A measurement of the transverse momentum spectra of jets in Pb-Pb collisions at root s(NN) = 2.76 TeV is reported. Jets are reconstructed from charged particles using the anti-k(T) jet algorithm with jet resolution parameters R of 0.2 and 0.3 in pseudorapidity vertical bar eta vertical bar < 0.5. The transverse momentum p(T) of charged particles is measured down to 0.15 GeV/c which gives access to the low p(T) fragments of the jet. Jets found in heavy-ion collisions are corrected event-by-event for average background density and on an inclusive basis (via unfolding) for residual background fluctuations and detector effects. A strong suppression of jet production in central events with respect to peripheral events is observed. The suppression is found to be similar to the suppression of charged hadrons, which suggests that substantial energy is radiated at angles larger than the jet resolution parameter R = 0.3 considered in the analysis. The fragmentation bias introduced by selecting jets with a high p(T) leading particle, which rejects jets with a soft fragmentation pattern, has a similar effect on the jet yield for central and peripheral events. The ratio of jet spectra with R = 0.2 and R = 0.3 is found to be similar in Pb-Pb and simulated PYTHIA pp events, indicating no strong broadening of the radial jet structure in the reconstructed jets with R < 0.3.

Measurement of charged jet suppression in Pb-Pb collisions at root s(NN)=2.76 TeV

CASULA, ESTER ANNA RITA;Cicalo C.;COLLU, ALBERTO;DE FALCO, ALESSANDRO;FIONDA, FIORELLA MARIA CELESTE;INCANI, ELISA;PUDDU, GIOVANNA;SIDDHANTA, SABYASACHI;USAI, GIANLUCA;
2014-01-01

Abstract

A measurement of the transverse momentum spectra of jets in Pb-Pb collisions at root s(NN) = 2.76 TeV is reported. Jets are reconstructed from charged particles using the anti-k(T) jet algorithm with jet resolution parameters R of 0.2 and 0.3 in pseudorapidity vertical bar eta vertical bar < 0.5. The transverse momentum p(T) of charged particles is measured down to 0.15 GeV/c which gives access to the low p(T) fragments of the jet. Jets found in heavy-ion collisions are corrected event-by-event for average background density and on an inclusive basis (via unfolding) for residual background fluctuations and detector effects. A strong suppression of jet production in central events with respect to peripheral events is observed. The suppression is found to be similar to the suppression of charged hadrons, which suggests that substantial energy is radiated at angles larger than the jet resolution parameter R = 0.3 considered in the analysis. The fragmentation bias introduced by selecting jets with a high p(T) leading particle, which rejects jets with a soft fragmentation pattern, has a similar effect on the jet yield for central and peripheral events. The ratio of jet spectra with R = 0.2 and R = 0.3 is found to be similar in Pb-Pb and simulated PYTHIA pp events, indicating no strong broadening of the radial jet structure in the reconstructed jets with R < 0.3.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/106340
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 118
  • ???jsp.display-item.citation.isi??? 96
social impact