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

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 〈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

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The COMPASS Collaboration (2019). Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 793, 188-194. https://doi.org/10.1016/j.physletb.2019.04.038

@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 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±0.6stat|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±0.04stat|sys−0.02+0.01±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 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 M. Dziewiecki and A. Efremov and {Grosse Perdekamp}, M. and Makins, {Naomi C R} and Peng, {J. C.} and C. Riedl",

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",

}

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 - Denisov, O. Yu

AU - Dhara, L.

AU - Donskov, S. V.

AU - Doshita, N.

AU - Dreisbach, Ch

AU - Dünnweber, W.

AU - Dusaev, R. R.

AU - Dziewiecki, M.

AU - Efremov, A.

AU - Grosse Perdekamp, M.

AU - Makins, Naomi C R

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 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±0.6stat|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±0.04stat|sys−0.02+0.01±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 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±0.6stat|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±0.04stat|sys−0.02+0.01±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

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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

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 -