Eur. Phys. J. A (2022) 58: 87
https://doi.org/10.1140/epja/s10050-022-00732-8

Regular Article - Theoretical Physics

Collision energy dependence of the critical end point from baryon number fluctuations in the Linear Sigma Model with quarks

¹ Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, 04510, CdMx, Mexico
² Centre for Theoretical and Mathematical Physics, and Department of Physics, University of Cape Town, 7700, Rondebosch, South Africa
³ Departamento de Investigación en Física, Universidad de Sonora, Boulevard Luis Encinas J. y Rosales, 83000, Hermosillo, Sonora, Mexico
⁴ Departamento de Física, Universidad de Sonora, Boulevard Luis Encinas J. y Rosales, 83000, Hermosillo, Sonora, Mexico
⁵ Institute for Nuclear Theory, University of Washington, 98195, Seattle, WA, USA
⁶ Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, C.P, 09340, CdMx, Mexico
⁷ Facultad de Ciencias de la Educación, Universidad Autónoma de Tlaxcala, 90000, Tlaxcala, Mexico
⁸ Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Ciudad Universitaria, Francisco J. Mújica s/n Col. Felícitas del Río. C. P., 58040, Morelia, Michoacán, Mexico
⁹ Centro de Ciencias Exactas, Universidad del Bío-Bío, Avda. Andrés Bello 720, Casilla 447, 3800708, Chillán, Chile
¹⁰ Facultad de Ciencias-CUICBAS, Universidad de Colima, Bernal Díaz del Castillo No. 340, Col. Villas San Sebastián, 28045, Colima, Mexico

^g matejeda@ucol.mx

Received: 15 December 2021
Accepted: 13 April 2022
Published online: 4 May 2022

Abstract

We show that the Linear Sigma Model with quarks produces an effective description of the QCD phase diagram and of the system’s equilibrium distribution properties that deviate from those of the Hadron Resonance Gas Model. The deviation is due to the inclusion of plasma screening properties, encoded in the contribution of the ring diagrams and thus to the introduction of a key feature of plasmas near phase transitions, namely, long-range correlations. After fixing the model parameters using input from LQCD for the crossover transition at vanishing chemical potential, we study the location of the Critical End Point in the effective QCD phase diagram. We use the model to study baryon number fluctuations and show that in heavy-ion collisions, the CEP can be located for collision energies GeV, namely, in the lowest NICA or within the HADES energy domain.