Naslov
Measurement of neutral strange particle production in the underlying event in proton-proton collisions at sqrt(s) = 7 TeV

Autori
Chatrchyan, S. ; ... ; Godinović, Nikola ; Lelas, Damir ; Pleština, Roko ; Polić, Dunja ; Puljak, Ivica ; Antunović, Željko ; Kovač, Marko ; Brigljević, Vuko ; Đurić, Senka ; Kadija, Krešo ; Luetić, Jelena ; Morović, Srećko ; Mekterović, Darko ; Tikvica, Lucija ; ... ; Swanson, J.

Izvornik
Physical Review D - Particles, Fields, Gravitation, and Cosmology (1550-7998) 88 (2013); 052001-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
LHC. CMS; strange particle

Sažetak
Measurements are presented of the production of primary K(S)0 and Lambda particles in proton-proton collisions at sqrt(s) = 7 TeV in the region transverse to the leading charged-particle jet in each event. The average multiplicity and average scalar transverse momentum sum of K(S)0 and Lambda particles measured at pseudorapidities abs(eta) < 2 rise with increasing charged-particle jet pt in the range 1-10 GeV and saturate in the region 10-50 GeV. The rise and saturation of the strange particle yields and transverse momentum sums in the underlying event are similar to those observed for inclusive charged particles, which confirms the impact-parameter picture of multiple parton interactions. The results are compared to recent tunes of the PYTHIA Monte Carlo event generator. The PYTHIA simulations underestimate the data by 15-30% for K(S)0 mesons and by about 50% for Lambda baryons, a deficit similar to that observed for the inclusive strange particle production in non-single-diffractive proton-proton collisions. The constant strange- to charged-particle activity ratios and the similar trends for mesons and baryons indicate that the multiparton- interaction dynamics is decoupled from parton hadronization, which occurs at a later stage.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA