Speaker
Description
From the analysis of light (anti)nuclei multiplicities [1, 2] that were measured recently by the ALICE collaboration in Pb+Pb collisions at the center-of-mass collision energy √s =2.76 TeV [3] there arose a highly non-trivial question about the excluded volume of composite particles. Surprisingly, the hadron resonance gas model (HRGM) is able to perfectly describe the light (anti)nuclei multiplicities [1, 2] under various assumptions. For instance, one can consider the (anti)nuclei with a vanishing hard-core radius (as the point-like particles) or with the hard-core radius of proton, but the fit quality is the same for these assumptions. However, it is clear that such assumptions are unphysical. Hence we derived a new formula for the hard-core radius of a nuclei consisting of A baryons or antibaryons which does not lead to the hard-core radius expression R(A) = R(1) ∛A used in [2] recently for A>1. To implement a new relation into the HRMG we employ the induced surface tension concept [1, 4] and perform a thorough analysis of hadronic and (anti)nuclei multiplicities measured by the ALICE collaboration. The HRGM with the induced surface tension allows us to verify different assumptions on the values of hard-core radii and different scenarios of chemical freeze-out of (anti)nuclei. It is shown that the most successful description of hadrons can be achieved at the chemical freeze-out temperature of about Th=150 MeV, while the one for all (anti)nuclei is TA=168-172 MeV. Similar analysis is made for the 6-quark states suggested in [5] and their yields for the central high energy nuclear collisions are predicted.
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K. A. Bugaev, V. V. Sagun, A. I. Ivanytskyi, I. P. Yakimenko, E. G. Nikonov, A.V. Taranenko and G. M. Zinovjev, Nucl. Phys. A 970, 133 (2018).
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K. A. Bugaev, B. E. Grinyuk, A. I. Ivanytskyi, V. V. Sagun, D. O. Savchenko, G. M. Zinovjev, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, D. B. Blaschke, S. Kabana and A. V. Taranenko, arXiv:1812.02509v1 [hep-ph].
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J. Adam et al. [ALICE Collaboration], Phys. Rev. C 93, no. 2, 024917 (2016).
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V. V. Sagun, K. A. Bugaev, A. I. Ivanytskyi, I. P. Yakimenko, E. G. Nikonov, A.V. Taranenko, C. Greiner, D. B. Blaschke and G. M. Zinovjev, Eur. Phys. J. A 54, 100 (2018).
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G. R. Farrar, arXiv:1708.08951v2 [hep-ph].