The first measurement of the γ(1S) elliptic flow coefficient (v2) is performed at forward rapidity (2.5<4) in Pb-Pb collisions at sNN=5.02 TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (pT) up to 15 GeV/c in the 5%-60% centrality interval. The measured γ(1S)v2 is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v2 coefficient in 2<15 GeV/c is lower than that of inclusive J/ψ mesons in the same pT interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the γ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.

Measurement of γ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sNN =5.02 TeV

Baruffaldi F.;Dainese A.;Giubilato P.;Lunardon M.;Moretto S.;Rossi A.;Soramel F.;Turrisi R.;
2019

Abstract

The first measurement of the γ(1S) elliptic flow coefficient (v2) is performed at forward rapidity (2.5<4) in Pb-Pb collisions at sNN=5.02 TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (pT) up to 15 GeV/c in the 5%-60% centrality interval. The measured γ(1S)v2 is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v2 coefficient in 2<15 GeV/c is lower than that of inclusive J/ψ mesons in the same pT interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the γ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

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/11577/3326898
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 51
  • ???jsp.display-item.citation.isi??? 30
social impact