Longitudinal double-spin asymmetry A1                             p and spin-dependent structure function g1                             p of the proton at small values of x and Q2

COMPASS Collaboration

doi:10.1016/j.physletb.2018.03.044

Longitudinal double-spin asymmetry A₁ ^p and spin-dependent structure function g₁ ^p of the proton at small values of x and Q²

COMPASS Collaboration

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

Abstract

We present a precise measurement of the proton longitudinal double-spin asymmetry A₁ ^p and the proton spin-dependent structure function g₁ ^p at photon virtualities 0.006(GeV/c)²<Q²<1(GeV/c)² in the Bjorken x range of 4×10⁻⁵<x<4×10⁻². The results are based on data collected by the COMPASS Collaboration at CERN using muon beam energies of 160GeV and 200GeV. The statistical precision is more than tenfold better than that of the previous measurement in this region. In the whole range of x, the measured values of A₁ ^p and g₁ ^p are found to be positive. It is for the first time that spin effects are found at such low values of x.

Original language	English (US)
Pages (from-to)	464-472
Number of pages	9
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	781
DOIs	https://doi.org/10.1016/j.physletb.2018.03.044
State	Published - Jun 10 2018

Keywords

A
Inelastic muon scattering
Low Q
Low x
Spin structure function
g

ASJC Scopus subject areas

Nuclear and High Energy Physics

Online availability

10.1016/j.physletb.2018.03.044

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Cite this

COMPASS Collaboration (2018). Longitudinal double-spin asymmetry A₁ ^p and spin-dependent structure function g₁ ^p of the proton at small values of x and Q² Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 781, 464-472. https://doi.org/10.1016/j.physletb.2018.03.044

Longitudinal double-spin asymmetry A₁ ^p and spin-dependent structure function g₁ ^p of the proton at small values of x and Q² . / COMPASS Collaboration.
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol. 781, 10.06.2018, p. 464-472.

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

COMPASS Collaboration 2018, 'Longitudinal double-spin asymmetry A₁ ^p and spin-dependent structure function g₁ ^p of the proton at small values of x and Q² ', Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 781, pp. 464-472. https://doi.org/10.1016/j.physletb.2018.03.044

COMPASS Collaboration. Longitudinal double-spin asymmetry A₁ ^p and spin-dependent structure function g₁ ^p of the proton at small values of x and Q² Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 2018 Jun 10;781:464-472. doi: 10.1016/j.physletb.2018.03.044

@article{4b8a9ea1922e4d65ba94825b3abd7f57,

title = "Longitudinal double-spin asymmetry A1 p and spin-dependent structure function g1 p of the proton at small values of x and Q2 ",

abstract = "We present a precise measurement of the proton longitudinal double-spin asymmetry A1 p and the proton spin-dependent structure function g1 p at photon virtualities 0.006(GeV/c)2<Q2<1(GeV/c)2 in the Bjorken x range of 4×10−5−2. The results are based on data collected by the COMPASS Collaboration at CERN using muon beam energies of 160GeV and 200GeV. The statistical precision is more than tenfold better than that of the previous measurement in this region. In the whole range of x, the measured values of A1 p and g1 p are found to be positive. It is for the first time that spin effects are found at such low values of x.",

keywords = "A, Inelastic muon scattering, Low Q, Low x, Spin structure function, g",

author = "{COMPASS Collaboration} and M. Aghasyan and Alexeev, {M. G.} and Alexeev, {G. D.} and A. Amoroso and V. Andrieux and Anfimov, {N. V.} and V. Anosov and A. Antoshkin and K. Augsten and W. Augustyniak and A. Austregesilo and Azevedo, {C. D.R.} and B. Bade{\l}ek and F. Balestra and M. Ball and J. Barth and R. Beck and Y. Bedfer and J. Bernhard and K. Bicker and Bielert, {E. R.} and R. Birsa and M. Bodlak and P. Bordalo and F. Bradamante and A. Bressan and M. B{\"u}chele and Burtsev, {V. E.} and L. Capozza and Chang, {W. C.} and C. Chatterjee and M. Chiosso and I. Choi and Chumakov, {A. G.} and Chung, {S. U.} and A. Cicuttin and Crespo, {M. L.} and {Dalla Torre}, S. and Dasgupta, {S. S.} and S. Dasgupta and Denisov, {O. Yu} and L. Dhara and Donskov, {S. V.} and N. Doshita and Ch Dreisbach and W. D{\"u}nnweber and {Grosse Perdekamp}, M. and N. Makins and Peng, {J. C.} and C. Riedl",

