takahiro Iwata, I. Konorov, K. Schmidt, V.F. Konstantinov, N. Horikawa, A. Filin, Yu.V. Mikhailov, R. Beck, S. Sosio, P. Sznajder, M. Slunecka, M.G. Alexeev, S. Dalla Torre, C. Braun, P. Jörg, A. Efremov, M. Virius, F. Herrmann, F. Balestra, G. Reicherz, J. Bisplinghoff, J. Pochodzalla, A. Sandacz, C. Quintans, M. Büchele, H. Fischer, A. Rychter, A. Lehmann, Günter Baum, O.Yu. Shevchenko, R. Panknin, Christian Schill, S. Takekawa, J.H. Koivuniemi, K. Königsmann, A. Grasso, I. Gnesi, S. Uhl, E.R. Bielert, A. Nagaytsev, S.-U. Chung, K. Klimaszewski, W.-D. Nowak, Franco Bradamante, M. Ostrick, Bakur Parsamyan, J. Marzec, Johannes Bernhard, F.H. Heinsius, W. Eyrich, A.G. Olshevsky, Andrea Bressan, S. Neubert, R.P. Kurjata, M. Stolarski, Yu. Kisselev, K. Zaremba, F. Nerling, F. Hinterberger, P. Schiavon, L. Steiger, Lei Wang, S. Ramos, A.B. Ivanov, S. Grabmüller, H. Suzuki, T. Schlüter, R. Jahn, A. Ferrero, E. Burtin, V. Duic, Q. Curiel, A. Guskov, I. Uman, J. Pretz, L. Capozza, J. Bieling, E. M. Kabuß, Z.V. Kroumchtein, C. Regali, M. Schott, Ch. Höppner, P. Bordalo, Y. Bedfer, S. Huber, A. Amoroso, Y. Miyachi, A.A. Lednev, F. Gautheron, M. Gorzellik, K. Kurek, S. Platchkov, H. Matsuda, M. Quaresma, A.M. Kotzinian, V. Anosov, N. du Fresne von Hohenesche, I.A. Savin, T. Michigami, G.K. Mallot, V.I. Nikolaenko, Yu. Ivanshin, A. Austregesilo, M. A. Faessler, M. Boer, E. Rocco, C. Franco, D. von Harrach, T. Nagel, S. Schopferer, B. Badełek, S. Goertz, J. Novy, M. Ziembicki, F. Haas, W. Meyer, Maria Liz Crespo, B. Gobbo, S. Paul, C. Adolph, V.A. Polyakov, A. Berlin, C. Elia, G.V. Khaustov, N. Kuchinski, J.M. Friedrich, V. Jary, O.M. Kouznetsov, P.D. Eversheim, N. Makke, A. Magnon, M. Sulc, K. Schönning, V.N. Kolosov, S. Sarkar, N. d'Hose, M. Finger, A.S. Nunes, D. Panzieri, T. Grussenmeyer, S. Ishimoto, R. Birsa, J. Lichtenstadt, T. Szameitat, G.D. Alexeev, D. Neyret, J. Matousek, M. Krämer, B. Grube, J. Barth, H. Schmieden, K. Bicker, R. Hashimoto, D.I. Ryabchikov, F. Tessarotto, M. Levillain, V. Frolov, O.Yu. Denisov, S. Levorato, V. Andrieux, F. Klein, G.V. Meshcheryakov, N.S. Rossiyskaya, S. Sirtl, S.V. Donskov, B. Ketzer, C. Marchand, R. Akhunzyanov, M. Bodlak, and F. Thibaud
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Compass, Hadron, Analytical chemistry, Sigma, High Energy Physics::Experiment, Production (computer science), Tetraquark, Zc(3900), Range (computer programming)
Abstract: A search for the exclusive production of the Z(c)(+/-)(3900) hadron by virtual photons has been performed in the channel Z(c)(+/-)(3900). J/Psi pi(+/-). The data cover the range from 7GeV to 19GeV 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)(+/-)(3900)-> J/Psi pi(+/-)) x sigma(gamma N) -> Z(c)(+/-)(3900) N/sigma gamma N -> J/Psi N 3.7 x10(-3) has been established at the confidence level of90%. (C) 2015 The Authors. Published by Elsevier B.V.
Published: 2015

