Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering

M. G. Alekseev; V. Alexakhin; Y. Alexandrov; G. D. Alexeev; A. Amoroso; A. Austregesilo; F. Balestra; J. Barth; G. Baum; Y. Bedfer; J. Bernhard; R. Bertini; M. Bettinelli; R. Birsa; J. Bisplinghoff; P. Bordalo; F. Bradamante; A. Bravar; A. Bressan; G. Brona; E. Burtin; M. P. Bussa; D. Chaberny; M. Chiosso; S. U. Chung; A. Cicuttin; M. Colantoni; M. L. Crespo; S. Dalla Torre; S. Das; S. S. Dasgupta; O. Yu Denisov; L. Dhara; V. Diaz; S. V. Donskov; N. Doshita; V. Duic; W. Dünnweber; A. Efremov; A. El Alaoui; P. D. Eversheim; W. Eyrich; M. Faessler; A. Ferrero; A. Filin; M. Finger; M. Finger; H. Fischer; C. Franco; J. M. Friedrich; R. Garfagnini; F. Gautheron; O. P. Gavrichtchouk; R. Gazda; S. Gerassimov; R. Geyer; M. Giorgi; I. Gnesi; B. Gobbo; S. Goertz; S. Grabmüller; A. Grasso; B. Grube; R. Gushterski; A. Guskov; F. Haas; D. von Harrach; T. Hasegawa; F. H. Heinsius; F. Herrmann; C. Heß; F. Hinterberger; N. Horikawa; Ch Höppner; N. d'Hose; C. Ilgner; S. Ishimoto; O. Ivanov; Yu Ivanshin; T. Iwata; R. Jahn; P. Jasinski; G. Jegou; R. Joosten; E. Kabuß; D. Kang; B. Ketzer; G. V. Khaustov; Yu A. Khokhlov; Yu Kisselev; F. Klein; K. Klimaszewski; S. Koblitz; J. H. Koivuniemi; V. N. Kolosov; K. Kondo; K. Königsmann; R. Konopka; I. Konorov; V. F. Konstantinov; A. Korzenev; A. M. Kotzinian; O. Kouznetsov; K. Kowalik; M. Krämer; A. Kral; Z. V. Kroumchtein; R. Kuhn; F. Kunne; K. Kurek; L. Lauser; J. M. Le Goff; A. A. Lednev; A. Lehmann; S. Levorato; J. Lichtenstadt; T. Liska; A. Maggiora; M. Maggiora; A. Magnon; N. Makke; G. K. Mallot; A. Mann; C. Marchand; A. Martin; J. Marzec; F. Massmann; T. Matsuda; W. Meyer; T. Michigami; Yu V. Mikhailov; M. A. Moinester; A. Mutter; A. Nagaytsev; T. Nagel; J. Nassalski; T. Negrini; F. Nerling; S. Neubert; D. Neyret; V. I. Nikolaenko; A. S. Nunes; A. G. Olshevsky; M. Ostrick; A. Padee; R. Panknin; D. Panzieri; B. Parsamyan; S. Paul; B. Pawlukiewicz-Kaminska; E. Perevalova; G. Pesaro; D. V. Peshekhonov; G. Piragino; S. Platchkov; J. Pochodzalla; J. Polak; V. A. Polyakov; G. Pontecorvo; J. Pretz; C. Quintans; J. F. Rajotte; S. Ramos; V. Rapatsky; G. Reicherz; A. Richter; F. Robinet; E. Rocco; E. Rondio; D. I. Ryabchikov; V. D. Samoylenko; A. Sandacz; H. Santos; M. G. Sapozhnikov; S. Sarkar; I. A. Savin; G. Sbrizzai; P. Schiavon; C. Schill; T. Schlüter; L. Schmitt; S. Schopferer; W. Schröder; O. Yu Shevchenko; H. W. Siebert; L. Silva; L. Sinha; A. N. Sissakian; M. Slunecka; G. I. Smirnov; S. Sosio; F. Sozzi; A. Srnka; M. Stolarski; M. Sulc; R. Sulej; S. Takekawa; S. Tessaro; F. Tessarotto; A. Teufel; L. G. Tkatchev; S. Uhl; I. Uman; M. Virius; N. V. Vlassov; A. Vossen; Q. Weitzel; R. Windmolders; W. Wiślicki; H. Wollny; K. Zaremba; M. Zavertyaev; E. Zemlyanichkina; M. Ziembicki; J. Zhao; N. Zhuravlev; A. Zvyagin

