The first measurement of the Υ(1S) elliptic flow coefficient (v2) is performed at forward rapidity (2.5 < y < 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 Υ(1S) v2 is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v2 coefficient in 2 < pT < 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 Υ(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
Camerini P.;Contin G.;Faggin M.;Lea R.;Luparello G.;Margagliotti G. V.;Piano S.;Rui R.;Zaccolo V.;
2019-01-01
Abstract
The first measurement of the Υ(1S) elliptic flow coefficient (v2) is performed at forward rapidity (2.5 < y < 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 Υ(1S) v2 is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v2 coefficient in 2 < pT < 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 Υ(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 | Dimensione | Formato | |
---|---|---|---|
PRL_123(2019)192301_1-13.pdf
accesso aperto
Tipologia:
Documento in Versione Editoriale
Licenza:
Creative commons
Dimensione
385.98 kB
Formato
Adobe PDF
|
385.98 kB | Adobe PDF | Visualizza/Apri |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.