32. Quark helicity distributions from longitudinal spin asymmetries in muon–proton and muon–deuteron scattering

Author: M.G. Alekseev, V.Yu. Alexakhin, Yu. Alexandrov, G.D. Alexeev, A. Amoroso, A. Austregesilo, B. Badełek, F. Balestra, J. Barth, G. Baum, Y. Bedfer, J. Bernhard, R. Bertini, M. Bettinelli, R. Birsa, J. Bisplinghoff, P. Bordalo, F. Bradamante, A. Bravar, A. Bressan, G. Brona, E. Burtin, M.P. Bussa, D. Chaberny, M. Chiosso, S.U. Chung, A. Cicuttin, M. Colantoni, M.L. Crespo, S. Dalla Torre, S. Das, S.S. Dasgupta, O.Yu. Denisov, L. Dhara, V. Diaz, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, A. Efremov, A. El Alaoui, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, A. Filin, M. Finger, H. Fischer, C. Franco, J.M. Friedrich, R. Garfagnini, F. Gautheron, O.P. Gavrichtchouk, R. Gazda, S. Gerassimov, R. Geyer, M. Giorgi, I. Gnesi, B. Gobbo, S. Goertz, S. Grabmüller, A. Grasso, B. Grube, R. Gushterski, A. Guskov, F. Haas, D. von Harrach, T. Hasegawa, F.H. Heinsius, F. Herrmann, C. Heß, F. Hinterberger, N. Horikawa, Ch. Höppner, N. d'Hose, C. Ilgner, S. Ishimoto, O. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, P. Jasinski, G. Jegou, R. Joosten, E. Kabuß, D. Kang, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, S. Koblitz, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, R. Konopka, I. Konorov, V.F. Konstantinov, A. Korzenev, A.M. Kotzinian, O. Kouznetsov, K. Kowalik, M. Krämer, A. Kral, Z.V. Kroumchtein, R. Kuhn, F. Kunne, K. Kurek, L. Lauser, J.M. Le Goff, A.A. Lednev, A. Lehmann, S. Levorato, J. Lichtenstadt, T. Liska, A. Maggiora, M. Maggiora, A. Magnon, N. Makke, G.K. Mallot, A. Mann, C. Marchand, A. Martin, J. Marzec, F. Massmann, T. Matsuda, W. Meyer, T. Michigami, Yu.V. Mikhailov, M.A. Moinester, A. Mutter, A. Nagaytsev, T. Nagel, J. Nassalski, T. Negrini, F. Nerling, S. Neubert, D. Neyret, V.I. Nikolaenko, A.S. Nunes, A.G. Olshevsky, M. Ostrick, A. Padee, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, B. Pawlukiewicz-Kaminska, E. Perevalova, G. Pesaro, D.V. Peshekhonov, G. Piragino, S. Platchkov, J. Pochodzalla, J. Polak, V.A. Polyakov, G. Pontecorvo, J. Pretz, C. Quintans, J.-F. Rajotte, S. Ramos, V. Rapatsky, G. Reicherz, A. Richter, F. Robinet, E. Rocco, E. Rondio, D.I. Ryabchikov, V.D. Samoylenko, A. Sandacz, H. Santos, M.G. Sapozhnikov, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, L. Schmitt, S. Schopferer, W. Schröder, O.Yu. Shevchenko, H.-W. Siebert, L. Silva, L. Sinha, A.N. Sissakian, M. Slunecka, G.I. Smirnov, S. Sosio, F. Sozzi, A. Srnka, M. Stolarski, M. Sulc, R. Sulej, S. Takekawa, S. Tessaro, F. Tessarotto, A. Teufel, L.G. Tkatchev, S. Uhl, I. Uman, M. Virius, N.V. Vlassov, A. Vossen, Q. Weitzel, R. Windmolders, W. Wiślicki, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, J. Zhao, N. Zhuravlev, A. Zvyagin, M. G., Alekseev, Alexakhin, V. Y. u., Alexandrovo, Y. u., G. D., Alexeev, A., Amoroso, A., Austregesilo, B., Badełek, F., Balestra, J., Barth, G., Baum, Y., Bedfer, J., Bernhard, R., Bertini, M., Bettinelli, R., Birsa, J., Bisplinghoff, P., Bordalo, Bradamante, Franco, A., Bravar, Bressan, Andrea, G., Brona, E., Burtin, M. P., Bussa, D., Chaberny, M., Chiosso, S. U., Chung, A., Cicuttin, M., Colantoni, M. L., Crespo, S., Dalla Torre, S., Da, S. S., Dasgupta, Denisov, O. Y. u., L., Dhara, V., Diaz, S. V., Donskov, N., Doshita, Duic, Venicio, W., Dunnweber, A., Efremov, A., El Alaoui, P. D., Eversheim, W., Eyrich, M., Faessler, A., Ferrero, A., Filin, M., Finger, M. Finger J., R., H., Fischeri, C., Franco, J. M., Friedrich, R., Garfagnini, F., Gautheron, O. P., Gavrichtchouk, R., Gazda, S., Gerassimov, R., Geyer, Giorgi, Marcello, I., Gnesi, B., Gobbo, S., Goertz, S., Grabmuller, A., Grasso, B., Grube, R., Gushterski, A., Guskov, F., Haa, D., von Harrach, T., Hasegawa, F. H., Heinsiu, F., Herrmann, C., He, F., Hinterberger, N., Horikawa, Hoppner, C. h., N., D’Hose, C., Ilgnerj, S., Ishimoto, O., Ivanov, Ivanshin, Y. u., T., Iwata, R., Jahn, P., Jasinski, G., Jegou, R., Joosten, E., Kabu, D., Kang, B., Ketzer, G. V., Khaustov, Khokhlov, Y. u. A., Kisselev, Y. u., F., Klein, K., Klimaszewski, S., Koblitz, J. H., Koivuniemi, V. N., Kolosov, K., Kondo, K., Konigsmann, R., Konopka, I., Konorov, V. F., Konstantinov, A., Korzenev, A. M., Kotzinian, O., Kouznetsov, K., Kowalik, M., Kramer, A., Kral, Z. V., Kroumchtein, R., Kuhn, F., Kunne, K., Kurek, L., Lauseri, J. M., Le Goff, A. A., Lednev, A., Lehmann, Levorato, Stefano, J., Lichtenstadt, T., Liska, A., Maggiora, M., Maggiora, A., Magnon, N., Makke, G. K., Mallot, A., Mann, C., Marchand, Martin, Anna, J., Marzec, F., Massmann, T., Matsuda, W., Meyer, T., Michigami, Mikhailov, Y. u. V., M. A., Moinester, A., Mutteri, A., Nagaytsev, T., Nagel, J., Nassalski, T., Negrini, F., Nerling, S., Neubert, D., Neyret, V. I., Nikolaenko, A. S., Nune, A. G., Olshevsky, M., Ostrick, A., Padee, R., Panknin, D., Panzieri, B., Parsamyan, S., Paul, B., Pawlukiewicz Kaminska, E., Perevalova, Pesaro, Giulia, D. V., Peshekhonov, G., Piragino, S., Platchkov, J., Pochodzalla, J., Polak, V. A., Polyakov, G., Pontecorvo, J., Pretz, C., Quintan, J. F., Rajotte, S., Ramo, V., Rapatsky, G., Reicherz, A., Richter, F., Robinet, E., Rocco, E., Rondio, D. I., Ryabchikov, V. D., Samoylenko, A., Sandacz, H., Santo, M. G., Sapozhnikov, S., Sarkar, I. A., Savin, Sbrizzai, Giulio, Schiavon, Paolo, C., Schill, T., Schluter, L., Schmitt, S., Schopfereri, W., Schroder, Shevchenko, O. Y. u., H. W., Siebert, L., Silva, L., Sinha, A. N., Sissakian, M., Slunecka, G. I., Smirnov, S., Sosio, Sozzi, Federica, A., Srnka, M., Stolarskij, M., Sulc, R., Sulej, Takekawa, Stefano, S., Tessaro, F., Tessarotto, A., Teufel, L. G., Tkatchev, S., Uhl, I., Uman, M., Viriu, N. V., Vlassov, A., Vossen, Q., Weitzel, R., Windmolder, W., Wi´slicki, H., Wollny, K., Zaremba, M., Zavertyaev, E., Zemlyanichkina, M., Ziembicki, J., Zhao, N., Zhuravlev, and A., Zvyagin
Subjects: Quark, Nuclear and High Energy Physics, Proton, High Energy Physics::Lattice, media_common.quotation_subject, Nuclear Theory, FOS: Physical sciences, COMPASS, 01 natural sciences, Asymmetry, Semi-inclusive deep inelastic scattering, Spin, Structure function, Parton distribution functions, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, COMPASS experiment, Nuclear Experiment, 010306 general physics, Spin-½, media_common, Physics, function, Muon, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Structure, Helicity, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract: Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a longitudinally polarised NH_3 target, cover a range of the Bjorken variable x between 0.004 and 0.7. A leading order evaluation of the helicity distributions for the three lightest quarks and antiquark flavours derived from these asymmetries and from our previous deuteron data is presented. The resulting values of the sea quark distributions are small and do not show any sizable dependence on x in the range of the measurements. No significant difference is observed between the strange and antistrange helicity distributions, both compatible with zero. The integrated value of the flavour asymmetry of the helicity distribution of the light-quark sea, \Delta u-bar - \Delta d-bar, is found to be slightly positive, about 1.5 standard deviations away from zero., Comment: 13 pages, 5 figures
Published: 2010

