8,728 research outputs found
Basis invariant conditions for supersymmetry in the two-Higgs-doublet model
The minimal supersymmetric standard model involves a rather restrictive Higgs
potential with two Higgs fields. Recently, the full set of classes of
symmetries allowed in the most general two Higgs doublet model was identified;
these classes do not include the supersymmetric limit as a particular class.
Thus, a physically meaningful definition of the supersymmetric limit must
involve the interaction of the Higgs sector with other sectors of the theory.
Here we show how one can construct basis invariant probes of supersymmetry
involving both the Higgs sector and the gaugino-higgsino Higgs interactions.Comment: RevTex, 11 pages, v2-small section adde
Custodial SO(4) symmetry and CP violation in N-Higgs-doublet potentials
We study the implementation of global
symmetry in general potentials with N-Higgs-doublets in order to obtain models
with custodial symmetry. We conclude that any implementation of the
custodial SO(4) symmetry is equivalent, by a basis transformation, to a
canonical one if is the gauge factor, is embedded in
and we require copies of the doublet representation of .
The invariance by SO(4) automatically leads to a CP invariant potential and the
basis of the canonical implementation of SO(4) is aligned to a basis where
CP-symmetry acts in the standard fashion. We show different but equivalent
implementations for the 2HDM, including an implementation not previously
considered.Comment: 22pp, REVTeX4. Published versio
Helioseismic Ring Analysis of CME Source Regions
We apply the ring diagram technique to source regions of halo coronal mass
ejections (CMEs) to study changes in acoustic mode parameters before, during,
and after the onset of CMEs. We find that CME regions associated with a low
value of magnetic flux have line widths smaller than the quiet regions implying
a longer life-time for the oscillation modes. We suggest that this criterion
may be used to forecast the active regions which may trigger CMEs.Comment: Accepted for publication in J. Astrophys. Astr. Also available at
http://www2.nso.edu/staff/sushant/paper.htm
Complete High Temperature Expansions for One-Loop Finite Temperature Effects
We develop exact, simple closed form expressions for partition functions
associated with relativistic bosons and fermions in odd spatial dimensions.
These expressions, valid at high temperature, include the effects of a
non-trivial Polyakov loop and generalize well-known high temperature
expansions. The key technical point is the proof of a set of Bessel function
identities which resum low temperature expansions into high temperature
expansions. The complete expressions for these partition functions can be used
to obtain one-loop finite temperature contributions to effective potentials,
and thus free energies and pressures.Comment: 9 pages, RevTeX, no figures. To be published in Phys. Rev D. v2 has
revised introduction and conclusions, plus a few typographical errors are
corrected; v3 corrects one typ
Sneutrino Mixing Phenomena
In any model with nonzero Majorana neutrino masses, the sneutrino and
antisneutrino of the supersymmetric extended theory mix. We outline the
conditions under which sneutrino-antisneutrino mixing is experimentally
observable. The mass-splitting of the sneutrino mass eigenstates and sneutrino
oscillation phenomena are considered.Comment: 12 pages, revtex + axodraw, 1 figure included. Minor change
Higgs and SUSY Searches at LHC
I start with a brief introduction to Higgs mechanism and supersymmetry. Then
I discuss the theoretical expectations, current limits and search strategies
for Higgs boson(s) at LHC --- first in the SM and then in the MSSM. Finally I
discuss the signatures and search strategies for the superparticles.Comment: Typos and figure styles corrected; LaTeX (28 pages) including 13 ps
files containing 11 figures; Invited talk at the 5th Workshop on High Energy
Physics Phenomenology (WHEPP-5), Pune, India, 12 - 25 January 199
A Note On R-Parity Violation and Fermion Masses
We consider a class of supersymmetric SU(3)\times SU(2)\times U(1) multihiggs
models in which R-parity is violated through bilinear Higgs-lepton
interactions. The required, due to R-parity violation, higgs-lepton rotations
introduce an alternative way to generate the phenomenologically desirable
fermion mass matrix structures independently of the equality of Yukawas,
possibly imposed by superstring or other unification.Comment: 8 pages, uses LaTeX2
Supersymmetry and Broken Symmetries at High Temperature
It is generally believed that internal symmetries are necessarily restored at
high temperature in supersymmetric theories. We provide simple and natural
counterexamples to this no-go theorem for systems having a net background
charge. We exemplify our findings on abelian models, for both cases of global
and local symmetries and discuss their possible implications.Comment: Four pages, LaTeX file; a couple of refs. added. Final version
accepted for publication in Phys. Rev. Let
Tunable sub-luminal propagation of narrowband x-ray pulses
Group velocity control is demonstrated for x-ray photons of 14.4 keV energy
via a direct measurement of the temporal delay imposed on spectrally narrow
x-ray pulses. Sub-luminal light propagation is achieved by inducing a steep
positive linear dispersion in the optical response of Fe M\"ossbauer
nuclei embedded in a thin film planar x-ray cavity. The direct detection of the
temporal pulse delay is enabled by generating frequency-tunable spectrally
narrow x-ray pulses from broadband pulsed synchrotron radiation. Our
theoretical model is in good agreement with the experimental data.Comment: 8 pages, 4 figure
Effects of Bose-Einstein Condensation on forces among bodies sitting in a boson heat bath
We explore the consequences of Bose-Einstein condensation on
two-scalar-exchange mediated forces among bodies that sit in a boson gas. We
find that below the condensation temperature the range of the forces becomes
infinite while it is finite at temperatures above condensation.Comment: 10 pages, 2 figure
- …