Centrality and transverse momentum dependence of inclusive J/ψ production at midrapidity in Pb–Pb collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msqrt><mml:mrow><mml:msub><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mtext>NN</mml:mtext></mml:mrow></mml:msub></mml:mrow></mml:msqrt><mml:mo linebreak="goodbreak" linebreakstyle="after">=</mml:mo><mml:mn>5.02</mml:mn></mml:math> TeV
S. Acharya, D. Adamová, A. Adler, J. Adolfsson, M. M. Aggarwal, G. Aglieri Rinella, M. Agnello, N. Agrawal, Z. Ahammed, S. Ahmad, S. U. Ahn, A. Akindinov, M. Al-Turany, S.N. Alam, D. S. D. Albuquerque, D. Aleksandrov, B. Alessandro, H. M. Alfanda, R. Alfaro Molina, B. Ali, Y. Ali, A. Alici, A. Alkin, J. Alme, T. Alt, L. Altenkamper, I. Altsybeev, M.N. Anaam, C. Andrei, D. Andreou, H.A. Andrews, A. Andronic, M. Angeletti, V. Anguelov, C. Anson, T. Antičić, F. Antinori, P. Antonioli, R. Anwar, N. Apadula, L. Aphecetche, H. Appelshäuser, S. Arcelli, R. Arnaldi, M. Arratia, I. C. Arsene, M. Arslandok, A. Augustinus, R. Averbeck, S. Aziz, M. D. Azmi, A. Badalà, Yong Wook Baek, S. Bagnasco, Xiaozhi Bai, R. Bailhache, R. Bala, A. Baldisseri, M. Ball, Samah Balouza, R. Barbera, L. Barioglio, G. G. Barnaföldi, L. S. Barnby, V. Barret, P. Bartalini, K. Barth, E. Bartsch, F. Baruffaldi, N. Bastid, S. Basu, G. Batigne, B. Batyunya, D. Bauri, J. L. Bazo Alba, I. G. Bearden, C. Bedda, N. K. Behera, I. Belikov, A. D. C. Bell Hechavarria, F. Bellini, R. Bellwied, V. Belyaev, G. Bencedi, S. Beolè, A. Bercuci, Y. Berdnikov, D. Berenyi, R.A. Bertens, D. Berzano, M. G. Besoiu, L. Betev, A. Bhasin, I. R. Bhat, M. A. Bhat, H. Bhatt, B. Bhattacharjee, A. Bianchi, L. Bianchi, N. Bianchi
Abstract
The inclusive J / ψ meson production in Pb–Pb collisions at a center-of-mass energy per nucleon–nucleon collision of s NN = 5.02 TeV at midrapidity ( | y | < 0.9 ) is reported by the ALICE Collaboration. The measurements are performed in the dielectron decay channel, as a function of event centrality and J / ψ transverse momentum p T , down to p T = 0 . The J / ψ mean transverse momentum 〈 p T 〉 and r AA ratio, defined as 〈 p T 2 〉 PbPb / 〈 p T 2 〉 pp , are evaluated. Both observables show a centrality dependence decreasing towards central (head-on) collisions. The J / ψ nuclear modification factor R AA exhibits a strong p T dependence with a large suppression at high p T and an increase to unity for decreasing p T . When integrating over the measured momentum range p T < 10 GeV / c , the J / ψ R AA shows a weak centrality dependence. Each measurement is compared with results at lower center-of-mass energies and with ALICE measurements at forward rapidity, as well as to theory calculations. All reported features of the J / ψ production at low p T are consistent with a dominant contribution to the J / ψ yield originating from charm quark (re)combination.