doi:10.1016/j.physletb.2010.08.034

Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering

M. G. Alekseev, V. Alexakhin, Y. Alexandrov, G. D. Alexeev, A. Amoroso, A. Austregesilo, F. Balestra, J. Barth, G. Baum, Y. Bedfer, J. Bernhard, R. Bertini, M. Bettinelli, R. Birsa, J. Bisplinghoff, P. Bordalo, F. Bradamante, A. Bravar, A. Bressan, G. BronaE. Burtin, M. P. Bussa, D. Chaberny, M. Chiosso, S. U. Chung, A. Cicuttin, M. Colantoni, M. L. Crespo, S. Dalla Torre, S. Das, S. S. Dasgupta, O. Yu Denisov, L. Dhara, V. Diaz, S. V. Donskov, N. Doshita, V. Duic, W. Dünnweber, A. Efremov, A. El Alaoui, P. D. Eversheim, W. Eyrich, M. Faessler, A. Ferrero, A. Filin, M. Finger, M. Finger, H. Fischer, C. Franco, J. M. Friedrich, R. Garfagnini, F. Gautheron, O. P. Gavrichtchouk, R. Gazda, S. Gerassimov, R. Geyer, M. Giorgi, I. Gnesi, B. Gobbo, S. Goertz, S. Grabmüller, A. Grasso, B. Grube, R. Gushterski, A. Guskov, F. Haas, D. von Harrach, T. Hasegawa, F. H. Heinsius, F. Herrmann, C. Heß, F. Hinterberger, N. Horikawa, Ch Höppner, N. d'Hose, C. Ilgner, S. Ishimoto, O. Ivanov, Yu Ivanshin, T. Iwata, R. Jahn, P. Jasinski, G. Jegou, R. Joosten, E. Kabuß, D. Kang, B. Ketzer, G. V. Khaustov, Yu A. Khokhlov, Yu Kisselev, F. Klein, K. Klimaszewski, S. Koblitz, J. H. Koivuniemi, V. N. Kolosov, K. Kondo, K. Königsmann, R. Konopka, I. Konorov, V. F. Konstantinov, A. Korzenev, A. M. Kotzinian, O. Kouznetsov, K. Kowalik, M. Krämer, A. Kral, Z. V. Kroumchtein, R. Kuhn, F. Kunne, K. Kurek, L. Lauser, J. M. Le Goff, A. A. Lednev, A. Lehmann, S. Levorato, J. Lichtenstadt, T. Liska, A. Maggiora, M. Maggiora, A. Magnon, N. Makke, G. K. Mallot^*, A. Mann, C. Marchand, A. Martin, J. Marzec, F. Massmann, T. Matsuda, W. Meyer, T. Michigami, Yu V. Mikhailov, M. A. Moinester, A. Mutter, A. Nagaytsev, T. Nagel, J. Nassalski, T. Negrini, F. Nerling, S. Neubert, D. Neyret, V. I. Nikolaenko, A. S. Nunes, A. G. Olshevsky, M. Ostrick, A. Padee, R. Panknin, D. Panzieri, B. Parsamyan, S. Paul, B. Pawlukiewicz-Kaminska, E. Perevalova, G. Pesaro, D. V. Peshekhonov, G. Piragino, S. Platchkov, J. Pochodzalla, J. Polak, V. A. Polyakov, G. Pontecorvo, J. Pretz, C. Quintans, J. F. Rajotte, S. Ramos, V. Rapatsky, G. Reicherz, A. Richter, F. Robinet, E. Rocco, E. Rondio, D. I. Ryabchikov, V. D. Samoylenko, A. Sandacz, H. Santos, M. G. Sapozhnikov, S. Sarkar, I. A. Savin, G. Sbrizzai, P. Schiavon, C. Schill, T. Schlüter, L. Schmitt, S. Schopferer, W. Schröder, O. Yu Shevchenko, H. W. Siebert, L. Silva, L. Sinha, A. N. Sissakian, M. Slunecka, G. I. Smirnov, S. Sosio, F. Sozzi, A. Srnka, M. Stolarski, M. Sulc, R. Sulej, S. Takekawa, S. Tessaro, F. Tessarotto, A. Teufel, L. G. Tkatchev, S. Uhl, I. Uman, M. Virius, N. V. Vlassov, A. Vossen, Q. Weitzel, R. Windmolders, W. Wiślicki, H. Wollny, K. Zaremba, M. Zavertyaev, E. Zemlyanichkina, M. Ziembicki, J. Zhao, N. Zhuravlev, A. Zvyagin

^*Corresponding author for this work

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract

Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a longitudinally polarised NH₃ target, cover a range of the Bjorken variable x between 0.004 and 0.7. A leading order evaluation of the helicity distributions for the three lightest quarks and antiquark flavours derived from these asymmetries and from our previous deuteron data is presented. The resulting values of the sea quark distributions are small and do not show any sizable dependence on x in the range of the measurements. No significant difference is observed between the strange and antistrange helicity distributions, both compatible with zero. The integrated value of the flavour asymmetry of the helicity distribution of the light-quark sea, Δū-sΔd̄, is found to be slightly positive, about 1.5 standard deviations away from zero.

Original language	English
Pages (from-to)	227-235
Number of pages	9
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	693
Issue number	3
DOIs	https://doi.org/10.1016/j.physletb.2010.08.034
State	Published - Oct 2010

Keywords

COMPASS
Parton distribution functions
Semi-inclusive deep inelastic scattering
Spin
Structure function

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10.1016/j.physletb.2010.08.034

Cite this

Alekseev, M. G., Alexakhin, V., Alexandrov, Y., Alexeev, G. D., Amoroso, A., Austregesilo, A., Balestra, F., Barth, J., Baum, G., Bedfer, Y., Bernhard, J., Bertini, R., Bettinelli, M., Birsa, R., Bisplinghoff, J., Bordalo, P., Bradamante, F., Bravar, A., Bressan, A., ... Zvyagin, A. (2010). Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 693(3), 227-235. https://doi.org/10.1016/j.physletb.2010.08.034

@article{2072a2f1b12c4137a8a130a47e8a0667,

title = "Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering",

abstract = "Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a longitudinally polarised NH3 target, cover a range of the Bjorken variable x between 0.004 and 0.7. A leading order evaluation of the helicity distributions for the three lightest quarks and antiquark flavours derived from these asymmetries and from our previous deuteron data is presented. The resulting values of the sea quark distributions are small and do not show any sizable dependence on x in the range of the measurements. No significant difference is observed between the strange and antistrange helicity distributions, both compatible with zero. The integrated value of the flavour asymmetry of the helicity distribution of the light-quark sea, Δū-sΔ{\=d}, is found to be slightly positive, about 1.5 standard deviations away from zero.",

keywords = "COMPASS, Parton distribution functions, Semi-inclusive deep inelastic scattering, Spin, Structure function",

