20 research outputs found
Lepton Flavour Violating Leptonic/Semileptonic Decays of Charged Leptons in the Minimal Supersymmetric Standard Model
We consider the leptonic and semileptonic (SL) lepton flavour violating (LFV)
decays of the charged leptons in the minimal supersymmetric standard model
(MSSM). The formalism for evaluation of branching fractions for the SL LFV
charged-lepton decays with one or two pseudoscalar mesons, or one vector meson
in the final state, is given. Previous amplitudes for the SL LFV charged-lepton
decays in MSSM are improved, for instance the -penguin amplitude is
corrected to assure the gauge invariance. The decays are studied not only in
the model-independent formulation of the theory in the frame of MSSM, but also
within the frame of the minimal supersymmetric SO(10) model within which the
parameters of the MSSM are determined. The latter model gives predictions for
the neutrino-Dirac Yukawa coupling matrix, once free parameters in the model
are appropriately fixed to accommodate the recent neutrino oscillation data.
Using this unambiguous neutrino-Dirac Yukawa couplings, we calculate the LFV
leptonic and SL decay processes assuming the minimal supergravity scenario. A
very detailed numerical analysis is done to constrain the MSSM parameters.
Numerical results for SL LFV processes are given, for instance for tau -> e
(mu) pi0, tau -> e (mu) eta, tau -> e (mu) eta', tau -> e (mu) rho0, tau -> e
(mu) phi, tau -> e (mu) omega, etc.Comment: 36 pages, 3 tables, 5 .eps figure
Softening the Supersymmetric Flavor Problem in Orbifold GUTs
The infra-red attractive force of the bulk gauge interactions is applied to
soften the supersymmetric flavor problem in the orbifold SU(5) GUT of Kawamura.
Then this force aligns in the infra-red regime the soft supersymmetry breaking
terms out of their anarchical disorder at a fundamental scale, in such a way
that flavor-changing neutral currents as well as dangerous CP-violating phases
are suppressed at low energies. It is found that this dynamical alignment is
sufficiently good compared with the current experimental bounds, as long as the
diagonalization matrices of the Yukawa couplings are CKM-like.Comment: 15 pages,4 figure
Factors Affecting the Nasal Carriage of Methicillin-resistant Staphylococcus aureus in Human Immunodeficiency Virus-infected Patients
Human immunodeficiency virus-infected patients attending skin
outpatient department were studied for nasal carriage of
methicillin-resistant Staphylococcus aureus (MRSA)and associated
factors affecting nasal colonization. Nasal swabs were used for
isolation of S. aureus. MRSA were detected by agar screen and agar
dilution methods. Careful examination for dermatoses was carried out.
Forty-six of the 60 (76.67%) outpatients with HIV infection were
colonized with S. aureus in the anterior nares. Significant number of
S. aureus carriers were in the 31-40 year age group. Methicillin
resistance was found in eight (17.39%) isolates. Of the 46 S. aureus
strains, 29 (63%) were resistant to erythromycin, 69.5% to
co-trimoxazole and 41.3% to ciprofloxacin. Co-trimoxazole use was found
to be a risk factor for S. aureus carriage ( P = 0.0214) but not for
methicillin resistance. Hospital stay for more than 10 days was a risk
factor for methicillin resistance whereas stay for more than 25 days
was found to be a highly significant risk factor. Dermatophytosis and
herpes simplex virus infection were other risk factors for nasal
carriage of S. aureus