Center of Chiral

Biophotonics

~School of Biomedicine~

Title: Study of dense baryonic matter by the methods of lattice quantum chromodynamics(RUS).
Leader: prof. V. Bornyakov

RFBR Grant: 18-02-40130 мега

Project team:
  • Begun Alexander
  • Goy Vladimir
  • Korneev Anatoly
  • Kotov Andrey
  • Martemyanov Boris
  • Nakamura Atsushi
  • Rogalyov Roman


Abstract:

One of the main tasks of theoretical physics in the field of strong interactions of elementary particles is the study of QCD with a nonzero baryon chemical potential. The importance of this task is determined by the need to know the properties of QCD with a nonzero baryon density to understand the results of heavy-ion collisions experiments, as well as the properties of compact stars.

Lattice QCD is one of the few theoretical approaches that allows the study of the nonperturbative properties of QCD based on the first principles of quantum field theory. Important results (transition temperature, equation of state) were obtained in lattice QCD with zero baryon chemical potential and nonzero temperature. However, with a nonzero baryon chemical potential, standard computational methods of lattice QCD do not work. There are ways to get fairly reliable results for small values of baryon chemical potential, for example, calculating the coefficients of the Taylor series. However, there are no computational methods for large values of the baryon chemical potential. In this situation, a number of authors have proposed the study of theories, which in their properties may be close to the properties of QCD for large values of the baryon chemical potential. In this project we will study one of such theories - QCD with the gauge group SU (2), or SU (2) QCD.

SU (2) QCD is the simplest non-Abelian gauge theory without the sign problem for a finite quark density. This project is aimed at studying the properties and calculating a large number of physical observables in this theory at nonzero temperature and high quark density, as well as developing and testing new computational methods applicable in the usual 3-color lattice QCD for large values of baryon chemical potential. The results will also allow us to create a testing ground for testing other nonperturbative approaches at finite density, which include additional simplifications or assumptions.

It is planned to study such phenomena as the confinement-deconfinement transition in the phase plane, temperature-quark chemical potential, properties of the color-magnetic sector of the theory for large values of the quark chemical potential. We also plan to study the equation of state, the mechanism of mass gap formation in the fermion spectrum, the properties of gluons in a dense medium, the influence of a dense medium on the topological properties of QCD, the possibility of the existence of the quarkionic phase in this theory, fluctuations of quark density.

The results obtained in this project will make predictions for QCD with high baryon density and low temperature — an area of the phase diagram that is critical for future experiments at the NICA accelerator complex. In addition, the results of the presented project will be important in various applications to the physics of neutron stars.



Talks at conferences:
  1. Nakamura A. Canonical partition functions in lattice QCD at high temperature.
    The 37th International Symposium on Lattice Field Theory (Lattice 2019).
    Wuhan, China, June 16 to June 22, 2019
  2. Bornyakov V. Confinement-deconfinement transition in QC_2D at T=0 and large quark density.
    The 8th International Conference on New Frontiers in Physics (ICNFP 2019).
    21-29 August 2019, Kolimbari, Greece.
  3. Rogalev R. Gluons in two-colour QCD at high baryon density.
    The 8th International Conference on New Frontiers in Physics (ICNFP 2019).
    21-29 August 2019, Kolimbari, Greece.
  4. Nakamura A. Finite Density Lattice QCD for NICA energy regions.
    The II International Workshop on Theory of Hadronic Matter Under Extreme Conditions.
    Dubna, 16-19 September 2019
  5. Bornyakov V. Phase structure of QC_2D at T=0 and large quark density.
    The II International Workshop on Theory of Hadronic Matter Under Extreme Conditions.
    Dubna, 16-19 September 2019
  6. Rogalev R. Gluon propagators in QC_2D at high baryon density.
    The II International Workshop on Theory of Hadronic Matter Under Extreme Conditions.
    Dubna, 16-19 September 2019

Publications:
  1. Density and correlations of topological objects near the transition temperature in lattice gluodynamics.
    V.G. Bornyakov, E.M. Ilgenfritz, B.V. Martemyanov.
    e-Print: arXiv:1908.08709 [hep-lat]