Measurement of charm and beauty production at central rapidity versus charged-particle multiplicity in proton-proton collisions at √s = 7 TeV

Scientific paper - Original scientific paper

• Author: J. Adam
• Author: ...
• Author: Tome Antičić
• Author: ...
• Author: Sven Gotovac
• Author: ...
• Author: Eugen Mudnić
• Author: ...
• Author: Mirko Planinić
• Author: ...
• Author: Nikola Poljak
• Author: ...
• Author: Goran Simatović
• Author: ...
• Author: Antonija Utrobičić
• Author: ...
• Author: Linda Vicković
• Author: ...
• Author: M. Zyzak
• Collaboration: ALICE Collaboration
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Prompt D meson and non-prompt J/ψ yields are studied as a function of the multiplicity of charged particles produced in inelastic proton-proton collisions at a centreof-mass energy of √s = 7 TeV. The results are reported as a ratio between yields in a given multiplicity interval normalised to the multiplicity-integrated ones (relative yields). They are shown as a function of the multiplicity of charged particles normalised to the average value for inelastic collisions (relative charged-particle multiplicity). D0 , D+ and D∗+ mesons are measured in five pT intervals from 1 GeV/c to 20 GeV/c and for |y| < 0.5 via their hadronic decays. The D-meson relative yield is found to increase with increasing charged-particle multiplicity. For events with multiplicity six times higher than the average multiplicity of inelastic collisions, a yield enhancement of a factor about 15 relative to the multiplicity-integrated yield in inelastic collisions is observed. The yield enhancement is independent of transverse momentum within the uncertainties of the measurement. The D0 -meson relative yield is also measured as a function of the relative multiplicity at forward pseudo-rapidity. The non-prompt J/ψ, i.e. the B hadron, contribution to the inclusive J/ψ production is measured in the di-electron decay channel at central rapidity. It is evaluated for pT > 1.3 GeV/c and |y| < 0.9, and extrapolated to pT > 0. The fraction of non-prompt J/ψ in the inclusive J/ψ yields shows no dependence on the charged-particle multiplicity at central rapidity. Charm and beauty hadron relative yields exhibit a similar increase with increasing charged-particle multiplicity. The measurements are compared to PYTHIA 8, EPOS 3 and percolation calculations.

• Keywords (english): hadron-hadron scattering; charm; beauty; central rapidity; multiplicity; pp; 7 TeV
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Journal of High Energy Physics
• Numbering: vol. 2015, no. 9, 148
• p-ISSN: 1126-6708
• e-ISSN: 1029-8479
• DOI: https://doi.org/10.1007/JHEP09(2015)148
• URN:NBN: urn:nbn:hr:217:685495
• Publication: 2015
• Document URL: https://link.springer.com/article/10.1007%2FJHEP09%282015%29148
• Type of resource: Text
• Access conditions: Open access
• Public note: Open Access. © Copyright CERN, for the benefit of the ALICE Collaboration. Article funded by SCOAP3. Received: May 11, 2015. Revised: June 5, 2015. Accepted: August 10, 2015. Published: September 22, 2015.
• Created on: 2020-01-18 18:39:05