119439619
COSMIC STRING SPACETIME IN DILATON GRAVITY AND FLAT ROTATION CURVES
In dilaton gravity theories, we consider a string-like topological defect formed during U(1) gauge symmetry-breaking phase transition in the early Universe, and far from the cosmic string we have vacuum solutions of the generalized Einstein equation. We discuss how they can be related to the flatness of galactic rotation curves.
39461914
Heavy quark mass determination from the quarkonium ground state energy: a pole mass approach
The heavy quark pole mass in perturbation theory suffers from a renormalon caused, inherent uncertainty of O(?QCD). This fundamental difficulty of determining the pole mass to an accuracy better than the inherent uncertainty can be overcome by direct resummation of the first infrared renormalon. We show how a properly defined pole mass as well as the mass for the top and bottom quarks can be determined accurately from the O(m?s5) quarkonium ground state energy.
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.
119360577
Neutrino clustering in the galaxy with a global monopole
In spherically symmetric, static spacetime, we show that only j=1/2 fermions can satisfy both Einstein's field equation and Dirac's equation. It is also shown that neutrinos are able to have effective masses and cluster in the galactic halo when they are coupled to a global monopole situated at the galactic core. Astronomical implications of the results are discussed.
119348284
Constraining renormalon effects in lattice determination of heavy quark mass
The Borel summation technique of infrared renormalons is applied to the lattice determination of heavy-quark mass. With Borel summation a physical heavy-quark pole mass and binding energy of a heavy-light meson can be defined in a rigorous and calculable manner. A notable feature of the Borel summation, compared to the usual perturbative cancellation of IR renormalons, is an automatic scale isolation. The two approaches of handling renormalon divergence are compared in the B-meson as well as in an (imaginary) heavy-light meson with a mass much larger than the inverse of the lattice spacing.
18339659
Resummations with renormalon effects for the leading hadronic contribution to the muon (g-2)
The leading hadronic contribution to the muon (g − 2) value is calculated by considering a known dispersion integral which involves the Re+e−(s) ratio. The theoretical part stemming from the region below 1.8 GeV is calculated by using a contour integral involving the associated Adler function D(Q2). In the resummations, we account for the renormalon structure of the usual and the modified Borel transform of D(Q2) via an explicit ansatz and by employing judiciously chosen conformal transformations. This pushes the value of the leading hadronic contribution to the muon (g − 2)/2 upwards as compared to the value given by Davier and Höcker [Phys. Lett. B435 (1998) 427], and therefore diminishes the difference between the recently measured and the SM/QCD-predicted value of (g − 2). Typeset using REVTEX
124705504
TIME-DEPENDENT SOLUTIONS OF 5D VACUUM EINSTEIN EQUATIONS WITH COSMOLOGICAL CONSTANT
We solve vacuum field equations in five-dimensional gravity with cosmological constant to determine the time-dependence of the Robertson–Walker scale factor. We discuss its cosmological implications.
119489587
Fermion representation of the rolling tachyon boundary conformal field theory
A free fermion representation of the rolling tachyon boundary conformal field theory is constructed. The representation is used to obtain an explicit, compact, exact expression for the boundary state. We use the boundary state to compute the disc and cylinder amplitudes for the half-S-brane.
15486524
Boundary String Field Theory at One-loop
We discuss the open string one-loop partition function in tachyon condensation background of a unstable D-brane system. We evaluate the partition function by using the boundary state formulation and find that it is in complete agreement with the result obtained in the boundary string field theory. It suggests that the open string higher loop diagrams may be produced consistently by a closed string field theory, where the D-brane plays a role of source for the closed string field.
12710825
Coherent state quantization of SU(N) non-Abelian Chern-Simons particles
Abstract We present a new method of formulating the classical theory of SU( N + 1) non-Abelian Chern-Simons (NACS) particles for arbitrary N ⩾ 1 using the symplectic reduction of CP( N ) manifold from S 2 N +1 . Quantizing the theory using BRST formulation and coherent state path integral method, we obtain a quantum mechanical model for SU( N + 1) NACS particles.
123683308
STRING THEORY AND DUALITIES IN THE QUANTUM DISSIPATIVE HOFSTADTER SYSTEM
We study the dualities of the quantum dissipative Hofstadter system which describes particles moving in two dimensions, subject to a uniform magnetic field, a periodic potential and a dissipative force. Using the string theory formulation, we show that the system has two kinds of dualities. The duality, previously known as the exact duality in the literature is shown to correspond to a subgroup of the T-dual symmetry group unbroken by the periodic boundary potential in string theory. The other duality is a particle–kink duality in the noncommutative open string theory which is a generalized Schmid duality in the presence of the uniform magnetic field. The kinks of the dissipative Hofstadter model are found to be noncommutative objects. The particle–kink duality, which is called previously the approximate duality, is shown to be also exact. In contrast to the previous derivation, which is based on the Coulomb gas expansion of the partition function and asserts that the duality holds only approximately in t...