@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 = "Funding Information: Supported by BMBF - Bundesministerium f{\"u}r Bildung und Forschung (Germany).Supported by FP7, HadronPhysics3, Grant 283286 (European Union).Supported by MEYS, Grant LG13031 (Czech Republic).Supported by B.Sen fund (India).Supported by CERN-RFBR Grant 12-02-91500.Supported by FCT - Funda{\c c}{\~a}o para a Ci{\^e}ncia e Tecnologia, COMPETE and QREN, Grants CERN/FP 116376/2010, 123600/2011 and CERN/FIS-NUC/0017/2015 (Portugal).Supported by MEXT and JSPS, Grants 18002006, 20540299, 18540281 and 26247032, the Daiko and Yamada Foundations (Japan).Supported by the DFG cluster of excellence {\textquoteleft}Origin and Structure of the Universe{\textquoteright} (www.universe-cluster.de) (Germany).Supported by the Ministry of Science and Technology (Taiwan).Supported by the Israel Academy of Sciences and Humanities (Israel).Supported by the National Science Foundation, Grant no. PHY-1506416 (USA).Supported by NCN, Grant 2017/26/M/ST2/00498 (Poland).Supported by the Laboratoire d'excellence P2IO (France).Supported by the DFG Research Training Group Programmes 1102 and 2044 (Germany). We gratefully acknowledge the support of the CERN management and staff, as well as the skill and effort of the technicians of our collaborating institutes. We thank Pierre Guichon for the evaluation of the Bethe-Heitler contribution taking into account the muon mass, Sergey Goloskokov and Peter Kroll for their continuous support with model predictions for the π 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",
}