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

The COMPASS Collaboration

doi:10.1016/j.physletb.2019.04.038

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

The COMPASS Collaboration

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

Abstract

We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160GeV/cpolarised 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^+0.1_-0.3]_sys) (GeV/c)^-2. This result can be converted into a transverse extension of partons in the proton, √〈r²_⊥〉 = (0.58 ± 0.04_stat^+0.01_-0.02]_sys ± 0.04_model) fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q²〉 = 1.8 (GeV/c)² and the average value of the Bjorken variable is 〈x_Bj〉 = 0.056.

Original language	English (US)
Pages (from-to)	188-194
Number of pages	7
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	793
DOIs	https://doi.org/10.1016/j.physletb.2019.04.038
State	Published - Jun 10 2019

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

Online availability

10.1016/j.physletb.2019.04.038

Library availability

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Cite this

@article{f1c15f16bec64a4aa6b417f8816aec9d,

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 160GeV/cpolarised μ+ and μ- beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ+ and μ- cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B = (4.3 ± 0.6stat+0.1-0.3]sys) (GeV/c)-2. This result can be converted into a transverse extension of partons in the proton, √〈r2⊥〉 = (0.58 ± 0.04stat+0.01-0.02]sys ± 0.04model) fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q2〉 = 1.8 (GeV/c)2 and the average value of the Bjorken variable is 〈xBj〉 = 0.056.",

keywords = "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. 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 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 Perdekamp, {M. Grosse} and N. Makins and Peng, {J. C.} and C. Riedl",

note = "Publisher Copyright: {\textcopyright} 2019 Published by Elsevier B.V.",

year = "2019",

month = jun,

day = "10",

doi = "10.1016/j.physletb.2019.04.038",

language = "English (US)",

volume = "793",

pages = "188--194",

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

issn = "0370-2693",

publisher = "Elsevier",

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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 - Perdekamp, M. Grosse

AU - Makins, N.

AU - Peng, J. C.

AU - Riedl, C.

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 160GeV/cpolarised μ+ and μ- beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ+ and μ- cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B = (4.3 ± 0.6stat+0.1-0.3]sys) (GeV/c)-2. This result can be converted into a transverse extension of partons in the proton, √〈r2⊥〉 = (0.58 ± 0.04stat+0.01-0.02]sys ± 0.04model) fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q2〉 = 1.8 (GeV/c)2 and the average value of the Bjorken variable is 〈xBj〉 = 0.056.

AB - We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160GeV/cpolarised μ+ and μ- beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ+ and μ- cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t-dependence is fitted with a single exponential function, which yields B = (4.3 ± 0.6stat+0.1-0.3]sys) (GeV/c)-2. This result can be converted into a transverse extension of partons in the proton, √〈r2⊥〉 = (0.58 ± 0.04stat+0.01-0.02]sys ± 0.04model) fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈Q2〉 = 1.8 (GeV/c)2 and the average value of the Bjorken variable is 〈xBj〉 = 0.056.

KW - COMPASS

KW - Deep inelastic scattering

KW - Deeply virtual Compton scattering

KW - Exclusive reactions

KW - Generalized Parton Distributions

KW - Proton size

KW - Quantum chromodynamics

UR - http://www.scopus.com/inward/record.url?scp=85064947776&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85064947776&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2019.04.038

DO - 10.1016/j.physletb.2019.04.038

M3 - Article

AN - SCOPUS:85064947776

SN - 0370-2693

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

ER -

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

Abstract

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