Jet-like correlations with respect to KS0 and Λ (Λ ¯) in pp and central Pb–Pb collisions at √sNN=5.02 TeV

Abstract

Two-particle correlations with KS0 , Λ / Λ ¯ , and charged hadrons as trigger particles in the transverse momentum range 8 < pT , trig< 16 GeV/ c , and associated charged particles within 1 < pT , assoc< 8 GeV/ c , are studied at midrapidity in pp and central Pb–Pb collisions at a centre-of-mass energy per nucleon–nucleon collision sNN=5.02 TeV with the ALICE detector at the LHC. After subtracting the contributions of the flow background, the per-trigger yields are extracted on both the near and away sides, and the ratio in Pb–Pb collisions with respect to pp collisions (IAA) is computed. The per-trigger yield in Pb–Pb collisions on the away side is strongly suppressed to the level of IAA≈ 0.6 for pT , assoc> 3 GeV/ c as expected from strong in-medium energy loss, while an enhancement develops at low pT , assoc on both the near and away sides, reaching IAA≈ 1.8 and 2.7 respectively. These findings are in good agreement with previous ALICE measurements from two-particle correlations triggered by neutral pions (π –h) and charged hadrons (h–h) in Pb–Pb collisions at sNN=2.76 TeV. Moreover, the correlations with KS0 mesons and Λ / Λ ¯ baryons as trigger particles are compared to those of inclusive charged hadrons. The results are compared with the predictions of Monte Carlo models.