相关论文: Is the Up Quark Massless?

During the past year the MILC Collaboration has continued its study of heavy-light meson decay constants with three dynamical quarks. Calculations have been extended to a second lattice spacing of about 0.09 fm. At this lattice spacing,…

We evaluate lower bounds on the sum of the up and down quark masses. The bounds follow from the constraints provided by the dispersion relation obeyed by the two--point function of the scalar current density when combined with properties of…

We have simulated lattice QCD with an irrelevant 4-fermion interaction and 2 zero mass quarks. The chiral phase transition is observed to be second order and we discuss extraction of critical exponents.

I review the current status of lattice calculations of light and heavy quark masses. Significant progresses, in these studies, have been allowed by the introduction of improved actions and non-perturbative renormalization techniques.…

An analysis of the pion mass and pion decay constant is performed using mixed-action Lattice QCD calculations with domain-wall valence quarks on ensembles of rooted, staggered n_f = 2+1 MILC configurations. Calculations were performed at…

We present a quenched lattice calculation of low energy constants using the chirally improved Dirac operator. Several lattice sizes at different lattice spacings are studied. We systematically compare various methods for computing these…

We review the quark-mass dependence of the baryon octet and decuplet masses as obtained from recent lattice simulations of the BMW, PACS-CS, LHPC, HSC and QCDSF-UKQCD groups. Our discussion relies on the relativistic chiral Lagrangian and…

We consider the standard model in the formulationo of non-commutative geometry, for a Euclidean space-time consisting of two copies. The electroweak scale is set by the vacuum expectation value of a scalar field and is undetermined at the…

The static $B^{*}B\pi$ coupling, $\hat{g}_\chi$, a low energy constant in the leading order heavy meson chiral Lagrangian, is determined using $N_\mathrm{f} = 2$ lattice QCD. We use CLS ensembles with lattice spacings and pion masses down…

We present a determination of the strong coupling constant and heavy quark masses in (2+1)-flavor QCD using lattice calculations of the moments of the pseudo-scalar quarkonium correlators at several values of the heavy valence quark mass…

We investigate the anomalous interactions of heavy up-type quark t' in a $\gamma \gamma$ collision at the LHC. We have obtained 95% confidence level(CL)limit of $t'q \gamma$ anomalous coupling by taking into account three forward detector…

In our recent analysis of lattice data of the BMW, LHPC and PACS-CS groups we determined a parameter set of the chiral Lagrangian that allows a simultaneous description of the baryon octet and decuplet masses as measured by those lattice…

We present the results of the lattice QCD calculation of the average up-down and strange quark masses and of the light meson pseudoscalar decay constants, recently performed with Nf=2 dynamical fermions by the ETM Collaboration. The…

We briefly review how precise determinations of the strong coupling constant and of the heavy quark masses may be obtained from heavy quarkonium. Such determinations are competitive with heavy quark masses extraction from other systems and…

Schemes for describing the light quark mass dependence of the nucleon mass calculated in lattice QCD are compared. The three schemes in consideration include a fully relativistic and Lorentz covariant scheme, one that is fully relativistic…

We provide a non-perturbative determination of the scheme- and scale-independent low-energy constant $\ell_{\scriptscriptstyle{7}}$, appearing in the QCD effective chiral Lagrangian at next-to-leading order, by means of lattice QCD…

We determine the strange and light quark condensates in full lattice QCD for the first time. This is done by direct calculation of the expectation value of the trace of the quark propagator followed by subtraction of the appropriate…

We determine f_K for lattice QCD in the two flavor approximation with non-perturbatively improved Wilson fermions. The result is used to set the scale for dimensionful quantities in CLS/ALPHA simulations. To control its dependence on the…

We study the light quark-mass dependence of charmed baryon masses as measured by various QCD lattice collaborations. A global fit to such data based on the chiral SU(3) Lagrangian is reported on. All low-energy constants that are relevant…

Chiral low-energy constants incorporate short-distance information from the dynamics involving heavier degrees of freedom not present in the chiral Lagrangian. We have studied the contribution of the lightest resonances to the chiral…