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Start Over Author "Kravchuk, N." Topic high energy physics - experiment
43 results on '"Kravchuk, N."'

1. Search for the X17 particle in $^{7}\mathrm{Li}(\mathrm{p},\mathrm{e}^+ \mathrm{e}^{-}) ^{8}\mathrm{Be}$ processes with the MEG II detector

Author

The MEG II collaboration, Afanaciev, K., Baldini, A. M., Ban, S., Benmansour, H., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Corvaglia, A., Maso, G. Dal, De Bari, A., De Gerone, M., Barusso, L. Ferrari, Francesconi, M., Galli, L., Gallucci, G., Gatti, F., Gerritzen, L., Grancagnolo, F., Grandoni, E. G., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Ignatov, F., Ikeda, F., Iwamoto, T., Karpov, S., Kettle, P. -R., Khomutov, N., Kolesnikov, A., Kravchuk, N., Krylov, V., Kuchinskiy, N., Leonetti, F., Li, W., Malyshev, V., Matsushita, A., Meucci, M., Mihara, S., Molzon, W., Mori, T., Nicolò, D., Nishiguchi, H., Ochi, A., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Popov, A., Renga, F., Ritt, S., Rossella, M., Scarpellini, A. Rozhdestvensky. S., Schwendimann, P., Signorelli, G., Takahashi, M., Uchiyama, Y., Venturini, A., Vitali, B., Voena, C., Yamamoto, K., Yokota, R., and Yonemoto, T.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The observation of a resonance structure in the opening angle of the electron-positron pairs in the $^{7}$Li(p,\ee) $^{8}$Be reaction was claimed and interpreted as the production and subsequent decay of a hypothetical particle (X17). Similar excesses, consistent with this particle, were later observed in processes involving $^{4}$He and $^{12}$C nuclei with the same experimental technique. The MEG II apparatus at PSI, designed to search for the $\mu^+ \rightarrow \mathrm{e}^+ \gamma$ decay, can be exploited to investigate the existence of this particle and study its nature. Protons from a Cockroft-Walton accelerator, with an energy up to 1.1 MeV, were delivered on a dedicated Li-based target. The $\gamma$ and the e$^{+}$e$^{-}$ pair emerging from the $^8\mathrm{Be}^*$ transitions were studied with calorimeters and a spectrometer, featuring a broader angular acceptance than previous experiments. We present in this paper the analysis of a four-week data-taking in 2023 with a beam energy of 1080 keV, resulting in the excitation of two different resonances with Q-value \SI{17.6}{\mega\electronvolt} and \SI{18.1}{\mega\electronvolt}. No significant signal was found, and limits at \SI{90}{\percent} C.L. on the branching ratios (relative to the $\gamma$ emission) of the two resonances to X17 were set, $R_{17.6} < 1.8 \times 10^{-6} $ and $R_{18.1} < 1.2 \times 10^{-5} $., Comment: 11 pages, 9 figures, submitted to EPJC

Published
2024

2. A search for $\mu^+\to e^+\gamma$ with the first dataset of the MEG II experiment

Author

MEG II collaboration, Afanaciev, K., Baldini, A. M., Ban, S., Baranov, V., Benmansour, H., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Corvaglia, A., Cuna, F., Maso, G. Dal, De Bari, A., De Gerone, M., Barusso, L. Ferrari, Francesconi, M., Galli, L., Gallucci, G., Gatti, F., Gerritzen, L., Grancagnolo, F., Grandoni, E. G., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Ieki, K., Ignatov, F., Ikeda, F., Iwamoto, T., Karpov, S., Kettle, P. -R., Khomutov, N., Kobayashi, S., Kolesnikov, A., Kravchuk, N., Krylov, V., Kuchinskiy, N., Kyle, W., Libeiro, T., Malyshev, V., Matsushita, A., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Nakao, M., Nicolò, D., Nishiguchi, H., Ochi, A., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Popov, A., Renga, F., Ritt, S., Rossella, M., Rozhdestvensky, A., Schwendimann, P., Shimada, K., Signorelli, G., Takahashi, M., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Venturini, A., Vitali, B., Voena, C., Yamamoto, K., Yanai, K., Yonemoto, T., Yoshida, K., and Yudin, Yu. V.

Subjects
High Energy Physics - Experiment
Abstract

The MEG II experiment, based at the Paul Scherrer Institut in Switzerland, reports the result of a search for the decay $\mu^+\to e^+\gamma$ from data taken in the first physics run in 2021. No excess of events over the expected background is observed, yielding an upper limit on the branching ratio of B($\mu^+\to e^+\gamma$) < $7.5 \times 10^{-13}$ (90% C.L.). The combination of this result and the limit obtained by MEG gives B($\mu^+\to e^+\gamma$) < $3.1 \times 10^{-13}$ (90% C.L.), which is the most stringent limit to date. A ten-fold larger sample of data is being collected during the years 2022-2023, and data-taking will continue in the coming years., Comment: 10 pages, 6 figures. To be published in EPJC

Published
2023

3. Operation and performance of MEG II detector

Author

MEG II Collaboration, Afanaciev, K., Baldini, A. M., Ban, S., Baranov, V., Benmansour, H., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Corvaglia, A., Cuna, F., Maso, G. Dal, De Bari, A., De Gerone, M., Barusso, L. Ferrari, Francesconi, M., Galli, L., Gallucci, G., Gatti, F., Gerritzen, L., Grancagnolo, F., Grandoni, E. G., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Ieki, K., Ignatov, F., Ikeda, F., Iwamoto, T., Karpov, S., Kettle, P. -R., Khomutov, N., Kobayashi, S., Kolesnikov, A., Kravchuk, N., Krylov, V., Kuchinskiy, N., Kyle, W., Libeiro, T., Malyshev, V., Matsushita, A., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Morsani, F., Nakao, M., Nicolò, D., Nishiguchi, H., Ochi, A., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Popov, A., Raffaelli, F., Renga, F., Ritt, S., Rossella, M., Rozhdestvensky, A., Schwendimann, P., Shimada, K., Signorelli, G., Stoykov, A., Takahashi, M., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Venturini, A., Vitali, B., Voena, C., Yamamoto, K., Yanai, K., Yonemoto, T., Yoshida, K., and Yudin, Yu. V.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The MEG II experiment, located at the Paul Scherrer Institut (PSI) in Switzerland, is the successor to the MEG experiment, which completed data taking in 2013. MEG II started fully operational data taking in 2021, with the goal of improving the sensitivity of the mu+ -> e+ gamma decay down to 6e-14 almost an order of magnitude better than the current limit. In this paper, we describe the operation and performance of the experiment and give a new estimate of its sensitivity versus data acquisition time., Comment: 42 pages, 55 figures. Submitted to EPJC

Published
2023

4. Beam particle tracking with a low-mass mini time projection chamber in the PEN experiment

Author

Glaser, C. J., Pocanic, D., van der Schaaf, A., Baranov, V. A., Khomutov, N. V., Kravchuk, N. P., and Kuchinsky, N. A.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

The international PEN collaboration aims to obtain the branching ratio for the pion electronic decay $\pi^+ \to e^+\nu_e(\gamma)$, aka $\pi_{e2}$, to a relative precision of $5\times 10^{-4}$ or better. The PEN apparatus comprises a number of detection systems, all contributing vital information to the PEN event reconstruction. This paper discusses the design, performance, and Monte Carlo simulation of the mini time projection chamber (mTPC) used for pion, muon, and positron beam particle tracking. We also review the use of the extracted trajectory coordinates in the analysis, in particular in constructing observables critical for discriminating background processes, and in maximizing the fiducial volume of the target in which decay event vertices can be accepted for branching ratio extraction without introducing bias., Comment: 24 pages, 23 figures

Published
2020
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5. Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment

Author

Baldini, A. M., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Corvaglia, A., de Bari, A., De Gerone, M., Francesconi, M., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kobayashi, S., Kettle, P. -R., Kyle, W., Khomutov, N., Kolesnikov, A., Kravchuk, N., Kuchinskiy, N., Libeiro, T., Lim, G. M. A., Malyshev, V., Matsuzawa, N., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedilishvili, A., Nakao, M., Natori, H., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Pizzigoni, G., Popov, A., Renga, F., Ritt, S., Rozhdestvensky, A., Rossella, M., Sawada, R., Schwendimann, P., Signorelli, G., Stoykov, A., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Voena, C., Yanai, K., and Yudin, Yu. V.

Subjects
High Energy Physics - Experiment
Abstract

We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, $\mu^+ \to \mathrm{e}^+\mathrm{X}, \mathrm{X} \to \gamma\gamma$. This search uses a dataset resulting from $7.5\times 10^{14}$ stopped muons collected by the MEG experiment at the Paul Scherrer Institut in the period 2009--2013. No significant excess is found in the mass region 20--45 MeV/c$^2$ for lifetimes below 40 ps, and we set the most stringent branching ratio upper limits in the mass region of 20--40 MeV/c$^2$, down to $\mathcal{O}(10^{-11})$ at 90\% confidence level.

Published
2020
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6. PEN experiment: a precise test of lepton universality

Author

Glaser, C. J., Pocanic, D., Alonzi, L. P., Baranov, V. A., Bertl, W., Bychkov, M., Bystritsky, Yu. M., Frlez, E., Kalinnikov, V. A., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Lehman, M. C., Munyangabe, E., Mzhavia, D., Palladino, A., Robmann, P., Rozhdestvensky, A. M., Smith, R. T., Supek, I., Truöl, P., van der Schaaf, A., Velicheva, E. P., Vitz, M. G., and Volnykh, V. P.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

With few open channels and uncomplicated theoretical description, charged pion decays are uniquely sensitive to certain standard model (SM) symmetries, the universality of weak fermion couplings, and to aspects of pion structure and chiral dynamics. We review the current knowledge of the pion electronic decay $\pi^+ \to e^+ \nu_e({\gamma})$, or $\pi_{e2({\gamma})}$, and the resulting limits on non-SM processes. Focusing on the PEN experiment at the Paul Scherrer Institute (PSI), Switzerland, we examine the prospects for further improvement in the near term., Comment: Talk presented at CIPANP2018. 9 pages, LaTeX, 4 pdf figures, 1 table. arXiv admin note: substantial text overlap with arXiv:1701.05254

Published
2018

7. The design of the MEG II experiment

Author

Baldini, A. M., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Cocciolo, G., Corvaglia, A., de Bari, A., De Gerone, M., D'Onofrio, A., Francesconi, M., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kaneko, D., Kasami, K., Kettle, P. -R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Libeiro, T., Maki, M., Matsuzawa, N., Mihara, S., Milgie, M., Molzon, W., Mori, Toshinori, Morsani, F., Mtchedilishvili, A., Nakao, M., Nakaura, S., Nicoló, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Popov, A., Raffaelli, F., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Signorelli, G., Simonetta, M., Tassielli, G. F., Uchiyama, Y., Usami, M., Venturini, M., Voena, C., Yoshida, K., Yudin, Yu. V., and Zhang, Y.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The MEG experiment, designed to search for the mu+->e+ gamma decay at a 10^-13 sensitivity level, completed data taking in 2013. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of 6 x 10-14 for the branching ratio, a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance., Comment: 61 pages and 97 figures

Published
2018
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8. PEN: a low energy test of lepton universality

Author

Pocanic, D., Alonzi, L. P., Baranov, V. A., Bertl, W., Bychkov, M., Bystritsky, Yu. M., Frlez, E., Glaser, C. J., Kalinnikov, V. A., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Lehman, M. C., Mzhavia, D., Palladino, A., Robmann, P., Rozhdestvensky, A. M., Supek, I., Truoel, P., van der Schaaf, A., Velicheva, E. P., Vitz, M. G., and Volnykh, V. P.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

Allowed charged $\pi$ meson decays are characterized by simple dynamics, few available decay channels, mainly into leptons, and extremely well controlled radiative and loop corrections. In that sense, pion decays represent a veritable triumph of the standard model (SM) of elementary particles and interactions. This relative theoretical simplicity makes charged pion decays a sensitive means for testing the underlying symmetries and the universality of weak fermion couplings, as well as for studying pion structure and chiral dynamics. Even after considerable recent improvements, experimental precision is lagging far behind that of the theoretical description for pion decays. We review the current state of experimental study of the pion electronic decay $\pi^+ \to e^+\nu_e(\gamma)$, or $\pi_{e2(\gamma)}$, where the $(\gamma)$ indicates inclusion and explicit treatment of radiative decay events. We briefly review the limits on non-SM processes arising from the present level of experimental precision in $\pi_{e2(\gamma)}$ decays. Focusing on the PEN experiment at the Paul Scherrer Institute (PSI), Switzerland, we examine the prospects for further improvement in the near term., Comment: 11 pages, 5 figures; paper presented at the XIII International Conference on Heavy Quarks and Leptons, 22-27 May 2016, Blacksburg, Virginia, USA

Published
2017

9. Muon polarization in the MEG experiment: predictions and measurements

Author

Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, G., Chiri, C., De Bari, A., De Gerone, M., DÓnofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, T. I., Kettle, P. R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, T., Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, G., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., and Yudin, Y. V.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The MEG experiment makes use of one of the world's most intense low energy muon beams, in order to search for the lepton flavour violating process $\mu^{+} \rightarrow {\rm e}^{+} \gamma$. We determined the residual beam polarization at the thin stopping target, by measuring the asymmetry of the angular distribution of Michel decay positrons as a function of energy. The initial muon beam polarization at the production is predicted to be $P_{\mu} = -1$ by the Standard Model (SM) with massless neutrinos. We estimated our residual muon polarization to be $P_{\mu} = -0.85 \pm 0.03 ~ {\rm (stat)} ~ { }^{+ 0.04}_{-0.05} ~ {\rm (syst)}$ at the stopping target, which is consistent with the SM predictions when the depolarizing effects occurring during the muon production, propagation and moderation in the target are taken into account. The knowledge of beam polarization is of fundamental importance in order to model the background of our ${\megsign}$ search induced by the muon radiative decay: $\mu^{+} \rightarrow {\rm e}^{+} \bar{\nu}_{\mu} \nu_{\rm e} \gamma$.

Published
2015
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10. 2-D straw detectors with high rate capability

Author

Kuchinskiy, N. A., Baranov, V. A., Duginov, V. N., Zyazyulya, F. E., Korenchenko, A. S., Kolesnikov, A. O., Kravchuk, N. P., Movchan, S. A., Rudenko, A. I., Smirnov, V. S., Khomutov, N. V., Chekhovsky, V. A., Lobko, A. S., and Misevich, O. V.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Precise measurement of straw axial coordinate (along the anode wire) with accuracy compatible with straw radial coordinate determination by drift time measurement and increase of straw detector rate capability by using straw cathode readout instead of anode readout are presented., Comment: 16 pages, 10 figures

Published
2015

11. New results in rare allowed muon and pion decays

Author

Pocanic, D., Munyangabe, E., Bychkov, M., Baranov, V. A., Bertl, W., Bystritsky, Yu. M., Frlez, E., Kalinnikov, V. A., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Lehman, M. C., Mekterovic, D., Mzhavia, D., Palladino, A., Robmann, P., Rozhdestvensky, A. M., Supek, I., Truoel, P., Tsamalaidze, Z., van der Schaaf, A., Vandevender, B., Velicheva, E. P., and Volnykh, V. P.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

Simple dynamics, few available decay channels, and highly controlled radiative and loop corrections, make pion and muon decays a sensitive means of exploring details of the underlying symmetries. We review the current status of the rare decays: pi+ -> e+ nu, pi+ -> e+ nu gamma, pi+ -> pi0 e+ nu, and mu+ -> e+ nu nu-bar gamma. For the latter we report new preliminary values for the branching ratio B(E_gamma >10 MeV, theta_(e-gamma) > 30deg) = 4.365 (9)_stat (42)_syst x 10^{-3}, and the decay parameter eta-bar = 0.006 (17)_stat (18)_syst, both in excellent agreement with standard model predictions. We review recent measurements, particularly by the PIBETA and PEN experiments, and near-term prospects for improvement. These and other similar precise low energy studies complement modern collider results materially., Comment: 5 pages, 2 figures, talk presented at the 9th International Workshop on e+ e- Collisions "From phi to psi 2013", held in Rome, 9-12 Sept 2013

Published
2014
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12. Measurement of the radiative decay of polarized muons in the MEG experiment

Author

MEG Collaboration, Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, G., Chiri, C., de Bari, A., De Gerone, M., D'Onofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, Tae Im, Kettle, P. -R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, G. F., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., and Yudin, Yu. V.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We studied the radiative muon decay $\mu^+ \to e^+\nu\bar{\nu}\gamma$ by using for the first time an almost fully polarized muon source. We identified a large sample (~13000) of these decays in a total sample of 1.8x10^14 positive muon decays collected in the MEG experiment in the years 2009--2010 and measured the branching ratio B($\mu^+ \to e^+\nu\bar{\nu}\gamma$) = (6.03+-0.14(stat.)+-0.53(sys.))x10^-8 for E_e > 45 MeV and E_{\gamma} > 40 MeV, consistent with the Standard Model prediction. The precise measurement of this decay mode provides a basic tool for the timing calibration, a normalization channel, and a strong quality check of the complete MEG experiment in the search for $\mu^+ \to e^+\gamma$ process., Comment: 8 pages, 7 figures. Added an introduction to NLO calculation which was recently calculated. Published version

Published
2013
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13. The use of segmented cathode of a drift tube for designing a track detector with a high rate capability

Author

Kuchinskiy, N. A., Baranov, V. A., Duginov, V. N., Zyazyulya, F. E., Korenchenko, A. S., Kolesnikov, A. O., Kravchuk, N. P., Movchan, S. A., Rudenko, A. I., Smirnov, V. S., Khomutov, N. V., and Chekhovsky, V. A.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Detector rate capability is one of the main parameters for designing a new detector for high energy physics due to permanent rise of the beam luminosity of modern accelerators. One of the widely used detectors for particle track reconstruction is a straw detector based on drift tubes. The rate capability of such detectors is limited by the parameters of readout electronics. The traditional method of increasing detector rate capability is increasing their granularity (a number of readout channels) by reducing the straw diameter and/or by dividing the straw anode wire into two parts (for decreasing the rate per readout channel). A new method of designing straw detectors with a high rate capability is presented and tested. The method is based on dividing the straw cathode into parts and independent readout of each part., Comment: 10 pages, 8 figures