33. Transverse target spin asymmetries in exclusive ρ0 muoproduction

Author: C. Adolph, R. Akhunzyanov, M.G. Alekseev, V.Yu. Alexakhin, Yu. Alexandrov, G.D. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Austregesilo, B. Badełek, F. Balestra, J. Barth, G. Baum, R. Beck, Y. Bedfer, A. Berlin, J. Bernhard, R. Bertini, K. Bicker, J. Bieling, R. Birsa, J. Bisplinghoff, M. Bodlak, M. Boer, P. Bordalo, F. Bradamante, C. Braun, A. Bravar, A. Bressan, M. Büchele, E. Burtin, L. Capozza, M. Chiosso, S.U. Chung, A. Cicuttin, M.L. Crespo, Q. Curiel, S. Dalla Torre, S.S. Dasgupta, S. Dasgupta, O.Yu. Denisov, S.V. Donskov, N. Doshita, V. Duic, W. Dünnweber, M. Dziewiecki, A. Efremov, C. Elia, P.D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, A. Filin, M. Finger, H. Fischer, C. Franco, N. du Fresne von Hohenesche, J.M. Friedrich, V. Frolov, R. Garfagnini, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, R. Geyer, M. Giorgi, I. Gnesi, B. Gobbo, S. Goertz, M. Gorzellik, S. Grabmüller, A. Grasso, B. Grube, R. Gushterski, A. Guskov, T. Guthörl, F. Haas, D. von Harrach, D. Hahne, R. Hashimoto, F.H. Heinsius, F. Herrmann, C. Heß, F. Hinterberger, Ch. Höppner, N. Horikawa, N. d'Hose, S. Huber, S. Ishimoto, A. Ivanov, Yu. Ivanshin, T. Iwata, R. Jahn, V. Jary, P. Jasinski, P. Joerg, R. Joosten, E. Kabuß, D. Kang, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, Yu. Kisselev, F. Klein, K. Klimaszewski, J.H. Koivuniemi, V.N. Kolosov, K. Kondo, K. Königsmann, I. Konorov, V.F. Konstantinov, A.M. Kotzinian, O. Kouznetsov, Z. Kral, M. Krämer, Z.V. Kroumchtein, N. Kuchinski, F. Kunne, K. Kurek, R.P. Kurjata, A.A. Lednev, A. Lehmann, S. Levorato, J. Lichtenstadt, A. Maggiora, A. Magnon, N. Makke, G.K. Mallot, C. Marchand, A. Martin, J. Marzec, J. Matousek, H. Matsuda, T. Matsuda, G. Meshcheryakov, W. Meyer, T. Michigami, Yu.V. Mikhailov, Y. Miyachi, A. Nagaytsev, T. Nagel, F. Nerling, S. Neubert, D. Neyret, V.I. Nikolaenko, J. Novy, W.-D. Nowak, A.S. Nunes, I. Orlov, A.G. Olshevsky, M. Ostrick, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, M. Pesek, D. Peshekhonov, G. Piragino, S. Platchkov, J. Pochodzalla, J. Polak, V.A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, S. Ramos, G. Reicherz, E. Rocco, V. Rodionov, E. Rondio, N.S. Rossiyskaya, D.I. Ryabchikov, V.D. Samoylenko, A. Sandacz, M.G. Sapozhnikov, S. Sarkar, I.A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, A. Schmidt, K. Schmidt, L. Schmitt, H. Schmïden, K. Schönning, S. Schopferer, M. Schott, O.Yu. Shevchenko, L. Silva, L. Sinha, S. Sirtl, M. Slunecka, S. Sosio, F. Sozzi, A. Srnka, L. Steiger, M. Stolarski, M. Sulc, R. Sulej, H. Suzuki, A. Szabelski, T. Szameitat, P. Sznajder, S. Takekawa, J. Ter Wolbeek, S. Tessaro, F. Tessarotto, F. Thibaud, S. Uhl, I. Uman, M. Vandenbroucke, M. Virius, J. Vondra, L. Wang, T. Weisrock, M. Wilfert, R. Windmolders, W. Wiślicki, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, N. Zhuravlev, and M. Ziembicki
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Meson, 010308 nuclear & particles physics, media_common.quotation_subject, Hadron, Elementary particle, Parton, 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, media_common, Lepton
Abstract: COMPASS has studied exclusive production of ρ 0 mesons using a 160 GeV/ c muon beam and a transversely polarised NH 3 target. Five single-spin and three double-spin azimuthal aymmetries were measured in dependence on Q 2 , x Bj , or p T 2 . Except the sin ϕ S asymmetry, obtained to be − 0.019 ± 0.008( stat .) ± 0.003( syst .), all others were found to be consistent with zero within experimental uncertainties. Phenomenological GPD-based model calculations agree well with the data and interpret the result as evidence for the existence of chiral-odd, transverse generalised parton distributions.
Published: 2014

