We propose an extended Nambu–Jona-Lasinio model to include the heavy mesons with the heavy quark symmetry. The quark current-current interaction is generalized to include the heavy quark currents. In order to comply with the heavy quark spin symmetry at the heavy quark limit, the quark mass dependence of the interaction strength is introduced. The light and heavy pseudo-scalar and vector meson,...

We present a calculation of the three-quark core contribution to the mass of the ∆-resonance in a Poincaré-covariant Faddeev framework. A consistent setup for the dressed-quark propagator, the quark-quark and quark-’diquark’ interactions is used, where all the ingredients are solutions of their respective Dyson-Schwinger or Bethe-Salpeter equations in rainbow-ladder truncation. We discuss the e...

Top quark pair production cross section and properties of the top quark in p ¯ p collisions at √ s = 1.96 TeV An overview over measurements of top quark pair production in p ¯ p collisions at a center-of-mass energy of √ s = 1.96 TeV is given. Emphasis is given to measurements of the t ¯ t cross section in lepton+jets and dilepton final states with up to 5.4 fb −1 of integrated luminosity. Exam...

We study how the quasiparticle picture of the quark can be modified near but above the critical tempearture (Tc) of the chiral phase transition; we incorporate into the quark self-energy the effects of the precursory soft modes of the phase transition, i.e., ‘para-σ(π) meson’. It is found that the quark spectrum has a three-peak structure near Tc: We show that the additional new spectra origina...

Tevatron experiments have recently set or improved limits on quark and lepton compositeness. Included here are results from p s = 1:8 TeV pp collider experiments D and CDF and from xed target neutrino experiment CCFR, who report limits on quark-quark, quark-lepton, and quark-neutrino compositeness, respectively.

In 1994, the top quark was discovered by the CDF and D0 collaborations . The measured top quark mass is approximately 175 GeV, which is nearly twice the mass scale of electro-weak symmetry breaking. So the top quark with large mass brings a good opportunity to understand electro-weak symmetry breaking and to search hints of any new physics. The top quark decays electroweakly before hadronizing ...

The study of hadronic matter at high baryon density has recently attracted a lot of interest. At zero baryon density chiral symmetry is broken by a quark-anti-quark condensate. At high density condensation in the quarkanti-quark channel is suppressed. Instead, attractive interactions in the color anti-symmetric quark-quark channel favor the formation of diquark condensates. As a consequence, co...

In the high-temperature quark-gluon plasma and its subsequent hadronic matter created in a high-energy nucleus-nucleus collision, the quark-antiquark potential depends on the temperature. The temperature-dependent potential is expected to be derived from the free energy obtained in lattice gauge theory calculations. This requires one to study the relation between the quark-antiquark potential a...

We study the electromagnetic form factors of lowest-lying singly heavy baryons in a pion mean-field approach, which is also known as SU(3) chiral quark-soliton model. In limit heavy-quark mass, dynamics inside baryon governed by $N_c-1$ valence quarks, while quark remains mere static color source. this framework, described combining colored soliton with quark. infinitely mass limit, we can comp...