Published
2013

14. The MEG detector for ${\mu}+\to e+{\gamma}$ decay search

Author

Adam, J., Bai, X., Baldini, A. M., Baracchini, E., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Cerri, C., Corbo, M., Curalli, N., De Bari, A., De Gerone, M., Del Frate, L., Doke, S., Dussoni, S., Egger, J., Fratini, K., Fujii, Y., Galli, L., Galeotti, S., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hisamatsu, M. Hildebrandt Y., Ignatov, F., Iwamoto, T., Kaneko, D., Kasami, K., Kettle, P. -R., Khazin, B. I., Korenchenko, O. Kiselev A., Kravchuk, N., Lim, G., Maki, A., Mihara, S., Molzon, W., Mori, T., Morsani, F., Mzavia, D., Nardò, R., Natori, H., Nicolò, D., Nishiguchi, H., Ootani, Y. Nishimura W., Ozone, K., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Raffaelli, F., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Sawada, R., Schneebeli, M., Sergiampietri, F., Signorelli, G., Suzuki, S., Tenchini, F., Topchyan, C., Uchiyama, Y., Voena, R. Valle C., Xiao, F., Yamada, S., Yamamoto, S., Yamashita, S., Yudin, Yu. V., and Zanello, D.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The MEG (Mu to Electron Gamma) experiment has been running at the Paul Scherrer Institut (PSI), Switzerland since 2008 to search for the decay \meg\ by using one of the most intense continuous $\mu^+$ beams in the world. This paper presents the MEG components: the positron spectrometer, including a thin target, a superconducting magnet, a set of drift chambers for measuring the muon decay vertex and the positron momentum, a timing counter for measuring the positron time, and a liquid xenon detector for measuring the photon energy, position and time. The trigger system, the read-out electronics and the data acquisition system are also presented in detail. The paper is completed with a description of the equipment and techniques developed for the calibration in time and energy and the simulation of the whole apparatus., Comment: 59 pages, 90 figures

Published
2013
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15. New constraint on the existence of the mu+-> e+ gamma decay

Author

MEG Collaboration, Adam, J., Bai, X., Baldini, A. M., Baracchini, E., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Cerri, C., de Bari, A., De Gerone, M., Doke, T., Dussoni, S., Egger, J., Fratini, K., Fujii, Y., Galli, L., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hisamatsu, Y., Ignatov, F., Iwamoto, T., Kaneko, D., Kettle, P. -R., Khazin, B. I., Khomotov, N., Kiselev, O., Korenchenko, A., Kravchuk, N., Lim, G., Maki, A., Mihara, S., Molzon, W., Mori, T., Mzavia, D., Nardo, R., Natori, H., Nicolo, D., Nishiguchi, H., Nishimura, Y., Ootani, W., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., Tenchini, F., Topchyan, C., Uchiyama, Y., Valle, R., Voena, C., Xiao, F., Yamada, S., Yamamoto, A., Yamashita, S., You, Z., Yudin, Yu. V., and Zanello, D.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The analysis of a combined data set, totaling 3.6 \times 10^14 stopped muons on target, in the search for the lepton flavour violating decay mu^+ -> e^+ gamma is presented. The data collected by the MEG experiment at the Paul Scherrer Institut show no excess of events compared to background expectations and yield a new upper limit on the branching ratio of this decay of 5.7 \times 10^-13 (90% confidence level). This represents a four times more stringent limit than the previous world best limit set by MEG., Comment: 5 pages, 3 figures, a version accepted in Phys. Rev. Lett

Published
2013

16. MEG Upgrade Proposal

Author

Baldini, A. M., Cei, F., Cerri, C., Dussoni, S., Galli, L., Grassi, M., Nicolò, D., Raffaelli, F., Sergiampietri, F., Signorelli, G., Tenchini, F., Bagliani, D., De Gerone, M., Gatti, F., Baracchini, E., Fujii, Y., Iwamoto, T., Kaneko, D., Mori, T., Nishimura, M., Ootani, W., Sawada, R., Uchiyama, Y., Boca, G., Cattaneo, P. W., de Bari, A., Nardò, R., Rossella, M., Cascella, M., Grancagnolo, F., L'Erario, A., Maffezzoli, A., Miccoli, A., Onorato, G., Palamà, G., Panareo, M., Pepino, A., Rella, S., Tassielli, G. F., Zavarise, G., Cavoto, G., Graziosi, A., Piredda, G., Ripiccini, E., Voena, C., Grigoriev, D. N., Ignatov, F., Khazin, B. I., Popov, A., Yudin, Yu. V., Haruyama, T., Mihara, S., Nishiguchi, H., Yamamoto, A., Hildebrandt, M., Kettle, P. -R., Papa, A., Renga, F., Ritt, S., Stoykov, A., Kang, T. I., Lim, G., Molzon, W., You, Z., Khomutov, N., Korenchenko, A., Kravchuk, N., and Kuchinksy, N.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We propose the continuation of the MEG experiment to search for the charged lepton flavour violating decay (cLFV) \mu \to e \gamma, based on an upgrade of the experiment, which aims for a sensitivity enhancement of one order of magnitude compared to the final MEG result, down to the $6 \times 10^{-14}$ level. The key features of this new MEG upgrade are an increased rate capability of all detectors to enable running at the intensity frontier and improved energy, angular and timing resolutions, for both the positron and photon arms of the detector. On the positron-side a new low-mass, single volume, high granularity tracker is envisaged, in combination with a new highly segmented, fast timing counter array, to track positron from a thinner stopping target. The photon-arm, with the largest liquid xenon (LXe) detector in the world, totalling 900 l, will also be improved by increasing the granularity at the incident face, by replacing the current photomultiplier tubes (PMTs) with a larger number of smaller photosensors and optimizing the photosensor layout also on the lateral faces. A new DAQ scheme involving the implementation of a new combined readout board capable of integrating the diverse functions of digitization, trigger capability and splitter functionality into one condensed unit, is also under development. We describe here the status of the MEG experiment, the scientific merits of the upgrade and the experimental methods we plan to use., Comment: A. M. Baldini and T. Mori Spokespersons. Research proposal submitted to the Paul Scherrer Institute Research Committee for Particle Physics at the Ring Cyclotron. 131 Pages

Published
2013

17. New studies of allowed pion and muon decays

Author

Pocanic, D., Palladino, A., Alonzi, L. P., Baranov, V. A., Bertl, W., Bychkov, M., Bystritsky, Yu. M., Frlez, E., Kalinnikov, V. A., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Lehman, M. C., Mekterovic, D., Munyangabe, E., Mzhavia, D., Robmann, P., Rozhdestvensky, A. M., Shkarovskiy, S. N., Straumann, U., Supek, I., Truöl, P., Tsamalaidze, Z., van der Schaaf, A., Velicheva, E. P., and Volnykh, V. P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

Building on the rare pion and muon decay results of the PIBETA experiment, the PEN collaboration has undertaken a precise measurement of B_{\pi e2} = R^\pi_{e/\mu}, the \pi^+ -> e^+\nu(\gamma) decay branching ratio, at the Paul Scherrer Institute, to reduce the present 40\times experimental precision lag behind theory to ~ 6-7\times. Because of large helicity suppression, R^\pi_{e/\mu} is uniquely sensitive to contributions from non-(V-A) physics, making this decay a particularly suitable subject of study. Even at current precision, the experimental value of B_{\pi e2} provides the most accurate test of lepton universality available. During runs in 2008-10, PEN has accumulated over 2\times 10^7 \pi_{e2} events; a comprehensive maximum-likelihood analysis is currently under way. The new data will also lead to improved precision of the earlier PIBETA results on radiative \pi and \mu decays., Comment: 3 pages, 3 figures, to appear in Proceedings, 11th Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2012), held at St. Petersburg, Florida, 29 May - 3 June 2012

Published
2012
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18. Detector with a profile-based cathode and a two-coordinate pad-strip readout system

Author

Kuchinskiy, N. A., Baturitskii, V. A., Kravchuk, N. P., Korenchenko, A. S., Khomutov, N. V., Smirnov, V. S., Chekhovskii, V. A., Movchan, S. A., and Zyazyulya, F. E.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

A detector with a profile-based cathode and a pad-strip cathode readout system is experimentally investigated. Cathode pads arranged along each anode wire are diagonally interconnected and form strips that cross the detector at an angle with respect to the anode wire. Two coordinates from the cathodes and one from the anode wire allow identification of tracks in high multiplicity events with a single detector plane., Comment: 6 pages, 5 figures

Published
2011

19. New limit on the lepton-flavour violating decay mu -> e gamma

Author

MEG collaboration, Adam, J., Bai, X., Baldini, A. M., Baracchini, E., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Cerri, C., de Bari, A., De Gerone, M., Doke, T., Dussoni, S., Egger, J., Fratini, K., Fujii, Y., Galli, L., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hisamatsu, Y., Ignatov, F., Iwamoto, T., Kettle, P. -R., Khazin, B. I., Kiselev, O., Korenchenko, A., Kravchuk, N., Maki, A., Mihara, S., Molzon, W., Mori, T., Mzavia, D., Natori, H., Nicolò, D., Nishiguchi, H., Nishimura, Y., Ootani, W., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Renga, F., Ritt, S., Rossella, M., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., Tenchini, F., Topchyan, C., Uchiyama, Y., Valle, R., Voena, C., Xiao, F., Yamada, S., Yamamoto, A., Yamashita, S., Yudin, Yu. V., and Zanello, D.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton flavour violating decay mu->e gamma. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8 x 10**14 muon decays, gives a 90% C.L. upper limit of 2.4 x 10**-12 on the branching ratio of the mu->e gamma decay, constituting the most stringent limit on the existence of this decay to date., Comment: 5 pages, 2 figures, accepted for publication at Phys. Rev. Lett

Published
2011
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20. PEN: a sensitive search for non-(V-A) weak processes

Author

PEN Collaboration, Pocanic, D., Alonzi, L. P., Baranov, V. A., Bertl, W., Bychkov, M., Bystritsky, Yu. M., Frlez, E., Kalinnikov, V. A., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Mekterovic, D., Mzhavia, D., Palladino, A., Robmann, P., Rozhdestvensky, A. M., Shkarovskiy, S. N., Straumann, U., Supek, I., Truoel, P., Tsamalaidze, Z., van der Schaaf, A., Velicheva, E. P., and Volnykh, V. P.

Subjects
High Energy Physics - Experiment
Abstract

A new measurement of $B_{\pi e2}$, the $\pi^+ \to e^+\nu(\gamma)$ decay branching ratio, is currently under way at the Paul Scherrer Institute. The present experimental result on $B_{\pi e2}$ constitutes the most accurate test of lepton universality available. The accuracy, however, still lags behind the theoretical precision by over an order of magnitude. Thanks to the large helicity suppression of $\pi_{e2}$ decay, the branching ratio is susceptible to significant contributions from new physics, making this decay a particularly suitable subject of study., Comment: 4 pages, 1 figure, talk given at the 18th International Conference on Particles and Nuclei (PANIC08), held 9 -14 November 2008 in Eilat, Israel; to appear in the Proceedings published by North Holland

Published
2009

21. PEN experiment: a precise measurement of the pi+ -> e+ nu decay branching fraction

Author

PEN Collaboration, Pocanic, D., Alonzi, L. P., Baranov, V. A., Bertl, W., Bychkov, M., Bystritsky, Yu. M., Frlez, E., Kalinnikov, V. A., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Mekterovic, D., Mzhavia, D., Palladino, A., Robmann, P., Rozhdestvensky, A. M., Shkarovskiy, S. N., Straumann, U., Supek, I., Truoel, P., Tsamalaidze, Z., van der Schaaf, A., Velicheva, E. P., and Volnykh, V. P.

Subjects
High Energy Physics - Experiment
Abstract

A new measurement of $B_{\pi e2}$, the $\pi^+ \to e^+\nu(\gamma)$ decay branching ratio, is currently under way at the Paul Scherrer Institute. The present experimental result on $B_{\pi e2}$ constitutes the most accurate test of lepton universality available. The accuracy, however, still lags behind the theoretical precision by over an order of magnitude. Because of the large helicity suppression of the $\pi_{e2}$ decay, its branching ratio is susceptible to significant contributions from new physics, making this decay a particularly suitable subject of study., Comment: 4 pages, 3 figures, talk given at the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), La Jolla/San Diego, CA, 26-31 May 2009; to appear in Proceedings to be published by the American Institute of Physics

Published
2009
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22. A limit for the mu -> e gamma decay from the MEG experiment

Author

MEG collaboration, Adam, J., Bai, X., Baldini, A., Baracchini, E., Barchiesi, A., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cecchet, G., Cei, F., Cerri, C., De Bari, A., De Gerone, M., Doke, T., Dussoni, S., Egger, J., Galli, L., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hisamatsu, Y., Ignatov, F., Iwamoto, T., Kaneko, D., Kettle, P. -R., Khazin, B. I., Kiselev, O., Korenchenko, A., Kravchuk, N., Maki, A., Mihara, S., Molzon, W., Mori, T., Mzavia, D., Natori, H., Nardò, R., Nicolò, D., Nishiguchi, H., Nishimura, Y., Ootani, W., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Renga, F., Ritt, S., Rossella, M., Sawada, R., Schneebeli, M., Sergiampietri, F., Signorelli, G., Suzuki, S., Topchyan, C., Tumakov, V., Uchiyama, Y., Valle, R., Voena, C., Xiao, F., Yamada, S., Yamamoto, A., Yamashita, S., Yudin, Yu. V., and Zanello, D.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

A search for the decay mu -> e gamma, performed at PSI and based on data from the initial three months of operation of the MEG experiment, yields an upper limit on the branching ratio of BR(mu -> e gamma) < 2.8 x 10**-11 (90% C.L.). This corresponds to the measurement of positrons and photons from ~ 10**14 stopped mu-decays by means of a superconducting positron spectrometer and a 900 litre liquid xenon photon detector., Comment: 13 pages, 9 figures. v2: improved estimate of photon reconstruction efficiency

Published
2009
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23. Precise Measurement of pi+ -> e+ nu Branching Ratio

Author

Frlež, E., Alonzi, L. P., Baranov, V. A., Bertl, W., Bychkov, M., Bystritsky, Yu. M., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Mekterović, D., Mzhavia, D., Palladino, A., Počanić, D., Robmann, P., Rozhdestvensky, A. M., Sidorkin, V. V., Straumann, U., Supek, I., Truöl, P., van der Schaaf, A., Velicheva, E. P., and Volnykh, V. P.

Subjects
High Energy Physics - Experiment
Abstract

The PEN Collaboration is conducting a new measurement of the pi+ -> e+ nu branching ratio at the Paul Scherrer Institute, with the goal uncertainty of delta B/B(pie2)=5E-4 or lower. At present, the combined accuracy of all published pie2 decay measurements lags behind the theoretical calculation by a factor of 40. In this contribution we report on the PEN detector configuration and its performance during two development runs done in 2007 and 2008., Comment: pdflatex, 11 pages, 5 figures, to be published in "Progress in High-Energy Physics and Nuclear Safety", NATO Science for Peace Series: B - Physics and Biophysics

Published
2008
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24. New Precise Measurement of the Pion Weak Form Factors in the Pi+ -> e+ nu gamma Decay

Author

Bychkov, M., Počanić, D., VanDevender, B. A., Baranov, V. A., Bertl, W., Bystritsky, Yu. M., Frlež, E., Kalinnikov, V. A., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Korolija, M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Li, W., Mekterović, D., Mzhavia, D., Ritt, S., Robmann, P., Rondon-Aramayo, O. A., Rozhdestvensky, A. M., Sakhelashvili, T., Scheu, S., Straumann, U., Supek, I., Tsamalaidze, Z., van der Schaaf, A., Velicheva, E. P., Volnykh, V. P., Wang, Y., and Wirtz, H. -P.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

We have measured the $\pi^+\to {\rm e}^+\nu\gamma$ branching ratio over a wide region of phase space, based on a total of 65,460 events acquired using the PIBETA detector. Minimum-$\chi^2$ fits to the measured $(E_{e^+},E_\gamma)$ energy distributions result in the weak form factor value of $F_A=0.0119(1)$ with a fixed value of $F_V=0.0259$. An unconstrained fit yields $F_V=0.0258(17)$ and $F_A=0.0117(17)$. In addition, we have measured $a=0.10(6)$ for the dependence of $F_V$ on $q^2$, the ${\rm e}^{+}\nu$ pair invariant mass squared, parametrized as $F_V(q^2)=F_V(0)(1+a\cdot q^2)$. The branching ratio for the kinematic region $E_\gamma > 10 $MeV and $\theta_{{\rm e^+}\gamma} > 40^\circ $ is measured to be $B^{\rm exp}=73.86(54) \times 10^{-8}$. Earlier deviations we reported in the high-$E_\gamma$/low-$E_{{\rm e}^+}$ kinematic region are resolved, and we find full compatibility with CVC and standard $V$$-$$A$ calculations without a tensor term. We also derive new values for the pion polarizability, $\alpha_E = \rm 2.78(10) \times 10^{-4} fm^3$, and neutral pion lifetime, $\tau_{\pi 0} = (8.5 \pm 1.1) \times 10^{-17} $s., Comment: 4 pages, 2 PDF figures

Published
2008
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25. Collins and Sivers asymmetries for pions and kaons in muon-deuteron DIS

