1,021 research outputs found
The 2004 UTfit Collaboration Report on the Status of the Unitarity Triangle in the Standard Model
Using the latest determinations of several theoretical and experimental
parameters, we update the Unitarity Triangle analysis in the Standard Model.
The basic experimental constraints come from the measurements of |V_ub/V_cb|,
Delta M_d, the lower limit on Delta M_s, epsilon_k, and the measurement of the
phase of the B_d - anti B_d mixing amplitude through the time-dependent CP
asymmetry in B^0 to J/psi K^0 decays. In addition, we consider the direct
determination of alpha, gamma, 2 beta + gamma and cos(2 beta) from the
measurements of new CP-violating quantities, recently performed at the B
factories. We also discuss the opportunities offered by improving the precision
of the various physical quantities entering in the determination of the
Unitarity Triangle parameters. The results and the plots presented in this
paper can also be found at http://www.utfit.org, where they are continuously
updated with the newest experimental and theoretical results.Comment: 32 pages, 17 figures. High resolution figures and updates can be
found at http://www.utfit.org v2: misprints correcte
COLOROMETRIC DETERMINATION OF RANTIDINE HYDROCHLORIDE
A simple, precise and cost effective colorometric method have been developed for the estimation of Rantidine hydrochloride in its pharmaceutical formulations. RNH shows λmax at 520.0 nm. The drug follows the Beer-Lambert’s law. The method validated by following the analytical performance parameters suggested by the International Conference on Harmonization. All validation parameters were within the acceptable range. The developed methods were successfully applied to estimate the amount of RNH in pharmaceutical dosage form
Flavor SU(3) analysis of charmless B meson decays to two pseudoscalar mesons
Global fits to charmless B --> PP decays in the framework of flavor SU(3)
symmetry are updated and improved without reference to the \sin2\beta measured
from the charmonium decay modes. Fit results directly constrain the
(\bar\rho,\bar\eta) vertex of the unitarity triangle, and are used to predict
the branching ratios and CP asymmetries of all decay modes, including those of
the B_s system. Different schemes of SU(3) breaking in decay amplitude sizes
are analyzed. The major breaking effect between strangeness-conserving and
strangeness-changing decays can be accounted for by including a ratio of decay
constants in tree and color-suppressed amplitudes. The possibility of having a
new physics contribution to K \pi decays is also examined from the data fitting
point of view.Comment: 22 pages and 2 figures; some comments and references added; more
references added, version to appear in journa
Forward-backward and isospin asymmetry for B -> K* l+ l- decay in the standard model and in supersymmetry
We discuss two dedicated observables in exclusive B -> K* l+ l- decay that
can be used to study effects of physics beyond the standard model, namely the
forward-backward asymmetry in the lepton spectrum and the isospin-asymmetry
between decays of charged and neutral B mesons. We consider the region of large
recoil-energy (i.e. small invariant mass of the lepton pair), and employ the
QCD factorization approach to exclusive B meson decays. Sub-leading effects in
the heavy quark mass expansion have been taken into account for the calculation
of the isospin-asymmetry. We give predictions for decay asymmetries in the
standard model, and its supersymmetric extension with minimal flavor violation,
using parameter values allowed by current experimental constraints on B->X_s
gamma decay.Comment: 21 pages, LaTeX with 6 figures, added reference
APC-β-catenin-TCF signaling silences the intestinal guanylin-GUCY2C tumor suppressor axis.
Sporadic colorectal cancer initiates with mutations in APC or its degradation target β-catenin, producing TCF-dependent nuclear transcription driving tumorigenesis. The intestinal epithelial receptor, GUCY2C, with its canonical paracrine hormone guanylin, regulates homeostatic signaling along the crypt-surface axis opposing tumorigenesis. Here, we reveal that expression of the guanylin hormone, but not the GUCY2C receptor, is lost at the earliest stages of transformation in APC-dependent tumors in humans and mice. Hormone loss, which silences GUCY2C signaling, reflects transcriptional repression mediated by mutant APC-β-catenin-TCF programs in the nucleus. These studies support a pathophysiological model of intestinal tumorigenesis in which mutant APC-β-catenin-TCF transcriptional regulation eliminates guanylin expression at tumor initiation, silencing GUCY2C signaling which, in turn, dysregulates intestinal homeostatic mechanisms contributing to tumor progression. They expand the mechanistic paradigm for colorectal cancer from a disease of irreversible mutations in APC and β-catenin to one of guanylin hormone loss whose replacement, and reconstitution of GUCY2C signaling, could prevent tumorigenesis
Direct CP Violation, Branching Ratios and Form Factors , in Decays
The and transitions involved in hadronic B decays are
investigated in a phenomenological way through the framework of QCD
factorization. By comparing our results with experimental branching ratios from
the BELLE, BABAR and CLEO Collaborations for all the B decays including either
a pion or a kaon, we propose boundaries for the transition form factors and depending on the CKM matrix element parameters and
. From this analysis, the form factors required to reproduce the
experimental data for branching ratios are and
. We calculate the direct CP violating asymmetry
parameter, , for and decays, in the case where mixing effects are taken into
account. Based on these results, we find that the direct CP asymmetry for
, ,
, and , reaches its maximum when the invariant mass is
in the vicinity of the meson mass. The inclusion of
mixing provides an opportunity to erase, without ambiguity, the phase
uncertainty mod in the determination of the CKM angles in case
of and in case of .Comment: 74 pages, 15 figures, 8 tables. A few misprints corrected, two
references adde
Architecting in global software engineering
Cataloged from PDF version of article.This paper summarizes the results of the First Workshop on Architecting
in Global Software Engineering (GSE), which was organized
in conjunction with the 6th International Conference on
Global Software Engineering (ICGSE 2011). The workshop
aimed to bring together researchers and practitioners for defining
and advancing the state-of-the-art and state-of-the practice in
architecture design of global software development systems
Heavy Quark Spectroscopy -- Theory Overview
Some recent discoveries in the spectroscopy of hadrons containing heavy
quarks, and some of their theoretical interpretations, are reviewed.Comment: 13 pages, 6 figures. Presented at Second Meeting of APS Topical Group
on Hadron Physics, Nashville, TN, 22-24. Proceedings to be published by
Journal of Physics (UK), Conference Series. Uses jpconf.cls, jpconf11.clo.
Some corrections; references update
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