Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section

The COMPASS Collaboration, Sergey Alexandrovich Mamon

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/c polarised μ + and μ beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ + and μ cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B=(4.3±0.6 stat |sys−0.3+0.1)(GeV/c) −2 . This result can be converted into a transverse extension of partons in the proton, 〈r 2 〉=(0.58±0.04 stat |sys−0.02+0.01±0.04 model )fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q 2 〉=1.8(GeV/c) 2 and the average value of the Bjorken variable is 〈x Bj 〉=0.056.

Original languageEnglish
Pages (from-to)188-194
Number of pages7
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume793
DOIs
Publication statusPublished - 10 Jun 2019

Fingerprint

partons
quarks
protons
cross sections
COMPASS (programming language)
liquid hydrogen
exponential functions
photons
momentum transfer
slopes
scattering
interactions

Keywords

  • COMPASS
  • Deep inelastic scattering
  • Deeply virtual Compton scattering
  • Exclusive reactions
  • Generalized Parton Distributions
  • Proton size
  • Quantum chromodynamics

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

@article{142744f9ee354bcd99294eb02a4f0011,
title = "Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section",
abstract = "We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/c polarised μ + and μ − beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ + and μ − cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B=(4.3±0.6 stat |sys−0.3+0.1)(GeV/c) −2 . This result can be converted into a transverse extension of partons in the proton, 〈r ⊥ 2 〉=(0.58±0.04 stat |sys−0.02+0.01±0.04 model )fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q 2 〉=1.8(GeV/c) 2 and the average value of the Bjorken variable is 〈x Bj 〉=0.056.",
keywords = "COMPASS, Deep inelastic scattering, Deeply virtual Compton scattering, Exclusive reactions, Generalized Parton Distributions, Proton size, Quantum chromodynamics",
author = "{The COMPASS Collaboration} and R. Akhunzyanov 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. Badełek 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 E. Burtin and Burtsev, {V. E.} 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 Dusaev, {R. R.} and Levchenko, {E. A.} and Lyubovitskij, {V. E.} and Vasilishin, {B. I.} and Mamon, {Sergey Alexandrovich}",
year = "2019",
month = "6",
day = "10",
doi = "10.1016/j.physletb.2019.04.038",
language = "English",
volume = "793",
pages = "188--194",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",

}

TY - JOUR

T1 - Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section

AU - The COMPASS Collaboration

AU - Akhunzyanov, R.

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 - Burtin, E.

AU - Burtsev, V. E.

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 - Dusaev, R. R.

AU - Levchenko, E. A.

AU - Lyubovitskij, V. E.

AU - Vasilishin, B. I.

AU - Mamon, Sergey Alexandrovich

PY - 2019/6/10

Y1 - 2019/6/10

N2 - We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/c polarised μ + and μ − beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ + and μ − cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B=(4.3±0.6 stat |sys−0.3+0.1)(GeV/c) −2 . This result can be converted into a transverse extension of partons in the proton, 〈r ⊥ 2 〉=(0.58±0.04 stat |sys−0.02+0.01±0.04 model )fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q 2 〉=1.8(GeV/c) 2 and the average value of the Bjorken variable is 〈x Bj 〉=0.056.

AB - We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/c polarised μ + and μ − beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ + and μ − cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B=(4.3±0.6 stat |sys−0.3+0.1)(GeV/c) −2 . This result can be converted into a transverse extension of partons in the proton, 〈r ⊥ 2 〉=(0.58±0.04 stat |sys−0.02+0.01±0.04 model )fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q 2 〉=1.8(GeV/c) 2 and the average value of the Bjorken variable is 〈x Bj 〉=0.056.

KW - COMPASS

KW - Deep inelastic scattering

KW - Deeply virtual Compton scattering

KW - Exclusive reactions

KW - Generalized Parton Distributions

KW - Proton size

KW - Quantum chromodynamics

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U2 - 10.1016/j.physletb.2019.04.038

DO - 10.1016/j.physletb.2019.04.038

M3 - Article

VL - 793

SP - 188

EP - 194

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

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

SN - 0370-2693

ER -