34. Leading order determination of the gluon polarisation from DIS events with high-pThadron pairs

Author: S. Koblitz, S. Ramos, F. Haas, R. Geyer, R. Panknin, E. Rondio, Fabrice Gautheron, M. A. Faessler, V.Yu. Alexakhin, J. Polak, V.N. Kolosov, Christian Schill, N.S. Rossiyskaya, F. Kunne, R. Jahn, F. Tessarotto, C. Heß, C. Adolph, A. Korzenev, A. Grasso, J. M. Le Goff, D. Chaberny, V. Duic, E. M. Kabuß, O.P. Gavrichtchouk, A.A. Lednev, A. Nagaytsev, F. Balestra, A. Srnka, L. Sinha, T. Matsuda, G. D. Alexeev, F. Nerling, A.V. Efremov, W. Dünnweber, Yu.V. Mikhailov, R. Gushterski, Yu. Alexandrov, Yu. Kisselev, George I. Smirnov, S. Hedicke, Z.V. Kroumchtein, I.A. Savin, S. Grabmüller, I. Konorov, W.-D. Nowak, O.Yu. Denisov, A. Zvyagin, M. Ostrick, Bakur Parsamyan, C. Quintans, K. Zaremba, Alessandro Bressan, D. von Harrach, S. Gerassimov, G. Piragino, T. Guthörl, N. Horikawa, Sergey Donskov, L. Dhara, S. Ishimoto, Frank Klein, C. Braun, V.A. Polyakov, G. Sbrizzai, Ch. Höppner, A. Amoroso, S. Uhl, S.U. Chung, L. Schmitt, Oleg V. Ivanov, Maxence Vandenbroucke, B. Badelek, R. Birsa, Matthias Schott, N. du Fresne von Hohenesche, T. Schlüter, M. Giorgi, Michal Dziewiecki, E. Perevalova, S. Tessaro, E. Rocco, A. Richter, K. Klimaszewski, S. Das, R. Gazda, M. Chiosso, A.G. Olshevsky, Laura Silva, B. Ketzer, I. Uman, A. Morreale, Andres Cicuttin, A. Filin, A. Magnon, G. Reicherz, R. Joosten, V.D. Samoylenko, K. Kurek, A. Padee, L. G. Tkatchev, Yu.A. Khokhlov, D. Neyret, S. Paul, J. Pochodzalla, M. Stolarski, J.M. Friedrich, K. Bicker, R. Bertini, Andrea Ferrero, S. Dalla Torre, J. Bisplinghoff, S. Huber, G.V. Khaustov, S.S. Dasgupta, A. Mutter, Jean-Francois Rajotte, D.I. Ryabchikov, A.S. Nunes, Vladimir Nikolaenko, Miroslav Sulc, Aram Kotzinian, F. Hinterberger, P. Bordalo, D. Kang, R. Windmolders, H. Wollny, D. Panzieri, L. Lauser, O. Kouznetsov, E. Zemlyanichkina, W. Meyer, Maria Liz Crespo, J. Lichtenstadt, J. Marzec, Yu. Ivanshin, M.G. Alekseev, P. Jasinski, Franco Bradamante, M. V. Zavertyaev, Anne-Laure Martin, K. Schönning, Alexey Antonov, A. Bravar, P. Sznajder, J. ter Wolbeek, Johannes Bernhard, J. Nassalski, S. Sosio, S. Takekawa, M. Bettinelli, Michael Kramer, A. Guskov, K. Kondo, J. Barth, Y. Bedfer, E. Burtin, V.F. Konstantinov, A. Lehmann, C. Franco, J.H. Koivuniemi, C. Marchand, Gerhard K. Mallot, S. Goertz, V. Rapatsky, Sarben Sarkar, H. Fischer, P. Schiavon, K. Königsmann, A. Maggiora, B. Grube, N. dʼHose, N.V. Vlassov, Günter Baum, O.Yu. Shevchenko, S. Levorato, R. Garfagnini, M. Finger, Murray Moinester, François Herrmann, S. Platchkov, Lei Wang, M. Slunecka, M. Virius, W. Wiślicki, G.B. Pontecorvo, B. Gobbo, N. I. Zhuravlev, Federica Sozzi, S. Schopferer, T. Nagel, J. Pretz, R. Sulej, S. Procureur, T. Michigami, A. Mann, W. Eyrich, Nour Makke, J. Bieling, A. Sandacz, M. Quaresma, M.G. Sapozhnikov, K. Schmidt, D.V. Peshekhonov, Norihiro Doshita, A. N. Sissakian, G. Pesaro, I. Gnesi, P.D. Eversheim, S. Neubert, T. Iwata, M. Ziembicki, F. H. Heinsius, A. Austregesilo, and C. Elia
Subjects: Physics, Quantum chromodynamics, Nuclear and High Energy Physics, Particle physics, Muon, Proton, 010308 nuclear & particles physics, Hadron, Deep inelastic scattering, 01 natural sciences, Gluon, Nuclear physics, 0103 physical sciences, COMPASS experiment, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with Q(2) > 1 (GeV/c)(2) including a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam scattering off a polarised (LiD)-Li-6 target. The gluon polarisation is evaluated by a Neural Network approach for three intervals of the gluon momentum fraction x(g) covering the range 0.04 < x(g) < 0.27. The values obtained at leading order in QCD do not show any significant dependence on x(g). Their average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at average x(g) = 0.09 and a scale of mu(2) = 3 (GeV/c)(2).
Published: 2013

