ar X iv : h ep - p h / 92 10 24 5 v 1 1 9 O ct 1 99 2 Scaling limit of a non - relativistic model of confined “ quarks ”

ar X iv : h ep - p h / 97 10 29 8 v 1 9 O ct 1 99 7 Decay constants in the heavy quark limit in models

In quark modelsà la Bakamjian and Thomas, that yield covariance and Isgur-Wise scaling of form factors in the heavy quark limit, we compute the decay constants f (n) and f (n) 1/2 of S-wave and P-wave mesons composed of heavy and light quarks. Heavy quark limit scaling √ M f = Cst. is obtained, and it is shown that this class of models satisfies the sum rules involving decay constants and Isgur...

ar X iv : h ep - p h / 92 10 24 7 v 1 1 9 O ct 1 99 2 The Perturbative Onset of Multiparticle Production in Weak Interactions ∗

We use perturbation theory to estimate the energy scale beyond which multiparticle final states become a dominant feature of high energy weak interactions. Using estimates from a weak parton model and comparing two, three and four body final states we deduce that multiparticle states become important at energy scales in the range 10 7 − 10 9 GeV.

ar X iv : h ep - p h / 99 10 24 8 v 1 6 O ct 1 99 9 1 Effect of σ ( 600 ) - Production in pp̄ → 3 π 0 at rest

ar X iv : h ep - p h / 99 10 54 7 v 1 2 9 O ct 1 99 9 Stability of Multiquark Systems 1

We give a brief review of developments in the field of exotic hadrons formed of more than three quarks and/or antiquarks. In particular we discuss the stability of multiquark systems containing heavy flavours. We show that the gluon exchange model and the chiral constituent quark model based Goldstone boson (pseudoscalar meson) exchange give entirely different results.

ar X iv : h ep - l at / 9 71 00 31 v 1 8 O ct 1 99 7 1 Finite - temperature chiral transitions in QCD with the Wilson quark

We investigate the finite-temperature phase structure and the scaling of the chiral condensate in lattice QCD with two degenerate light quarks, using a renormalization group improved gauge action and the Wilson quark action. We obtain a phase diagram which is consistent with that from the parity-flavor breaking scenario. The scaling relation for the chiral condensate assuming the critical expon...