The production of Z0 bosons at large rapidities in Pb–Pb collisions at √sNN = 5.02 TeV is reported. Z0 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 pT > 20 GeV/c. The invariant yield and the nuclear modification factor, RAA , are presented as a function of rapidity and collision centrality. The value of RAA 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 $\sqrt{s_{\rm NN}}=5.02$ TeV} / The ALICE collaboration, ., Acharya, S., Acosta, F.T.-., Adamová, D., Adolfsson, J., Aggarwal, M.M., Aglieri Rinella, G., Agnello, M., Agrawal, N., Ahammed, Z., Ahn, S.U., Aiola, S., Akindinov, A., Al-Turany, M., Alam, S.N., Albuquerque, D.S.D., Aleksandrov, D., Alessandro, B., Alfaro Molina, R., Ali, Y., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 780:(2018), pp. 372-383. [10.1016/j.physletb.2018.03.010]
{Measurement of Z$^0$-boson production at large rapidities in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV}
L. CunqueiroMembro del Collaboration Group
;
2018
Abstract
The production of Z0 bosons at large rapidities in Pb–Pb collisions at √sNN = 5.02 TeV is reported. Z0 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 pT > 20 GeV/c. The invariant yield and the nuclear modification factor, RAA , are presented as a function of rapidity and collision centrality. The value of RAA 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