author = "Alekseev, {M. G.} and V. Alexakhin and Y. Alexandrov and Alexeev, {G. D.} and A. Amoroso and A. Austregesilo and F. Balestra and J. Barth and G. Baum and Y. Bedfer and J. Bernhard and R. Bertini and M. Bettinelli and R. Birsa and J. Bisplinghoff and P. Bordalo and F. Bradamante and A. Bravar and A. Bressan and G. Brona and E. Burtin and Bussa, {M. P.} and D. Chaberny and M. Chiosso and Chung, {S. U.} and A. Cicuttin and M. Colantoni and Crespo, {M. L.} and Torre, {S. Dalla} and S. Das and Dasgupta, {S. S.} and Denisov, {O. Yu} and L. Dhara and V. Diaz and Donskov, {S. V.} and N. Doshita and V. Duic and W. D{\"u}nnweber and A. Efremov and {El Alaoui}, A. and Eversheim, {P. D.} and W. Eyrich and M. Faessler and A. Ferrero and A. Filin and M. Finger and M. Finger and H. Fischer and C. Franco and Friedrich, {J. M.} and R. Garfagnini and F. Gautheron and Gavrichtchouk, {O. P.} and R. Gazda and S. Gerassimov and R. Geyer and M. Giorgi and I. Gnesi and B. Gobbo and S. Goertz and S. Grabm{\"u}ller and A. Grasso and B. Grube and R. Gushterski and A. Guskov and F. Haas and {von Harrach}, D. and T. Hasegawa and Heinsius, {F. H.} and F. Herrmann and C. He{\ss} and F. Hinterberger and N. Horikawa and Ch H{\"o}ppner and N. d'Hose and C. Ilgner and S. Ishimoto and O. Ivanov and Yu Ivanshin and T. Iwata and R. Jahn and P. Jasinski and G. Jegou and R. Joosten and E. Kabu{\ss} and D. Kang and B. Ketzer and Khaustov, {G. V.} and Khokhlov, {Yu A.} and Yu Kisselev and F. Klein and K. Klimaszewski and S. Koblitz and Koivuniemi, {J. H.} and Kolosov, {V. N.} and K. Kondo and K. K{\"o}nigsmann and R. Konopka and I. Konorov and Konstantinov, {V. F.} and A. Korzenev and Kotzinian, {A. M.} and O. Kouznetsov and K. Kowalik and M. Kr{\"a}mer and A. Kral and Kroumchtein, {Z. V.} and R. Kuhn and F. Kunne and K. Kurek and L. Lauser and {Le Goff}, {J. M.} and Lednev, {A. A.} and A. Lehmann and S. Levorato and J. Lichtenstadt and T. Liska and A. Maggiora and M. Maggiora and A. Magnon and N. Makke and Mallot, {G. K.} and A. Mann and C. Marchand and A. Martin and J. Marzec and F. Massmann and T. Matsuda and W. Meyer and T. Michigami and Mikhailov, {Yu V.} and Moinester, {M. A.} and A. Mutter and A. Nagaytsev and T. Nagel and J. Nassalski and T. Negrini and F. Nerling and S. Neubert and D. Neyret and Nikolaenko, {V. I.} and Nunes, {A. S.} and Olshevsky, {A. G.} and M. Ostrick and A. Padee and R. Panknin and D. Panzieri and B. Parsamyan and S. Paul and B. Pawlukiewicz-Kaminska and E. Perevalova and G. Pesaro and Peshekhonov, {D. V.} and G. Piragino and S. Platchkov and J. Pochodzalla and J. Polak and Polyakov, {V. A.} and G. Pontecorvo and J. Pretz and C. Quintans and Rajotte, {J. F.} and S. Ramos and V. Rapatsky and G. Reicherz and A. Richter and F. Robinet and E. Rocco and E. Rondio and Ryabchikov, {D. I.} and Samoylenko, {V. D.} and A. Sandacz and H. Santos and Sapozhnikov, {M. G.} and S. Sarkar and Savin, {I. A.} and G. Sbrizzai and P. Schiavon and C. Schill and T. Schl{\"u}ter and L. Schmitt and S. Schopferer and W. Schr{\"o}der and Shevchenko, {O. Yu} and Siebert, {H. W.} and L. Silva and L. Sinha and Sissakian, {A. N.} and M. Slunecka and Smirnov, {G. I.} and S. Sosio and F. Sozzi and A. Srnka and M. Stolarski and M. Sulc and R. Sulej and S. Takekawa and S. Tessaro and F. Tessarotto and A. Teufel and Tkatchev, {L. G.} and S. Uhl and I. Uman and M. Virius and Vlassov, {N. V.} and A. Vossen and Q. Weitzel and R. Windmolders and W. Wi{\'s}licki and H. Wollny and K. Zaremba and M. Zavertyaev and E. Zemlyanichkina and M. Ziembicki and J. Zhao and N. Zhuravlev and A. Zvyagin",