Author

The COMPASS Collaboration, Alekseev, M., Alexakhin, V. Yu., Alexandrov, Yu., Alexeev, G. D., Amoroso, A., Arbuzov, A., Badełek, B., Balestra, F., Ball, J., Barth, J., Baum, G., Bedfer, Y., Bernet, C., Bertini, R., Bettinelli, M., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, F., Bravar, A., Bressan, A., Brona, G., Burtin, E., Bussa, M. P., Chapiro, A., Chiosso, M., Cicuttin, A., Colantoni, M., Costa, S., Crespo, M. L., Torre, S. Dalla, Dafni, T., Das, S., Dasgupta, S. S., De Masi, R., Dedek, N., Denisov, O. Yu., Dhara, L., Diaz, V., Dinkelbach, A. M., Donskov, S. V., Dorofeev, V. A., Doshita, N., Duic, V., Dünnweber, W., Eversheim, P. D., Efremov, A. V., Eyrich, W., Faessler, M., Falaleev, V., Ferrero, A., Ferrero, L., Finger, M., Finger Jr., M., Fischer, H., Franco, C., Franz, J., Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gazda, R., Gerassimov, S., Geyer, R., Giorgi, M., Gobbo, B., Goertz, S., Gorin, A. M., Grabmüller, S., Grajek, O. A., Grasso, A., Grube, B., Gushterski, R., Guskov, A., Haas, F., Hannappel, J., von Harrach, D., Hasegawa, T., Heckmann, J., Hedicke, S., Heinsius, F. H., Hermann, R., Heß, C., Hinterberger, F., von Hodenberg, M., Horikawa, N., Horikawa, S., d'Hose, N., Ilgner, C., Ioukaev, A. I., Ishimoto, S., Ivanov, O., Ivanshin, Yu., Iwata, T., Jahn, R., Janata, A., Jasinski, P., Joosten, R., Jouravlev, N. I., Kabuß, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Kisselev, Yu., Klein, F., Klimaszewski, K., Koblitz, S., Koivuniemi, J. H., Kolosov, V. N., Komissarov, E. V., Kondo, K., Königsmann, K., Konorov, I., Konstantinov, V. F., Korentchenko, A. S., Korzenev, A., Kotzinian, A. M., Koutchinski, N. A., Kouznetsov, O., Kral, A., Kravchuk, N. P., Kroumchtein, Z. V., Kuhn, R., Kunne, F., Kurek, K., Ladygin, M. E., Lamanna, M., Goff, J. M. Le, Lednev, A. A., Lehmann, A., Levorato, S., Lichtenstadt, J., Liska, T., Ludwig, I., Maggiora, A., Maggiora, M., Magnon, A., Mallot, G. K., Mann, A., Marchand, C., Marroncle, J., Martin, A., Marzec, J., Massmann, F., Matsuda, T., Maximov, A. N., Meyer, W., Mielech, A., Mikhailov, Yu. V., Moinester, M. A., Mutter, A., Nagaytsev, A., Nagel, T., Nähle, O., Nassalski, J., Neliba, S., Nerling, F., Neubert, S., Neyret, D. P., Nikolaenko, V. I., Nikolaev, K., Olshevsky, A. G., Ostrick, M., Padee, A., Pagano, P., Panebianco, S., Panknin, R., Panzieri, D., Paul, S., Pawlukiewicz-Kaminska, B., Peshekhonov, D. V., Peshekhonov, V. D., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Procureur, S., Quintans, C., Rajotte, J. -F., Ramos, S., Rapatsky, V., Reicherz, G., Reggiani, D., Richter, A., Robinet, F., Rocco, E., Rondio, E., Rozhdestvensky, A. M., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Santos, H., Sapozhnikov, M. G., Sarkar, S., Savin, I. A., Schiavon, P., Schill, C., Schmitt, L., Schönmeier, P., Schröder, W., Shevchenko, O. Yu., Siebert, H. -W., Silva, L., Sinha, L., Sissakian, A. N., Slunecka, M., Smirnov, G. I., Sosio, S., Sozzi, F., Srnka, A., Stinzing, F., Stolarski, M., Sugonyaev, V. P., Sulc, M., Sulej, R., Tchalishev, V. V., Tessaro, S., Tessarotto, F., Teufel, A., Tkatchev, L. G., Venugopal, G., Virius, M., Vlassov, N. V., Vossen, A., Webb, R., Weise, E., Weitzel, Q., Windmolders, R., Wirth, S., Wiślicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Zhao, J., Ziegler, R., and Zvyagin, A.

Subjects
High Energy Physics - Experiment
Abstract

The measurements of the Collins and Sivers asymmetries of identified hadrons produced in deep-inelastic scattering of 160 GeV/c muons on a transversely polarised 6LiD target at COMPASS are presented. The results for charged pions and charged and neutral kaons correspond to all data available, which were collected from 2002 to 2004. For all final state particles both the Collins and Sivers asymmetries turn out to be small, compatible with zero within the statistical errors, in line with the previously published results for not identified charged hadrons, and with the expected cancellation between the u- and d-quark contributions., Comment: 16 pages, 9 figures, added author Efremov, calculated pure kaon asymmetries instead of those for experimental kaon/pion mixture (mainly error affected)

Published
2008
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26. Precise Measurement of the Pi+ -> Pi0 e+ nu Branching Ratio

Author

Pocanic, D., Frlez, E., Baranov, V. A., Bertl, W., Broennimann, C., Bychkov, M., Crawford, J. F., Daum, M., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Li, W., Minehart, R. C., Mzhavia, D., Ritchie, B. G., Ritt, S., Rozhdestvensky, A. M., Sidorkin, V. V., Smith, L. C., Supek, I., Tsamalaidze, Z., VanDevender, B. A., Wang, Y., Wirtz, H. -P., and Ziock, K. O. H.

Subjects
High Energy Physics - Experiment
Abstract

Using a large acceptance calorimeter and a stopped pion beam we have made a precise measurement of the rare Pi+ -> Pi0 e+ Nu,(pi_beta) decay branching ratio. We have evaluated the branching ratio by normalizing the number of observed pi_beta decays to the number of observed Pi+ -> e+ Nu, (pi_{e2}) decays. We find the value of Gamma(Pi+ -> Pi0 e+ Nu)/Gamma(total) = [1.036 +/- 0.004(stat.) +/- 0.004(syst.) +/- 0.003(pi_{e2})] x 10^{-8}$, where the first uncertainty is statistical, the second systematic, and the third is the pi_{e2} branching ratio uncertainty. Our result agrees well with the Standard Model prediction., Comment: 4 pages, 5 figures, 1 table, revtex4; changed content; updated analysis

Published
2003
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27. Precise Measurement of the Pion Axial Form Factor in the Pi+ -> e+ nu gamma Decay

Author

Frlez, E., Pocanic, D., Baranov, V. A., Bertl, W., Bychkov, M., Khomutov, N. V., Korenchenko, A. S., Korenchenko, S. M., Kozlowski, T., Kravchuk, N. P., Kuchinsky, N. A., Li, W., Minehart, R. C., Mzhavia, D., Ritchie, B. G., Ritt, S., Rozhdestvensky, A. M., Sidorkin, V. V., Smith, L. C., Supek, I., Tsamalaidze, Z., VanDevender, B. A., Velicheva, E. P., Wang, Y., Wirtz, H. -P., and Ziock, K. O. H.

Subjects
High Energy Physics - Experiment
Abstract

We have studied radiative pion decays Pi+ -> e+ nu gamma in three broad kinematic regions using the PIBETA detector and a stopped pion beam. Based on Dalitz distributions of 42,209 events we have evaluated absolute Pi -> e nu gamma branching ratios in the three regions. Minimum chi^2 fits to the integral and differential (E(e+),E(gamma)) distributions result in the axial-to-vector weak form factor ratio of gamma = F_A/F_V = 0.443(15),or F_A = 0.0115(4) with F_V = 0.0259. However, deviations from Standard Model predictions in the high-E(gamma)/low-E(e+) kinematic region indicate the need for further theoretical and experimental work., Comment: 5 pages, 4 figures, 1 table, revtex4

Published
2003
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28. Design, Commissioning and Performance of the PIBETA Detector at PSI

Author

Frlez, E., Pocanic, D., Assamagan, K. A., Bagaturia, Yu., Baranov, V. A., Bertl, W., Broennimann, Ch., Bychkov, M. A., Crawford, J. F., Daum, M., Fluegel, Th., Frosch, R., Horisberger, R., Kalinnikov, V. A., Karpukhin, V. V., Khomutov, N. V., Koglin, J. E., Korenchenko, A. S., Korenchenko, S. M., Kozlowski, T., Krause, B., Kravchuk, N. P., Kuchinsky, N. A., Li, W., Lawrence, D. W., Minehart, R. C., Mzhavia, D., Obermeier, H., Renker, D., Ritchie, B. G., Ritt, S., Sakhelashvili, T., Schnyder, R., Sidorkin, V. V., Slocum, P. L., Smith, L. C., Soic, N., Stephens, W. A., Supek, I., Tsamalaidze, Z., VanDevender, B. A., Wang, Y., Wirtz, H. -P., and Ziock, K. O. H.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

We describe the design, construction and performance of the PIBETA detector built for the precise measurement of the branching ratio of pion beta decay, pi+ -> pi0 e+ nu, at the Paul Scherrer Institute. The central part of the detector is a 240-module spherical pure CsI calorimeter covering 3*pi sr solid angle. The calorimeter is supplemented with an active collimator/beam degrader system, an active segmented plastic target, a pair of low-mass cylindrical wire chambers and a 20-element cylindrical plastic scintillator hodoscope. The whole detector system is housed inside a temperature-controlled lead brick enclosure which in turn is lined with cosmic muon plastic veto counters. Commissioning and calibration data were taken during two three-month beam periods in 1999/2000 with pi+ stopping rates between 1.3*E3 pi+/s and 1.3*E6 pi+/s. We examine the timing, energy and angular detector resolution for photons, positrons and protons in the energy range of 5-150 MeV, as well as the response of the detector to cosmic muons. We illustrate the detector signatures for the assorted rare pion and muon decays and their associated backgrounds., Comment: 117 pages, 48 Postscript figures, 5 tables, Elsevier LaTeX, submitted to Nucl. Instrum. Meth. A

Published
2003
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29. New Bounds from Searching for Muonium to Antimuonium Conversion

Author

Willmann, L., Schmidt, P. V., Wirtz, H. P., Abela, R., Baranov, V., Bagaturia, J., Bertl, W., Engfer, R., Grossmann, A., Hughes, V. W., Jungmann, K., Karpuchin, V., Kisel, I., Korenchenko, A., Korenchenko, S., Kravchuk, N., Kuchinsky, N., Leuschner, A., Meyer, V., Merkel, J., Moiseenko, A., Mzavia, D., Putlitz, G. zu, Reichart, W., Reinhard, I., Renker, D., Sakhelashvilli, T., Tr"ager, K., and Walter, H. K.

Subjects
High Energy Physics - Experiment
Abstract

A new upper limit for the probability of spontaneous muonium to antimuonium conversion was established at ${\rm P_{M\bar{M}}} \leq 8.2 \cdot 10^{-11}$ (90%C.L.) in 0.1~T magnetic field, which implies consequences for speculative extensions to the standard model. Coupling parameters in R-parity violating supersymmetry and the mass of a flavour diagonal bileptonic gauge boson can be significantly restricted. A Z$_8$ model with radiative mass generation through heavy lepton seed and the minimal version of 331-GUT models are ruled out.

Published
1998
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30. Increased Sensitivity to Possible Muonium to Antimuonium Conversion

Author

Meyer, V., Grossmann, A., Jungmann, K., Merkel, J., Putlitz, G. zu, Reinhard, I., Träger, K., Schmidt, P. V., Willmann, L., Engfer, R ., Wirtz, H. P., Abela, R., Bertl, W., Renker, D., Walter, H. K., Karpuchin, V., Kisel, I., Korenchenko, A., Korenchenko, S., Kravchuk, N., Kuchinsky, N., Moiseenko, A., Bagaturia, J., Mzavia, D., Sakhelashvili, T., and Hughes, V. W.

Subjects
High Energy Physics - Experiment
Abstract

A new experimental search for muonium-antimuonium conversion was conducted at the Paul Scherrer Institute, Villigen, Switzerland. The preliminary analysis yielded one event fulfilling all required criteria at an expected background of 1.7(2) events due to accidental coincidences. An upper limit for the conversion probability in 0.1 T magnetic field is extracted as $8 \cdot 10^{-11}$ (90% CL)., Comment: 2 figures

Published
1998
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31. Muon polarization in the MEG experiment: predictions and measurements

Author

Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, Gianluca, Cei, F., Chiarello, G., Chiri, C., De Bari, A., De Gerone, M., D’Onofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, T. I., Kettle, P. R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, Emanuele, Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, G. F., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., Yudin, Y. u. V., Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, Gianluigi, Chiri, Claudio, Bari, A. De, Gerone, M. De, D’Onofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, T. I., Kettle, P. R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, Marco, Papa, A., Pepino, Aurora, Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, GIOVANNI FRANCESCO, Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., and Yudin, Y. u. V.

Subjects
Muon, Polarization, Lepton Flavor Violation, Michel decay, Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), High Energy Physics::Phenomenology, lepton flavour violation, FOS: Physical sciences, muon decay, Instrumentation and Detectors (physics.ins-det), High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Physics::Accelerator Physics, High Energy Physics::Experiment, Engineering (miscellaneous)
Abstract

The MEG experiment makes use of one of the world's most intense low energy muon beams, in order to search for the lepton flavour violating process $\mu^{+} \rightarrow {\rm e}^{+} \gamma$. We determined the residual beam polarization at the thin stopping target, by measuring the asymmetry of the angular distribution of Michel decay positrons as a function of energy. The initial muon beam polarization at the production is predicted to be $P_{\mu} = -1$ by the Standard Model (SM) with massless neutrinos. We estimated our residual muon polarization to be $P_{\mu} = -0.85 \pm 0.03 ~ {\rm (stat)} ~ { }^{+ 0.04}_{-0.05} ~ {\rm (syst)}$ at the stopping target, which is consistent with the SM predictions when the depolarizing effects occurring during the muon production, propagation and moderation in the target are taken into account. The knowledge of beam polarization is of fundamental importance in order to model the background of our ${\megsign}$ search induced by the muon radiative decay: $\mu^{+} \rightarrow {\rm e}^{+} \bar{\nu}_{\mu} \nu_{\rm e} \gamma$.

Published
2016
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32. Search for the $\phi1860$ Pentaquark at COMPASS

Author

Ageev, E. S., Alexakhin, V. Y. U., Alexandrov, Y. U., Alexeev, G. D., Amoroso, A., Badelek, B., Balestra, F., Ball, J., Baum, G., Bedfer, Y., Berglund, P., Bernet, C., Bertini, R., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, Franco, Bressan, Andrea, Brona, G., Burtin, E., Bussa, M. P., Bytchkov, V. N., Cerini, L., Chapiro, A., Cicuttin, A., Colantoni, M., Colavita, A. A., Costa, S., Crespo, M. L., D'Hose, N., DALLA TORRE, S., Dasgupta, S. S., DE MASI, R., Dedek, N., Denisov, O. Y. U., Dhara, L., DIAZ KAVKA, V., Dinkelbach, A. M., Dolgopolov, A. V., Donskov, S. V., Dorofeev, V. A., Doshita, N., Duic, V., Dunnweber, W., Ehlers, J., Eversheim, P. D., Eyrich, W., Faessler, M., Falaleev, V., Fauland, P., Ferrero, A., Ferrero, L., Finger, M., Fischer, H., Franz, J., Friedrich, J. M., Frolov, V., Fuchs, U., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, Marcello, Gobbo, B., Goertz, S., Gorin, A. M., Grajek, O. A., Grasso, A., Grube, B., Grunemaier, A., Hannappel, J., VON HARRACH, D., Hasegawa, T., Hedicke, S., Heinsius, F. H., Hermann, R., Hess, C., Hinterberger, F., VON HODENBERG, M., Horikawa, N., Horikawa, S., Ilgner, C., Ioukaev, A. I., Ishimoto, S., Ivanov, O., Iwata, T., Jahn, R., Janata, A., Joosten, R., Jouravlev, N. I., Kabuss, E., Kalinnikov, V., Kang, D., Karstens, F., Kastaun, W., Ketzer, B., Khaustov, G. V., Khokhlov, Y. U. A., Khomutov, N. V., Kisselev, Y. U., Klein, F., Koivuniemi, J. H., Kolosov, V. N., Komissarov, E. V., Kondo, K., Konigsmann, K., Konoplyannikov, A. K., Konorov, I., Konstantinov, V. F., Korentchenko, A. S., Korzenev, A., Kotzinian, A. M., Koutchinski, N. A., Kowalik, K., Kravchuk, N. P., Krivokhizhin, G. V., Kroumchtein, Z. V., Kuhn, R., Kunne, F., Kurek, K., Ladygin, M. E., Lamanna, M., LE GOFF, J. M., Leberig, M., Lichtenstadt, J., Liska, T., Ludwig, I., Maggiora, A., Maggiora, M., Magnon, A., Mallot, G. K., Manuilov, I. V., Marchand, C., Marroncle, J., Martin, Anna, Marzec, J., Matsuda, T., Maximov, A. N., Medved, K. S., Meyer, W., Mielech, A., Mikhailov, Y. U. V., Moinester, M. A., Nahle, O., Nassalski, J., Neliba, S., Neyret, D. P., Nikolaenko, V. I., Nozdrin, A. A., Obraztsov, V. F., Olshevsky, A. G., Ostrick, M., Padee, A., Pagano, P., Panebianco, S., Panzieri, D., Paul, S., Pereira, H. D., Peshekhonov, D. V., Peshekhonov, V. D., Piragino, G., Platchkov, S., Platzer, K., Pochodzalla, J., Polyakov, V. A., Popov, A. A., Pretz, J., Procureur, S., Quintans, C., Ramos, S., Rebourgeard, P. C., Reicherz, G., Reymann, J., Rozhdestvensky, A. M., Rondio, E., Sadovski, A. B., Saller, E., Samoylenko, V. D., Sandacz, A., Sapozhnikov, M. G., Savin, IGOR A., Schiavon, Paolo, Schill, C., Schmidt, T., Schmitt, H., Schmitt, L., Shevchenko, O. Y. U., Shishkin, A. A., Siebert, H. W., Sinha, L., Sissakian, A. N., Skachkova, A., Slunecka, M., Smirnov, G. I., Sozzi, F., Sugonyaev, V. P., Srnka, A., Stinzing, F., Stolarski, M., Sulc, M., Sulej, R., Takabayashi, N., Tchalishev, V. V., Tessarotto, F., Teufel, A., Tkatchev, L. G., Toeda, T., Tretyak, V. I., Trousov, S., Varanda, M., Virius, M., Vlassov, N. V., Wagner, M., Webb, R., Weise, E., Weitzel, Q., Wiesmann, M., Windmolders, R., Wirth, S., Wislicki, W., Zanetti, A. M., Zaremba, K., Zhao, J., Ziegler, R., Zvyagin, A., E. S., Ageev, Alexakhin, V. Y. U., Alexandrov, Y. U., G. D., Alexeev, A., Amoroso, B., Badelek, F., Balestra, J., Ball, G., Baum, Y., Bedfer, P., Berglund, C., Bernet, R., Bertini, R., Birsa, J., Bisplinghoff, P., Bordalo, Bradamante, Franco, Bressan, Andrea, G., Brona, E., Burtin, M. P., Bussa, V. N., Bytchkov, L., Cerini, A., Chapiro, A., Cicuttin, M., Colantoni, A. A., Colavita, S., Costa, M. L., Crespo, N., D'Hose, S., DALLA TORRE, S. S., Dasgupta, R., DE MASI, N., Dedek, Denisov, O. Y. U., L., Dhara, V., DIAZ KAVKA, A. M., Dinkelbach, A. V., Dolgopolov, S. V., Donskov, V. A., Dorofeev, N., Doshita, V., Duic, W., Dunnweber, J., Ehler, P. D., Eversheim, W., Eyrich, M., Faessler, V., Falaleev, P., Fauland, A., Ferrero, L., Ferrero, M., Finger, Jr, H., Fischer, J., Franz, J. M., Friedrich, V., Frolov, U., Fuch, R., Garfagnini, F., Gautheron, O. P., Gavrichtchouk, S., Gerassimov, R., Geyer, Giorgi, Marcello, B., Gobbo, S., Goertz, A. M., Gorin, O. A., Grajek, A., Grasso, B., Grube, A., Grunemaier, J., Hannappel, D., VON HARRACH, T., Hasegawa, S., Hedicke, F. H., Heinsiu, R., Hermann, C., He, F., Hinterberger, M., VON HODENBERG, N., Horikawa, S., Horikawa, C., Ilgner, A. I., Ioukaev, S., Ishimoto, O., Ivanov, T., Iwata, R., Jahn, A., Janata, R., Joosten, N. I., Jouravlev, E., Kabu, V., Kalinnikov, D., Kang, F., Karsten, W., Kastaun, B., Ketzer, G. V., Khaustov, Khokhlov, Y. U. A., N. V., Khomutov, Kisselev, Y. U., F., Klein, J. H., Koivuniemi, V. N., Kolosov, E. V., Komissarov, K., Kondo, K., Konigsmann, A. K., Konoplyannikov, I., Konorov, V. F., Konstantinov, A. S., Korentchenko, A., Korzenev, A. M., Kotzinian, N. A., Koutchinski, K., Kowalik, N. P., Kravchuk, G. V., Krivokhizhin, Z. V., Kroumchtein, R., Kuhn, F., Kunne, K., Kurek, M. E., Ladygin, M., Lamanna, J. M., LE GOFF, M., Leberig, J., Lichtenstadt, T., Liska, I., Ludwig, A., Maggiora, M., Maggiora, A., Magnon, G. K., Mallot, I. V., Manuilov, C., Marchand, J., Marroncle, Martin, Anna, J., Marzec, T., Matsuda, A. N., Maximov, K. S., Medved, W., Meyer, A., Mielech, Mikhailov, Y. U. V., M. A., Moinester, O., Nahle, J., Nassalski, S., Neliba, D. P., Neyret, V. I., Nikolaenko, A. A., Nozdrin, V. F., Obraztsov, A. G., Olshevsky, M., Ostrick, A., Padee, P., Pagano, S., Panebianco, D., Panzieri, S., Paul, H. D., Pereira, D. V., Peshekhonov, V. D., Peshekhonov, G., Piragino, S., Platchkov, K., Platzer, J., Pochodzalla, V. A., Polyakov, A. A., Popov, J., Pretz, S., Procureur, C., Quintan, S., Ramo, P. C., Rebourgeard, G., Reicherz, J., Reymann, A. M., Rozhdestvensky, E., Rondio, A. B., Sadovski, E., Saller, V. D., Samoylenko, A., Sandacz, M. G., Sapozhnikov, IGOR A., Savin, Schiavon, Paolo, C., Schill, T., Schmidt, H., Schmitt, L., Schmitt, Shevchenko, O. Y. U., A. A., Shishkin, H. W., Siebert, L., Sinha, A. N., Sissakian, A., Skachkova, M., Slunecka, G. I., Smirnov, F., Sozzi, V. P., Sugonyaev, A., Srnka, F., Stinzing, M., Stolarski, M., Sulc, R., Sulej, N., Takabayashi, V. V., Tchalishev, F., Tessarotto, A., Teufel, L. G., Tkatchev, T., Toeda, V. I., Tretyak, S., Trousov, M., Varanda, M., Viriu, N. V., Vlassov, M., Wagner, R., Webb, E., Weise, Q., Weitzel, M., Wiesmann, R., Windmolder, S., Wirth, W., Wislicki, A. M., Zanetti, K., Zaremba, J., Zhao, R., Ziegler, and A., Zvyagin