35. The spin-dependent structure function of the proton g1p and a test of the Bjorken sum rule

Author: P. Schiavon, I. Konorov, C. Hess, Miroslav Sulc, M. Ziembicki, F. Hinterberger, F.H. Heinsius, Achim Richter, A. Magnon, F. Massmann, S. Ramos, Norihiro Doshita, N. d'Hose, Alan D. Martin, D. Kang, K. Königsmann, Soumen Paul, T. Hasegawa, E. Rondio, A. Austregesilo, R. Gazda, A. Maggiora, E. Perevalova, R. Kuhn, A. N. Sissakian, S. Das, A.G. Olshevsky, R. Jahn, A. Ferrero, A. Maximov, C. Quintans, D. Cotic, M.P. Bussa, V.D. Samoylenko, O.P. Gavrichtchouk, Vladimir A. Polyakov, D. Neyret, Elena Rocco, J. Polak, W. Kafer, J.H. Koivuniemi, R. Joosten, L. Sinha, S. Neubert, A. Korzenev, T. Matsuda, K. Zaremba, Laura Silva, A.A. Lednev, A. Mutter, A. Lehmann, J. Ball, J. M. Le Goff, S. Platchkov, O. Kouznetsov, Yu.V. Mikhailov, A. Král, R. Windmolders, S. Sarkar, R. Bertini, Franco Bradamante, B. Pawlukiewicz-Kaminska, S.S. Dasgupta, M. V. Zavertyaev, C. Marchand, V. Rapatsky, A. Nagaytsev, F. Balestra, A. Srnka, L. Lauser, S. Grabmüller, W. Wislicki, J. Pochodzalla, V. Duic, G. Sbrizzai, A. Padee, F. Tessarotto, Moinester, P. Jasinski, O.Yu. Denisov, V. Diaz, T. Negrini, J. Marzec, G. Piragino, S. Uhl, P.D. Eversheim, G.B. Pontecorvo, K. Klimaszewski, M. Maggiora, P. Bordalo, F. Nerling, A. Amoroso, M. Chiosso, F. Haas, R. Geyer, Jean-Francois Rajotte, Takahiro Iwata, D.I. Ryabchikov, D. von Harrach, M. Giorgi, A.S. Nunes, S. Koblitz, Andres Cicuttin, L. Schmitt, T. Nagel, D. Panzieri, J. Pretz, T. Schlüter, A. El Alaoui, S. Gerassimov, M. Krämer, N. Horikawa, J. Zhao, K. Kondo, M.G. Alekseev, Sergey Donskov, T. Liška, G. Reicherz, H.-W. Siebert, F. Kunne, R. Gushterski, W. Eyrich, M. Virius, S. Tessaro, V.F. Konstantinov, Johannes Bernhard, A. Guskov, Y. Bedfer, G.V. Khaustov, A. Zvyagin, T. Michigami, S. Dalla Torre, E. Burtin, H. Santos, Q. Weitzel, M. Bettinelli, M. Slunecka, A. Sandacz, B. Gobbo, I.A. Savin, Andrea Bressan, W. Schröder, N. I. Zhuravlev, Ch. Höppner, Yu.A. Khokhlov, A. M. Kotzinian, W. Meyer, Maria Liz Crespo, H. Fischer, M. L. Colantoni, C. Ilgner, J. Barth, R. Konopka, A. Teufel, S. Schopferer, N.V. Vlassov, Günter Baum, M.G. Sapozhnikov, O.Yu. Shevchenko, S. Levorato, Yu. Kisselev, D. Chaberny, S.-U. Chung, V.N. Kolosov, V.I. Nikolaenko, D.V. Peshekhonov, J. Marroncle, A.V. Efremov, R. Garfagnini, Z.V. Kroumchtein, François Herrmann, A. Bravar, A. Mann, M. Ostrick, G. Jegou, K. Kurek, E. Kabuss, Oleg V. Ivanov, R. Hermann, H. Wollny, S. Sosio, Christian Schill, I. Uman, G. Pesaro, S. Takekawa, Yu. Alexandrov, J. Lichtenstadt, M. Stolarski, I. Gnesi, Bakur Parsamyan, G.I. Smirnov, Fabrice Gautheron, M. A. Faessler, R. Panknin, V.Yu. Alexakhin, A. Grasso, R. Sulej, M. Finger, C. Franco, R. Birsa, G. D. Alexeev, W. Dünnweber, J.M. Friedrich, J. Bisplinghoff, E. Zemlyanichkina, L. Dhara, B. Badelek, B. Ketzer, F. Robinet, A. Filin, Grzegorz Brona, Gerhard K. Mallot, A. Vossen, F. Sozzi, J. Nassalski, S. Ishimoto, Frank Klein, K. Kowalik, Yu. Ivanshin, L. G. Tkatchev, S. Goertz, and B. Grube
Subjects: Quantum chromodynamics, Physics, Coupling constant, Nuclear and High Energy Physics, Particle physics, Muon, Isovector, Proton, 010308 nuclear & particles physics, Deep inelastic scattering, 01 natural sciences, Nuclear physics, 0103 physical sciences, Sum rule in quantum mechanics, 010306 general physics, Spin-½
Abstract: The inclusive double-spin asymmetry, A 1 p , has been measured at COMPASS in deep-inelastic polarised muon scattering off a large polarised NH3 target. The data, collected in the year 2007, cover the range Q 2 > 1 ( GeV / c ) 2 , 0.004 x 0.7 and improve the statistical precision of g 1 p ( x ) by a factor of two in the region x 0.02 . The new proton asymmetries are combined with those previously published for the deuteron to extract the non-singlet spin-dependent structure function g 1 NS ( x , Q 2 ) . The isovector quark density, Δ q 3 ( x , Q 2 ) , is evaluated from a NLO QCD fit of g 1 NS . The first moment of Δ q 3 is in good agreement with the value predicted by the Bjorken sum rule and corresponds to a ratio of the axial and vector coupling constants | g A / g V | = 1.28 ± 0.07 ( stat . ) ± 0.10 ( syst. ) .
Published: 2010

