Programme

O.36 -- Oral, VCTP-51

Date: Thursday, 6 August 2026

Time: 11:10 - 11:30

Classification of phase transitions in hot nuclei

Le Thi Quynh Huong (1), Tran Quoc Viet (2,3), Le Tan Phuc (2,3), Tran Vu Dong (2,3), Hoang Anh Tuan Kiet (4), Balaram Dey (5), Nguyen Ngoc Anh (6), and Nguyen Quang Hung (2,3)

(1) University of Khanh Hoa, 01 Nguyen Chanh, Nha Trang, Khanh Hoa Province 65000, Vietnam (2) Institute of Fundamental and Applied Sciences, Duy Tan University, Ho Chi Minh City 70000, Vietnam (3) Faculty of Natural Sciences, Duy Tan University, Danang City 50000, Vietnam (4) Department of Physics & Engineering, West Chester University of PA, West Chester, PA 19383, United States of America (5) Department of Physics, Bankura University, Bankura, West Bengal-722155, India (6) Phenikaa Institute for Advanced Study (PIAS), PHENIKAA University, Yen Nghia, Ha Dong, Hanoi 12116, Vietnam

Phase transitions in finite nuclei, particularly pairing and shape transitions, provide insight for advancing our understanding of fundamental physics, from the behavior of matter under extreme conditions to the nature of the strong force. However, classification of those transitions is always complex task due to the occurrence of several distinct phase transitions rather than a single one. In this work, phase transitions in hot 160−164Dy nuclei are classified using the distribution of zeros of the canonical ensemble (CE) partition function in the complex inverse temperature plane. Semi-empirical nuclear level densities (NLD), which are obtained by combining experimental data in the excitation-energy region below the neutron binding energy and the back-shifted Fermi gas model prediction for the high excitation-energy up to 250 MeV, are utilized to determine the CE partition function. Results obtained show that two phase transitions can appear in 160−164Dy isotopes, namely the pairing and shape phase transitions. The pairing phase transition is found to be of first-order and its critical temperature is ∼0.5 MeV, while the shape phase transition is found to be also of first-order but it occurs at higher temperatures, i.e. around 2.2–2.5 MeV. A comparison between the present work and previous ones that involve the same classification scheme but employ purely theoretical NLD has shown a considerable inconsistency. However, our findings should be more conclusive due to various supports from previous theoretical and experimental studies [1]. References: [1] Le Thi Quynh Huong, Tran Quoc Viet, Le Tan Phuc, Tran Vu Dong, Hoang Anh Tuan Kiet, Balaram Dey, Nguyen Quang Hung, and Nguyen Ngoc Anh, Analysis of phase transitions in hot 160−164Dy nuclei, J. Phys. G: Nucl. Part. Phys. 52, 065102 (2025).

Presenter: Nguyen Quang Hung