Subjects
Physics, Particle physics, Large Hadron Collider, Photon, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Nuclear Theory, High Energy Physics::Phenomenology, Hyperon, FOS: Physical sciences, 01 natural sciences, Pentaquark, High Energy Physics - Experiment, Baryon, High Energy Physics - Experiment (hep-ex), Exotic baryon, Compass, 0103 physical sciences, COMPASS experiment, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Engineering (miscellaneous), Particle Physics - Experiment
Abstract

Narrow Xi-pi+- and Xi-bar+pi+- resonances produced by quasi-real photons have been searched for by the COMPASS experiment at CERN. The study was stimulated by the recent observation of an exotic baryonic state decaying into Xi-pi-, at a mass of 1862 MeV, interpreted as a pentaquark. While the ordinary hyperon states Xi(1530)^0 and Xi-bar(1530)^0 are clearly seen, no exotic baryon is observed in the data taken in 2002 and 2003., Comment: 10 pages, 5 figures

Published
2005
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33. Direct Measurement of the Gluon Polarisation in the Nucleon via Charmed Meson Production

Author

Alekseev, M., Alexakhin, V. Yu, Alexandrov, Yu, Alexeev, G. D, Amoroso, A., Arbuzov, A., Badelek, Barbara Maria, Balestra, F., Ball, J., Barth, J., Baum, Günter, Bedfer, Y., Bernet, Colin, Bertini, R., Bettinelli, M., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, Franco, Brona, G., Burtin, E., Bussa, M. P, Chapiro, A., Chiosso, M., Cicuttin, A., Colantoni, M., Crespo, M. L, Dalla Torre, S., Dafni, T., Das, S., Dasgupta, S. S, De Masi, R., Dedek, N., Dhara, L., Diaz, V., Dinkelbach, A. M, Donskov, S. V, Dorofeev, V. A, Doshita, N., Duic, V., Dunnweber, W., Eversheim, P. D, Eyrich, W., Faessler, M., Falaleev, V., Ferrero, L., Finger, M., Fischer, H., Franco, C., Franz, J., Friedrich, J. M, Garfagnini, R., Gautheron, Fabrice, Gavrichtchouk, O. P, Gazda, R., Geyer, R., Giorgi, M., Gobbo, Benigno, Gorin, A. M, Grabmuller, S., Grajek, O. A, Grasso, A., Grube, B., Gushterski, R., Guskov, A., Haas, F., Hannappel, J., von Harrach, D., Hasegawa, T., Heckmann, J., Hedicke, S., Heinsius, Fritz-Herbert, Hermann, R., Hess, C., Hinterberger, F., von Hodenberg, M., Horikawa, S., d'Hose, N., Ilgner, C., Ioukaev, A. I, Ishimoto, S., Ivanov, O., Ivanshin, Yu, Jahn, R., Janata, A., Jasinski, P., Joosten, R., Jouravlev, N. I, Kabuss, E., Kang, D., Ketzer, Bernhard, Khaustov, G. V, Khokhlov, Yu. A, Klein, F., Klimaszewski, K., Koblitz, S., Kolosov, V. N, Komissarov, E. V, Kondo, K., Konigsmann, Kay, Konstantinov, V. F, Korentchenko, A. S, Koutchinski, N. A, Kral, A., Kravchuk, N. P, Kroumchtein, Z. V, Kuhn, R., Kunne, Fabienne, Kurek, Krzysztof, Ladygin, M. E, Le Goff, Jean-Marc, Lednev, A. A, Lehmann, A., Levorato, S., Lichtenstadt, J., Liska, T., Ludwig, I., Maggiora, A., Maggiora, M., Magnon, A., Mallot, G. K, Mann, A., Marchand, C., Marroncle, J., Martin, A., Marzec, J., Massmann, F., Matsuda, T., Meyer, W. Thomas, Mikhailov, Yu. V, Moinester, M. A, Nagaytsev, A., Nagel, T., Nahle, O., Nassalski, J., Neliba, S., Nerling, F., Neubert, S., Neyret, D. P, Nikolaenko, V. I, Nikolaev, K., Olshevsky, A. G, Ostrick, M., Padee, A., Pagano, P., Panebianco, S., Panknin, R., Panzieri, D., Paul, S., Pawlukiewicz-Kaminska, B., Peshekhonov, D. V, Peshekhonov, V. D, Piragino, G., Platchkov, Stephane, Pochodzalla, J., Polak, J., Polyakov, V. A, Pretz, J., Procureur, S., Quintans, C., Rajotte, J. F, Ramos, S., Rapatsky, V., Reicherz, G., Reggiani, D., Richter, A., Robinet, F., Rondio, Ewa, Rozhdestvensky, A. M, Ryabchikov, D. I, Samoylenko, V. D, Sandacz, A., Sapozhnikov, M. G, Sarkar, S., Savin, Igor A, Schiavon, P., Schill, Christian, Schonmeier, P., Schroder, W., Shevchenko, O. Yu, Silva, L., Sinha, L., Sissakian, A. N, Slunecka, M., Smirnov, G. I, Sosio, S., Sozzi, F., Srnka, A., Stinzing, F., Sugonyaev, V. P, Sulc, M., Sulej, R., Tchalishev, V. V, Tessaro, S., Tessarotto, F., Teufel, A., Tkatchev, L. G, Venugopal, G., Virius, M., Vlassov, N. V, Vossen, A., Webb, Robert C, Weitzel, Q., Windmolders, R., Wirth, S., Wislicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Ziegler, R., and Zvyagin, A.

Subjects
High Energy Physics - Experiment (hep-ex), High Energy Physics::Phenomenology, Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract

We present the first measurement of the gluon polarisation in the nucleon based on the photon-gluon fusion process tagged by charmed meson production and decay to charged K and pi. The data were collected in polarised muon scattering off a polarised deuteron target by the COMPASS collaboration at CERN during 2002-2004. The result of this LO analysis is _x = -0.47 +- 0.44 (stat) +- 0.15 (syst) at ~= 0.11 and a scale mu^2 ~ 13 (GeV/c)^2., Comment: 7 pages, 3 figures

Published
2008
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34. Double spin asymmetry in exclusive rho0 muoproduction at COMPASS

Author

Alekseev, M., Alexakhin, V. Y. U., Alexandrov, Y. U., Alexeev, G. D., Amoroso, A., Arbuzov, A., Badelek, B., Balestra, F., Ball, J., Barth, J., Baum, G., Bedfer, Y., Bernet, C., Bertini, R., Bettinelli, M., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, Franco, Bravar, A., Bressan, Andrea, Brona, G., Burtin, E., Bussa, M. P., Chapiro, A., Chiosso, M., Cicuttin, A., Colantoni, M., Costa, S., Crespo, M. L., DALLA TORRE, S., Dafni, T., Das, S., Dasgupta, S. S., DE MASSI, R., Dedek, N., Denisov, O. Y. U., Dhara, L., Diaz, V., Dinkelbach, A. M., Donskov, S. V., Dorofeev, V. A., Doshita, N., Duic, V., Dunnweber, W., Eversheim, P. D., Eyrich, W., Fabro, M., Faessler, M., Falaleev, V., Ferrero, A., Ferrero, L., Finger, M., Fischer, H., Franco, C., Franz, J., Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. P., Gazda, R., Gerassimov, S., Geyer, R., Giorgi, Marcello, Gobbo, B., Goertz, S., Gorin, A. M., Grabmuller, S., Grajek, O. A., Grasso, A., Grube, B., Gushterski, R., Guskov, A., Haas, F., Hannappel, J., VON HARRACH, D., Hasegawa, T., Heckmann, J., Hedicke, S., Heinsius, F. H., Hermann, R., Hess, C., Hinterberger, F., VON HODENBERG, M., Horikawa, N., Horikawa, S., D'Hose, N., Ilgner, C., Ioukaev, A. I., Ishimoto, S., Ivanov, O., Ivanshin, Y. U., Iwata, T., Jahn, R., Janata, A., Jasinski, P., Joosten, R., Jouravlev, N. I., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Y. U. A., Kisselev, Y. U., Klein, F., Klimaszewski, K., Koblitz, S., Koivuniemi, J. H., Kolosov, V. N., Komissarov, E. V., Kondo, K., Konigsmann, K., Konorov, I., Konstantinov, V. F., Korentchenko, A. S., Korzenev, A., Kotzinian, A. M., Koutchinski, N. A., Kouznetsov, O., Kral, A., Kravchuk, N. P., Kroumchtein, Z. V., Kuhn, R., Kunne, F., Kurek, K., Ladygin, M. E., Lamanna, M., LE GOFF, J. M., Lednev, A. A., Lehmann, A., Lichtenstadt, J., Liska, T., Ludwig, I., Maggiora, A., Maggiora, M., Magnon, A., Mallot, G. K., Mann, A., Marchand, C., Marroncle, J., Martin, Anna, Marzec, J., Massmann, F., Matsuda, T., Maximov, A. N., Meyer, W., Mielech, A., Mikhailov, Y. U. V., Moinester, M. A., Mutter, A., Nagaytsev, A., Nagel, T., Nahle, O., Nassalski, J., Neliba, S., Nerling, F., Neubert, S., Neyret, D. P., Nikolenko, V. I., Nikolaev, K., Olshevsky, A. G., Ostrick, M., Padee, A., Pagano, P., Panebianco, S., Panknin, R., Panzieri, D., Paul, S., PAWLUKIEWICZ KAMINSKA, B., Peshekhonov, D. V., Peshekhonov, V. D., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Procureur, S., Quintans, C., Rajotte, J. F., Ramos, S., Rapatsky, V., Reicherz, G., Richter, A., Robinet, F., Rocco, E., Rondio, E., Rozhdestvensky, A. M., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Santos, H., Sapozhnikov, M. G., Sarkar, S., Savin, I. A., Schiavon, Paolo, Schill, C., Schmitt, L., Schonmeier, P., Schroder, W., Shevchenko, O. Y. U., Siebert, H. W., Silva, L., Sinha, L., Sissakian, A. N., Slunecka, M., Smirnov, G. I., Sosio, S., Sozzi, F., Srnka, A., Stinzing, F., Stolarski, M., Sugonyaev, V. P., Sulc, M., Sulej, R., Tchalishev, V. V., Tessaro, S., Tessarotto, F., Teufel, A., Tkatchev, L. G., Venugopal, G., Virius, M., Vlassov, N. V., Vossen, A., Webb, R., Weise, E., Weitzel, Q., Windmolders, R., Wirth, S., Wislicki, W., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Zhao, J., Ziegler, R., Zvyagin, A., M., Alekseev, Alexakhin, V. Y. U., Alexandrov, Y. U., G. D., Alexeev, A., Amoroso, A., Arbuzov, B., Badelek, F., Balestra, J., Ball, J., Barth, G., Baum, Y., Bedfer, C., Bernet, R., Bertini, M., Bettinelli, R., Birsa, J., Bisplinghoff, P., Bordalo, Bradamante, Franco, A., Bravar, Bressan, Andrea, G., Brona, E., Burtin, M. P., Bussa, A., Chapiro, M., Chiosso, A., Cicuttin, M., Colantoni, S., Costa, M. L., Crespo, S., DALLA TORRE, T., Dafni, S., Da, S. S., Dasgupta, R., DE MASSI, N., Dedek, Denisov, O. Y. U., L., Dhara, V., Diaz, A. M., Dinkelbach, S. V., Donskov, V. A., Dorofeev, N., Doshita, V., Duic, W., Dunnweber, P. D., Eversheim, W., Eyrich, M., Fabro, M., Faessler, V., Falaleev, A., Ferrero, L., Ferrero, M., Finger, Jr, H., Fischer, C., Franco, J., Franz, J. M., Friedrich, V., Frolov, R., Garfagnini, F., Gautheron, O. P., Gavrichtchouk, R., Gazda, S., Gerassimov, R., Geyer, Giorgi, Marcello, B., Gobbo, S., Goertz, A. M., Gorin, S., Grabmuller, O. A., Grajek, A., Grasso, B., Grube, R., Gushterski, A., Guskov, F., Haa, J., Hannappel, D., VON HARRACH, T., Hasegawa, J., Heckmann, S., Hedicke, F. H., Heinsiu, R., Hermann, C., He, F., Hinterberger, M., VON HODENBERG, N., Horikawa, S., Horikawa, N., D'Hose, C., Ilgner, A. I., Ioukaev, S., Ishimoto, O., Ivanov, Ivanshin, Y. U., T., Iwata, R., Jahn, A., Janata, P., Jasinski, R., Joosten, N. I., Jouravlev, 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, E. V., Komissarov, K., Kondo, K., Konigsmann, I., Konorov, V. F., Konstantinov, A. S., Korentchenko, A., Korzenev, A. M., Kotzinian, N. A., Koutchinski, O., Kouznetsov, A., Kral, N. P., Kravchuk, Z. V., Kroumchtein, R., Kuhn, F., Kunne, K., Kurek, M. E., Ladygin, M., Lamanna, J. M., LE GOFF, A. A., Lednev, A., Lehmann, J., Lichtenstadt, T., Liska, I., Ludwig, A., Maggiora, M., Maggiora, A., Magnon, G. K., Mallot, A., Mann, C., Marchand, J., Marroncle, Martin, Anna, J., Marzec, F., Massmann, T., Matsuda, A. N., Maximov, W., Meyer, A., Mielech, Mikhailov, Y. U. V., M. A., Moinester, A., Mutter, A., Nagaytsev, T., Nagel, O., Nahle, J., Nassalski, S., Neliba, F., Nerling, S., Neubert, D. P., Neyret, V. I., Nikolenko, K., Nikolaev, A. G., Olshevsky, M., Ostrick, A., Padee, P., Pagano, S., Panebianco, R., Panknin, D., Panzieri, S., Paul, B., PAWLUKIEWICZ KAMINSKA, D. V., Peshekhonov, V. D., Peshekhonov, G., Piragino, S., Platchkov, J., Pochodzalla, J., Polak, V. A., Polyakov, J., Pretz, S., Procureur, C., Quintan, J. F., Rajotte, S., Ramo, V., Rapatsky, G., Reicherz, A., Richter, F., Robinet, E., Rocco, E., Rondio, A. M., Rozhdestvensky, D. I., Ryabchikov, V. D., Samoylenko, A., Sandacz, H., Santo, M. G., Sapozhnikov, S., Sarkar, I. A., Savin, Schiavon, Paolo, C., Schill, L., Schmitt, P., Schonmeier, W., Schroder, Shevchenko, O. Y. U., H. W., Siebert, L., Silva, L., Sinha, A. N., Sissakian, M., Slunecka, G. I., Smirnov, S., Sosio, F., Sozzi, A., Srnka, F., Stinzing, M., Stolarski, V. P., Sugonyaev, M., Sulc, R., Sulej, V. V., Tchalishev, S., Tessaro, F., Tessarotto, A., Teufel, L. G., Tkatchev, G., Venugopal, M., Viriu, N. V., Vlassov, A., Vossen, R., Webb, E., Weise, Q., Weitzel, R., Windmolder, S., Wirth, W., Wislicki, K., Zaremba, M., Zavertyaev, E., Zemlyanichkina, J., Zhao, R., Ziegler, and A., Zvyagin

