Suppression of Λ(1520) resonance production in central Pb-Pb collisions at √sNN=2.76 TeV
Acharya, Shreyasi; Adamová, Dagmar; Adolfsson, Jonatan; Aggarwal, Madan M.; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Nikita; Ahammed, Zubayer; Ahn, Sang Un; Aiola, Salvatore; Alme, Johan; Altenkaemper, Lucas; Djuvsland, Øystein; Ersdal, Magnus Rentsch; Fionda, Fiorella Maria Celeste; Nystrand, Joakim; Rehman, Attiq ur; Røhrich, Dieter; Tambave, Ganesh Jagannath; Ullaland, Kjetil; Wagner, Boris; Zhou, Zhuo; Arsene, Ionut Cristian; Bätzing, Paul Christoph; Dordic, Olja; Lardeux, Antoine Xavier; Lindal, Svein; Mahmood, Sohail Musa; Malik, Qasim Waheed; Richter, Matthias; Røed, Ketil; Skaali, Toralf Bernhard; Tveter, Trine Spedstad; Wikne, Jon Christopher; Zhao, Chengxin; Helstrup, Håvard; Hetland, Kristin Fanebust; Kileng, Bjarte; Nesbø, Simon Voigt; Storetvedt, Maksim Melnik; Langøy, Rune; Lien, Jørgen André; Akindinov, Alexander; Al-Turany, Mohammed; Alam, Sk Noor; De Albuquerque, Danilo Silva; Aleksandrov, Dimitry; Alessandro, Bruno; Alfaro Molina, José Rubén; Ali, Yasir Turki Ben; ALICE, Collaboration
Peer reviewed, Journal article
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The production yield of the Λ (1520) baryon resonance is measured at midrapidity in Pb-Pb collisions at √sNN = 2.76 TeV with the ALICE detector at the Large Hadron Collider (LHC). The measurement is performed in the Λ (1520) → pK − (and charge conjugate) hadronic decay channel as a function of the transverse momentum (pT) and collision centrality. The ratio of the pT -integrated production of Λ (1520) baryons relative to Λ baryons in central collisions is suppressed by about a factor of 2 with respect to peripheral collisions. This is the first observation of the suppression of a baryonic resonance at the LHC and the first 3 σ evidence of Λ (1520) suppression within a single collision system. The measured Λ (1520) / Λ ratio in central collisions is smaller than the value predicted by the statistical hadronization model calculations. The shape of the measured p T distribution and the centrality dependence of the suppression are reproduced by the EPOS3 Monte Carlo event generator. The measurement adds further support to the formation of a dense hadronic phase in the final stages of the evolution of the fireball created in heavy-ion collisions, lasting long enough to cause a significant reduction in the observable yield of short-lived resonances.