Measurements of K∗(892)0 and φ(1020) resonance production in Pb–Pb and pp collisions at √sNN = 5.02 TeV with the ALICE detector at the Large Hadron Collider are reported. The resonances are measured at midrapidity (|y| < 0.5) via their hadronic decay channels and the transverse momentum (pT ) distributions are obtained for various collision centrality classes up to pT = 20 GeV/c. The pT -integrated yield ratio K∗(892)0/K in Pb–Pb collisions shows significant suppression relative to pp collisions and decreases towards more central collisions. In contrast, the φ(1020)/K ratio does not show any suppression. Furthermore, the measured K∗(892)0/K ratio in central Pb–Pb collisions is significantly suppressed with respect to the expectations based on a thermal model calculation, while the φ(1020)/K ratio agrees with the model prediction. These measurements are an experimental demonstration of rescattering of K∗(892)0 decay products in the hadronic phase of the collisions. The K∗(892)0/K yield ratios in Pb–Pb and pp collisions are used to estimate the time duration between chemical and kinetic freeze-out, which is found to be ∼ 4–7 fm/c for central collisions. The pT -differential ratios of K∗(892)0/K, φ(1020)/K, K∗(892)0/ π , φ(1020)/ π , p/K∗(892)0 and p/φ(1020) are also presented for Pb–Pb and pp collisions at √sNN = 5.02 TeV. These ratios show that the rescattering effect is predominantly a low-pT phenomenon.

Evidence of rescattering effect in Pb–Pb collisions at the LHC through production of K∗(892)0 and φ(1020) mesons / The ALICE collaboration, ., Acharya, S., Adamová, D., Adler, A., Aglieri Rinella, G., Agnello, M., Agrawal, N., Ahammed, Z., Ahn, S.U., Ahuja, I., Akbar, Z., Akindinov, A., Al-Turany, M., Alam, S.N., Aleksandrov, D., Alessandro, B., Alfanda, H.M., Alfaro Molina, R., Ali, B., Ali, Y., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 802:(2020), pp. 1-14. [10.1016/j.physletb.2020.135225]

Evidence of rescattering effect in Pb–Pb collisions at the LHC through production of K∗(892)0 and φ(1020) mesons

L. Cunqueiro
Membro del Collaboration Group
;
2020

Abstract

Measurements of K∗(892)0 and φ(1020) resonance production in Pb–Pb and pp collisions at √sNN = 5.02 TeV with the ALICE detector at the Large Hadron Collider are reported. The resonances are measured at midrapidity (|y| < 0.5) via their hadronic decay channels and the transverse momentum (pT ) distributions are obtained for various collision centrality classes up to pT = 20 GeV/c. The pT -integrated yield ratio K∗(892)0/K in Pb–Pb collisions shows significant suppression relative to pp collisions and decreases towards more central collisions. In contrast, the φ(1020)/K ratio does not show any suppression. Furthermore, the measured K∗(892)0/K ratio in central Pb–Pb collisions is significantly suppressed with respect to the expectations based on a thermal model calculation, while the φ(1020)/K ratio agrees with the model prediction. These measurements are an experimental demonstration of rescattering of K∗(892)0 decay products in the hadronic phase of the collisions. The K∗(892)0/K yield ratios in Pb–Pb and pp collisions are used to estimate the time duration between chemical and kinetic freeze-out, which is found to be ∼ 4–7 fm/c for central collisions. The pT -differential ratios of K∗(892)0/K, φ(1020)/K, K∗(892)0/ π , φ(1020)/ π , p/K∗(892)0 and p/φ(1020) are also presented for Pb–Pb and pp collisions at √sNN = 5.02 TeV. These ratios show that the rescattering effect is predominantly a low-pT phenomenon.
2020
heavy-ion collisions; rescattering effects; resonance production
01 Pubblicazione su rivista::01a Articolo in rivista
Evidence of rescattering effect in Pb–Pb collisions at the LHC through production of K∗(892)0 and φ(1020) mesons / The ALICE collaboration, ., Acharya, S., Adamová, D., Adler, A., Aglieri Rinella, G., Agnello, M., Agrawal, N., Ahammed, Z., Ahn, S.U., Ahuja, I., Akbar, Z., Akindinov, A., Al-Turany, M., Alam, S.N., Aleksandrov, D., Alessandro, B., Alfanda, H.M., Alfaro Molina, R., Ali, B., Ali, Y., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 802:(2020), pp. 1-14. [10.1016/j.physletb.2020.135225]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1654995
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