Antiproton over proton and K− over K+ multiplicity ratios at high z in DIS

Alexeev G. D.; Alexeev M. G.; Amoroso A.; Andrieux V.; Anosov V.; Antoshkin A.; Augsten K.; Augustyniak W.; Azevedo C. D. R.; Badelek B.; Balestra F.; Ball M.; Barth J.; Beck R.; Bedfer Y.; Berenguer Antequera J.; Bernhard J.; Bodlak M.; Bradamante F.; Bressan A.; Buchele M.; Burtsev V. E.; Chang W. -C.; Chatterjee C.; Chiosso M.; Chumakov A. G.; Chung S. -U.; Cicuttin A.; Correia P. M. M.; Crespo M. L.; D'Ago D.; Dalla Torre S.; Dasgupta S. S.; Dasgupta S.; Denisenko I.; Denisov O. Y.; Donskov S. V.; Doshita N.; Dreisbach C.; Dunnweber W.; Dusaev R. R.; Efremov A.; Eversheim P. D.; Faccioli P.; Faessler M.; Finger M.; Fischer H.; Franco C.; Friedrich J. M.; Frolov V.; Gautheron F.; Gavrichtchouk O. P.; Gerassimov S.; Giarra J.; Gnesi I.; Gorzellik M.; Grasso A.; Gridin A.; Grosse Perdekamp M.; Grube B.; Guskov A.; von Harrach D.; Heitz R.; Herrmann F.; Horikawa N.; d'Hose N.; Hsieh C. -Y.; Huber S.; Ishimoto S.; Ivanov A.; Iwata T.; Jandek M.; Jary V.; Joosten R.; Jorg P.; Kabuss E.; Kaspar F.; Kerbizi A.; Ketzer B.; Khaustov G. V.; Khokhlov Y. A.; Kisselev Y.; Klein F.; Koivuniemi J. H.; Kolosov V. N.; Kondo Horikawa K.; Konorov I.; Konstantinov V. F.; Kotzinian A. M.; Kouznetsov O. M.; Koval A.; Kral Z.; Krinner F.; Kulinich Y.; Kunne F.; Kurek K.; Kurjata R. P.; Kveton A.; Lavickova K.; Levorato S.; Lian Y. -S.; Lichtenstadt J.; Lin P. -J.; Longo R.; Lyubovitskij V. E.; Maggiora A.; Magnon A.; Makins N.; Makke N.; Mallot G. K.; Maltsev A.; Mamon S. A.; Marianski B.; Martin A.; Marzec J.; Matousek J.; Matsuda T.; Mattson G.; Meshcheryakov G. V.; Meyer M.; Meyer W.; Mikhailov Y. V.; Mikhasenko M.; Mitrofanov E.; Mitrofanov N.; Miyachi Y.; Moretti A.; Nagaytsev A.; Naim C.; Neyret D.; Novy J.; Nowak W. -D.; Nukazuka G.; Nunes A. S.; Olshevsky A. G.; Ostrick M.; Panzieri D.; Parsamyan B.; Paul S.; Pekeler H.; Peng J. -C.; Pesek M.; Peshekhonov D. V.; Peskova M.; Pierre N.; Platchkov S.; Pochodzalla J.; Polyakov V. A.; Pretz J.; Quaresma M.; Quintans C.; Reicherz G.; Riedl C.; Rudnicki T.; Ryabchikov D. I.; Rybnikov A.; Rychter A.; Samoylenko V. D.; Sandacz A.; Sarkar S.; Savin I. A.; Sbrizzai G.; Schmieden H.; Selyunin A.; Sinha L.; Slunecka M.; Smolik J.; Srnka A.; Steffen D.; Stolarski M.; Subrt O.; Sulc M.; Suzuki H.; Sznajder P.; Tessaro S.; Tessarotto F.; Thiel A.; Tomsa J.; Tosello F.; Townsend A.; Tskhay V.; Uhl S.; Vasilishin B. I.; Vauth A.; Veit B. M.; Veloso J.; Ventura B.; Vidon A.; Virius M.; Wagner M.; Wallner S.; Zaremba K.; Zavada P.; Zavertyaev M.; Zemko M.; Zemlyanichkina E.; Zhao Y.; Ziembicki M.

Antiproton over proton and K− over K+ multiplicity ratios at high z in DIS

Alexeev G. D.

•

Alexeev M. G.

•

Amoroso A.

altro

Ziembicki M.

2020

journal article

Periodico

PHYSICS LETTERS. SECTION B

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.