@article{791bc6660aac43d2a13132699f809fd3,
title = "Antiproton over proton and K− over K+ multiplicity ratios at high z in DIS",
abstract = "The antiparticle-over-particle multiplicity ratio is measured in deep-inelastic scattering for negatively and positively charged kaons and, for the first time, for antiprotons and protons. The data were obtained by the COMPASS Collaboration using a 160 GeV muon beam impinging on an isoscalar 6LiD target. The regime of deep-inelastic scattering is ensured by requiring Q2 > 1 (GeV/c)2 for the photon virtuality and W>5 GeV/c2 for the invariant mass of the produced hadronic system. Bjorken-x is restricted to the range 0.01 to 0.40. Protons and antiprotons are identified in the momentum range from 20 GeV/c to 60 GeV/c and required to carry a large fraction of the virtual-photon energy, z>0.5. In the whole studied z-region, the p¯ over p multiplicity ratio is found to be below the lower limit expected from calculations based on leading-order perturbative Quantum Chromodynamics (pQCD). Kaons were previously analysed in the momentum range 12 GeV/c to 40 GeV/c. In the present analysis this range is extended up to 55 GeV/c, whereby events with larger virtual-photon energies are included in the analysis and the observed K− over K+ ratio becomes closer to the expectation of next-to-leading order pQCD. The results of both analyses strengthen our earlier conclusion that at COMPASS energies the phase space available for single-hadron production in deep-inelastic scattering should be taken into account in the standard pQCD formalism.",
keywords = "COMPASS, Deep-inelastic scattering, Hadron multiplicities, Quantum chromodynamics, pQCD",
author = "{The COMPASS Collaboration} and Alexeev, {G. D.} and Alexeev, {M. G.} and A. Amoroso and V. Andrieux 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 {Berenguer Antequera}, J. and J. Bernhard and M. Bodlak 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 Correia, {P. M.M.} and Crespo, {M. L.} and D. D'Ago and {Dalla Torre}, S. and Dasgupta, {S. S.} and S. Dasgupta and I. Denisenko and Denisov, {O. Yu} 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 P. Faccioli and M. Faessler and M. Finger 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 CERN-RFBR Grant 12-02-91500.Supported by FCT, Grants CERN/FIS-PAR/0007/2017 and CERN/FIS-PAR/0022/2019 (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 ANR, France with P2IO LabEx (ANR-10-LABX-0038) in the framework “Investissements d'Avenir” (ANR-11-IDEX-0003-01). Publisher Copyright: {\textcopyright} 2020",
year = "2020",
month = aug,
day = "10",
doi = "10.1016/j.physletb.2020.135600",
language = "English (US)",
volume = "807",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",
}