Impact of the MIT bag model parameters values

Impact of the MIT bag model parameters values on the maximum mass of neutron star with a quark core G. B. Alaverdyan, Yu. L. Vartanyan Yerevan State University , Armenia The Modern Physics of Neutron Stars and Relativistic Gravity Yerevan, Armenia, Sept. 18 - 22, 2017. 1

Ø Precise measurements of neutron stars. PSR J 1614 -2230 1. 97 ± 0. 04 1. 928 ± 0. 017 Demorest et al. 2010 Fonseca et al. 2016 PSR J 0348+0432 2. 01 ± 0. 04 Antoniadis et al. 2013 2

Ø Deconfinement phase transition leads to softening of EOS Lowering of Compact star maximum mass ……………………… N. S. Ayvazyan, G. Colucci, D. H. Rischke, A. Sedrakian, A&A 559, A 118 , 2013. M. Orsaria, H. Rodrigues, F. Weber, G. A. Contrera, Phys. Rev. C 89, 015806, 2014. Li, W. Zuo, G. X. Peng, Phys. Rev. C 91, 035803, 3015. Yu. L. Vartanyan, A. K. Grigoryan, H. A. Shahinyan, Astrophysics 58, 276– 288, 2015. R. Lastowiecki, D. Blaschke, T. Fischer, et al. , Phys. Part. Nuclei 46: 843, 2015. S. Benic, D. B. , D. Alvarez-Castillo, T. Fischer, S. Typel, A&A 577, A 40, 2015. D-R. Zhang, W-Z. Jiang, S-N. Wei, et al. , Eur. Phys. J. A 52: 142, 2016 ……………………… 3

Hadronic matter EOS (npe. A) At subnuclear and supranuclear densities, we used the relativistic equation of state for neutron matter that was calculated by taking into account two particle correlations based on the Bonn meson exchange potential. (Machleidt et al. 1987) Quark matter EOS (udse) Extended MIT quark bag model with one-gluon exchange corrections taken into account. (Chodos et al. 1974, Farhi and Jaffi 1984) 4

Thermodynamic potentials of quarks (Farhi and Jaffi 1984) - Bag parameter - Quark-gluon coupling constant - Equilibrium conditions Electrical neutrality condition 5

Maxwell construction for phase equilibrium

EOS 7

Tolman, Oppenheimer and Volkoff equations: Equation of State ? 8

Range of values of model parameters Strange uds matter is absolutely stable (Self-bound quark matter hypothesis) Neutrons should not coagulate into electrically neutral droplets of the ud matter Upper bounds for existence of self-bound strange quark matter (SS) and lower bounds for hybrid stars Lower bounds for existence of self-bound strange quark matter (SS)

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Summary • 15