44,059 research outputs found
Standard Model Higgs and Top Mass Measurements at the Tevatron
A summary of the present Standard Model Higgs search and measurement of top
quark mass at the Tevatron are presented. The sensitivity of the present Higgs
search at the Tevatron is limited by statistics to a cross section
approximately two orders of magnitude higher than the predicted cross section
for Standard Model Higgs production. With 30/fb of integrated luminosity, the
Tevatron offers an unique potential discovery window for the Standard Model
Higgs mass up to 130 GeV before LHC era. The study of top at the Tevatron has
moved from discovery phase to one of characterizing its properties. The
combined result of top quark mass is 174.3+- 5.1 GeV.Comment: 7 pages, latex source-file, 5 figures as ps-file. Talk given at The
Division of Particles and Fields Conference 1999, January 5-9, 1999, UCLA,
US
Quark and lepton mass matrices with family symmetry
Realistic quark masses and mixing angles are obtained applying the successful
family symmetry for leptons, motivated by the quark-lepton assignments of
SU(5). The symmetry is suitable to give tri-bimaximal neutrino mixing
matrix which is consistent with current experimental data. We study new
scenario for the quark sector with the symmetry.Comment: 16 pages, 2 figures, Talk given at International Workshop on Neutrino
Masses and Mixings, Shizuoka, Japan, 17-19 December 200
Dynamics of strong and radiative decays of Ds-mesons in the hadrogenesis conjecture
The positive parity scalar D(2317) and axial-vector D(2460)
charmed strange mesons are generated by coupled-channel dynamics through the
s-wave scattering of Goldstone bosons off the pseudoscalar and vector
D(D)-meson ground states. The specific masses of these states are obtained
as a consequence of the attraction arising from the Weinberg-Tomozawa
interaction in the chiral Lagrangian. Chiral corrections to order Q
are calculated and found to be small. The D(2317) and D(2460)
mesons decay either strongly into the isospin-violating D and
D channels or electromagnetically. We show that the -
and (KD-KD) mixings act constructively to generate strong
widths of the order of 140 keV and emphasize the sensitivity of this value to
the component of the states. The one-loop contribution to the radiative
decay amplitudes of scalar and axial-vector states is calculated using the
electromagnetic Lagrangian to chiral order Q. We show the importance
of taking into account processes involving light vector mesons explicitly in
the dynamics of electromagnetic decays. The radiative width are sensitive to
both and components, hence providing information complementary
to the strong widths on the positive parity -meson structure.Comment: 4 pages, Invited Contribution to QNP09, Beijing, September 21-26,
200
Charm mixing in the Standard Model and beyond
The motivation most often cited in searches for D0-anti-D0 mixing and
CP-violation in charm system lies with the possibility of observing a signal
from New Physics which dominates that from the Standard Model. We review recent
theoretical predictions and experimental constraints on D0-anti-D0 mixing
parameters, concentrating on possible effects of New Physics.Comment: 8 pages, 2 figures, Invited talk at International Workshop on
Tau-Charm Physics (Charm 2006), Beijing, China, 5-7 Jun 200
Direct test of time reversal invariance violation in B mesons
In this letter we reinterpret and reanalyze the available data of the B meson
factories showing the existence of direct experimental evidence of time
reversal invariance violation in B mesons. This reinterpretation consists of
using the available observables to define a new observable which, in a model
independent way and without assuming CPT invariance, compares a transition
between a and a here-defined -state, with its time reversed
transition. The observable then offers a direct way to probe time reversal
invariance and it is therefore independent of any conclusion obtained from
current experimental information on CP violation and CPT invariance. As far as
the authors are concerned, this is the first direct evidence of time reversal
invariance violation in B mesons and also the first one obtained from decaying
particles whose mean life time difference is negligible.Comment: 9 pages, no figures. Refined version matching published article in
Modern Physics Letters
Lepton flavor violating decays induced by scalar unparticle
We study the radiative lepton flavor violating l_i -> l_j \gamma\gamma decays
in the case that the lepton flavor violation is induced by the scalar
unparticle mediation. We restrict the scaling dimension d_u and the scalar
unparticle-photon-photon coupling by using the experimental upper limit of the
branching ratio of the decay \mu -> e \gamma\gamma. Furthermore, we predict the
BRs of the other radiative decays by using the restrictions we get. We observe
that the measurements of upper limits of BRs of these decays ensure
considerable information for testing the possible signals coming from
unparticle physicsComment: 10 pages, 5 figures, 1 tabl
Final stare interaction enhancement effect on the near threshold p\bar p system in B^\pm\to p\bar p \p^\pm decay
We discuss the low-mass enhancement effect in the baryon-antibaryon invariant
mass in three-body baryonic B decays using final state interactions in the
framework of Regge theory. We show that the rescattering between baryonic pair
can reproduce the observed mass spectrum.Comment: 7 pages, 11 figure
Nondecoupling of Heavy Fermions and a Special Yukawa Texture
Talk based on work entitled ``Yukawa textures, new physics and
nondecoupling,'' done in collaboration with G. C. Branco and J. I.
Silva-Marcos, arXiv:hep-ph/0612252, to appear in Phys. Rev. D. In this work we
pointed out that New Physics can play an important r\^ ole in rescuing some of
the Yukawa texture zero ans\" atze which would otherwise be eliminated by the
recent, more precise measurements of . We have shown that the presence
of an isosinglet vector-like quark which mixes with standard quarks, can render
viable a particularly interesting four texture zero Yukawa ansatz. The crucial
point is the nondecoupling of the effects of the isosinglet quark, even for
arbitrary large values of its mass.Comment: Invited talk at CTP Symposium on Supersymmetry at LHC: Theoretical
and Experimental Prospectives, Cairo, Egypt, 11-14 Mar 200
New neighborhood based rough sets
Neighborhood based rough sets are important generalizations of the classical rough sets of Pawlak, as neighborhood operators generalize equivalence classes. In this article, we introduce nine neighborhood based operators and we study the partial order relations between twenty-two different neighborhood operators obtained from one covering. Seven neighborhood operators result in new rough set approximation operators. We study how these operators are related to the other fifteen neighborhood based approximation operators in terms of partial order relations, as well as to seven non-neighborhood-based rough set approximation operators
Search for Rare b-hadron Decays at CDF
We report on searches for B^0_s to \mu^+ \mu^-, B^0_d to \mu^+ \mu^- decays
and b to s \mu^+\mu^- transitions in exclusive decays of B mesons.
Using 2 fb^{-1} of data collected by the CDF II detector we find upper limits
on the branching fractions B(B^0_s to \mu^+ \mu^-) < 5.8 x 10^{-8} and B(B^0_d
to \mu^+ \mu^-) < 1.8 x 10^{-8} at 95% confidence level.
Using 924 pb^{-1} of data we measure the branching fractions B(B^+ to \mu^+
\mu^- K^+) = (0.60 \pm 0.15 \pm 0.04) x 10^{-6}, B(B^0_d to \mu^+ \mu^- K^{*0})
= (0.82 \pm 0.31 \pm 0.10) x 10^{-6} and the limit B(B^0_s to \mu^+ \mu^-
phi)/B(B^0_s to J/\psi\phi) < 2.61(2.30) x 10^{-3} at 95(90)% confidence level.Comment: 3 pages, 5 figures, conference proceedings to the 2007 Europhysics
Conference on High Energy Physics (Manchester, July 2007
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