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.
| 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 | |
| State | Published - Jun 10 2019 |
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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
Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section. / The COMPASS Collaboration.
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol. 793, 10.06.2019, p. 188-194.Research output: Contribution to journal › Article
}
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 - Eversheim, P. D.
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
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
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 -