Subjects
Physics, Particle physics, Physics and Astronomy (miscellaneous), Meson, 010308 nuclear & particles physics, media_common.quotation_subject, FOS: Physical sciences, 01 natural sciences, Asymmetry, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Deuterium, Compass, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Engineering (miscellaneous), Particle Physics - Experiment, Spin-½, media_common
Abstract

The longitudinal double spin asymmetry A_1^rho for exclusive leptoproduction of rho^0 mesons, mu + N -> mu + N + rho, is studied using the COMPASS 2002 and 2003 data. The measured reaction is incoherent exclusive rho^0 production on polarised deuterons. The Q^2 and x dependence of A_1^rho is presented in a wide kinematical range: 3x10^-3 < Q^2 < 7 (GeV/c)^2 and 5x10^-5 < x < 0.05. The presented results are the first measurements of A_1^rho at small Q2 (Q2 < 0.1 (GeV/c)^2) and small x (x < 3x10^-3). The asymmetry is in general compatible with zero in the whole kinematical range., 6 Figures, 15 pages, version 2 with updated author list, technical latex problem fixed

Published
2007

35. Spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron at low values of x and Q^2

Author

Alexakhin, V. Yu., Amoroso, A., Badelek, B., Balestra, F., Ball, J., Baum, Günter, Bedfer, Y., Bernet, C., Bertini, R., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, F., Bravar, A., Bressan, A., Brona, G., Burtin, E., Bussa, M. P., Chapiro, A., Cicuttin, A., Colantoni, M., Costa, S., Crespo, M. L., d'Hose, N., Dalla Torre, S., Dasgupta, S. S., De Masi, R., Denisov, O. Yu., Dhara, L., Kavka, V. Diaz, Dinkelbach, A. M., Donskov, S. V., Dorofeev, V. A., Doshita, N., Duic, V., Duennweber, W., Eversheim, P. D., Eyrich, W., Fabro, M., Faessler, M., Falaleev, V., Ferrero, A., Ferrero, L., Finger, M., Finger, M., Jr., Fischer, H., Franz, J., Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, Fabrice, Gavrichtchouk, O. P., Gerassimov, S., Geyer, R., Giorgi, M., Gobbo, B., Goertz, S., Gorin, A. M., Grajek, O. A., Grasso, A., Grube, B., Hannappel, J., von Harrach, D., Hasegawa, T., Heckmann, J., Hedicke, S., Heinsius, F. H., Hermann, R., Hess, C., Hinterberger, F., von Hodenberg, M., Horikawa, N., Horikawa, S., Ilgner, C., Ioukaev, A. I., Ishimoto, S., Ivanov, O., Iwata, T., Jahn, R., Janata, A., Joosten, R., Jouravlev, N. I., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Yu. A., Khomutov, N. V., Kisselev, Yu., Klein, F., Koblitz, S., Koivuniemi, J. H., Kolosov, V. N., Komissarov, E. V., Kondo, K., Koenigsmann, K., Konorov, I., Konstantinov, V. F., Korentchenko, A. S., Korzenev, A., Kotzinian, A. M., Koutchinski, N. A., Kravchuk, N. P., Kroumchtein, Z. V., Kuhn, R., Kunne, F., Kurek, K., Ladygin, M. E., Lamanna, M., Le Goff, J. M., Lichtenstadt, J., Liska, T., Ludwig, I., Maggiora, A., Maggiora, M., Magnon, A., Mallot, G. K., Marchand, C., Marroncle, J., Martin, A., Marzec, J., Matsuda, T., Maximov, A. N., Meyer, W., Mielech, A., Mikhailov, Yu. V., Moinester, M. A., Naehle, O., Nassalski, J., Neliba, S., Neyret, D. P., Nikolaenko, V. I., Nozdrin, A. A., Obraztsov, V. F., Olshevsky, A. G., Ostrick, M., Padee, A., Pagano, P., Panebianco, S., Panzieri, D., Paul, S., Peshekhonov, D. V., Peshekhonov, V. D., Piragino, G., Platchkov, S., Pochodzalla, J., Polyakov, V. A., Popov, A. A., Pretz, J., Procureur, S., Quintans, C., Ramos, S., Reicherz, G., Rozhdestvensky, A. M., Rondio, E., Sadovski, A. B., Samoylenko, V. D., Sandacz, A., Sapozhnikov, M. G., Savin, I. A., Schiavon, P., Schill, C., Schmitt, L., Shevchenko, O. Yu., Shishkin, A. A., Siebert, H. -W., Sinha, L., Sissakian, A. N., Slunecka, M., Smirnov, G. I., Sozzi, F., Sugonyaev, V. P., Srnka, A., Stinzing, F., Stolarski, M., Sulc, M., Sulej, R., Takabayashi, N., Tchalishev, V. V., Tessarotto, F., Teufel, A., Tkatchev, L. G., Virius, M., Vlassov, N. V., Webb, R., Weise, E., Weitzel, Q., Windmolders, R., Wirth, S., Wislicki, W., Zaremba, K., Zhao, J., Ziegler, R., and Zvyagin, A.

Subjects
High Energy Physics - Experiment (hep-ex), g(1), structure function, low x, A(1), FOS: Physical sciences, inelastic muon scattering, spin, low Q(2), High Energy Physics - Experiment
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^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., 17 pages, 10 figures

Published
2007
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36. MEG Upgrade Proposal

Author

Baldini, A. M., Cei, F., Cerri, C., Dussoni, S., Galli, L., Grassi, M., Nicolo, D., Raffaelli, F., Sergiampietri, F., Signorelli, G., Tenchini, F., Bagliani, D., Gerone, M., Gatti, F., Baracchini, E., Fujii, Y., Iwamoto, T., Kaneko, D., Mori, T., Nishimura, M., Ootani, W., Sawada, R., Uchiyama, Y., Boca, G., Paolo Walter Cattaneo, Bari, A., Nardo, R., Rossella, M., Cascella, M., Grancagnolo, F., L Erario, A., Maffezzoli, A., Miccoli, A., Onorato, G., Palama, G., Panareo, M., Pepino, A., Rella, S., Tassielli, G. F., Zavarise, G., Cavoto, G., Graziosi, A., Piredda, G., Ripiccini, E., Voena, C., Grigoriev, D. N., Ignatov, F., Khazin, B. I., Popov, A., Yudin, Yu V., Haruyama, T., Mihara, S., Nishiguchi, H., Yamamoto, A., Hildebrandt, M., Kettle, P. -R, Papa, A., Renga, F., Ritt, S., Stoykov, A., Kang, T. I., Lim, G., Molzon, W., You, Z., Khomutov, N., Korenchenko, A., Kravchuk, N., and Kuchinksy, N.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, High Energy Physics - Phenomenology (hep-ph), Physics::Instrumentation and Detectors, FOS: Physical sciences, High Energy Physics::Experiment, Instrumentation and Detectors (physics.ins-det), High Energy Physics - Experiment
Abstract

We propose the continuation of the MEG experiment to search for the charged lepton flavour violating decay (cLFV) \mu \to e \gamma, based on an upgrade of the experiment, which aims for a sensitivity enhancement of one order of magnitude compared to the final MEG result, down to the $6 \times 10^{-14}$ level. The key features of this new MEG upgrade are an increased rate capability of all detectors to enable running at the intensity frontier and improved energy, angular and timing resolutions, for both the positron and photon arms of the detector. On the positron-side a new low-mass, single volume, high granularity tracker is envisaged, in combination with a new highly segmented, fast timing counter array, to track positron from a thinner stopping target. The photon-arm, with the largest liquid xenon (LXe) detector in the world, totalling 900 l, will also be improved by increasing the granularity at the incident face, by replacing the current photomultiplier tubes (PMTs) with a larger number of smaller photosensors and optimizing the photosensor layout also on the lateral faces. A new DAQ scheme involving the implementation of a new combined readout board capable of integrating the diverse functions of digitization, trigger capability and splitter functionality into one condensed unit, is also under development. We describe here the status of the MEG experiment, the scientific merits of the upgrade and the experimental methods we plan to use., Comment: A. M. Baldini and T. Mori Spokespersons. Research proposal submitted to the Paul Scherrer Institute Research Committee for Particle Physics at the Ring Cyclotron. 131 Pages

37. Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment

Author

A. Stoykov, Valerio Pettinacci, Andrey Popov, S. Ogawa, Toshinori Mori, Stefan Ritt, K. Ieki, G. F. Tassielli, N. P. Kravchuk, Satoru Kobayashi, M. Panareo, M. De Gerone, P. Schwendimann, Malte Hildebrandt, Flavio Gatti, A. Papa, G. Pizzigoni, M. Francesconi, William Kyle, T. Libeiro, M. Usami, W. R. Molzon, Michele Biasotti, Yusuke Uchiyama, M. Chiappini, Satoshi Mihara, D. Nicolò, R. Onda, Dylan Palo, P.-R. Kettle, G. M. A. Lim, N. V. Khomutov, L. Galli, M. Nakao, Vladimir Malyshev, M. Nishimura, F. Ignatov, A. Kolesnikov, C. Chiri, Gianluigi Boca, F. Renga, Atsushi Oya, Ryu Sawada, G. Signorelli, A. de Bari, F. Grancagnolo, G. Cavoto, P. W. Cattaneo, H. Natori, Z. Hodge, R. Iwai, Yu.V. Yudin, Fabrizio Cei, F. Berg, Kazuki Toyoda, T. Iwamoto, M. Rossella, K. Yanai, Marco Grassi, Wataru Ootani, C. Voena, A. Corvaglia, A. M. Baldini, Nikolay Kuchinskiy, Aleksander Rozhdestvensky, Hajime Nishiguchi, Manuel Meucci, G. Chiarello, D. N. Grigoriev, A. Mtchedilishvili, Nobuo Matsuzawa, Baldini, A. M., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Corvaglia, A., de Bari, A., De Gerone, M., Francesconi, M., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kobayashi, S., Kettle, P. -R., Kyle, W., Khomutov, N., Kolesnikov, A., Kravchuk, N., Kuchinskiy, N., Libeiro, T., Lim, G. M. A., Malyshev, V., Matsuzawa, N., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedilishvili, A., Nakao, M., Natori, H., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Pizzigoni, G., Popov, A., Renga, F., Ritt, S., Rozhdestvensky, A., Rossella, M., Sawada, R., Schwendimann, P., Signorelli, G., Stoykov, A., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Voena, C., Yanai, K., and Yudin, Yu. V.

Subjects
Particle physics, Physics and Astronomy (miscellaneous), Flavour, Light particle, FOS: Physical sciences, lcsh:Astrophysics, MEG experiment, lepton flavour violation, muon decay, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, lcsh:QB460-466, Direct search, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, Lepton Flavour Violation, MEG experiment, 010306 general physics, Engineering (miscellaneous), Physics, Muon, 010308 nuclear & particles physics, Branching fraction, lcsh:QC770-798, High Energy Physics::Experiment, Lepton Flavour Violation, Lepton
Abstract

We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, $$\upmu ^+ \rightarrow \mathrm {e}^+\mathrm {X}, \mathrm {X} \rightarrow \upgamma \upgamma \ $$ μ + → e + X , X → γ γ . This search uses a dataset resulting from $$7.5\times 10^{14}$$ 7.5 × 10 14 stopped muons collected by the MEG experiment at the Paul Scherrer Institut in the period 2009–2013. No significant excess is found in the mass region 20–45 MeV/c$$^2$$ 2 for lifetimes below 40 ps, and we set the most stringent branching ratio upper limits in the mass region of 20–40 MeV/c$$^2$$ 2 , down to $${\mathcal {O}}(10^{-11})$$ O ( 10 - 11 ) at 90% confidence level.

Published
2020
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38. The COMPASS experiment at CERN

