55,628 research outputs found
Black Hole Evaporation by Thermal Bath Removal
We study the evaporation process of 2D black holes in thermal equilibrium
when the incoming radiation is turned off. Our analysis is based on two
different classes of 2D dilaton gravity models which are exactly solvable in
the semiclassical aproximation including back-reaction. We consider a one
parameter family of models interpolating between the Russo-Susskind-Thorlacius
and Bose-Parker-Peleg models. We find that the end-state geometry is the same
as the one coming from an evaporating black hole formed by gravitational
collapse. We also study the quantum evolution of black holes arising in a model
with classical action . The black hole temperature is proportional to the
mass and the exact semiclassical solution indicates that these black holes
never disappear completely.Comment: LaTeX, psfig.sty. 10 pages. 3 figures (included as PS files
New Physics and novel Higgs signals
We review some of the results of our recent work dealing with the novel type
of Higgs signals that arise when one considers extensions of the standard
model.
We discuss first possible deviations on the Higgs couplings due to heavy
particles, in the context of the MSSM and with large extra-dimensions. Then, we
present several models where it is possible to induce flavor violating Higgs
couplings, and probe them at future hadron colliders through the LFV Higgs
decay h-> tau mu or with rare top decays.Comment: Talk given at the X Mexican School of Particles and Fields, Playa del
Carmen, Mexico, 200
FCNC and non-standard soft-breaking terms in weak-scale Supersymmetry
We study the inclusion of non-standard soft-breaking terms in the minimal
SUSY extension of the SM, considering it as a model of weak-scale SUSY. These
terms modify the sfermion mass matrices, which can induce new sources of
flavour violation. Bounds on the new soft parameters can be estimated from
current data. The results are then applied to evaluate FCNC top decay t -> c +
hi (hi= h,H,A). Implications of complex soft parameters for CP violation are
also addressed.Comment: Revised version (8 pages), title changed and references corrected.
Presented at VIII Mexican Workshop on Particles and Fields, Merida (1999
A redshift survey towards the CMB Cold Spot
We have carried out a redshift survey using the VIMOS spectrograph on the VLT
towards the Cosmic Microwave Background cold spot. A possible cause of the cold
spot is the Integrated Sachs-Wolfe effect imprinted by an extremely large void
(hundreds of Mpc in linear dimension) at intermediate or low redshifts. The
redshift distribution of over seven hundred z<1 emission-line galaxies drawn
from an I-band flux limited sample of galaxies in the direction of the cold
spot shows no evidence of a gap on scales of Delta-z> 0.05 as would be expected
if such a void existed at 0.35<z<1. There are troughs in the redshift
distribution on smaller scales (Delta-z ~0.01) indicating that smaller scale
voids may connect regions separated by several degrees towards the cold spot. A
comparison of this distribution with that generated from similarly-sized
subsamples drawn from widely-spaced pointings of the VVDS survey does not
indicate that the redshift distribution towards the cold spot is anomalous or
that these small gaps can be uniquely attributed to real voids.Comment: MNRAS in press, 6 page
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