It has recently been suggested that the observed structure of parity doublets, seen in the spectrum of highly excited baryons, may be due to the effective restoration of chiral symmetry for these states. This chiral symmetry restoration high in the spectrum is consistent with the concept of quark-hadron duality. Moreover, if QCD dynamics implies the linear Regge trajectories for highly excited ...

The exotic baryon Θ+(uudds̄) is studied with microscopic calculations in a quark model by using a method of antisymmetrized molecular dynamics(AMD). We predict narrow states, J = 1/2+(I = 0), J = 3/2+(I = 0), and J = 3/2(I = 1), which nearly degenerate in a low-energy region of the uudds̄ system. We discuss NK decay widths and estimate them to be Γ < 7 for the J = {1/2+, 3/2+}, and Γ < 1 MeV for ...

In R-parity conserving supersymmetric (SUSY) models, sleptons are produced in pairs at hadron colliders through neutral and charged electroweak currents. We demonstrate that the polarization of the initial hadron beams allows for a direct extraction of the slepton mixing angle and thus for a determination of the underlying SUSY-breaking mechanism. We also perform a first precision calculation o...

In this paper, we develop a weak-coupling treatment of nonperturbative QCD to heavy hadrons on the light-front. First, we present a derivation of quark confining interaction in light-front QCD for heavy quark systems, based on the recently developed light-front similarity renormalization group approach and the light-front heavy quark effective theory. The resulting effective lightfront QCD Hami...

simulation of gamma and hadron showers in the energy range 100gev- 25tev has been carried out. for a big ideal cherenkov light array, characteristics of lateral distribution of cherenkov photon density have been studied. results from this ideal detector are compared with those simulated for a real tunka- like array to investigate experimental potential of using existence of a hump in lateral di...

The weak charge QW measured in atomic parity violation experiments can receive compensating contributions from more than one new physics source. We show explicitly that the ∆QW contribution from the exchange of an extra Z-boson can cancel that from the s-channel scalar top or scalar charm exchange in R-parity violating SUSY models proposed to explain the HERA high-Q2 anomaly. Parity violation i...

We calculate purely weak virtual one-loop corrections to the production cross section of topantitop pairs at the Large Hadron Collider via the gluon-gluon fusion subprocess. We find very small negative corrections to the total cross section, of order −0.3%, but significantly larger effects to the differential one, particularly in the transverse momentum distribution, of order −5% to −10% (in ob...