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Measurement of the cross section for hard exclusive pi(0) muoproduction on the proton

SYSNO ASEP	0532103
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Measurement of the cross section for hard exclusive pi(0) muoproduction on the proton
Author(s)	Alexeev, M. G. (IT) Alexeev, A. (RU) Amoroso, A. (IT) Srnka, Aleš (UPT-D)_{RID, ORCID, SAI}
Number of authors	203
Article number	135454
Source Title	Physics Letters. B. - : Elsevier - ISSN 0370-2693 Roč. 805, JUN (2020)
Number of pages	8 s.
Publication form	Print - P
Language	eng - English
Country	NL - Netherlands
Keywords	quantum chromodynamics ; muoproduction ; hard exclusive meson production ; generalised Parton Distributions ; compass
Subject RIV	BJ - Thermodynamics
OECD category	Particles and field physics
Method of publishing	Open access
Institutional support	UPT-D - RVO:68081731
UT WOS	000541379800025
EID SCOPUS	85084498386
DOI	10.1016/j.physletb.2020.135454
Annotation	We report on a measurement of hard exclusive pi(0) muoproduction on the proton by COMPASS using 160GeV/cpolarised mu+ and mu- beams of the CERN SPS impinging on a liquid hydrogen target. From the average of the measured mu+ and mu- 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) <vertical bar t vertical bar < 0.64 (GeV/c)(2). The average kinematics of the measurement are Q(2) = 2.0 (GeV/c)(2), nu = 12.8 GeV, x(Bj) = 0.093andt = 0.256 (GeV/c)(2). Fitting the azimuthal dependence reveals a combined contribution by transversely and longitudinally polarised photons of (8.2 +/- 0.9(stat-1.2)(+1.2)vertical bar(sys)) nb/(GeV/c)(2), as well as transverse-transverse and longitudinal-transverse interference contributions of (-6.1 +/- 1.3(stat- 0.7)(+0.7) vertical bar sys) nb/(GeV/c)(2) and (1.5 +/- 0.5(stat-0.2)(+ 0.3) vertical bar(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 transversetransverse interference contribution constitutes clear experimental evidence for the chiral-odd GPD ET. (C) 2020 The Author(s). Published by Elsevier B.V.
Workplace	Institute of Scientific Instruments
Contact	Martina Šillerová, sillerova@ISIBrno.Cz, Tel.: 541 514 178
Year of Publishing	2021
Electronic address	https://www.sciencedirect.com/science/article/pii/S0370269320302586

Number of the records: 1