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.
19450734
Rephasing invariant parametrization of flavor mixing matrices
The three-flavor mixing matrix can be parameterized by the rephasing invariants {gamma}{sub ijk}=V{sub 1i}V{sub 2j}V{sub 3k}. This formulation brings out the inherent symmetry of the problem and has some appealing features. Examples illustrating the parametrization and applications to quark mixing are presented.
121048591
Some power-law cosmological solutions derived from the 5D Brans-Dicke vacuum theory
We solve vacuum field equations in five-dimensional Brans–Dicke gravity to find power-law growth for the cosmological scale factor, with the range of its parameter values extended by the Brans–Dicke field. We discuss its implications for the onset of late-time cosmic acceleration.
118949045
N=4 supersymmetric quantum mechanics with magnetic monopole
Abstract We propose an N = 4 supersymmetric quantum mechanics of a charged particle on a sphere in the background of Dirac magnetic monopole and study the system in the CP ( 1 ) model approach. By using the Dirac quantization method, we explicitly calculate the symmetry algebra taking the operator ordering ambiguity into consideration. We find that it is given by the superalgebra su ( 1 | 2 ) × su ( 2 ) rot . We also show that the Hamiltonian can be written in terms of the Casimir invariant of su ( 2 ) rot algebra. Using this relation and analyzing the lower bound for angular momentum, we find the energy spectrum. We, then, examine the ground energy sector to find that the N = 4 supersymmetry is spontaneously broken to N = 2 for certain values of the monopole charge.
10685204
Higher dimension operators and chiral symmetry breaking in Nambu–Jona-Lasinio model
Abstract We point out that adding higher dimension operators to the Nambu–Jona-Lasinio model can stabilize chiral symmetry breaking and resolve the issue raised by Kleinert and Van den Bossche that chiral symmetry breaking cannot occur for N c ≤ N c cr due to large quantum fluctuations of the composite fields.
118939493
The final fate of the rolling tachyon
We propose an alternative interpretation of the boundary state for the rolling tachyon, which may depict the time evolution of unstable D-branes in string theory. Splitting the string variable in the temporal direction into the classical part, which we may call ``time and the quantum one, we observe the time dependent behaviour of the boundary. Using the fermion representation of the rolling tachyon boundary state, we show that the boundary state correctly describes the time-dependent decay process of the unstable D-brane into a S-brane at the classical level.
118715383
Global monopole asymptotic solutions in Horava gravity
In Hořava's theory of gravity coupled to a global monopole source, we seek for static, spherically symmetric spacetime, solutions for general values of λ. We obtain the explicit solutions with deficit solid angles, in the IR modified Hořava gravity model, at the IR fixed point λ = 1 and at the conformal point λ = 1/3. For the other values of 1 > λ > 0 we also find special solutions to the inhomogenous equation of the gravity model with detailed balance, and we discuss a possibility of astrophysical applications of the λ = 1/2 solution that has a deficit angle for a finite range.