The production of Z 0 bosons at large rapidities in Pb–Pb collisions at s NN =5.02TeV is reported. Z 0 candidates are reconstructed in the dimuon decay channel (Z 0 →μ + μ − ), based on muons selected with pseudo-rapidity −4.0<η<−2.5 and p T >20GeV/c. The invariant yield and the nuclear modification factor, R AA , are presented as a function of rapidity and collision centrality. The value of R AA for the 0–20% central Pb–Pb collisions is 0.67±0.11(stat.)±0.03(syst.)±0.06(corr. syst.), exhibiting a deviation of 2.6σ from unity. The results are well-described by calculations that include nuclear modifications of the parton distribution functions, while the predictions using vacuum PDFs deviate from data by 2.3σ in the 0–90% centrality class and by 3σ in the 0–20% central collisions.

Measurement of Z(0)-boson production at large rapidities in Pb-Pb collisions at root s(NN)=5.02 TeV

Cicalo, C.;De Falco, A.;Fionda, F. M.;Usai, G. L.;
2018-01-01

Abstract

The production of Z 0 bosons at large rapidities in Pb–Pb collisions at s NN =5.02TeV is reported. Z 0 candidates are reconstructed in the dimuon decay channel (Z 0 →μ + μ − ), based on muons selected with pseudo-rapidity −4.0<η<−2.5 and p T >20GeV/c. The invariant yield and the nuclear modification factor, R AA , are presented as a function of rapidity and collision centrality. The value of R AA for the 0–20% central Pb–Pb collisions is 0.67±0.11(stat.)±0.03(syst.)±0.06(corr. syst.), exhibiting a deviation of 2.6σ from unity. The results are well-described by calculations that include nuclear modifications of the parton distribution functions, while the predictions using vacuum PDFs deviate from data by 2.3σ in the 0–90% centrality class and by 3σ in the 0–20% central collisions.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/255579
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