A quark-cluster state, rather than the color-super-conductivity state, may appear in matter with low-temperature but high density, since the phase transition of chiral symmetry broken and that of color-confinement could not occur simultaneously. Such quark clusters might be stable in strange quark matter. Quark stars would have temperatures to be low enough to freeze by residual color interacti...

QCD sum rules are derived for the heavy hybrid mesons with one heavy quark and JPC = 1−+, 0++, 1+−, 0−− in the leading order of heavy quark effective theory. We obatin the binding energy ΛH = (1.1±0.1), (1.51±0.10), (1.28±0.10), (1.5±0.1) GeV and decay constant fH = (0.205± 0.02), (0.415 ± 0.04), (0.217 ± 0.02), (0.317 ± 0.03)GeV 7 2 for 1−+, 0++, 1+−, 0−− respectively when the light quark is u...

Since the observation of the top quark in 1995, considerable progress has been made by the CDF and D0 collaborations in measuring top quark production and decay properties. The combined top quark mass from both experiments is mt = 174:3 5:1 GeV/c . With this determination of the top quark mass, the remaining properties of the top quark are predicted by the standard model, allowing for many new ...

The chemical evolution of nascent quark matter core in a newborn compact neutron star is studied in presence of a strong magnetic field. The effective rate of strange quark production in degenerate quark matter core in presence of strong magnetic fields is obtained. The investigations show that in presence of strong magnetic fields a quark matter core becomes energetically unstable and hence a ...

According to QED in the hard charged longitudinally polarized lepton–unpolarized quark scattering l + q → l + q lepton transfers its polarization to final quark. Within the simple parton model description of SIDIS the hadron production in the current fragmentation region is described by independent fragmentation of scattered quark. Then the (anti)quark polarization can be transferred to produce...

We study the heavy baryon mass spectrum on gauge configurations that include 2+1 flavors of dynamical improved staggered quarks. A valence clover heavy quark is combined with two improved staggered light quark propagators to form baryons with different flavors. We are using MILC coarse gauge configurations with a lattice spacing of about 0.12 fm. In this preliminary investigation, we explore th...

We have computed the light and strange quark masses and the renormalization constants of the quark bilinear operators, by studying the large-p behaviour of the lattice quark propagator and 3-point functions. The calculation is non-perturbatively improved, at O(a), in the chiral limit. The method used to compute the quark masses has never been applied so far, and it does not require an explicit ...

We have computed the light and strange quark masses and the renormalization constants of the quark bilinear operators, by studying the large-p behaviour of the lattice quark propagator and 3-point functions. The calculation is non-perturbatively improved, at O(a), in the chiral limit. The method used to compute the quark masses has never been applied so far, and it does not require an explicit ...

The Sivers mechanism for the single-spin asymmetry in unpolarized lepton scattering from a transversely polarized nucleon is driven by the orbital angular momentum carried by its quark and gluon constituents, combined with QCD final-state interactions. Both quark and gluon mechanisms can generate such a single-spin asymmetry, though only the quark mechanism can explain the small single-spin asy...

The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and D0 / collaborations are reviewed, including the top quark cross section, mass, branching fractions and production prop...