Related papers: Quark masses in two-flavor QCD
We present a determination of the strange, charm and bottom quark masses as well as the strong coupling constant in 2+1 flavor lattice QCD simulations using highly improved staggered quark action. The ratios of the charm quark mass to the…
We have simulated QCD using 2+1 flavors of domain wall quarks on a $(2.74 {\rm fm})^3$ volume with an inverse lattice scale of $a^{-1} = 1.729(28)$ GeV. The up and down (light) quarks are degenerate in our calculations and we have used four…
We calculate the pressure in QCD with two and three light quarks on a lattice of size 16^3x4 using tree level improved gauge and fermion actions. We argue that for temperatures T > 2T_c systematic effects due to the finite lattice cut-off…
Effects of heavy sea quarks on the low energy physics are described by an effective theory where the expansion parameter is the inverse quark mass, 1/$M$. At leading order in 1/$M$ (and neglecting light quark masses) the dependence of any…
QCD lattice simulations with 2+1 flavours typically start at rather large up-down and strange quark masses and extrapolate first the strange quark mass to its physical value and then the up-down quark mass. An alternative method of tuning…
We discuss the phase structure of quantum chromodynamics (QCD) with two colors and two flavors of light quarks. This is motivated by the increasing interest in the QCD phase diagram as follows: (1) The QCD critical point search has been…
We discuss a new mass matrix with specific texture zeros for the quarks. The three flavor mixing angles for the quarks are functions of the quark masses and can be calculated. The following ratios among CKM matrix elements are given by…
In neutral cold quark matter that is sufficiently dense that the strange quark mass M_s is unimportant, all nine quarks (three colors; three flavors) pair in a color-flavor locked (CFL) pattern, and all fermionic quasiparticles have a gap.…
A physically viable ansatz for quark mass matrices must satisfy certain constraints, like the constraint imposed by CP-violation. In this article we study a concrete example, by looking at some generic matrices with a nearly democratic…
We explore the phenomenological quark-lepton mass matrices, which are devised following the S$_3$ flavour symmetry principle, yet fully consistent with SU(5) gauge models with the Higgs particles of {\bf 5}, {\bf 45} and their conjugates.…
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…
We investigate the phase transitions of (2+Nf)-flavor QCD, where two light flavors and Nf massive flavors exist, aiming to understand the phase structure of (2+1)-flavor QCD. Performing simulations of 2-flavor QCD with improved staggered…
Results from our recent investigations of quark number susceptibilities in both quenched and 2-flavour QCD are presented as a function of valence quark mass and temperature. A strong reduction (approx. 40%) is seen in the strange quark…
We evaluate the $\pi N!N$, $\pi\Sigma\Sigma$, $\pi\Lambda\Sigma$, $K\Lambda N$ and $K \Sigma N $ coupling constants and the corresponding monopole masses in lattice QCD with two flavors of dynamical quarks. The parameters representing the…
Common lore suggests that $N$-color QCD with massive quarks has no useful order parameters which can be non-trivial at zero baryon density. However, such order parameters do exist when there are $n_f$ quark flavors with a common mass and…
Results from our recent investigations of quark number susceptibilities in both quenched and 2-flavour QCD are presented as a function of valence quark mass and temperature. A strong reduction (~40%) is seen in the strange quark…
Some interesting heavy-flavor questions are mentioned that may yield to the methods of lattice QCD. Special emphasis is placed on topics which arise in the discussion of CP violation in $B$ decays. Other subjects include quarkonium and…
A simple breaking of the subnuclear democracy among the quarks leads to a mixing between the second and the third family, in agreement with observation. Introducing the mixing between the first and the second family, one finds an…
We present a QCD based interpretation of heavy quark fragmentation which utilizes the heavy quark mass expansion. By distinguishing between perturbative and non-perturbative QCD effects, we show how to reliably extract mass independent…
Partition functions of two different matrix models for QCD with chemical potential are computed for an arbitrary number of quark and complex conjugate anti-quark flavors. In the large-N limit of weak nonhermiticity complete agreement is…