Phase diagram of dense two-color QCD within lattice simulations
1 Institute for High Energy Physics NRC “Kurchatov Institute”, Protvino, 142281 Russia
2 Institute for Theoretical and Experimental Physics NRC “Kurchatov Institute”, Moscow, 117218 Russia
3 School of Biomedicine, Far Eastern Federal University, Sukhanova 8, Vladivostok, 690950 Russia
4 Moscow Institute of Physics and Technology, Institutskii per. 9, Dolgoprudny, Moscow Region, 141700 Russia
5 Joint Institute for Nuclear Research, BLTP, Dubna, 141980 Russia
6 National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe Highway, 31, Moscow 115409, Russia
Published online: 22 March 2017
We present the results of a low-temperature scan of the phase diagram of dense two-color QCD with Nf = 2 quarks. The study is conducted using lattice simulation with rooted staggered quarks. At small chemical potential we observe the hadronic phase, where the theory is in a confining state, chiral symmetry is broken, the baryon density is zero and there is no diquark condensate. At the critical point μ = mπ/2 we observe the expected second order transition to Bose-Einstein condensation of scalar diquarks. In this phase the system is still in confinement in conjunction with nonzero baryon density, but the chiral symmetry is restored in the chiral limit. We have also found that in the first two phases the system is well described by chiral perturbation theory. For larger values of the chemical potential the system turns into another phase, where the relevant degrees of freedom are fermions residing inside the Fermi sphere, and the diquark condensation takes place on the Fermi surface. In this phase the system is still in confinement, chiral symmetry is restored and the system is very similar to the quarkyonic state predicted by SU(Nc) theory at large Nc.
© The Authors, published by EDP Sciences, 2017
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