203 research outputs found
Left-right mixing on leptonic and semileptonic decays
It has been known that there exists a disagreement emerged between the
determination of from inclusive decays and
exclusive decays. In order to solve the mismatch, we
investigate the left-right (LR) mixing effects, denoted by , in leptonic
and semileptonic decays. We find that the new interactions
induced via the LR mixing can explain the mismatch between
the values of if Re. Furthermore, we
also find that the LR mixing effects can enhance the branching fractions for and decays by 30% and 17%, respectively, while
reducing the branching fraction for decays by 18%.Comment: 11 pages, 6 eps figure
CP violating dimuon charge asymmetry in general left-right models
The recently measured charge asymmetry of like-sign dimuon events by the D0
collaboration at Tevatron shows the 3.9 \sigma\ deviation from the standard
model prediction. In order to solve this mismatch, we investigate the
right-handed current contributions to and
mixings which are the major source of the like-sign dimuon events in production in general left-right models without imposing manifest or
pseudo-manifest left-right symmetry. We find the allowed region of new physics
parameters satisfying the current experimental data.Comment: 9 pages, 4 figure
Singlet Fermionic Dark Matter with Dark
We present a fermionic dark matter model mediated by the hidden gauge boson.
We assume the QED-like hidden sector which consists of a Dirac fermion and
U(1) gauge symmetry, and introduce an additional scalar electroweak doublet
field with the U(1) charge as a mediator. The hidden U(1) symmetry is
spontaneously broken by the electroweak symmetry breaking and there exists a
massive extra neutral gauge boson in this model which is the mediator between
the hidden and visible sectors. Due to the U(1) charge, the additional
scalar doublet does not couple to the Standard Model fermions, which leads to
the Higgs sector of type I two Higgs doublet model. The new gauge boson couples
to the Standard Model fermions with couplings proportional to those of the
ordinary boson but very suppressed, thus we call it the dark boson. We
study the phenomenology of the dark boson and the Higgs sector, and show
the hidden fermion can be the dark matter candidate.Comment: 10 pages, 3 figure
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