note = "Funding Information: Supported by the DFG Research Training Group Programmes 1102 and 2044 (Germany). Publisher Copyright: {\textcopyright} 2018 The Author(s)",

year = "2018",

month = jun,

day = "10",

doi = "10.1016/j.physletb.2018.03.044",

language = "English (US)",

volume = "781",

pages = "464--472",

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

issn = "0370-2693",

publisher = "Elsevier",

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TY - JOUR

T1 - Longitudinal double-spin asymmetry A1 p and spin-dependent structure function g1 p of the proton at small values of x and Q2

AU - COMPASS Collaboration

AU - Aghasyan, M.

AU - Alexeev, M. G.

AU - Alexeev, G. D.

AU - Amoroso, A.

AU - Andrieux, V.

AU - Anfimov, N. V.

AU - Anosov, V.

AU - Antoshkin, A.

AU - Augsten, K.

AU - Augustyniak, W.

AU - Austregesilo, A.

AU - Azevedo, C. D.R.

AU - Badełek, B.

AU - Balestra, F.

AU - Ball, M.

AU - Barth, J.

AU - Beck, R.

AU - Bedfer, Y.

AU - Bernhard, J.

AU - Bicker, K.

AU - Bielert, E. R.

AU - Birsa, R.

AU - Bodlak, M.

AU - Bordalo, P.

AU - Bradamante, F.

AU - Bressan, A.

AU - Büchele, M.

AU - Burtsev, V. E.

AU - Capozza, L.

AU - Chang, W. C.

AU - Chatterjee, C.

AU - Chiosso, M.

AU - Choi, I.

AU - Chumakov, A. G.

AU - Chung, S. U.

AU - Cicuttin, A.

AU - Crespo, M. L.

AU - Dalla Torre, S.

AU - Dasgupta, S. S.

AU - Dasgupta, S.

AU - Denisov, O. Yu

AU - Dhara, L.

AU - Donskov, S. V.

AU - Doshita, N.

AU - Dreisbach, Ch

AU - Dünnweber, W.

AU - Grosse Perdekamp, M.

AU - Makins, N.

AU - Peng, J. C.

AU - Riedl, C.

PY - 2018/6/10

Y1 - 2018/6/10

N2 - We present a precise measurement of the proton longitudinal double-spin asymmetry A1 p and the proton spin-dependent structure function g1 p at photon virtualities 0.006(GeV/c)2<Q2<1(GeV/c)2 in the Bjorken x range of 4×10−5−2. The results are based on data collected by the COMPASS Collaboration at CERN using muon beam energies of 160GeV and 200GeV. The statistical precision is more than tenfold better than that of the previous measurement in this region. In the whole range of x, the measured values of A1 p and g1 p are found to be positive. It is for the first time that spin effects are found at such low values of x.

AB - We present a precise measurement of the proton longitudinal double-spin asymmetry A1 p and the proton spin-dependent structure function g1 p at photon virtualities 0.006(GeV/c)2<Q2<1(GeV/c)2 in the Bjorken x range of 4×10−5−2. The results are based on data collected by the COMPASS Collaboration at CERN using muon beam energies of 160GeV and 200GeV. The statistical precision is more than tenfold better than that of the previous measurement in this region. In the whole range of x, the measured values of A1 p and g1 p are found to be positive. It is for the first time that spin effects are found at such low values of x.

KW - A

KW - Inelastic muon scattering

KW - Low Q

KW - Low x

KW - Spin structure function

KW - g

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U2 - 10.1016/j.physletb.2018.03.044

DO - 10.1016/j.physletb.2018.03.044

M3 - Article

AN - SCOPUS:85045934608

SN - 0370-2693

VL - 781

SP - 464

EP - 472

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

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

ER -