year = "2010",

month = oct,

doi = "10.1016/j.physletb.2010.08.034",

language = "אנגלית",

volume = "693",

pages = "227--235",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

publisher = "Elsevier",

number = "3",

}

Alekseev, MG, Alexakhin, V, Alexandrov, Y, Alexeev, GD, Amoroso, A, Austregesilo, A, Balestra, F, Barth, J, Baum, G, Bedfer, Y, Bernhard, J, Bertini, R, Bettinelli, M, Birsa, R, Bisplinghoff, J, Bordalo, P, Bradamante, F, Bravar, A, Bressan, A, Brona, G, Burtin, E, Bussa, MP, Chaberny, D, Chiosso, M, Chung, SU, Cicuttin, A, Colantoni, M, Crespo, ML, Torre, SD, Das, S, Dasgupta, SS, Denisov, OY, Dhara, L, Diaz, V, Donskov, SV, Doshita, N, Duic, V, Dünnweber, W, Efremov, A, El Alaoui, A, Eversheim, PD, Eyrich, W, Faessler, M, Ferrero, A, Filin, A, Finger, M, Finger, M, Fischer, H, Franco, C, Friedrich, JM, Garfagnini, R, Gautheron, F, Gavrichtchouk, OP, Gazda, R, Gerassimov, S, Geyer, R, Giorgi, M, Gnesi, I, Gobbo, B, Goertz, S, Grabmüller, S, Grasso, A, Grube, B, Gushterski, R, Guskov, A, Haas, F, von Harrach, D, Hasegawa, T, Heinsius, FH, Herrmann, F, Heß, C, Hinterberger, F, Horikawa, N, Höppner, C, d'Hose, N, Ilgner, C, Ishimoto, S, Ivanov, O, Ivanshin, Y, Iwata, T, Jahn, R, Jasinski, P, Jegou, G, Joosten, R, Kabuß, E, Kang, D, Ketzer, B, Khaustov, GV, Khokhlov, YA, Kisselev, Y, Klein, F, Klimaszewski, K, Koblitz, S, Koivuniemi, JH, Kolosov, VN, Kondo, K, Königsmann, K, Konopka, R, Konorov, I, Konstantinov, VF, Korzenev, A, Kotzinian, AM, Kouznetsov, O, Kowalik, K, Krämer, M, Kral, A, Kroumchtein, ZV, Kuhn, R, Kunne, F, Kurek, K, Lauser, L, Le Goff, JM, Lednev, AA, Lehmann, A, Levorato, S, Lichtenstadt, J, Liska, T, Maggiora, A, Maggiora, M, Magnon, A, Makke, N, Mallot, GK, Mann, A, Marchand, C, Martin, A, Marzec, J, Massmann, F, Matsuda, T, Meyer, W, Michigami, T, Mikhailov, YV, Moinester, MA, Mutter, A, Nagaytsev, A, Nagel, T, Nassalski, J, Negrini, T, Nerling, F, Neubert, S, Neyret, D, Nikolaenko, VI, Nunes, AS, Olshevsky, AG, Ostrick, M, Padee, A, Panknin, R, Panzieri, D, Parsamyan, B, Paul, S, Pawlukiewicz-Kaminska, B, Perevalova, E, Pesaro, G, Peshekhonov, DV, Piragino, G, Platchkov, S, Pochodzalla, J, Polak, J, Polyakov, VA, Pontecorvo, G, Pretz, J, Quintans, C, Rajotte, JF, Ramos, S, Rapatsky, V, Reicherz, G, Richter, A, Robinet, F, Rocco, E, Rondio, E, Ryabchikov, DI, Samoylenko, VD, Sandacz, A, Santos, H, Sapozhnikov, MG, Sarkar, S, Savin, IA, Sbrizzai, G, Schiavon, P, Schill, C, Schlüter, T, Schmitt, L, Schopferer, S, Schröder, W, Shevchenko, OY, Siebert, HW, Silva, L, Sinha, L, Sissakian, AN, Slunecka, M, Smirnov, GI, Sosio, S, Sozzi, F, Srnka, A, Stolarski, M, Sulc, M, Sulej, R, Takekawa, S, Tessaro, S, Tessarotto, F, Teufel, A, Tkatchev, LG, Uhl, S, Uman, I, Virius, M, Vlassov, NV, Vossen, A, Weitzel, Q, Windmolders, R, Wiślicki, W, Wollny, H, Zaremba, K, Zavertyaev, M, Zemlyanichkina, E, Ziembicki, M, Zhao, J, Zhuravlev, N & Zvyagin, A 2010, 'Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering', Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 693, no. 3, pp. 227-235. https://doi.org/10.1016/j.physletb.2010.08.034

TY - JOUR

T1 - Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering

AU - Alekseev, M. G.

