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

School of Physics and Astronomy

Joint Institute for Nuclear Research
University of Turin
National Institute for Nuclear Physics
Université Paris-Saclay
University of Illinois at Urbana-Champaign
Czech Technical University in Prague
National Centre for Nuclear Research
Technical University of Munich
University of Aveiro
University of Warsaw
University of Bonn
CERN
Johannes Gutenberg University Mainz
Charles University
Laboratório de Instrumentação e Física Experimental de Partículas
University of Lisbon
University of Trieste
University of Freiburg
Tomsk Polytechnic University
Academia Sinica - Institute of Physics
Matrivani Institute of Experimental Research & Education
Pusan National University
Brookhaven National Laboratory
Abdus Salam International Centre for Theoretical Physics
Institute for High Energy Physics
Yamagata University
Warsaw University of Technology
Ruhr University Bochum
RAS - P.N. Lebedev Physics Institute
Nagoya University
Chubu University
National Central University
High Energy Accelerator Research Organization, Tsukuba
Moscow Institute of Physics and Technology
A. Alikhanian Yerevan Institute of Physics
National Kaohsiung Normal University
University of Tübingen
University of Miyazaki
University of Eastern Piedmont
Czech Academy of Sciences
Technical University of Liberec

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

42 Scopus citations

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
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 - 10 Jun 2019

Funding

Funders	Funder number
Israel Academy of Sciences and Humanities
Bundesministerium für Bildung und Forschung
European Commission
California Department of Fish and Wildlife
Fundação para a Ciência e a Tecnologia	CERN/FIS-NUC/0017/2015
National Science Foundation	1506416, 1812377, PHY-1506416
Seventh Framework Programme	1506416, 283286
Ministerio de Ciencia y Tecnología	LG13031
Narodowym Centrum Nauki	2017/26/M/ST2/00498

Keywords

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

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10.1016/j.physletb.2019.04.038

Cite this

@article{fcadee154616473898efcd04614caac8,

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 Dusaev, \{R. R.\} and M. Dziewiecki and A. Efremov and J. Lichtenstadt",

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 = "אנגלית",

volume = "793",

pages = "188--194",

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

issn = "0370-2693",

publisher = "Elsevier B.V.",

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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 - Dusaev, R. R.

AU - Dziewiecki, M.

AU - Efremov, A.

AU - Lichtenstadt, J.

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 - https://www.scopus.com/pages/publications/85064947776

U2 - 10.1016/j.physletb.2019.04.038

DO - 10.1016/j.physletb.2019.04.038

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.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

Funding

Keywords

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