Related papers: Pionic BEC--BCS crossover at finite isospin chemic…
QCD at finite isospin chemical potential mu_I is studied. This theory has no fermion sign problem and can be simulated on the lattice using present-day techniques. We solve this theory analytically in two limits: low mu_I where chiral…
QCD at finite isospin chemical potential mu_I has no fermion sign problem and can be studied on the lattice. We solve this theory analytically in two limits: at low mu_I where chiral perturbation theory is applicable, and at asymptotically…
The BEC-BCS crossover in QCD at finite baryon and isospin chemical potentials is investigated in the Nambu--Jona-Lasinio model. The diquark condensation in two color QCD and the pion condensation in real QCD would undergo a BEC-BCS…
We study finite density QCD in an approximation in which the interaction between quarks is modelled on that induced by instantons. We sketch the mechanism by which chiral symmetry restoration at finite density occurs in this model. At all…
We investigate the properties of QCD at finite isospin chemical potential at zero and non-zero temperatures. This theory is not affected by the sign problem and can be simulated using Monte-Carlo techniques. With increasing isospin chemical…
QCD at finite isospin density is considered for a large number of colors $N_c$. A linear sigma model is used to model the meson content of the theory at low density. At isospin chemical potential $\mu_I << \Lambda_{QCD}$, this matter forms…
Coupling strength effect on the quark matter with finite isospin chemical potential is studied in a Pauli-Villars regularized NJL model. A BCS-BEC crossover occurs along the phase boundary of pion superfluid phase transition, as increasing…
We review the BCS-BEC crossover in relativistic Fermi systems, including the QCD matter at finite density. In the first part we study the BCS-BEC crossover in a relativistic four-fermion interaction model and show how the relativistic…
According to perturbation theory predictions, QCD matter in the zero-temperature, high-density limits of QCD at nonzero isospin chemical potential is expected to be in a superfluid Bardeen-Cooper-Schrieffer (BCS) phase of $u$ and $\bar{d}$…
For large isospin asymmetries, perturbation theory predicts the QCD ground state to be a superfluid phase of $u$ and $\bar{d}$ Cooper pairs. This phase, which is denoted as the BCS phase, is expected to be smoothly connected to the standard…
We investigate the crossover from Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) in a relativistic superfluid within a boson-fermion model. The model includes, besides the fermions, separate bosonic degrees of…
Introduction of a nonzero isospin chemical potential in QCD leads to the emergence of a pion condensed phase at sufficiently large $\mu_I$, bounded by a second order transition line. At zero temperature the pion condensate appears at $\mu_I…
We use the two-flavor linear sigma model with quarks to study the phase structure of isospin asymmetric matter at zero temperature. The meson degrees of freedom provide the mean field chiral- and isospin-condensates on top of which we…
In this contribution we investigate the phase diagram of QCD in the presence of an isospin chemical potential. To alleviate the infrared problems of the theory associated with pion condensation, we introduce the pionic source as an infrared…
We consider the problem of Bose condensation of charged pions in QCD at finite isospin chemical potential $\mu_I$ using the O(4)-symmetric linear sigma model as an effective field theory for two-flavor QCD. Using the 2PI $1/N$-expansion, we…
We summarize main points of our recent work where we studied the pion condensation for non-zero isospin chemical potential within a holographic QCD model. We confirmed that the second order phase transition with the mean field exponent…
Isoscalar Cooper pairing in isospin asymmetric nuclear matter occurs between states populating two distinct Fermi surfaces, each for neutrons and protons. The transition from a BCS-like to the normal (unpaired) state, as the isospin…
In contrast to the case of non-zero baryon chemical potential, the isospin chemical potential does not introduce a sign problem and can be simulated on the lattice. When the isospin chemical potential is large enough, a phase transition to…
We report on the results of the 2+1 flavour QCD simulations at nonzero isospin chemical potential performed at half the physical light quark mass. At low temperatures and large isospin chemical potential Bose-Einstein Condensation (BEC)…
The QCD phase diagram is studied in the presence of an isospin asymmetry using continuum extrapolated staggered quarks with physical masses. In particular, we investigate the phase boundary between the normal and the pion condensation…