Author

P. Abbon, E. Albrecht, V.Yu. Alexakhin, Yu. Alexandrov, G.D. Alexeev, M.G. Alekseev, A. Amoroso, H. Angerer, V.A. Anosov, B. Badełek, F. Balestra, J. Ball, J. Barth, G. Baum, M. Becker, Y. Bedfer, P. Berglund, C. Bernet, R. Bertini, M. Bettinelli, R. Birsa, J. Bisplinghoff, P. Bordalo, M. Bosteels, F. Bradamante, A. Braem, A. Bravar, A. Bressan, G. Brona, E. Burtin, M.P. Bussa, V.N. Bytchkov, M. Chalifour, A. Chapiro, M. Chiosso, P. Ciliberti, A. Cicuttin, M. Colantoni, A.A. Colavita, S. Costa, M.L. Crespo, P. Cristaudo, T. Dafni, N. d’Hose, S. Dalla Torre, C. d’Ambrosio, S. Das, S.S. Dasgupta, E. Delagnes, R. De Masi, P. Deck, N. Dedek, D. Demchenko, O.Yu. Denisov, L. Dhara, V. Diaz, N. Dibiase, A.M. Dinkelbach, A.V. Dolgopolov, A. Donati, S.V. Donskov, V.A. Dorofeev, N. Doshita, D. Durand, V. Duic, W. Dünnweber, A. Efremov, P.D. Eversheim, W. Eyrich, M. Faessler, V. Falaleev, P. Fauland, A. Ferrero, L. Ferrero, M. Finger, H. Fischer, C. Franco, J. Franz, F. Fratnik, J.M. Friedrich, V. Frolov, U. Fuchs, R. Garfagnini, L. Gatignon, F. Gautheron, O.P. Gavrichtchouk, S. Gerassimov, R. Geyer, J.M. Gheller, A. Giganon, M. Giorgi, B. Gobbo, S. Goertz, A.M. Gorin, F. Gougnaud, S. Grabmüller, O.A. Grajek, A. Grasso, B. Grube, A. Grünemaier, A. Guskov, F. Haas, R. Hagemann, J. Hannappel, D. von Harrach, T. Hasegawa, J. Heckmann, S. Hedicke, F.H. Heinsius, R. Hermann, C. Heß, F. Hinterberger, M. von Hodenberg, N. Horikawa, S. Horikawa, I. Horn, C. Ilgner, A.I. Ioukaev, S. Ishimoto, I. Ivanchin, O. Ivanov, T. Iwata, R. Jahn, A. Janata, R. Joosten, N.I. Jouravlev, E. Kabuß, V. Kalinnikov, D. Kang, F. Karstens, W. Kastaun, B. Ketzer, G.V. Khaustov, Yu.A. Khokhlov, J. Kiefer, Yu. Kisselev, F. Klein, K. Klimaszewski, S. Koblitz, J.H. Koivuniemi, V.N. Kolosov, E.V. Komissarov, K. Kondo, K. Königsmann, A.K. Konoplyannikov, I. Konorov, V.F. Konstantinov, A.S. Korentchenko, A. Korzenev, A.M. Kotzinian, N.A. Koutchinski, O. Kouznetsov, K. Kowalik, D. Kramer, N.P. Kravchuk, G.V. Krivokhizhin, Z.V. Kroumchtein, J. Kubart, R. Kuhn, V. Kukhtin, F. Kunne, K. Kurek, N.A. Kuzmin, M. Lamanna, J.M. Le Goff, M. Leberig, A.A. Lednev, A. Lehmann, V. Levinski, S. Levorato, V. I Lyashenko, J. Lichtenstadt, T. Liska, I. Ludwig, A. Maggiora, M. Maggiora, A. Magnon, G.K. Mallot, A. Mann, I.V. Manuilov, C. Marchand, J. Marroncle, A. Martin, J. Marzec, L. Masek, F. Massmann, T. Matsuda, D. Matthiä, A.N. Maximov, G. Menon, W. Meyer, A. Mielech, Yu.V. Mikhailov, M.A. Moinester, F. Molinié, F. Mota, A. Mutter, T. Nagel, O. Nähle, J. Nassalski, S. Neliba, F. Nerling, D. Neyret, M. Niebuhr, T. Niinikoski, V.I. Nikolaenko, A.A. Nozdrin, A.G. Olshevsky, M. Ostrick, A. Padee, P. Pagano, S. Panebianco, B. Parsamyan, D. Panzieri, S. Paul, B. Pawlukiewicz, H. Pereira, D.V. Peshekhonov, V.D. Peshekhonov, D. Piedigrossi, G. Piragino, S. Platchkov, K. Platzer, J. Pochodzalla, J. Polak, V.A. Polyakov, G. Pontecorvo, A.A. Popov, J. Pretz, S. Procureur, C. Quintans, J.-F. Rajotte, S. Ramos, I. Razaq, P. Rebourgeard, D. Reggiani, G. Reicherz, A. Richter, F. Robinet, E. Rocco, E. Rondio, L. Ropelewski, J.Y. Roussé, A.M. Rozhdestvensky, D. Ryabchikov, A.G. Samartsev, V.D. Samoylenko, A. Sandacz, M. Sans Merce, H. Santos, M.G. Sapozhnikov, F. Sauli, I.A. Savin, P. Schiavon, C. Schill, T. Schmidt, H. Schmitt, L. Schmitt, P. Schönmeier, W. Schroeder, D. Seeharsch, M. Seimetz, D. Setter, A. Shaligin, O.Yu. Shevchenko, A.A. Shishkin, H.-W. Siebert, L. Silva, F. Simon, L. Sinha, A.N. Sissakian, M. Slunecka, G.I. Smirnov, D. Sora, S. Sosio, F. Sozzi, A. Srnka, F. Stinzing, M. Stolarski, V.P. Sugonyaev, M. Sulc, R. Sulej, G. Tarte, N. Takabayashi, V.V. Tchalishev, S. Tessaro, F. Tessarotto, A. Teufel, D. Thers, L.G. Tkatchev, T. Toeda, V.V. Tokmenin, S. Trippel, J. Urban, R. Valbuena, G. Venugopal, M. Virius, N.V. Vlassov, A. Vossen, M. Wagner, R. Webb, E. Weise, Q. Weitzel, U. Wiedner, M. Wiesmann, R. Windmolders, S. Wirth, W. Wiślicki, H. Wollny, A.M. Zanetti, K. Zaremba, M. Zavertyaev, J. Zhao, R. Ziegler, M. Ziembicki, Y.L. Zlobin, A. Zvyagin, Abbon, P, Albrecht, E, ALEXAKHIN V., Yu, Alexandrov, Yu, ALEXEEV G., D, ALEKSEEV M., G, Amoroso, A, Angerer, H, ANOSOV V., A, Badelek, B, Balestra, F, Ball, J, Barth, J, Baum, G, Becker, M, Bedfer, Y, Berglund, P, Bernet, C, Bertini, R, Bettinelli, M, Birsa, R, Bisplinghoff, J, Bordalo, P, Bosteels, M, Bradamante, Franco, Braem, A, Bravar, A, Bressan, Andrea, Brona, G, Burtin, E, BUSSA M., P, BYTCHKOV V., N, Chalifour, M, Chapiro, A, Chiosso, M, Ciliberti, Piero, Cicuttin, A, Colantoni, M, COLAVITA A., A, Costa, S, CRESPO M., L, Cristaudo, P, Dafni, T, D'Hose, N, DALLA TORRE, S, D'Ambrosio, C, Das, S, DASGUPTA S., S, Delagnes, E, DE MASI, R, Deck, P, Dedek, N, Demchenko, D, DENISOV O., Yu, Dhara, L, Diaz, V, Dibiase, N, DINKELBACH A., M, DOLGOPOLOV A., V, Donati, A, DONSKOV S., V, DOROFEEV V., A, Doshita, N, Durand, D, Duic, V, Dünnweber, W, Efremov, A, EVERSHEIM P., D, Eyrich, W, Faessler, M, Falaleev, V, Fauland, P, Ferrero, A, Ferrero, L, Finger, M, FINGER M., Jr, Fischer, H, Franco, C, Franz, J, Fratnik, F, FRIEDRICH J., M, Frolov, V, Fuchs, U, Garfagnini, R, Gatignon, L, Gautheron, F, GAVRICHTCHOUK O., P, Gerassimov, S, Geyer, R, GHELLER J., M, Giganon, A, Giorgi, Marcello, Gobbo, B, Goertz, S, GORIN A., M, Gougnaud, F, Grabmüller, S, GRAJEK O., A, Grasso, A, Grube, B, Grünemaier, A, Guskov, A, Haas, F, Hagemann, R, Hannappel, J, VON HARRACH, D, Hasegawa, T, Heckmann, J, Hedicke, S, HEINSIUS F., H, Hermann, R, Hess, C, Hinterberger, F, VON HODENBERG, M, Horikawa, N, Horikawa, S, Horn, I, Ilgner, C, IOUKAEV A., I, Ishimoto, S, Ivanchin, I, Ivanov, O, Iwata, T, Jahn, R, Janata, A, Joosten, R, JOURAVLEV N., I, Kabuss, E, Kalinnikov, V, Kang, D, Karstens, F, Kastaun, W, Ketzer, B, KHAUSTOV G., V, KHOKHLOV Y. U., A, Kiefer, J, Kisselev, Yu, Klein, F, Klimaszewski, K, Koblitz, S, KOIVUNIEMI J., H, KOLOSOV V., N, KOMISSAROV E., V, Kondo, K, Königsmann, K, KONOPLYANNIKOV A., K, Konorov, I, KONSTANTINOV V., F, KORENTCHENKO A., S, Korzenev, A, KOTZINIAN A., M, KOUTCHINSKI N., A, Kouznetsov, O, Kowalik, K, Kramer, D, KRAVCHUK N., P, KRIVOKHIZHIN G., V, KROUMCHTEIN Z., V, Kubart, J, Kuhn, R, Kukhtin, V, Kunne, F, Kurek, K, KUZMIN N., A, Lamanna, M, LE GOFF J., M, Leberig, M, LEDNEV A., A, Lehmann, A, Levinski, V, Levorato, Stefano, I., LYASHENKO V, Lichtenstadt, J, Liska, T, Ludwig, I, Maggiora, A, Maggiora, M, Magnon, A, MALLOT G., K, Mann, A, MANUILOV I., V, Marchand, C, Marroncle, J, Martin, Anna, Marzec, J, Masek, L, Massmann, F, Matsuda, T, Matthiä, D, MAXIMOV A., N, Menon, G, Meyer, W, Mielech, A, MIKHAILOV Y. U., V, MOINESTER M., A, Molinié, F, Mota, F, Mutter, A, Nagel, T, Nähle, O, Nassalski, J, Neliba, S, Nerling, F, Neyret, D, Niebuhr, M, Niinikoski, T, NIKOLAENKO V., I, NOZDRIN A., A, OLSHEVSKY A., G, Ostrick, M, Padee, A, Pagano, P, Panebianco, S, Parsamyan, B, Panzieri, D, Paul, S, Pawlukiewicz, B, Pereira, H, PESHEKHONOV D., V, PESHEKHONOV V., D, Piedigrossi, D, Piragino, G, Platchkov, S, Platzer, K, Pochodzalla, J, Polak, J, POLYAKOV V., A, Pontecorvo, G, POPOV A., A, Pretz, J, Procureur, S, Quintans, C, RAJOTTE J., F, Ramos, S, Razaq, I, Rebourgeard, P, Reggiani, D, Reicherz, G, Richter, A, Robinet, F, Rocco, E, Rondio, E, Ropelewski, L, ROUSSÉ J., Y, ROZHDESTVENSKY A., M, Ryabchikov, D, SAMARTSEV A., G, SAMOYLENKO V., D, Sandacz, A, SANS MERCE, M, Santos, H, SAPOZHNIKOV M., G, Sauli, F, SAVIN I., A, Schiavon, Paolo, Schill, C, Schmidt, T, Schmitt, H, Schmitt, L, Schönmeier, P, Schroeder, W, Seeharsch, D, Seimetz, M, Setter, D, Shaligin, A, SHEVCHENKO O., Yu, SHISHKIN A., A, SIEBERT H., W, Silva, L, Simon, F, Sinha, L, SISSAKIAN A., N, Slunecka, M, SMIRNOV G., I, Sora, D, Sosio, S, Sozzi, F, Srnka, A, Stinzing, F, Stolarski, M, SUGONYAEV V., P, Sulc, M, Sulej, R, Tarte, G, Takabayashi, N, TCHALISHEV V., V, Tessaro, S, Tessarotto, F, Teufel, A, Thers, D, TKATCHEV L., G, Toeda, T, TOKMENIN V., V, Trippel, S, Urban, J, Valbuena, R, Venugopal, G, Virius, M, VLASSOV N., V, Vossen, A, Wagner, M, Webb, R, Weise, E, Weitzel, Q, Wiedner, U, Wiesmann, M, Windmolders, R, Wirth, S, Wisblicki, W, Wollny, H, ZANETTI A., M, Zaremba, K, Zavertyaev, M, Zhao, J, Ziegler, R, Ziembicki, M, ZLOBIN Y., L, and Zvyagin, A.

Subjects
Nuclear and High Energy Physics, straw tube detector, Physics::Instrumentation and Detectors, Project commissioning, FOS: Physical sciences, fixed-target experiment, RICH detector, hadron structure, High Energy Physics - Experiment, target, MWPC, Nuclear physics, High Energy Physics - Experiment (hep-ex), Compass, Hadron spectroscopy, COMPASS experiment, scintillating fibre detector, Nuclear Experiment, silicon microstrip detectors, Instrumentation, Silicon microstrip detectors, Physics, Large Hadron Collider, Structure function, MicroMegas detector, front-end electronics, DAQ, micromegas detector, drift chamber, Physics::Accelerator Physics, High Energy Physics::Experiment, polarised, GEM detector, calorimetry, Particle Physics - Experiment, polarised DIS
Abstract

The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the incoming muon or hadron. A large polarized target inside a superconducting solenoid is used for the measurements with the muon beam. Outgoing particles are detected by a two-stage, large angle and large momentum range spectrometer. The setup is built using several types of tracking detectors, according to the expected incident rate, required space resolution and the solid angle to be covered. Particle identification is achieved using a RICH counter and both hadron and electromagnetic calorimeters. The setup has been successfully operated from 2002 onwards using a muon beam. Data with a hadron beam were also collected in 2004. This article describes the main features and performances of the spectrometer in 2004; a short summary of the 2006 upgrade is also given., 84 papes, 74 figures

Published
2007
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39. Collins and Sivers asymmetries for pions and kaons in muon-deuteron DIS

Author

N. Dedek, Vladimir Peshekhonov, O.P. Gavrichtchouk, R. Birsa, J. Lichtenstadt, R. C. Webb, K. Zaremba, Colin Bernet, A. Srnka, L. Sinha, R. Ziegler, R. Bertini, V.A. Polyakov, D. Kang, K. Königsmann, Andrej Arbuzov, G. Sbrizzai, M. Slunecka, V. Diaz, K. Klimaszewski, Norihiro Doshita, N.P. Kravchuk, W. Wiślicki, A. Amoroso, A.I. Ioukaev, B. Gobbo, S. Gerassimov, N. d'Hose, Massimo Lamanna, Yu. Kisselev, G. Piragino, L. Dhara, C. Ilgner, N. Horikawa, A.M. Dinkelbach, M. Chiosso, W. Schröder, V.P. Sugonyaev, Yu.V. Mikhailov, A. N. Sissakian, Andres Cicuttin, B. Badelek, I. Konorov, Sergey Donskov, T. Iwata, A. Teufel, Yu. Alexandrov, T. Dafni, M. Ostrick, M. Giorgi, A. Maggiora, F. Tessarotto, C. Quintans, G. Reicherz, Jean-Francois Rajotte, B. Ketzer, F. Robinet, S. Paul, S. Tessaro, N.V. Vlassov, K. Kurek, A. Padee, M. von Hodenberg, W. Eyrich, D.I. Ryabchikov, S. Dalla Torre, Günter Baum, O.Yu. Shevchenko, S. Levorato, M. Alekseev, O.Yu. Denisov, F. Kunne, F.H. Heinsius, A.G. Olshevsky, Achim Richter, Z.V. Kroumchtein, A.M. Rozhdestvensky, R. Panknin, E.V. Komissarov, F. Massmann, T. Nagel, J. Pretz, D. Panzieri, S. Ramos, L. Ferrero, A. Magnon, A. Bravar, M.E. Ladygin, S. Sosio, A. Guskov, S. Grabmüller, A. Korzenev, Anne-Laure Martin, N.A. Koutchinski, M.G. Sapozhnikov, T. Matsuda, S. Procureur, G. Venugopal, T. Liška, V.I. Nikolaenko, Yu.A. Khokhlov, H. W. Siebert, C. Heß, D.V. Peshekhonov, M. Bettinelli, L. Schmitt, R. Hermann, E. Rondio, J. Heckmann, Miroslav Sulc, F. Hinterberger, A.V. Efremov, M. Stolarski, Andrea Bressan, C. Franco, A. Janata, A. Grasso, E. M. Kabuß, J. Polak, V.N. Kolosov, A. Sandacz, R. Joosten, R. Garfagnini, J. Nassalski, V.V. Tchalishev, S. Costa, M. Finger, Aram Kotzinian, A. Král, M.P. Bussa, O.M. Kouznetsov, G. Pesaro, P. Schönmeier, Franco Bradamante, R. Windmolders, J.M. Friedrich, J.H. Koivuniemi, E. Burtin, J. Marroncle, K. Kondo, V.F. Konstantinov, Q. Weitzel, J. Pochodzalla, Christian Schill, J. Bisplinghoff, I.A. Savin, Oleg V. Ivanov, H. Wollny, S. Panebianco, D. Reggiani, A. Lehmann, R. De Masi, P. Bordalo, Laura Silva, Y. Bedfer, B. Pawlukiewicz-Kaminska, M. L. Colantoni, P.D. Eversheim, J. M. Le Goff, V. Rapatsky, V.A. Dorofeev, E. Zemlyanichkina, Paolo Pagano, H. Fischer, S. Wirth, J. Ball, V. Duic, P. Schiavon, J. Hannappel, R. Gazda, M. V. Zavertyaev, A. Nagaytsev, K. Nikolaev, F. Balestra, P. Jasinski, J. Zhao, T. Hasegawa, V. Falaleev, V. Frolov, S.S. Dasgupta, A. Mann, A. Chapiro, S. Koblitz, D. Neyret, C. Marchand, Murray Moinester, A. Mutter, L. G. Tkatchev, F. Stinzing, R. Gushterski, J. Barth, A.S. Korentchenko, J. Marzec, St. Goertz, J. Franz, M. Virius, R. Kuhn, S. Neubert, Grzegorz Brona, Gerhard K. Mallot, E. Weise, O. Nähle, A. Vossen, F. Sozzi, S. Neliba, F. Haas, R. Geyer, G. D. Alexeev, W. Dünnweber, G.I. Smirnov, Fabrice Gautheron, M. A. Faessler, V.Yu. Alexakhin, R. Sulej, A. Mielech, S. Ishimoto, Frank Klein, S. Platchkov, M. Maggiora, Yu. Ivanshin, A. Gorin, O.A. Grajek, Sarit K. Das, B. Grube, S. Sarkar, D. von Harrach, A. Maximov, V.D. Samoylenko, Elena Rocco, G.V. Khaustov, N.I. Jouravlev, S. Horikawa, W. Meyer, Maria Liz Crespo, A. Zvyagin, H. Santos, R. Jahn, A. Ferrero, A.A. Lednev, I. Ludwig, F. Nerling, S. Hedicke, Alelseev, M., Alexakhin, V. Y., Alexandrov, Y., Alexeev, G. D., Amoroso, A., Arbuzov, A., Badelek, B., Balestra, F., Ball, J., Barth, J., Baum, G., Bedfer, Y., Bernet, C., Bertini, R., Bettinelli, M., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, Franco, Bravar, A., Bressan, Andrea, Brona, G., Burtin, E., Bussa, M. P., Chapiro, A., Chiosso, M., Cicuttin, A., Colantoni, M., Costa, S., Crespo, M. L., Torre, S. D., Dafni, T., Das, S., Dasgupta, S. S., De Masi, R., Dedek, N., Denisov, O. Y., Dhara, L., Diaz, V., Dinkelbach, A. M., Donskov, S. V., Dorofeev, V. A., Doshita, N., Duic, Venicio, Dunnweber, W., Efremov, A. V., Eversheim, P. D., Eyrich, W., Faessler, M., Falaleev, V., Ferrero, A., Ferrero, L., Finger, M., Fischer, H., Franco, C., Franz, J., Friedrich, J. M., Frolov, V., Garfagnini, R., Gautheron, F., Gavrichtchouk, O. R., Gazda, R., Gerassimov, S., Geyer, R., Giorgi, Marcello, Gobbo, B., Goertz, S., Gorin, A. M., Grabmuller, S., Grajek, O. A., Grasso, A., Grube, B., Gushterski, R., Guskov, A., Haas, F., Hannappel, J., von Harrach, D., Hasegawa, T., Heckmann, J., Hedicke, S., Heinsius, F. H., Hermann, R., Hess, C., Hinterberger, F., von Hodenberg, M., Horikawa, N., Horikawa, S., D'Hose, N., Ilgner, C., Loukaev, A. I., Ishimoto, S., Ivanov, O., Ivanshin, Y., Iwata, T., Jahn, R., Janata, A., Jasinski, P., Jouravlev, N. I., Kabuss, E., Kang, D., Ketzer, B., Khaustov, G. V., Khokhlov, Y. A., Kisselev, Y., Klein, F., Klimaszewski, K., Koblitz, S., Koivuniemi, J. H., Kolosov, V. N., Komissarov, E. V., Kondo, K., Konigsmann, K., Konorov, I., Konstantinov, V. F., Korentchenko, A. S., Korzenev, A., Kotzinian, A. M., Koutchinski, N. A., Kouznetsov, O., Kral, A., Kravchuk, N. P., Kroumchtein, Z. V., Kuhn, R., Kunne, F., Kurek, K., Ladygin, M. E., Lamanna, M., Le Goff, J. M., Lednev, A. A., Lehmann, A., Levorato, Stefano, Lichtenstadt, J., Liska, T., Ludwig, I., Maggiora, A., Maggiora, M., Magnon, A., Mallot, G. K., Mann, A., Marchand, C., Marroncle, J., Martin, Anna, Marzec, J., Massmann, F., Matsuda, T., Maximov, A. N., Meyer, W., Mielech, A., Mikhailov, Y. V., Moinester, M. A., Mutter, A., Nagaytsev, A., Nagel, T., Nahle, O., Nassalski, J., Neliba, S., Nerling, F., Neubert, S., Neyret, D. P., Nikolaenko, V. I., Nikolaev, K., Olshevsky, A. G., Ostrick, M., Padee, A., Pagano, P., Panebianco, S., Panknin, R., Panzieri, D., Paul, S., Pawlukiewicz Kaminska, B., Pesaro, Giulia, Peshekhonov, D. V., Peshekhonov, V. D., Piragino, G., Platchkov, S., Pochodzalla, J., Polak, J., Polyakov, V. A., Pretz, J., Procureur, S., Quintans, C., Rajotte, J. F., Ramos, S., Rapatsky, V., Reicherz, G., Reggiani, D., Richter, A., Robinet, F., Rocco, E., Rondio, E., Rozhdestvensky, A. M., Ryabchikov, D. I., Samoylenko, V. D., Sandacz, A., Santos, H., Sapozhnikov, M. G., Sarkar, S., Savin, I. A., Sbrizzai, Giulio, Schiavon, Paolo, Schill, C., Schmitt, L., Schonmeier, P., Schroder, W., Shevchenko, O. Y., Siebert, H. W., Silva, L., Sinha, L., Sissakian, A. N., Slunecka, M., Smirnov, G. I., Sosio, S., Sozzi, Federica, Srnka, A., Stinzing, F., Stolarski, M., Sugonyaev, V. P., Sulc, M., Sulej, R., Tchalishev, V. V., Tessaro, S., Tessarotto, F., Teufel, A., Tkatchev, L. G., Venugopal, G., Virius, M., Vlassov, N. V., Vossen, A., Webb, R., Weise, E., Weitzel, Q., Windmolders, R., Wirth, S., Wislicki, W., Wollny, H., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Zhao, J., Ziegler, R., and Zvyagin, A.