36. Spin asymmetry A1d and the spin-dependent structure function g1d of the deuteron at low values of x and Q2

Author: Aram Kotzinian, R. Windmolders, M.G. Sapozhnikov, S. Neliba, L. Schmitt, A. Janata, J. Zhao, E. Burtin, J. Lichtenstadt, R. Geyer, D.V. Peshekhonov, P. Schiavon, V.F. Konstantinov, Q. Weitzel, J. Pretz, L. Ferrero, H. Fischer, A.G. Olshevsky, T. Hasegawa, S. Procureur, R. Ziegler, Yu. Alexandrov, A. Chapiro, M. Fabro, V.F. Obraztsov, M. Maggiora, K. Zaremba, D. Neyret, G.I. Smirnov, Fabrice Gautheron, M. A. Faessler, V.A. Polyakov, R. C. Webb, A. Mielech, S. Ishimoto, Frank Klein, Andres Cicuttin, A. Amoroso, G. Reicherz, J. Marzec, St. Goertz, V.Yu. Alexakhin, A. Korzenev, Colin Bernet, Massimo Lamanna, Yu. Kisselev, A. Sandacz, A. Srnka, R. Sulej, C. Ilgner, S. Platchkov, S. Dalla Torre, V.P. Sugonyaev, N.P. Kravchuk, A. Bravar, M. Ostrick, I. Konorov, M. Stolarski, C. Quintans, Grzegorz Brona, Gerhard K. Mallot, A. Zvyagin, Murray Moinester, S. Ramos, Alessandro Bressan, F. Tessarotto, E. M. Kabuß, A.M. Rozhdestvensky, N. V. Khomutov, A. Gorin, I.A. Savin, T. Matsuda, T. Iwata, Z.V. Kroumchtein, F. Sozzi, D. von Harrach, F. Balestra, Franco Bradamante, F.H. Heinsius, Norihiro Doshita, S. Gerassimov, W. Eyrich, J. Ball, L. G. Tkatchev, V. Falaleev, N. Horikawa, H.-W. Siebert, Yu.V. Mikhailov, S. Koblitz, N. d'Hose, E.V. Komissarov, A. Grasso, Sergey Donskov, S. Paul, V. Diaz Kavka, R. Jahn, A. Magnon, A. N. Sissakian, B. Grube, D. Panzieri, J. Nassalski, O.Yu. Denisov, T. Liška, Yu.A. Khokhlov, I. Ludwig, R. Joosten, K. Kurek, G. D. Alexeev, O.A. Grajek, Miroslav Sulc, F. Hinterberger, C. Marchand, A. Maximov, W. Dünnweber, M. Virius, J.M. Friedrich, V.D. Samoylenko, E. Weise, J. Pochodzalla, M.L. Colantoni, S. Hedicke, O.P. Gavrichtchouk, L. Sinha, J. Marroncle, S.S. Dasgupta, N. Takabayashi, J. Bisplinghoff, A.I. Ioukaev, E. Rondio, K. Kondo, R. De Masi, P. Bordalo, M.P. Bussa, A.A. Shishkin, G.V. Khaustov, Alan D. Martin, J. Heckmann, J. Franz, S. Wirth, Y. Bedfer, J. Hannappel, Paolo Pagano, Vladimir Peshekhonov, J. M. Le Goff, R. Birsa, N.I. Jouravlev, S. Horikawa, P.D. Eversheim, G. Piragino, V. Duic, W. Meyer, Maria Liz Crespo, M.E. Ladygin, A.A. Nozdrin, C. Heß, M. Giorgi, V. Frolov, V.N. Kolosov, F. Stinzing, N.A. Koutchinski, R. Kuhn, D. Kang, K. Königsmann, Christian Schill, A. Padee, O. Nähle, R. Bertini, A.B. Sadovski, R. Hermann, Andrea Ferrero, A. Maggiora, V.A. Dorofeev, L. Dhara, M. Slunecka, B. Badelek, W. Wiślicki, B. Gobbo, A.S. Korentchenko, A.M. Dinkelbach, B. Ketzer, A. Teufel, Oleg V. Ivanov, M. von Hodenberg, F. Kunne, A.A. Popov, N.V. Vlassov, Günter Baum, O.Yu. Shevchenko, V.I. Nikolaenko, R. Garfagnini, M. Finger, V.V. Tchalishev, S. Costa, J.H. Koivuniemi, and S. Panebianco
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), Large Hadron Collider, 010308 nuclear & particles physics, media_common.quotation_subject, Structure function, Zero (complex analysis), 01 natural sciences, Asymmetry, Nuclear physics, Deuterium, 0103 physical sciences, COMPASS experiment, 010306 general physics, Spin-½, media_common
Abstract: We present a precise measurement of the deuteron longitudinal spin asymmetry A 1 d and of the deuteron spin-dependent structure function g 1 d at Q 2 1 ( GeV / c ) 2 and 4 × 10 −5 x 2.5 × 10 −2 based on the data collected by the COMPASS experiment at CERN during the years 2002 and 2003. The statistical precision is tenfold better than that of the previous measurement in this region. The measured A 1 d and g 1 d are found to be consistent with zero in the whole range of x.
Published: 2007

37. Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs

