Measurement of jet suppression in central Pb–Pb collisions at sNN=2.76 TeV

• Published in: Physics letters. B Vol. 746; no. C; pp. 1 - 14
• Main Authors: Aiola, S., Akindinov, A., Aleksandrov, D., Appelshäuser, H., Augustinus, A., Bagnasco, S., Baldisseri, A., Barnby, L.S., Bertens, R.A., Bhati, A.K., Bombara, M., Borissov, A., Broz, M., Caines, H., Carena, W., Christakoglou, P., Chujo, T., Colamaria, F., Colella, D., Corrales Morales, Y., Danu, A., Dobrin, A., Ehlers, R.J., Espagnon, B., Felea, D., Fragiacomo, E., Gagliardi, M., Gago, A.M., Ghosh, S.K., Giubilato, P., Graczykowski, L.K., Grosse-Oetringhaus, J.F., Haaland, Ø., Heide, M., Helstrup, H., Jang, H.J., Khan, P., Kim, M., Kiselev, S., Kondratiev, V., Krivda, M., Laudi, E., Lien, J., Lietava, R., Lunardon, M., Majka, R.D., Markert, C., Mas, A., Masoni, A., Mercado Pérez, J., Milosevic, J., Montes, E., Morando, M., Muhuri, S., Nellen, L., Pal, S.K., Papikyan, V., Pawlak, T., Poghosyan, M.G., Pop, A., Prino, F., Pruneau, C.A., Read, K.F., Reed, R.J., Rodriguez Manso, A., Romita, R., Rossi, A., Ryabinkin, E., Schmidt, C., Schukraft, J., Scioli, G., Seger, J.E., Sharma, N., Sibiriak, Y., Sinha, T., Snellings, R.J.M., Snellman, T.W., Søgaard, C., Stachel, J., Takahashi, J., Tejeda Muñoz, G., Terrevoli, C., Timmins, A.R., Tumkin, A., Tveter, T.S., Uras, A., Usai, G.L., Vande Vyvre, P., Velure, A., Viesti, G., Virgili, T., Völkl, M.A., Vranic, D., Wang, M., Yushmanov, I., Zaborowska, A., Zaman, A., Závada, P., Zhang, H., Zimmermann, M.B.
• Format: Journal Article
• Language: English; Norwegian
• Published: United States Elsevier B.V 30.06.2015; North-Holland; Elsevier
• Subjects: ATOMIC AND MOLECULAR PHYSICS
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2015.04.039

The transverse momentum (pT) spectrum and nuclear modification factor (RAA) of reconstructed jets in 0–10% and 10–30% central Pb–Pb collisions at sNN=2.76 TeV were measured. Jets were reconstructed using the anti-kT jet algorithm with a resolution parameter of R=0.2 from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal). The jet pT spectra are reported in the pseudorapidity interval of |ηjet|<0.5 for 40<pT,jet<120 GeV/c in 0–10% and for 30<pT,jet<100 GeV/c in 10–30% collisions. Reconstructed jets were required to contain a leading charged particle with pT>5 GeV/c to suppress jets constructed from the combinatorial background in Pb–Pb collisions. The leading charged particle requirement applied to jet spectra both in pp and Pb–Pb collisions had a negligible effect on the RAA. The nuclear modification factor RAA was found to be 0.28±0.04 in 0–10% and 0.35±0.04 in 10–30% collisions, independent of pT,jet within the uncertainties of the measurement. The observed suppression is in fair agreement with expectations from two model calculations with different approaches to jet quenching.