Subjects
Quark, Nuclear and High Energy Physics, Particle physics, Sivers asymmetry, Hadron, Nuclear Theory, FOS: Physical sciences, 01 natural sciences, COMPASS, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Pion, Identified, Compass, 0103 physical sciences, Transverse spin effects, Deuteron, Collins asymmetry, Transverse spin effect, 010306 general physics, Nuclear Experiment, Physics, Muon, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Transverse single-spin asymmetry, hadrons, Deuterium, Transversity, High Energy Physics::Experiment
Abstract

The measurements of the Collins and Sivers asymmetries of identified hadrons produced in deep-inelastic scattering of 160 GeV/c muons on a transversely polarised 6LiD target at COMPASS are presented. The results for charged pions and charged and neutral kaons correspond to all data available, which were collected from 2002 to 2004. For all final state particles both the Collins and Sivers asymmetries turn out to be small, compatible with zero within the statistical errors, in line with the previously published results for not identified charged hadrons, and with the expected cancellation between the u- and d-quark contributions., Comment: 16 pages, 9 figures, added author Efremov, calculated pure kaon asymmetries instead of those for experimental kaon/pion mixture (mainly error affected)

Published
2009

40. The Polarised Valence Quark Distribution from semi-inclusive DIS

Author

A. Padee, Yu. Alexandrov, Norihiro Doshita, P. Schiavon, N. d'Hose, Laura Silva, Sayantan Sarkar, A. N. Sissakian, A. Bravar, A. Chapiro, S. Sosio, V. Diaz, K. Klimaszewski, M. Maggiora, G. D. Alexeev, W. Dünnweber, A. Zvyagin, Soumen Paul, H. Santos, F. Tessarotto, M. Chiosso, Andres Cicuttin, R. Kuhn, S. Dasgupta, J. Polak, D. Kang, K. Königsmann, C. Franco, V.N. Kolosov, C. Ilgner, J. Nassalski, O. Nähle, J. Zhao, G. Reicherz, S. Dalla Torre, M.G. Sapozhnikov, V.A. Dorofeev, Christian Schill, T. Nagel, J. Pretz, L. Ferrero, Jean-Francois Rajotte, R. Gazda, Massimo Lamanna, Yu. Kisselev, C. Quintans, D.I. Ryabchikov, Colin Bernet, A. Srnka, T. Hasegawa, O.P. Gavrichtchouk, D.V. Peshekhonov, M. Stolarski, G.V. Khaustov, A. Maggiora, J. Franz, S. Das, A.S. Korentchenko, D. Panzieri, G.I. Smirnov, Fabrice Gautheron, L. Sinha, M. Ostrick, M. A. Faessler, Andrej Arbuzov, S. Procureur, T. Liška, O.A. Grajek, R. Jahn, A. Ferrero, Achim Richter, F. Massmann, S. Ramos, N.I. Jouravlev, S. Horikawa, V.Yu. Alexakhin, W. Meyer, Maria Liz Crespo, D. Neyret, A. Sandacz, L. Dhara, B. Badelek, T. Dafni, A. Mutter, K. Kurek, A. Guskov, M. Bettinelli, N.V. Vlassov, V.P. Sugonyaev, T. Matsuda, G. Venugopal, S. Koblitz, R. Sulej, O.Yu. Denisov, F. Kunne, A.A. Lednev, K. Zaremba, Günter Baum, O.Yu. Shevchenko, S. Levorato, Andrea Bressan, Franco Bradamante, I. Ludwig, G. Piragino, V.A. Polyakov, J. Marzec, B. Ketzer, S. Grabmüller, F. Robinet, L. G. Tkatchev, A.M. Rozhdestvensky, Z.V. Kroumchtein, E.V. Komissarov, F. Nerling, A. Maximov, J. Heckmann, M. Giorgi, R. Panknin, A. Lehmann, St. Goertz, V.I. Nikolaenko, A. Amoroso, V.D. Samoylenko, Elena Rocco, J. Ball, S. Hedicke, J.M. Friedrich, L. Schmitt, E. M. Kabuß, A. Mann, R. Garfagnini, J. Pochodzalla, A.I. Ioukaev, M. Finger, J. Bisplinghoff, F. Stinzing, R. Gushterski, Yu.V. Mikhailov, R. De Masi, P. Bordalo, Alan D. Martin, I.A. Savin, A. Janata, A. Grasso, M. L. Colantoni, Oleg V. Ivanov, H. Wollny, M. V. Zavertyaev, E. Zemlyanichkina, Paolo Pagano, Takahiro Iwata, E. Rondio, D. von Harrach, P. Schönmeier, M. Slunecka, V. Falaleev, C. Heß, E. Burtin, C. Marchand, V.F. Konstantinov, J. Marroncle, O.M. Kouznetsov, N. Dedek, W. Wiślicki, Murray Moinester, Q. Weitzel, J. M. Le Goff, S. Neubert, S. Wirth, J. Hannappel, V. Duic, B. Gobbo, Miroslav Sulc, F. Hinterberger, M. Virius, Vladimir Peshekhonov, R. Birsa, E. Weise, W. Schröder, J. Lichtenstadt, H. Fischer, B. Grube, P.D. Eversheim, V. Frolov, R. C. Webb, A. Teufel, A. Mielech, S. Ishimoto, Frank Klein, M.E. Ladygin, S. Platchkov, N.A. Koutchinski, R. Hermann, Yu. Ivanshin, A. Gorin, S. Gerassimov, N. Horikawa, Sergey Donskov, S. Tessaro, Yu.A. Khokhlov, H. W. Siebert, J. Barth, Grzegorz Brona, Gerhard K. Mallot, A. Vossen, F. Sozzi, Aram Kotzinian, A. Král, R. Windmolders, K. Nikolaev, P. Jasinski, V.V. Tchalishev, S. Costa, J.H. Koivuniemi, S. Panebianco, B. Pawlukiewicz-Kaminska, V. Rapatsky, F.H. Heinsius, A.G. Olshevsky, A. Magnon, I. Konorov, A. Korzenev, D. Reggiani, A. Nagaytsev, F. Balestra, S. Neliba, F. Haas, R. Geyer, N.P. Kravchuk, W. Eyrich, R. Bertini, A.M. Dinkelbach, M. von Hodenberg, K. Kondo, Maria Pia Bussa, Y. Bedfer, M. Alekseev, R. Joosten, R. Ziegler, Alekseev, M, ALEXAKHIN V., Yu, Alexandrov, Yu, ALEXEEV G., D, Amoroso, A, Arbuzov, A, Badelek, B, Balestra, F, Ball, J, Barth, J, Baum, G, Bedfer, Y, Bernet, C, Bertini, R, Bettinelli, M, Birsa, R, Bisplinghoff, J, Bordalo, P, Bradamante, Franco, Bravar, A, Bressan, Andrea, Brona, G, Burtin, E, BUSSA M., P, Chapiro, A, Chiosso, M, Cicuttin, A, Colantoni, M, Costa, S, CRESPO M., L, DALLA TORRE, S, Dafni, T, Das, S, DASGUPTA S., S, DE MASI, R, Dedek, N, DENISOV O., Yu, Dhara, L, Diaz, V, DINKELBACH A., M, DONSKOV S., V, DOROFEEV V., A, Doshita, N, Duic, V, Dünnweber, W, EVERSHEIM P., D, Eyrich, W, Faessler, M, Falaleev, V, Ferrero, A, Ferrero, L, Finger, M, FINGER M., Jr, Fischer, H, Franco, C, Franz, J, FRIEDRICH J., M, Frolov, V, Garfagnini, R, Gautheron, F, GAVRICHTCHOUK O., P, Gazda, R, Gerassimov, S, Geyer, R, Giorgi, M, Gobbo, B, Goertz, S, GORIN A., M, Grabmüller, S, GRAJEK O., A, Grasso, A, Grube, B, Gushterski, R, Guskov, A, Haas, F, Hannappel, J, VON HARRACH, D, Hasegawa, T, Heckmann, J, Hedicke, S, HEINSIUS F., H, Hermann, R, Hess, C, Hinterberger, F, VON HODENBERG, M, Horikawa, N, Horikawa, S, D'Hose, N, Ilgner, C, IOUKAEV A., I, Ishimoto, S, Ivanov, O, Ivanshin, Yu, Iwata, T, Jahn, R, Janata, A, Jasinski, P, Joosten, R, JOURAVLEV N., I, Kabuss, E, Kang, D, Ketzer, B, KHAUSTOV G., V, KHOKHLOV Y. U., A, Kisselev, Yu, Klein, F, Klimaszewski, K, Koblitz, S, KOIVUNIEMI J., H, KOLOSOV V., N, KOMISSAROV E., V, Kondo, K, Königsmann, K, Konorov, I, KONSTANTINOV V., F, KORENTCHENKO A., S, Korzenev, A, KOTZINIAN A., M, KOUTCHINSKI N., A, Kouznetsov, O, Kral, A, KRAVCHUK N., P, KROUMCHTEIN Z., V, Kuhn, R, Kunne, F, Kurek, K, LADYGIN M., E, Lamanna, M, LE GOFF J., M, LEDNEV A., A, Lehmann, A, Levorato, Stefano, Lichtenstadt, J, Liska, T, Ludwig, I, Maggiora, A, Maggiora, M, Magnon, A, MALLOT G., K, Mann, A, Marchand, C, Marroncle, J, Martin, Anna, Marzec, J, Massmann, F, Matsuda, T, MAXIMOV A., N, Meyer, W, Mielech, A, MIKHAILOV Y. U., V, MOINESTER M., A, Mutter, A, Nagaytsev, A, Nagel, T, Nähle, O, Nassalski, J, Neliba, S, Nerling, F, Neubert, S, NEYRET D., P, NIKOLAENKO V., I, Nikolaev, K, OLSHEVSKY A., G, Ostrick, M, Padee, A, Pagano, P, Panebianco, S, Panknin, R, Panzieri, D, Paul, S, PAWLUKIEWICZ KAMINSKA, B, PESHEKHONOV D., V, PESHEKHONOV V., D, Piragino, G, Platchkov, S, Pochodzalla, J, Polak, J, POLYAKOV V., A, Pretz, J, Procureur, S, Quintans, C, RAJOTTE J., F, Ramos, S, Rapatsky, V, Reicherz, G, Reggiani, D, Richter, A, Robinet, F, Rocco, E, Rondio, E, ROZHDESTVENSKY A., M, RYABCHIKOV D., I, SAMOYLENKO V., D, Sandacz, A, Santos, H, SAPOZHNIKOV M., G, Sarkar, S, SAVIN I., A, Schiavon, Paolo, Schill, C, Schmitt, L, Schönmeier, P, Schröder, W, SHEVCHENKO O., Yu, SIEBERT H., W, Silva, L, Sinha, L, SISSAKIAN A., N, Slunecka, M, SMIRNOV G., I, Sosio, S, Sozzi, F, Srnka, A, Stinzing, F, Stolarski, M, SUGONYAEV V., P, Sulc, M, Sulej, R, TCHALISHEV V., V, Tessaro, S, Tessarotto, F, Teufel, A, TKATCHEV L., G, Venugopal, G, Virius, M, VLASSOV N., V, Vossen, A, Webb, R, Weise, E, Weitzel, Q, Windmolders, R, Wirth, S, Wisblicki, W, Wollny, H, Zaremba, K, Zavertyaev, M, Zemlyanichkina, E, Zhao, J, Ziegler, R, and Zvyagin, A.

Subjects
Quark, Nuclear and High Energy Physics, Particle physics, magnetic spectrometer: COMPASS, Structure functions, media_common.quotation_subject, Hadron, polarization: longitudinal, FOS: Physical sciences, polarized target, cross section: ratio, Deep inelastic scattering, muon deuteron: deep inelastic scattering, 01 natural sciences, Asymmetry, x-dependence, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), charged particle: multiple production, negative particle: electroproduction, Experiment-HEP, 13.88.+e, 0103 physical sciences, structure function: moment, 010306 general physics, Nuclear Experiment, media_common, Physics, Quantum chromodynamics, Muon, Valence (chemistry), 010308 nuclear & particles physics, High Energy Physics::Phenomenology, cross section: difference, CERN SPS, positive particle: electroproduction, Deuterium, quark: valence, High Energy Physics::Experiment, muon: polarized beam, quark: polarization, 140-180 GeV, spin: asymmetry, 13.60.Hb, Particle Physics - Experiment, experimental results
Abstract

The semi-inclusive difference asymmetry A^{h^{+}-h^{-}} for hadrons of opposite charge has been measured by the COMPASS experiment at CERN. The data were collected in the years 2002-2004 using a 160 GeV polarised muon beam scattered off a large polarised ^6LiD target and cover the range 0.006 < x < 0.7 and 1 < Q^2 < 100 (GeV/c)^2. In leading order QCD (LO) the asymmetry A_d^{h^{+}-h^{-}} measures the valence quark polarisation and provides an evaluation of the first moment of Delta u_v + Delta d_v which is found to be equal to 0.40 +- 0.07 (stat.) +- 0.05 (syst.) over the measured range of x at Q^2 = 10 (GeV/c)^2. When combined with the first moment of g_1^d previously measured on the same data, this result favours a non-symmetric polarisation of light quarks Delta u-bar = - Delta d-bar at a confidence level of two standard deviations, in contrast to the often assumed symmetric scenario Delta u-bar = Delta d-bar = Delta s-bar = Delta s., 7 pages, 3 figures, COMPASS, revised: details added, author list updated

