164 research outputs found
Transverse Tau Polarization in Decays of the Top and Bottom Quarks in the Weinberg Model of CP Non-conservation
We show that the transverse polarization asymmetry of the -lepton in
the decay is extremely sensitive to CP violating
phases arising from the charged Higgs exchange in the Weinberg model of CP
non-conservation. Qualitatively, the polarization asymmetries are enhanced over
rate or energy asymmetries by a factor of . Thus for optimal values of the parameters the method requires top pairs to be observable rather than needed for rate or energy
asymmetries. We also examine polarization in b decays via and find that it can also be very effective in constraining the CP
violation parameters of the extended Higgs sector.Comment: 11,1 figure, SLAC-PUB-608
Unparticle effects on top quark rare decays
In this work we study the flavor changing neutral current(FCNC) decays of the
top quark, and . The Standard Model, predictions for
the branching ratios of these decays are about , and
, respectively. The recent study presented by the ATLAS
Collaboration gives a sensitivity on these branching ratios about at C.L. The parameter space of , , and
where the branching ratios of and decays exceed these
predictions is obtained
Bounds on the mass of the b' quark, revisited
Recent results from the DELPHI collaboration led us to review the present
bounds on the b' quark mass. We use all available experimental data for m_b' >
96 GeV to constrain the b' quark mass as a function of the
Cabibbo-Kobayashi-Maskawa elements in a sequential four generations model. We
find that there is still room for a b' with a mass larger than 96 GeV.Comment: 9 pages and 7 figures. REVTEX
New physics effects in the rare B_s --> \gamma \ell^+ \ell^- decays with polarized photon
Using the most general model independent form of the effective Hamiltonian,
the rare B_s --> \gamma \ell^+ \ell^- decays are studied by taking into account
the polarization of the photon. The total and the differential branching ratios
for these decays, when photon is in the positive and negative helicity states,
are presented. Dependence of these observables on the new Wilson coefficients
are studied. It is also investigated the sensitivity of "photon polarization
asymmetry" in B_s --> \gamma \ell^+ \ell^- decays to the new Wilson
coefficients. It has been shown that all these physical observables are very
sensitive to the existence of new physics beyond SM and their experimental
measurements can give valuable information about it.Comment: 17 pages, 14 figure
Flavor changing t -> c l_1^- l_2^+ decay in the general two Higgs doublet model
We study the flavor changing t-> c l_1^- l_2^+ decay in the framework of the
general two Higgs doublet model, the so called model III. We predict the
branching ratio for l_1=\tau, l_2=\mu at the order of magnitude of BR \sim
10^{-8}.Comment: 12 Pages, 5 Figure
Final-State-Interaction Simulation of T-Violation in the Top-Quark Semileptonic Decay
The standard electroweak final-state interaction induces a false T-odd
correlation in the top-quark semileptonic decay. The correlation parameter is
calculated in the standard model and found to be considerably larger than those
that could be produced by genuine T-violation effects in a large class of
theoretical models.Comment: 14 pages, 1 diagram (not included
Supersymmetric QCD flavor changing top quark decay
We present a detailed and complete calculation of the gluino and scalar
quarks contribution to the flavour-changing top quark decay into a charm quark
and a photon, gluon, or a Z boson within the minimal supersymmetric standard
model including flavour changing gluino-quarks-scalar quarks couplings in the
right-handed sector. We compare the results with the ones presented in an
earlier paper where we considered flavour changing couplings only in the
left-handed sector. We show that these new couplings have important
consequences leading to a large enhancement when the mixing of the scalar
partners of the left- and right-handed top quark is included. Furthermore CP
violation in the flavour changing top quark decay will occur when a SUSY phase
is taken into account.Comment: 14 pages, latex, 3 figure
Lepton polarization asymmetry in radiative dileptonic B-meson decays in MSSM
In this paper we study the polarization asymmetries of the final state lepton
in the radiative dileptonic decay of B meson (\bsllg) in the framework of
Minimal Supersymmetric Standard Model (MSSM) and various other unified models
within the framework of MSSM e.g. mSUGRA, SUGRA (where condition of
universality of scalar masses is relaxed) etc. Lepton polarization, in addition
of having a longitudinal component (\pl), can have two other components, \pt
and \pn, lying in and perpendicular to the decay plane, which are proportional
to \ml and hence are significant for final state being or
. We analyse the dependence of these polarization asymmetries
on the parameters of the various models.Comment: typos corrected to match with published versio
Knots: Attractive Places with High Path Tortuosity in Mouse Open Field Exploration
When introduced into a novel environment, mammals establish in it a preferred place marked by the highest number of visits and highest cumulative time spent in it. Examination of exploratory behavior in reference to this âhome baseâ highlights important features of its organization. It might therefore be fruitful to search for other types of marked places in mouse exploratory behavior and examine their influence on overall behavior
A tecpr2 knockout mouse exhibits age-dependent neuroaxonal dystrophy associated with autophagosome accumulation
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