119229405
CHIRAL RADIATIVE CORRECTIONS IN POTENTIAL MODEL AND THE P-WAVE STATES OF HEAVY-LIGHT MESONS
In relativistic potential model of heavy-light mesons it is essential to incorporate the chiral radiative corrections before comparing the model predictions with data. Once the radiative corrections are taken into account the potential model can explain the unusual mass spectra and absence of the spin orbit-inversion in P-wave states.
119660786
Baryon number violation in dense matter. On the relation with anomalous high energy scattering
Abstract The recent claim of the equivalence of baryon number violation in dense matter and that of high energy scattering is examined. We present a plausible argument against the claim. We also calculate the anomalous decay rate of dense matter to (μ/E 0 ) 8 3 In (μ/E 0 ) order. To this order, we find the anomalous decay rate is completely equivalent to the anomalous cross section of the high energy scattering calculated by the valley method.
119272116
Light bending by nonlinear electrodynamics under strong electric and magnetic field
We calculate the bending angles of light under the strong electric and magnetic fields by a charged black hole and a magnetized neutron star according to the nonlinear electrodynamics of Euler-Heisenberg interaction. The bending angle of light by the electric field of charged black hole is computed from geometric optics and a general formula is derived for light bending valid for any orientation of the magnetic dipole. The astronomical significance of the light bending by magnetic field of a neutron star is discussed.
14559352
Estimating higher order perturbative coefficients using Borel transform
A new method of estimating higher order perturbative coefficients is discussed. It exploits the rapid, asymptotic growth of perturbative coefficients and the information on the singularities in the complex Borel plane. A comparison with other methods is made in several Quantum Chromodynamics (QCD) expansions.
16719442
Chiral vacuum alignment in dense QCD
Abstract We discuss an interesting possibility of nontrivial, quark-mass induced chiral vacuum alignment in color–flavor locking phase of cold, dense QCD. With the simplifying assumption that the gaps for quarks are identical to those of antiquarks and the light quark masses are given by m u = m d and m s / m d =15, we find the true chiral vacuum can align only to one of the discrete number of directions in the continuum of chiral vacua. The alignment depends on the size of the diquark condensates, and the vacuum transitions between the discrete vacua caused by the evolution of the diquark condensates can be first order phase transition with vanishing or nonvanishing latent heat, depending on the vacua involved. It is also shown that as μ →∞, where μ is the baryon chemical potential, parity is spontaneously broken through the vacuum alignment.
3172088
RAPIDITY GAP OF WEAKLY COUPLED LEPTOQUARK PRODUCTION IN ep COLLIDER
We show that the current bounds on the leptoquark couplings imply that if leptoquarks are produced in ep collisions, a significant fraction of them could form a leptoquark–quark bound state. The decay of the bound state has a distinct event shape with rapidity gap. A possible application of this observation in the leptoquark search at HERA is discussed.
119319846
Dissipative hofstadter model at the magic points and critical boundary sine-gordon model
The dissipative Hofstadter model describes quantum particles moving in two dimensions subject to a uniform magnetic field, a periodic potential and a dissipative force. We discuss the dissipative Hofstadter model in the framework of the boundary state formulation in string theory and construct exact boundary states for the model at the magic points by using the fermion representation. The dissipative Hofstadter model at magic points is shown to be equivalent to the critical boundary sine-Gordon model.
16869054
Applications of Thirring Model to Inhomogenous Rolling Tachyon and Dissipative Quantum Mechanics
We study the rolling tachyon and the dissipative quantum mechanics using the Thirring model with a boundary mass. We construct a boundary state for the dissipative quantum system in one dimension, which describes the system at the off-critical points as well as at the critical point. Then we extend the Thirring model with a boundary mass in order to depict the time evolution of an unstable D-branes with one direction wrapped on a circle of radius R, which is termed the inhomogeneous rolling tachyon. The analysis based on the Thirring model shows that the time dependent evolution of the inhomogeneous tachyon is possible only when 2/(3)1/2 < R < 2.
119342247
Noncommutative Dirac–Born–Infeld action for D-brane
Abstract We derive the noncommutative Dirac–Born–Infeld action for the D -brane, which governs dynamics of D -brane with a NS-NS B -field in the low energy regime. Depending on some details of the path integral prescriptions, both ordinary Dirac–Born–Infeld action and noncommutative one can be obtained by evaluating the same Polyakov string path integral for the open string ending on the D -brane. Thus, it establishes the equivalence of the noncommutative Dirac–Born–Infeld action and the ordinary one.
14504724
Canonical quantization of open string and noncommutative geometry
We perform canonical quantization of open strings in the $D$-brane background with a $B$-field. Treating the mixed boundary condition as a primary constraint, we get a set of secondary constraints. Then these constraints are shown to be equivalent to orbifold conditions to be imposed on normal string modes. These orbifold conditions are a generalization of the familiar orbifold conditions which arise when we describe open strings in terms of closed strings. Solving the constraints explicitly, we obtain a simple Hamiltonian for the open string, which reveals the nature of noncommutativity transparently.
15173498
Mass matrices and their renormalization
We obtain explicitly the renormalization group equations for the quark mass matrices in terms of a set of rephasing invariant parameters. For a range of assumed high energy values for the mass ratios and mixing parameters, they are found to evolve rapidly and develop hierarchies as the energy scale decreases. To achieve the experimentally observed high degree of hierarchy, however, the introduction of new models with specific properties becomes necessary.