Published
2007

41. A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target

Author

K. Platzer, V.N. Bytchkov, C. Quintans, Achim Richter, F. Massmann, S. Ramos, T. Matsuda, G. Venugopal, O. Kouznetsov, N.V. Vlassov, A. Zvyagin, Massimo Lamanna, Yu. Kisselev, H. Santos, Franco Bradamante, Günter Baum, O.Yu. Shevchenko, S. Dasgupta, M. Ostrick, M. V. Zavertyaev, V.I. Nikolaenko, A. Lehmann, G.B. Pontecorvo, R. Garfagnini, P. Schiavon, N.P. Kravchuk, Laura Silva, M. Finger, M.E. Ladygin, J.M. Friedrich, G.I. Smirnov, Fabrice Gautheron, A. Chapiro, C. Marchand, V.A. Dorofeev, M. A. Faessler, J. Bisplinghoff, V. Diaz, Murray Moinester, K. Klimaszewski, D.I. Ryabchikov, S. Neliba, Colin Bernet, A. Srnka, F. Haas, R. Geyer, N.A. Koutchinski, W. Eyrich, D. von Harrach, D. Panzieri, A.I. Ioukaev, K. Kurek, Sebastian Trippel, A.G. Olshevsky, T. Hasegawa, T. Nagel, Alan D. Martin, M. Virius, J. Pretz, Andres Cicuttin, G. Reicherz, V.Yu. Alexakhin, R. Jahn, Ulrich Fuchs, Paolo Pagano, T. Liška, R. Sulej, R. Hermann, A.A. Lednev, I. Ludwig, A. Janata, A. Grasso, Victor Kukhtin, Anna Zanetti, L. Ferrero, J. Franz, S. Dalla Torre, G.V. Khaustov, G.V. Krivokhizhin, A.V. Efremov, F. Stinzing, E. Weise, M. Slunecka, M. Leberig, P. Schönmeier, D. Neyret, Sarit K. Das, S. Procureur, C. Heß, A. Padee, M.L. Colantoni, J. Barth, N.I. Jouravlev, S. Horikawa, J. Pochodzalla, W. Wiślicki, B. Gobbo, J. Polak, V.N. Kolosov, Oleg V. Ivanov, Yu.V. Mikhailov, K. Zaremba, S. Hedicke, A. Sandacz, W. Meyer, Maria Liz Crespo, G. D. Alexeev, R. De Masi, P. Bordalo, A.S. Korentchenko, W. Dünnweber, E. M. Kabuß, Michael Seimetz, V.A. Polyakov, C. Ilgner, Christian Schill, E.V. Komissarov, J. Kubart, Daniel Matthiä, A. Teufel, J. Zhao, O.Yu. Denisov, D. Kang, K. Königsmann, Miroslav Sulc, F. Hinterberger, A. Amoroso, P.D. Eversheim, M. Stolarski, Grzegorz Brona, Gerhard K. Mallot, Takahiro Iwata, I.A. Savin, A.A. Popov, F.H. Heinsius, Norihiro Doshita, N. d'Hose, O.P. Gavrichtchouk, J. Marroncle, J. Marzec, A. N. Sissakian, D. Setter, V. Frolov, L. Masek, St. Goertz, L. Sinha, J. Nassalski, A. Maximov, A. Maggiora, S. Koblitz, F. Kunne, V. Falaleev, I. Ivanchin, W. Schroeder, A.M. Rozhdestvensky, I. Horn, R. Kuhn, P. Berglund, V.D. Samoylenko, L. Dhara, E. Rondio, O. Nähle, B. Badelek, V. Kalinnikov, J. Hannappel, G. Piragino, B. Grube, M.P. Bussa, F. Sozzi, Marc Wagner, L. Schmitt, M.G. Alexeev, A.A. Nozdrin, B. Ketzer, J. Ball, M. Giorgi, F. Tessarotto, V.P. Sugonyaev, J. M. Le Goff, K. Kowalik, V. Duic, D. Seeharsch, A. Guskov, N. Dedek, L. G. Tkatchev, M. Bettinelli, Andrea Bressan, D. Demchenko, E. Burtin, Z.V. Kroumchtein, V.F. Konstantinov, Q. Weitzel, M. Becker, Aram Kotzinian, H. Fischer, R. Ziegler, Yu. Alexandrov, R. Windmolders, I. Konorov, Vladimir Peshekhonov, A. Korzenev, R. Birsa, O.A. Grajek, J. Lichtenstadt, F. Balestra, A. Magnon, E.S. Ageev, A. Colavita, S. Gerassimov, N. Horikawa, P. Fauland, Sergey Donskov, S. Paul, S. Tessaro, V.F. Obraztsov, V.V. Tchalishev, T. Toeda, A. Mielech, S. Ishimoto, Frank Klein, Yu.A. Khokhlov, H. W. Siebert, S. Costa, S. Platchkov, M. Maggiora, R. C. Webb, J.H. Koivuniemi, A. Gorin, S. Panebianco, K. Kondo, Y. Bedfer, R. Joosten, R. Bertini, Andrea Ferrero, M.G. Sapozhnikov, D.V. Peshekhonov, A.M. Dinkelbach, Daniel B. Kramer, M. von Hodenberg, AGEEV E., S, ALEXAKHIN V., Yu, Alexandrov, Yu, ALEXEEV G., D, Alexeev, M, Amoroso, A, Badelek, B, Balestra, F, Ball, J, Barth, J, Baum, G, Becker, M, Bedfer, Y, Berglund, P, Bernet, C, Bertini, R, Bettinelli, M, Birsa, R, Bisplinghoff, J, Bordalo, P, Bradamante, Franco, Bressan, Andrea, Brona, G, Burtin, E, BUSSA M., P, BYTCHKOV V., N, Chapiro, A, Cicuttin, A, Colantoni, M, COLAVITA A., A, Costa, S, CRESPO M., L, D'Hose, N, DALLA TORRE, S, Das, S, DASGUPTA S., S, DE MASI, R, Dedek, N, Demchenko, D, DENISOV O., Yu, Dhara, L, Diaz, V, DINKELBACH A., M, DONSKOV S., V, DOROFEEV V., A, Doshita, N, Duic, V, Dünnweber, W, Efremov, A, EVERSHEIM P., D, Eyrich, W, Faessler, M, Falaleev, V, Fauland, P, Ferrero, A, Ferrero, L, Finger, M, FINGER M., Jr, Fischer, H, Franz, J, FRIEDRICH J., M, Frolov, V, Fuchs, U, Garfagnini, R, Gautheron, F, GAVRICHTCHOUK O., P, Gerassimov, S, Geyer, R, Giorgi, Marcello, Gobbo, B, Goertz, S, GORIN A., M, GRAJEK O., A, Grasso, A, Grube, B, Guskov, A, Haas, F, Hannappel, J, VON HARRACH, D, Hasegawa, T, Hedicke, S, HEINSIUS F., H, Hermann, R, Hess, C, Hinterberger, F, VON HODENBERG, M, Horikawa, N, Horikawa, S, Horn, I, Ilgner, C, IOUKAEV A., I, Ishimoto, S, Ivanchin, I, Ivanov, O, Iwata, T, Jahn, R, Janata, A, Joosten, R, JOURAVLEV N., I, Kabuss, E, Kalinnikov, V, Kang, D, Ketzer, B, KHAUSTOV G., V, KHOKHLOV Y. U., A, Kisselev, Yu, Klein, F, Klimaszewski, K, Koblitz, S, KOIVUNIEMI J., H, KOLOSOV V., N, KOMISSAROV E., V, Kondo, K, Königsmann, K, Konorov, I, KONSTANTINOV V., F, KORENTCHENKO A., S, Korzenev, A, KOTZINIAN A., M, KOUTCHINSKI N., A, Kouznetsov, O, Kowalik, K, Kramer, D, KRAVCHUK N., P, KRIVOKHIZHIN G., V, KROUMCHTEIN Z., V, Kubart, J, Kuhn, R, Kukhtin, V, Kunne, F, Kurek, K, LADYGIN M., E, Lamanna, M, LE GOFF J., M, Leberig, M, LEDNEV A., A, Lehmann, A, Lichtenstadt, J, Liska, T, Ludwig, I, Maggiora, A, Maggiora, M, Magnon, A, MALLOT G., K, Marchand, C, Marroncle, J, Martin, Anna, Marzec, J, Masek, L, Massmann, F, Matsuda, T, Matthiä, D, MAXIMOV A., N, Meyer, W, Mielech, A, MIKHAILOV Y. U., V, MOINESTER M., A, Nagel, T, Nähle, O, Nassalski, J, Neliba, S, NEYRET D., P, NIKOLAENKO V., I, NOZDRIN A., A, OBRAZTSOV V., F, OLSHEVSKY A., G, Ostrick, M, Padee, A, Pagano, P, Panebianco, S, Panzieri, D, Paul, S, PESHEKHONOV D., V, PESHEKHONOV V., D, Piragino, G, Platchkov, S, Platzer, K, Pochodzalla, J, Polak, J, POLYAKOV V., A, Pontecorvo, G, POPOV A., A, Pretz, J, Procureur, S, Quintans, C, Ramos, S, Reicherz, G, Richter, A, Rondio, E, ROZHDESTVENSKY A., M, Ryabchikov, D, SAMOYLENKO V., D, Sandacz, A, Santos, H, SAPOZHNIKOV M., G, SAVIN I., A, Schiavon, Paolo, Schill, C, Schmitt, L, Schönmeier, P, Schroeder, W, Seeharsch, D, Seimetz, M, Setter, D, SHEVCHENKO O., Yu, SIEBERT H., W, Silva, L, Sinha, L, SISSAKIAN A., N, Slunecka, M, SMIRNOV G., I, Sozzi, F, Srnka, A, Stinzing, F, Stolarski, M, SUGONYAEV V., P, Sulc, M, Sulej, R, TCHALISHEV V., V, Tessaro, S, Tessarotto, F, Teufel, A, TKATCHEV L., G, Toeda, T, Trippel, S, Venugopal, G, Virius, M, VLASSOV N., V, Wagner, M, Webb, R, Weise, E, Weitzel, Q, Windmolders, R, Wisblicki, W, ZANETTI A., M, Zaremba, K, Zavertyaev, M, Zhao, J, Ziegler, R, and Zvyagin, A.

Subjects
Quark, deuteron, Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, Sivers asymmetry, Hadron, transversity and Sivers function, FOS: Physical sciences, COMPASS, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), nucleon structure, transverse spin and transverse momentum, transversity and Sivers functions, COMPASS experiment, Compass, 0103 physical sciences, Collins, 010306 general physics, Nuclear Experiment, transversity, Physics, Large Hadron Collider, Muon, Spectrometer, 010308 nuclear & particles physics, Scattering, High Energy Physics::Experiment, asymmetry, Particle Physics - Experiment, transverse single-spin asymmetry
Abstract

New high precision measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised 6LiD target are presented. The data were taken in 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible with zero, within the present statistical errors, which are more than a factor of 2 smaller than those of the published COMPASS results from the 2002 data. The final results from the 2002, 2003 and 2004 runs are compared with naive expectations and with existing model calculations., 40 pages, 28 figures

Published
2006

42. First measurement of the transverse spin asymmetries of the deuteron in semi-inclusive deep inelastic scattering

Author

V. Yu. Alexakhin, Yu. Alexandrov, G. D. Alexeev, A. Amoroso, B. Badełek, F. Balestra, J. Ball, G. Baum, Y. Bedfer, P. Berglund, C. Bernet, R. Bertini, R. Birsa, J. Bisplinghoff, F. Bradamante, A. Bravar, A. Bressan, E. Burtin, M. P. Bussa, L. Cerini, A. Chapiro, A. Cicuttin, M. Colantoni, A. A. Colavita, S. Costa, M. L. Crespo, N. d’Hose, S. Dalla Torre, S. S. Dasgupta, R. De Masi, N. Dedek, O. Yu. Denisov, L. Dhara, V. Diaz Kavka, A. V. Dolgopolov, S. V. Donskov, V. A. Dorofeev, N. Doshita, V. Duic, W. Dünnweber, A. Efremov, J. Ehlers, P. D. Eversheim, W. Eyrich, M. Fabro, M. Faessler, P. Fauland, A. Ferrero, L. Ferrero, M. Finger, H. Fischer, J. Franz, J. M. Friedrich, V. Frolov, U. Fuchs, R. Garfagnini, F. Gautheron, O. P. Gavrichtchouk, S. Gerassimov, R. Geyer, M. Giorgi, B. Gobbo, S. Goertz, O. A. Grajek, A. Grasso, B. Grube, A. Grünemaier, K. Gustafsson, J. Hannappel, D. von Harrach, T. Hasegawa, S. Hedicke, F. H. Heinsius, F. Hinterberger, M. von Hodenberg, N. Horikawa, S. Horikawa, R. B. Ijaduola, C. Ilgner, S. Ishimoto, T. Iwata, R. Jahn, A. Janata, R. Joosten, N. I. Jouravlev, E. Kabuß, V. Kalinnikov, D. Kang, F. Karstens, W. Kastaun, B. Ketzer, G. V. Khaustov, Yu. A. Khokhlov, Yu. Kisselev, F. Klein, J. H. Koivuniemi, V. N. Kolosov, E. V. Komissarov, K. Kondo, K. Königsmann, A. K. Konoplyannikov, I. Konorov, V. F. Konstantinov, A. S. Korentchenko, A. Korzenev, A. M. Kotzinian, N. A. Koutchinski, K. Kowalik, N. P. Kravchuk, G. V. Krivokhizhin, Z. V. Kroumchtein, R. Kuhn, F. Kunne, K. Kurek, M. Lamanna, J. M. Le Goff, M. Leberig, J. Lichtenstadt, A. Maggiora, M. Maggiora, A. Magnon, G. K. Mallot, I. V. Manuilov, C. Marchand, J. Marroncle, A. Martin, J. Marzec, T. Matsuda, A. N. Maximov, K. S. Medved, W. Meyer, A. Mielech, Yu. V. Mikhailov, M. A. Moinester, O. Nähle, J. Nassalski, D. P. Neyret, V. I. Nikolaenko, A. A. Nozdrin, V. F. Obraztsov, A. G. Olshevsky, M. Ostrick, A. Padee, P. Pagano, S. Panebianco, D. Panzieri, S. Paul, H. D. Pereira, D. V. Peshekhonov, V. D. Peshekhonov, G. Piragino, S. Platchkov, K. Platzer, J. Pochodzalla, V. A. Polyakov, A. A. Popov, J. Pretz, P. C. Rebourgeard, G. Reicherz, J. Reymann, A. M. Rozhdestvensky, E. Rondio, A. B. Sadovski, E. Saller, V. D. Samoylenko, A. Sandacz, M. Sans, M. G. Sapozhnikov, I. A. Savin, P. Schiavon, T. Schmidt, H. Schmitt, L. Schmitt, A. A. Shishkin, H. Siebert, L. Sinha, A. N. Sissakian, A. Skachkova, M. Slunecka, G. I. Smirnov, V. P. Sugonyaev, F. Stinzing, R. Sulej, N. Takabayashi, V. V. Tchalishev, F. Tessarotto, A. Teufel, D. Thers, L. G. Tkatchev, T. Toeda, V. I. Tretyak, S. Trousov, N. V. Vlassov, R. Webb, E. Weise, M. Wiesmann, R. Windmolders, S. Wirth, W. Wiślicki, A. M. Zanetti, K. Zaremba, J. Zhao, R. Ziegler, A. Zvyagin, ALEXAKHIN V., Yu, Alexandrov, Yu, ALEXEEV G., D, Amoroso, A, Badelek, B, Balestra, F, Ball, J, Baum, G, Bedfer, Y, Berglund, P, Bernet, C, Bertini, R, Birsa, R, Bisplinghoff, J, Bradamante, Franco, Bravar, A, Bressan, Andrea, Burtin, E, BUSSA M., P, Cerini, L, Chapiro, A, Cicuttin, A, Colantoni, M, COLAVITA A., A, Costa, S, CRESPO M., L, D'Hose, N, DALLA TORRE, S, DASGUPTA S., S, DE MASI, R, Dedek, N, DENISOV O., Yu, Dhara, L, DIAZ KAVKA, V, DOLGOPOLOV A., V, DONSKOV S., V, DOROFEEV V., A, Doshita, N, Duic, V, Dünnweber, W, Efremov, A, Ehlers, J, EVERSHEIM P., D, Eyrich, W, Fabro, M, Faessler, M, Fauland, P, Ferrero, A, Ferrero, L, Finger, M, FINGER M., Jr, Fischer, H, Franz, J, FRIEDRICH J., M, Frolov, V, Fuchs, U, Garfagnini, R, Gautheron, F, GAVRICHTCHOUK O., P, Gerassimov, S, Geyer, R, Giorgi, Marcello, Gobbo, B, Goertz, S, GRAJEK O., A, Grasso, A, Grube, B, Grünemaier, A, Gustafsson, K, Hannappel, J, VON HARRACH, D, Hasegawa, T, Hedicke, S, HEINSIUS F., H, Hinterberger, F, VON HODENBERG, M, Horikawa, N, Horikawa, S, IJADUOLA R., B, Ilgner, C, Ishimoto, S, Iwata, T, Jahn, R, Janata, A, Joosten, R, JOURAVLEV N., I, Kabuss, E, Kalinnikov, V, Kang, D, Karstens, F, Kastaun, W, Ketzer, B, KHAUSTOV G., V, KHOKHLOV Y. 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U., V, MOINESTER M., A, Nähle, O, Nassalski, J, NEYRET D., P, NIKOLAENKO V., I, NOZDRIN A., A, OBRAZTSOV V., F, OLSHEVSKY A., G, Ostrick, M, Padee, A, Pagano, P, Panebianco, S, Panzieri, D, Paul, S, PEREIRA H., D, PESHEKHONOV D., V, PESHEKHONOV V., D, Piragino, G, Platchkov, S, Platzer, K, Pochodzalla, J, POLYAKOV V., A, POPOV A., A, Pretz, J, REBOURGEARD P., C, Reicherz, G, Reymann, J, ROZHDESTVENSKY A., M, Rondio, E, SADOVSKI A., B, Saller, E, SAMOYLENKO V., D, Sandacz, A, Sans, M, SAPOZHNIKOV M., G, SAVIN I., A, Schiavon, Paolo, Schmidt, T, Schmitt, H, Schmitt, L, SHISHKIN A., A, Siebert, H, Sinha, L, SISSAKIAN A., N, Skachkova, A, Slunecka, M, SMIRNOV G., I, Sugonyaev, V. P, Stinzing, F, Sulej, R, Takabayashi, N, TCHALISHEV V., V, Tessarotto, F, Teufel, A, Thers, D, TKATCHEV L., G, Toeda, T, TRETYAK V., I, Trousov, S, VLASSOV N., V, Webb, R, Weise, E, Wiesmann, M, Windmolders, R, Wirth, S, Wisblicki, W, ZANETTI A., M, Zaremba, K, Zhao, J, Ziegler, R, and Zvyagin, A.

Subjects
Quark, Particle physics, Physics::Instrumentation and Detectors, media_common.quotation_subject, Hadron, FOS: Physical sciences, General Physics and Astronomy, Inelastic scattering, COMPASS, Asymmetry, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Nuclear Experiment, media_common, Physics, Quantum chromodynamics, Muon, Scattering, Deep inelastic scattering, QCD, nucleon structure, transverse spin and transverse momentum, Physics::Accelerator Physics, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6-LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors., Comment: 6 pages, 2 figures

Published
2005

43. Measurement of the radiative decay of polarized muons in the MEG experiment

Author

S. Nakaura, K. Ieki, G. M. A. Lim, P.-R. Kettle, B.I. Khazin, N. V. Khomutov, G. Signorelli, A. M. Baldini, F. Tenchini, G. Piredda, Yuki Fujii, Wataru Ootani, M. De Gerone, Yusuke Uchiyama, E. Baracchini, W. R. Molzon, T. Haruyama, Z. Hodge, A. Mtchedlishvili, Malte Hildebrandt, Michele Biasotti, G. F. Tassielli, S. Ogawa, G. Chiarello, D. N. Grigoriev, A. D’Onofrio, A. Papa, A. de Bari, Akira Yamamoto, Z. You, F. Berg, C. Voena, G. Rutar, E. Ripiccini, A. Graziosi, C. Bemporad, Ryu Sawada, T. Iwamoto, S. Dussoni, Toshinori Mori, F. Ignatov, Yu Bao, A. S. Korenchenko, G. Pizzigoni, F. Sergiampietri, D. Nicolò, Marco Grassi, A. Pepino, P. W. Cattaneo, F. Renga, Stefan Ritt, Andrey Popov, M. Panareo, Hajime Nishiguchi, G. Cavoto, Yu.V. Yudin, Tae Im Kang, L. Galli, M. Rossella, Fabrizio Cei, Satoshi Mihara, N. P. Kravchuk, C. Chiri, D. Kaneko, F. Grancagnolo, K. Yoshida, M. Venturini, M. Nishimura, Gianluigi Boca, Flavio Gatti, Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, Gianluigi, Chiri, Claudio, de Bari, A., De Gerone, M., D’Onofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, Tae Im, Kettle, P. R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, Marco, Papa, A., Pepino, Aurora, Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, GIOVANNI FRANCESCO, Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., and Yudin, Y. u. V.

Subjects
Particle physics, Antiparticle, Physics - Instrumentation and Detectors, Engineering (miscellaneous), Physics and Astronomy (miscellaneous), muon physics, FOS: Physical sciences, Elementary particle, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Particle decay, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, MC Simulation, SM Expectation, Muon Decay, Individual Uncertainty Source, Photon Energy Spectrum, Photon Detection Efficiency, Neutral Pion, Total Covariance Matrix, Acceptance Factor, Signal Window, QED Correction, Liquid Xenon, Kinematic Region, 010306 general physics, Physics, Muon, 010308 nuclear & particles physics, Branching fraction, Instrumentation and Detectors (physics.ins-det), Orientation (vector space), High Energy Physics - Phenomenology, High Energy Physics::Experiment, Dimensionless quantity, Lepton
Abstract

We studied the radiative muon decay $\mu^+ \to e^+\nu\bar{\nu}\gamma$ by using for the first time an almost fully polarized muon source. We identified a large sample (~13000) of these decays in a total sample of 1.8x10^14 positive muon decays collected in the MEG experiment in the years 2009--2010 and measured the branching ratio B($\mu^+ \to e^+\nu\bar{\nu}\gamma$) = (6.03+-0.14(stat.)+-0.53(sys.))x10^-8 for E_e > 45 MeV and E_{\gamma} > 40 MeV, consistent with the Standard Model prediction. The precise measurement of this decay mode provides a basic tool for the timing calibration, a normalization channel, and a strong quality check of the complete MEG experiment in the search for $\mu^+ \to e^+\gamma$ process., Comment: 8 pages, 7 figures. Added an introduction to NLO calculation which was recently calculated. Published version

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