4 research outputs found
Entropy of Non-Extreme Charged Rotating Black Holes in String Theory
We give the explicit expression for four-dimensional rotating charged black
hole solutions of N=4 (or N=8) superstring vacua, parameterized by the ADM
mass, four charges (two electric and two magnetic charges, each arising from a
different U(1) gauge factors), and the angular momentum (as well as the
asymptotic values of four toroidal moduli of two-torus and the dilaton-axion
field). The explicit form of the thermodynamic entropy is parameterized in a
suggestive way as a sum of the product of the `left-moving' and the
`right-moving' terms, which may have an interpretation in terms of the
microscopic degrees of freedom of the corresponding D-brane configuration. We
also give an analogous parameterization of the thermodynamic entropy for the
recently obtained five-dimensional rotating charged black holes parameterized
by the ADM mass, three U(1) charges and two rotational parameters (as well as
the asymptotic values of one toroidal modulus and the dilaton).Comment: 14 pages, uses RevTex, the revised version with minor corrections to
appear in Phys. Rev.
b -> s gamma in the left-right supersymmetric model
The rare decay is studied in the left-right supersymmetric
model. We give explicit expressions for all the amplitudes associated with the
supersymmetric contributions coming from gluinos, charginos and neutralinos in
the model to one-loop level. The branching ratio is enhanced significantly
compared to the standard model and minimal supersymmetric standard model values
by contributions from the right-handed gaugino and squark sector. We give
numerical results coming from the leading order contributions. If the only
source of flavor violation comes from the CKM matrix, we constrain the scalar
fermion-gaugino sector. If intergenerational mixings are allowed in the squark
mass matrix, we constrain such supersymmetric sources of flavor violation. The
decay sets constraints on the parameters of the model and
provides distinguishing signs from other supersymmetric scenarios.Comment: 12 figure
mixing in the left-right supersymmetric model
We analyze mixing in a fully left-right supersymmetric
model. We give explicit expressions for all the chargino, gluino,
gluino-neutralino and neutralino amplitudes involved in the process. We
calculate the mass difference and CP asymmetry in
both the constrained case (where the only flavor violation comes from the
Cabibbo-Kobayashi-Maskawa matrix) and the unconstrained case (including soft
supersymmetry breaking terms). The constrained case does not contain any new
information beyond the supergravity-inspired MSSM. In the unconstrained case,
the main contribution to and the CP asymmetry is due to
either gluino diagrams, if the dominating flavor mixing arises in the down
squark sector, or chargino diagrams, if the dominant flavor mixing comes from
the up squark sector. We include numerical results and compare this analysis
with the ones performed in other models.Comment: 26 pages, 10 figure