AU - Alexakhin, V.

AU - Alexandrov, Y.

AU - Alexeev, G. D.

AU - Amoroso, A.

AU - Austregesilo, A.

AU - Balestra, F.

AU - Barth, J.

AU - Baum, G.

AU - Bedfer, Y.

AU - Bernhard, J.

AU - Bertini, R.

AU - Bettinelli, M.

AU - Birsa, R.

AU - Bisplinghoff, J.

AU - Bordalo, P.

AU - Bradamante, F.

AU - Bravar, A.

AU - Bressan, A.

AU - Brona, G.

AU - Burtin, E.

AU - Bussa, M. P.

AU - Chaberny, D.

AU - Chiosso, M.

AU - Chung, S. U.

AU - Cicuttin, A.

AU - Colantoni, M.

AU - Crespo, M. L.

AU - Torre, S. Dalla

AU - Das, S.

AU - Dasgupta, S. S.

AU - Denisov, O. Yu

AU - Dhara, L.

AU - Diaz, V.

AU - Donskov, S. V.

AU - Doshita, N.

AU - Duic, V.

AU - Dünnweber, W.

AU - Efremov, A.

AU - El Alaoui, A.

AU - Eversheim, P. D.

AU - Eyrich, W.

AU - Faessler, M.

AU - Ferrero, A.

AU - Filin, A.

AU - Finger, M.

AU - Fischer, H.

AU - Franco, C.

AU - Friedrich, J. M.

AU - Garfagnini, R.

AU - Gautheron, F.

AU - Gavrichtchouk, O. P.

AU - Gazda, R.

AU - Gerassimov, S.

AU - Geyer, R.

AU - Giorgi, M.

AU - Gnesi, I.

AU - Gobbo, B.

AU - Goertz, S.

AU - Grabmüller, S.

AU - Grasso, A.

AU - Grube, B.

AU - Gushterski, R.

AU - Guskov, A.

AU - Haas, F.

AU - von Harrach, D.

AU - Hasegawa, T.

AU - Heinsius, F. H.

AU - Herrmann, F.

AU - Heß, C.

AU - Hinterberger, F.

AU - Horikawa, N.

AU - Höppner, Ch

AU - d'Hose, N.

AU - Ilgner, C.

AU - Ishimoto, S.

AU - Ivanov, O.

AU - Ivanshin, Yu

AU - Iwata, T.

AU - Jahn, R.

AU - Jasinski, P.

AU - Jegou, G.

AU - Joosten, R.

AU - Kabuß, E.

AU - Kang, D.

AU - Ketzer, B.

AU - Khaustov, G. V.

AU - Khokhlov, Yu A.

AU - Kisselev, Yu

AU - Klein, F.

AU - Klimaszewski, K.

AU - Koblitz, S.

AU - Koivuniemi, J. H.

AU - Kolosov, V. N.

AU - Kondo, K.

AU - Königsmann, K.

AU - Konopka, R.

AU - Konorov, I.

AU - Konstantinov, V. F.

AU - Korzenev, A.

AU - Kotzinian, A. M.

AU - Kouznetsov, O.

AU - Kowalik, K.

AU - Krämer, M.

AU - Kral, A.

AU - Kroumchtein, Z. V.

AU - Kuhn, R.

AU - Kunne, F.

AU - Kurek, K.

AU - Lauser, L.

AU - Le Goff, J. M.

AU - Lednev, A. A.

AU - Lehmann, A.

AU - Levorato, S.

AU - Lichtenstadt, J.

AU - Liska, T.

AU - Maggiora, A.

AU - Maggiora, M.

AU - Magnon, A.

AU - Makke, N.

AU - Mallot, G. K.

AU - Mann, A.

AU - Marchand, C.

AU - Martin, A.

AU - Marzec, J.

AU - Massmann, F.

AU - Matsuda, T.

AU - Meyer, W.

AU - Michigami, T.

AU - Mikhailov, Yu V.

AU - Moinester, M. A.

AU - Mutter, A.

AU - Nagaytsev, A.

AU - Nagel, T.

AU - Nassalski, J.

