Measurement of Ds+ production and nuclear modification factor in Pb-Pb collisions at √sNN = 2.76 TeV

Author(s): The ALICE collaboration; Adam, J; Adamova, D; Aggarwal, MM; Aglieri Rinella, G; Agnello, M; Agrawal, N; Ahammed, Z; Ahn, SU; Aiola, S; Akindinov, A; Alam, SN; Aleksandrov, D; Alessandro, B; Alexandre, D; Alfaro Molina, R; Alici, A; Alkin, A; Almaraz, JRM; Alme, J; Alt, T; Altinpinar, S; Altsybeev, I; Alves Garcia Prado, C; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Anticic, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshauser, H; Arcelli, S; Arnaldi, R; Arnold, OW; Arsene, IC; Arslandok, M; Audurier, B; Augustinus, A; Averbeck, R; Azmi, MD; Badala, A; Baek, YW; Bagnasco, S; Bailhache, R; Bala, R; Baldisseri, A; Baral, RC; Barbano, AM; Barbera, R; Barile, F; Barnafoldi, GG; Barnby, LS; Barret, V; Bartalini, P; Barth, K; Bartke, J; Bartsch, E; Basile, M; Bastid, N; Basu, S; Bathen, B; Batigne, G; Batista Camejo, A; Batyunya, B; Batzing, PC; Bearden, IG; Beck, H; Bedda, C; Behera, NK; Belikov, I; Bellini, F; Bello Martinez, H; Bellwied, R; Belmont, R; Belmont-Moreno, E; Belyaev, V; Bencedi, G; Beole, S; Berceanu, I; Bercuci, A; Berdnikov, Y; Berenyi, D; Bertens, RA | Abstract: © 2016, The Author(s). The production of prompt Ds+mesons was measured for the first time in collisions of heavy nuclei with the ALICE detector at the LHC. The analysis was performed on a data sample of Pb-Pb collisions at a centre-of-mass energy per nucleon pair, (Formula presented.),of 2.76 TeV in two different centrality classes, namely 0–10% and 20–50%. Ds+mesons and their antiparticleswere reconstructed at mid-rapidity from their hadronic decay channel Ds+→ ϕπ+, with ϕ → K−K+, in the transverse momentum intervals 4 l pTl 12GeV/c and 6 l pTl 12 GeV/c for the 0–10% and 20–50% centrality classes, respectively. The nuclear modification factor RAAwas computed by comparing the pT-differential production yields in Pb-Pb collisions to those in proton-proton (pp) collisions at the same energy. This pp reference was obtained using the cross section measured at (Formula presented.) TeV and scaled to (Formula presented.) TeV. The RAAof Ds+mesons was compared to that of non-strange D mesonsin the 10% most central Pb-Pb collisions. At high pT(8 l pTl 12 GeV/c) a suppression of the Ds+-meson yield by a factor of about three, compatible within uncertainties with that of non-strange D mesons, is observed. At lower pT(4 l pTl 8 GeV/c) the values of the Ds+-meson RAAare larger than those of non-strange D mesons, although compatible within uncertainties. The production ratios Ds+/D0and Ds+/D+were also measured in Pb-Pb collisions and compared to their values in proton-proton collisions.