@article{e5700604e3874f8d8ec15c7496ad7319,
title = "Measurement of the cross section for hard exclusive π0 muoproduction on the proton",
abstract = "We report on a measurement of hard exclusive π0 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. From the average of the measured μ+ and μ− cross sections, the virtual-photon proton cross section is determined as a function of the squared four-momentum transfer between initial and final proton in the range 0.08(GeV/c)2<|t|<0.64(GeV/c)2. The average kinematics of the measurement are 〈Q2〉=2.0(GeV/c)2, 〈ν〉=12.8GeV, 〈xBj〉=0.093 and 〈−t〉=0.256(GeV/c)2. Fitting the azimuthal dependence reveals a combined contribution by transversely and longitudinally polarised photons of (8.2±0.9stat −1.2 +1.2|sys)nb/(GeV/c)2, as well as transverse-transverse and longitudinal-transverse interference contributions of (−6.1±1.3stat −0.7 +0.7|sys)nb/(GeV/c)2 and (1.5±0.5stat −0.2 +0.3|sys)nb/(GeV/c)2, respectively. Our results provide important input for modelling Generalised Parton Distributions. In the context of the phenomenological Goloskokov-Kroll model, the statistically significant transverse-transverse interference contribution constitutes clear experimental evidence for the chiral-odd GPD E‾T.",
keywords = "COMPASS, Generalised Parton Distributions, Hard exclusive meson production, Muoproduction, Quantum chromodynamics",
author = "{The COMPASS Collaboration} 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 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 M. Bodlak and P. Bordalo and F. Bradamante and A. Bressan and M. B{\"u}chele and Burtsev, {V. E.} and Chang, {W. C.} and C. Chatterjee and M. Chiosso 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 A. Efremov and Eversheim, {P. D.} and M. Faessler and A. Ferrero and M. Finger and H. Fischer and {Grosse Perdekamp}, M. 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 LM20150581 (Czech Republic).Supported by B.Sen fund (India).Supported by FCT, 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 Russian Federation program “Nauka” (Contract No. 0.1764.GZB.2017) (Russia).Supported by the National Science Foundation, Grant no. PHY-1506416 (USA).Supported by NCN, Grant 2017/26/M/ST2/00498 (Poland).Supported by the DFG Research Training Group Programmes 1102 and 2044 (Germany).Supported by the P2IO LabEx Grant No. ANR-10-LABX-0038, Agence Nationale de la Recherche, France. Publisher Copyright: {\textcopyright} 2020 The Author(s)",
year = "2020",
month = jun,
day = "10",
doi = "10.1016/j.physletb.2020.135454",
language = "English (US)",
volume = "805",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",
}