Antiproton over proton and K− over K+ multiplicity ratios at high z in DIS
G.D Alexeev , K Kurek , Robert Kurjata , Janusz Marzec , W.-D. Nowak , Marcin Stolarski , Krzysztof Zaremba , Marcin Ziembicki
AbstractThe 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.
|Collective author||M.G. Alexeev, A Amoroso, V Andrieux, V Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C.....|
|Total number of authors||198|
|Journal series||Physics Letters B, [Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics], ISSN 0370-2693, e-ISSN 1873-2445|
|Publication size in sheets||6780|
|Score||= 140.0, 22-07-2020, ArticleFromJournal|
|Publication indicators||: 2017 = 1.548; : 2018 = 4.162 (2) - 2018=3.627 (5)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.