Электронный каталог

Статья

Acharya, S.
Multiplicity Dependence of Charged-Particle Intra-Jet Properties in pp Collisions at *%s=13 TeV / S.Acharya, B.Batyunya, C.Ceballos Sanchez, R.A.Diaz, S.Grigoryan, A.Kondratyev, L.Malinina, K.Mikhaylov, P.Nomokonov, V.Pozdniakov, E.Rogochaya, B.Rumyantsev, A.Vodopyanov, [ALICE Collab.] // The European Physical Journal C [Electronic resource]. – 2024. – Vol. 84, No. 10. – P. 1079. – URL: https://doi.org/10.1140/epjc/s10052-024-13228-0. – Bibliogr.: 88.

The first measurement of the multiplicity dependence of intra-jet properties of leading charged-particle jets in proton–proton (pp) collisions is reported. The mean chargedparticle multiplicity and jet fragmentation distributions are measured in minimum-bias and high-multiplicity pp collisions at center-of-mass energy √s = 13 TeV using the ALICE detector. Jets are reconstructed from charged particles produced in the midrapidity region (|η| < 0.9) using the sequential recombination anti-kT algorithm with jet resolution parameters R = 0.2, 0.3, and 0.4 for the transverse momentum (pT) interval 5–110 GeV/c. The highmultiplicity events are selected by the forward V0 scintillator detectors. The mean charged-particle multiplicity inside the leading jet cone rises monotonically with increasing jet pT in qualitative agreement with previous measurements at lower energies. The distributions of jet fragmentation function variables z&sup(ch) and ξ&sup(ch) are measured for different jet-p&sub(T) intervals. Jet-p&sub(T) independent fragmentation of leading jets is observed for wider jets except at high- and low-z&sup(ch) values. The observed “hump-backed plateau” structure in the ξ ch distribution indicates suppression of low-p&sub(T) particles. In high-multiplicity events, an enhancement of the fragmentation probability of low-z&sup(ch) particles accompanied by a suppression of high-z&sup(ch) particles is observed compared to minimum-bias events. This behavior becomes more prominent for low-p&sub(T) jets with larger jet radius. The results are compared with predictions of QCD-inspired event generators, PYTHIA 8 with Monash 2013 tune and EPOS LHC. It is found that PYTHIA 8 qualitatively reproduces the jet modification in high-multiplicity events except at high jet p&sub(T). These measurements provide important constraints to models of jet fragmentation.



ОИЯИ = ОИЯИ (JINR)2024