Author: R. Sulej, S. Neliba, P. Berglund, B. Grube, M.G. Sapozhnikov, H. Schmitt, A. Maggiora, E. Rondio, M. Varanda, A. Zvyagin, W. Kastaun, Colin Bernet, A. Srnka, I. Konorov, M.P. Bussa, A. Korzenev, E.S. Ageev, F. H. Heinsius, S. Gerassimov, J. M. Le Goff, T. Toeda, Marc Wagner, P.D. Eversheim, A. Mielech, S. Ishimoto, Frank Klein, K. Kondo, K. Zaremba, M. Wiesmann, J. Reymann, A.A. Shishkin, V. Duic, Sergey Donskov, O.P. Gavrichtchouk, S. Platchkov, P. Rebourgeard, Y. Bedfer, N. Dedek, L. Sinha, F. Balestra, S. Paul, R. Ziegler, V.N. Kolosov, V.A. Polyakov, N.P. Kravchuk, A.K. Konoplyannikov, J. Zhao, R. Jahn, A. Gorin, V. Diaz, M. Maggiora, R. Ijaduola, N. Takabayashi, R. De Masi, P. Bordalo, J. Bisplinghoff, Massimo Lamanna, Yu. Kisselev, A. Amoroso, Vladimir Peshekhonov, R. Birsa, E.V. Komissarov, Andres Cicuttin, J. Lichtenstadt, Norihiro Doshita, G. Piragino, N. d'Hose, Yu.A. Khokhlov, A. Maximov, G. Reicherz, Josef Pochodzalla, I. Ludwig, Naoaki Horikawa, M. Ostrick, Aram Kotzinian, R. Windmolders, A.A. Nozdrin, J. Nassalski, M. Giorgi, R. Bertini, Andrea Ferrero, Oleg V. Ivanov, R. Joosten, S. Dalla Torre, A. N. Sissakian, J.M. Friedrich, V.D. Samoylenko, Yu. Alexandrov, P. Fauland, Christian Schill, C. Marchand, M.E. Ladygin, V.F. Obraztsov, M. Finger, E. Weise, L. Ferrero, D. Kang, M.L. Colantoni, K. Königsmann, S. Hedicke, A. Colavita, S. Horikawa, R. C. Webb, A.M. Dinkelbach, K. Platzer, V.N. Bytchkov, A.V. Dolgopolov, S. Procureur, K. Kowalik, A.B. Sadovski, L. Cerini, V.I. Tretyak, J. Pretz, A. Grünemaier, G.V. Krivokhizhin, O.A. Grajek, N.A. Koutchinski, M. von Hodenberg, A. Sandacz, F. Karstens, U. Wiedner, S. S. Dasgupta, G.V. Khaustov, L. Schmitt, A. Grasso, M. Stolarski, J. Franz, L. G. Tkatchev, F. Stinzing, Grzegorz Brona, Miroslav Sulc, D. Thers, Anna Zanetti, A. Janata, Franco Bradamante, Gerhard K. Mallot, J. Ehlers, F. Kunne, V.V. Tchalishev, N.I. Jouravlev, S. Costa, E. Burtin, V.F. Konstantinov, W. Meyer, Maria Liz Crespo, A.I. Ioukaev, F. Sozzi, R. Hermann, E. M. Kabuß, Paolo Pagano, V.P. Sugonyaev, Q. Weitzel, A.A. Popov, S. Ramos, J.H. Koivuniemi, K. Rith, F. Hinterberger, P. Schiavon, S. Panebianco, H. Fischer, K. Medved, Alan D. Martin, Z.V. Kroumchtein, W. Eyrich, T. Hasegawa, A. Chapiro, Murray Moinester, T. Schmidt, D. Neyret, M. A. Faessler, Alessandro Bressan, D. von Harrach, C. Ilgner, Yu.V. Mikhailov, S. Trousov, J. Marzec, R. Geyer, A.G. Olshevsky, St. Goertz, O.Yu. Denisov, C. Heß, A. Magnon, L. Dhara, M. Slunecka, Takahiro Iwata, E. Saller, S. Koblitz, M. Sans, B. Gobbo, B. Badelek, J. Marroncle, A. Teufel, Miroslav Virius, K. Kurek, A. Padee, B. Ketzer, D. Peshekhonov, W. Wiślicki, H. D. Pereira, N.V. Vlassov, S. Wirth, C. Quintans, J. Hannappel, Günter Baum, O.Yu. Shevchenko, I.A. Savin, A. Bravar, V.I. Nikolaenko, R. Garfagnini, H.-W. Siebert, I. Manuilov, V. Falaleev, D. Panzieri, T. Liška, M. Fabro, M. Leberig, A.M. Rozhdestvensky, N. V. Khomutov, J. Ball, G.I. Smirnov, Fabrice Gautheron, T. Matsuda, V. Frolov, V.Yu. Alexakhin, W. Dünnweber, G. D. Alexeev, V.A. Dorofeev, A.S. Korentchenko, F. Tessarotto, R. Kuhn, O. Nähle, V. Kalinnikov, and A. Skachkova
Subjects: Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, Muon, 010308 nuclear & particles physics, Hadron, Deep inelastic scattering, 01 natural sciences, Helicity, Gluon, Nuclear physics, 0103 physical sciences, COMPASS experiment, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: We present a determination of the gluon polarization Δ G / G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q 2 1 ( GeV / c ) 2 , with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a polarized 6 LiD target. The helicity asymmetry for the selected events is 〈 A ∥ / D 〉 = 0.002 ± 0.019 ( stat ) ± 0.003 ( syst ) . From this value, we obtain in a leading-order QCD analysis Δ G / G = 0.024 ± 0.089 ( stat ) ± 0.057 ( syst ) at x g = 0.095 and μ 2 ≃ 3 ( GeV / c ) 2 .
Published: 2006

38. Transverse spin effects in hadron-pair production from semi-inclusive deep inelastic scattering

Author: T. Negrini, M. Chiosso, L. Schmitt, M. Ziembicki, K. Klimaszewski, Andres Cicuttin, G. Reicherz, R. Panknin, N.S. Rossiyskaya, E. Burtin, V.F. Konstantinov, A. Austregesilo, C. Elia, Murray Moinester, S. Dalla Torre, A. Grasso, K. Königsmann, M.G. Sapozhnikov, D.V. Peshekhonov, P.D. Eversheim, H. Fischer, Alan D. Martin, Achim Richter, F. Massmann, G. Pesaro, F. Tessarotto, E. Rondio, O.M. Kouznetsov, S. Ramos, M. Stolarski, C. Heß, I. Gnesi, Johannes Bernhard, A. Guskov, A. Maggiora, S. Neubert, P. Sznajder, Miroslav Sulc, F. Hinterberger, Yu. Kisselev, S. Grabmüller, V.N. Kolosov, M. Bettinelli, Andrea Bressan, E. Perevalova, A. Lehmann, M. Ostrick, Christian Schill, Laura Silva, Aram Kotzinian, R. Windmolders, J. Pochodzalla, R. Sulej, I. Uman, R. Joosten, P. Bordalo, D. Kang, O.P. Gavrichtchouk, L. Sinha, T. Matsuda, V. Duic, P. Jasinski, S.S. Dasgupta, Z.V. Kroumchtein, M. V. Zavertyaev, S. Koblitz, R. Bertini, Andrea Ferrero, J. ter Wolbeek, K. Bicker, C. Marchand, W. Eyrich, G. Piragino, Nour Makke, J. Bieling, J. Barth, L. Lauser, S. Uhl, M. Giorgi, Ch. Höppner, Yu.V. Mikhailov, M. Quaresma, Gerhard K. Mallot, Michal Dziewiecki, O.Yu. Denisov, Takahiro Iwata, A. Vossen, K. Kondo, Y. Bedfer, S. Gerassimov, N. Horikawa, Sergey Donskov, S. Tessaro, K. Schmidt, Norihiro Doshita, A. N. Sissakian, W.-D. Nowak, A. Morreale, P. Schiavon, M. Finger, M. Virius, Yu.A. Khokhlov, R. Gushterski, T. Guthörl, J.M. Friedrich, J. Bisplinghoff, K. Zaremba, S. Huber, Vladimir Nikolaenko, E. Zemlyanichkina, F. Haas, R. Geyer, Soumen Paul, G.I. Smirnov, Fabrice Gautheron, M. A. Faessler, M. Slunecka, W. Wiślicki, B. Gobbo, Yu. Alexandrov, Bakur Parsamyan, C. Quintans, A. Srnka, V.A. Polyakov, A. Korzenev, V.Yu. Alexakhin, N. I. Zhuravlev, A. Zvyagin, R. Birsa, J. Lichtenstadt, L. Wang, G. Sbrizzai, L. Dhara, Federica Sozzi, R. Gazda, S. Das, C. Braun, B. Badelek, S. Schopferer, Franco Bradamante, B. Ketzer, A. Filin, D. Neyret, A. Nagaytsev, F. Balestra, A. Amoroso, K. Schönning, Alexey Antonov, A. Bravar, S. Sosio, A. Mutter, S.-U. Chung, L. G. Tkatchev, S. Takekawa, R. Jahn, Matthias Schott, J. Marzec, G. D. Alexeev, M. Krämer, François Herrmann, W. Dünnweber, C. Franco, A. Mann, N. du Fresne von Hohenesche, T. Schlüter, S. Platchkov, K. Kurek, A.A. Lednev, N.V. Vlassov, Günter Baum, O.Yu. Shevchenko, S. Levorato, E. Rocco, S. Sarkar, F. Nerling, F. Kunne, A. Padee, G.B. Pontecorvo, T. Nagel, J. Pretz, D. Chaberny, R. Garfagnini, C. Adolph, T. Michigami, Oleg V. Ivanov, H. Wollny, Jean-Francois Rajotte, D.I. Ryabchikov, A.S. Nunes, A. Sandacz, D. Panzieri, E. M. Kabuß, I.A. Savin, A.V. Efremov, M.G. Alekseev, I. Konorov, F.H. Heinsius, A.G. Olshevsky, A. Magnon, A. Mielech, S. Ishimoto, Frank Klein, J. Polak, J.H. Koivuniemi, V. Rapatsky, Yu. Ivanshin, S. Goertz, V.D. Samoylenko, B. Grube, D. von Harrach, Maxence Vandenbroucke, G.V. Khaustov, W. Meyer, Maria Liz Crespo, N. dʼHose, C., Adolph, M. G., Alekseev, Alexakhin, V. Y. u., Alexandrov, Y. u., G. D., Alexeev, A., Amoroso, A. A., Antonov, A., Austregesilo, B., Badełek, F., Balestra, J., Barth, G., Baum, Y., Bedfer, J., Bernhard, R., Bertini, M., Bettinelli, K., Bicker, J., Bieling, Birsa, Renato, J., Bisplinghoff, P., Bordalo, Bradamante, Franco, C., Braun, A., Bravar, Bressan, Andrea, E., Burtin, D., Chaberny, M., Chiosso, S. U., Chung, A., Cicuttin, M. L., Crespo, DALLA TORRE, Silvia, S., Da, S. S., Dasgupta, Denisov, O. Y. u., L., Dhara, S. V., Donskov, N., Doshita, Duic, Venicio, W., Dünnweber, M., Dziewiecki, A., Efremov, Elia, Carmine, P. D., Eversheim, W., Eyrich, M., Faessler, A., Ferrero, A., Filin, M., Finger, H., Fischer, C., Franco, N., du Fresne von Hohenesche, J. M., Friedrich, R., Garfagnini, F., Gautheron, O. P., Gavrichtchouk, R., Gazda, S., Gerassimov, R., Geyer, Giorgi, Marcello, I., Gnesi, B., Gobbo, S., Goertz, S., Grabmüller, A., Grasso, B., Grube, R., Gushterski, A., Guskov, T., Guthörl, F., Haa, D., von Harrach, F. H., Heinsiu, F., Herrmann, C., Heß, F., Hinterberger, N., Horikawa, Höppner, C. h., N., Dʼhose, S., Huber, S., Ishimoto, O., Ivanov, Ivanshin, Y. u., T., Iwata, R., Jahn, P., Jasinski, R., Joosten, E., Kabuß, D., Kang, B., Ketzer, G. V., Khaustov, Khokhlov, Y. u. A., Kisselev, Y. u., F., Klein, K., Klimaszewski, S., Koblitz, J. H., Koivuniemi, V. N., Kolosov, K., Kondo, K., Königsmann, I., Konorov, V. F., Konstantinov, A., Korzenev, A. M., Kotzinian, O., Kouznetsov, M., Krämer, Z. V., Kroumchtein, F., Kunne, K., Kurek, L., Lauser, A. A., Lednev, A., Lehmann, Levorato, Stefano, J., Lichtenstadt, A., Maggiora, A., Magnon, Makke, Nour, G. K., Mallot, A., Mann, C., Marchand, Martin, Anna, J., Marzec, F., Massmann, T., Matsuda, W., Meyer, T., Michigami, A., Mielech, Mikhailov, Y. u. V., M. A., Moinester, A., Morreale, A., Mutter, A., Nagaytsev, T., Nagel, T., Negrini, F., Nerling, S., Neubert, D., Neyret, V. I., Nikolaenko, W. D., Nowak, A. S., Nune, A. G., Olshevsky, M., Ostrick, A., Padee, R., Panknin, D., Panzieri, B., Parsamyan, S., Paul, E., Perevalova, Pesaro, Giulia, D. V., Peshekhonov, G., Piragino, S., Platchkov, J., Pochodzalla, J., Polak, V. A., Polyakov, G., Pontecorvo, J., Pretz, M., Quaresma, C., Quintan, J. F., Rajotte, S., Ramo, V., Rapatsky, G., Reicherz, A., Richter, Rocco, Elena, E., Rondio, N. S., Rossiyskaya, D. I., Ryabchikov, V. D., Samoylenko, A., Sandacz, M. G., Sapozhnikov, S., Sarkar, I. A., Savin, Sbrizzai, Giulio, Schiavon, Paolo, C., Schill, T., Schlüter, K., Schmidt, L., Schmitt, K., Schönning, S., Schopferer, M., Schott, Shevchenko, O. Y. u., L., Silva, L., Sinha, A. N., Sissakian, M., Slunecka, G. I., Smirnov, S., Sosio, Sozzi, Federica, A., Srnka, M., Stolarski, M., Sulc, R., Sulej, P., Sznajder, S., Takekawa, J., Ter Wolbeek, Tessaro, Susanna, F., Tessarotto, L. G., Tkatchev, S., Uhl, I., Uman, M., Vandenbroucke, M., Viriu, N. V., Vlassov, A., Vossen, L., Wang, R., Windmolder, W., Wiślicki, H., Wollny, K., Zaremba, M., Zavertyaev, E., Zemlyanichkina, M., Ziembicki, N., Zhuravlev, and A., Zvyagin
Subjects: Nuclear and High Energy Physics, Particle physics, COMPASS, SIDIS, two hadron azimuthal asymmetries, transversity, Hadron, Nuclear Theory, FOS: Physical sciences, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, 010306 general physics, Nuclear Experiment, Physics, Large Hadron Collider, Muon, Spectrometer, ta114, 010308 nuclear & particles physics, Scattering, two hadron azimuthal asymmetrie, High Energy Physics::Phenomenology, Deep inelastic scattering, Pair production, Distribution function, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract: First measurements of azimuthal asymmetries in hadron-pair production in deep-inelastic scattering of muons on transversely polarised ^6LiD (deuteron) and NH_3 (proton) targets are presented. The data were taken in the years 2002-2004 and 2007 with the COMPASS spectrometer using a muon beam of 160 GeV/c at the CERN SPS. The asymmetries provide access to the transversity distribution functions, without involving the Collins effect as in single hadron production. The sizeable asymmetries measured on the NH_ target indicate non-vanishing u-quark transversity and two-hadron interference fragmentation functions. The small asymmetries measured on the ^6LiD target can be interpreted as indication for a cancellation of u- and d-quark transversities., Comment: 13 pages, 4 figures, updated to the published version
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38 results on '"L. Sinha"'

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