Related papers: On Mass Spectrum in SQCD. Unequal quark masses
We analyze (using a chiral effective Lagrangian model) the scalar and pseudoscalar meson mass spectrum of QCD at finite temperature, above the chiral transition at $T_c$, looking, in particular, for signatures of a possible breaking of the…
We study the effect of a non-zero strange quark mass on the color-flavor-locked (CFL) phase of high density quark matter. We have previously shown that for a strange quark mass $m_s\sim m_u^{1/3}\Delta^{2/3}$ the CFL state becomes unstable…
The ground state of dense up and down quark matter under local and global charge neutrality conditions with $\beta$-equilibrium has at least four possibilities: normal, regular 2SC, gapless 2SC phases, and mixed phase composed of 2SC phase…
We compute the static-light baryon spectrum with N_f = 2 flavors of sea quarks using Wilson twisted mass lattice QCD. As light valence quarks we consider quarks, which have the same mass as the sea quarks with corresponding pion masses in…
The dynamics in QCD with different number of fermion flavors N_f is discussed. The emphasis is on the description of the conformal phase transition with respect to N_f separating a phase with no confinement and chiral symmetry breaking and…
Considering four-point correlation functions of color-singlet quark bilinears, we investigate, in the large-$N_{\mathrm{c}}$ limit of QCD, the subleading diagrams that involve, in the $s$-channel of meson-meson scattering amplitudes,…
I explore the rich phase diagram of two-flavor QCD as a function of the quark masses. The theory involves three parameters, including one that is CP violating. As the masses vary, regions of both first and second order transitions are…
Instantons generate strong non-perturbative interactions between quarks. In the vacuum, these interactions lead to chiral symmetry breaking and generate constituent quark masses on the order of 300-400 MeV. The observation that the same…
We describe the interplay of two nonperturbative phenomena which should take place in the chirally invariant deconfined phase of QCD matter at finite density and T=0: (i) Cooper-pair quark-quark ground-state condensation in appropriate…
The spectrum of meson and diquark excitations of dense color neutral cold quark matter is investigated in the framework of a 2-flavored Nambu--Jona-Lasinio type model, including a quark $\mu$- and color $\mu_8$ chemical potential. It was…
The talk is an introduction into diquark condensation phenomena which occur in QCD at high energy density. They are driven by instantons and instanton-antiinstanton pairs (or ``molecules''), which generate attraction in some qq channels. A…
The phase diagram of three-flavor quark matter under compact star constraints is investigated within a Nambu--Jona-Lasinio model. Local color and electric charge neutrality is imposed for beta-equilibrated superconducting quark matter. The…
The present lecture is devoted to embedding the approximate genuine harmonic oscillator structure of valence q qbar mesons and in more detail the q q q configurations for up,down,strange - flavored baryons in Q C D for three light flavors…
We investigate the phases of dense QCD matter at finite temperature with Dyson-Schwinger equations for the quark propagator for N_f=2+1 flavors. For the gluon propagator we take a fit to quenched lattice data and add quark-loop effects…
A good agreement between a flux tube-based quark model of light baryons (strange and nonstrange) and the $1/N_c$ expansion mass formula has been found in previous studies. In the present work a larger connection is established between the…
We show that the quark condensates for the two light up and down flavors can have significantly different values in the hadronic phase at nonzero temperature, baryon and isospin chemical potentials. We quantify this difference using a…
The simplest pattern of color superconductivity involves BCS pairing between up and down quarks. We argue that this ``2SC'' phase will not arise within a compact star. A macroscopic volume of quark matter must be electrically neutral and…
We present a lattice QCD determination of light quark masses with three sea-quark flavours ($N_f = 2+1$). Bare quark masses are known from PCAC relations in the framework of CLS lattice computations with a non-perturbatively improved…
Quarks and antiquarks carry color and electric charges and belong to the color-triplet $3$ group and the color-antitriplet $\bar 3$ group respectively. The product groups of $3$ and $\bar 3$ consist of the color-singlet $1$ and the…
Recently, there have been reports that the chirally restored phase of QCD is effectively symmetric under $U(N_f) \times U(N_f)$ rather than $SU(N_f)\times SU(N_f)$. We supplement their argument by including the contributions from…