403 research outputs found
Radiative corrections to the decay
Full one-loop electroweak corrections to the on-shell decay
are computed in the framework of models with two Higgs doublets (THDM). Such a
decay may be dominant for over a wide range of parameter space
relevant at present and future colliders. We show that the corrections may
approach 40% and in particular are sensitive to , which parametrizes
the discrete symmetry breaking term. We suggest that a measurement of the
branching ratio of may offer a possibility of measuring the
magnitude of .Comment: 27 pages, LaTex, 6 figures, one figure added, appendix shortened. To
be published in Eur. Phys. Jour.
Inverse Seesaw Neutrino Mass from Lepton Triplets in the U(1)_Sigma Model
The inverse seesaw mechanism of neutrino mass, i.e. m_nu =
(m_D^2/m_N^2)epsilon_L where epsilon_L is small, is discussed in the context of
the U(1)_Sigma model. This is a gauge extension of the Standard Model of
particle interactions with lepton triplets (Sigma^+,Sigma^),Sigma^-) as (Type
III) seesaw anchors for obtaining small Majorana neutrino masses.Comment: 7 pages, no figur
Branching Ratio and CP-asymmetry for B-> 1^{1}P_{1}gamma decays
We calculate the branching ratios for B_{d}^{0}->(b_{1},h_{1})gamma at
next-to-leading order (NLO) of alpha_{s} where b_{1} and h_{1} are the
corresponding radially excited axial vector mesons of rho and omega
respectively. Using the SU(3)symmetry for the form factor, the branching ratio
for B_{d}^{0}->(b_{1},h_{1})gamma is expressed in terms of the branching ratio
of the B_{d}^{0}-> K_{1}gamma and it is found to be
B(B_{d}^{0}->b_{1}gamma)=0.71* 10^{-6} and B(B_{d}^{0}-> h_{1}gamma)
=0.74*10^{-6}. We also calculate direct CP asymmetry for these decays and find,
in confirmity with the observations made in the literature, that the hard
spectator contributions significantely reduces the asymmetry arising from the
vertex corrections alone. The value of CP-asymmetry is 10% and is negative like
rho and omega in the Standard Model.Comment: 10 pages, 2 figure
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