AU - Negrini, T.

AU - Nerling, F.

AU - Neubert, S.

AU - Neyret, D.

AU - Nikolaenko, V. I.

AU - Nunes, A. S.

AU - Olshevsky, A. G.

AU - Ostrick, M.

AU - Padee, A.

AU - Panknin, R.

AU - Panzieri, D.

AU - Parsamyan, B.

AU - Paul, S.

AU - Pawlukiewicz-Kaminska, B.

AU - Perevalova, E.

AU - Pesaro, G.

AU - Peshekhonov, D. V.

AU - Piragino, G.

AU - Platchkov, S.

AU - Pochodzalla, J.

AU - Polak, J.

AU - Polyakov, V. A.

AU - Pontecorvo, G.

AU - Pretz, J.

AU - Quintans, C.

AU - Rajotte, J. F.

AU - Ramos, S.

AU - Rapatsky, V.

AU - Reicherz, G.

AU - Richter, A.

AU - Robinet, F.

AU - Rocco, E.

AU - Rondio, E.

AU - Ryabchikov, D. I.

AU - Samoylenko, V. D.

AU - Sandacz, A.

AU - Santos, H.

AU - Sapozhnikov, M. G.

AU - Sarkar, S.

AU - Savin, I. A.

AU - Sbrizzai, G.

AU - Schiavon, P.

AU - Schill, C.

AU - Schlüter, T.

AU - Schmitt, L.

AU - Schopferer, S.

AU - Schröder, W.

AU - Shevchenko, O. Yu

AU - Siebert, H. W.

AU - Silva, L.

AU - Sinha, L.

AU - Sissakian, A. N.

AU - Slunecka, M.

AU - Smirnov, G. I.

AU - Sosio, S.

AU - Sozzi, F.

AU - Srnka, A.

AU - Stolarski, M.

AU - Sulc, M.

AU - Sulej, R.

AU - Takekawa, S.

AU - Tessaro, S.

AU - Tessarotto, F.

AU - Teufel, A.

AU - Tkatchev, L. G.

AU - Uhl, S.

AU - Uman, I.

AU - Virius, M.

AU - Vlassov, N. V.

AU - Vossen, A.

AU - Weitzel, Q.

AU - Windmolders, R.

AU - Wiślicki, W.

AU - Wollny, H.

AU - Zaremba, K.

AU - Zavertyaev, M.

AU - Zemlyanichkina, E.

AU - Ziembicki, M.

AU - Zhao, J.

AU - Zhuravlev, N.

AU - Zvyagin, A.

PY - 2010/10

Y1 - 2010/10

N2 - Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a longitudinally polarised NH3 target, cover a range of the Bjorken variable x between 0.004 and 0.7. A leading order evaluation of the helicity distributions for the three lightest quarks and antiquark flavours derived from these asymmetries and from our previous deuteron data is presented. The resulting values of the sea quark distributions are small and do not show any sizable dependence on x in the range of the measurements. No significant difference is observed between the strange and antistrange helicity distributions, both compatible with zero. The integrated value of the flavour asymmetry of the helicity distribution of the light-quark sea, Δū-sΔd̄, is found to be slightly positive, about 1.5 standard deviations away from zero.

AB - Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a longitudinally polarised NH3 target, cover a range of the Bjorken variable x between 0.004 and 0.7. A leading order evaluation of the helicity distributions for the three lightest quarks and antiquark flavours derived from these asymmetries and from our previous deuteron data is presented. The resulting values of the sea quark distributions are small and do not show any sizable dependence on x in the range of the measurements. No significant difference is observed between the strange and antistrange helicity distributions, both compatible with zero. The integrated value of the flavour asymmetry of the helicity distribution of the light-quark sea, Δū-sΔd̄, is found to be slightly positive, about 1.5 standard deviations away from zero.

KW - COMPASS

KW - Parton distribution functions

KW - Semi-inclusive deep inelastic scattering

KW - Spin

KW - Structure function

UR - http://www.scopus.com/inward/record.url?scp=77956878394&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2010.08.034

DO - 10.1016/j.physletb.2010.08.034

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:77956878394

SN - 0370-2693

VL - 693

SP - 227

EP - 235

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

IS - 3

ER -

Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering

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