2,712 research outputs found
CP Asymmetries of and Decays Using a Global Fit in QCD Factorization
We analyze the CP asymmetries of and
modes in the QCD improved factorization framework. For our calculation we use
the phenomenological parameters predetermined from the global fit for the
available and modes (without the quark-level subprocess ). We show that the large negative and
the large branching ratio for can be simultaneously
explained in the context of supersymmetry (SUSY). The R-parity conserving SUGRA
models are used and their parameter space is constrained with the observed dark
matter relic density along with other experimental constraints. The R-parity
violating SUSY models are also used to show that they can provide solutions. We
calculate the CP asymmetries for different
and modes and show that the SUSY model
predictions are consistent with the available experimental data.Comment: 13 pages, No figure; Some references adde
Los comuneros de Castilla
Copia digital. Valladolid : Junta de Castilla y LeĂłn. ConsejerĂa de Cultura y Turismo, 2009-201
La liga de Ăvila : novela del tiempo de las comunidades de Castilla
Copia digital. Valladolid : Junta de Castilla y LeĂłn. ConsejerĂa de Cultura y Turismo, 2012-201
Flavor and CP violating Z exchange and the rate asymmetry in B --> phi K_S
Recent measurements of time dependent CP asymmetry in B --> phi K_S, if
confirmed, would indicate a new source of CP violation. We examine flavor
violating tree-level Z currents in models with extra down-type quark singlets
that arise naturally in string compactified gauge groups like E_6. We evaluate
the new operators at the scale mu = m_b in NLO, and using QCD improved
factorization to describe B --> phi K_S, find the allowed range of parameters
for rho and psi, the magnitude and phase of the flavor violating parameter
U_{bs}. This allowed range does satisfy the constraint from flavor changing
process b --> s l+ l- . However, further improvement in measurement of these
rates could severely constrain the model.Comment: 15 pages, Latex, 2 postscript figures. Sections 2 and 3 are
reordered. More references are added. Version to be published in PL
ProFITS of maize: a database of protein families involved in the transduction of signalling in the maize genome
<p>Abstract</p> <p>Background</p> <p>Maize (<it>Zea mays </it>ssp. <it>mays </it>L.) is an important model for plant basic and applied research. In 2009, the B73 maize genome sequencing made a great step forward, using clone by clone strategy; however, functional annotation and gene classification of the maize genome are still limited. Thus, a well-annotated datasets and informative database will be important for further research discoveries. Signal transduction is a fundamental biological process in living cells, and many protein families participate in this process in sensing, amplifying and responding to various extracellular or internal stimuli. Therefore, it is a good starting point to integrate information on the maize functional genes involved in signal transduction.</p> <p>Results</p> <p>Here we introduce a comprehensive database 'ProFITS' (Protein Families Involved in the Transduction of Signalling), which endeavours to identify and classify protein kinases/phosphatases, transcription factors and ubiquitin-proteasome-system related genes in the B73 maize genome. Users can explore gene models, corresponding transcripts and FLcDNAs using the three abovementioned protein hierarchical categories, and visualize them using an AJAX-based genome browser (JBrowse) or Generic Genome Browser (GBrowse). Functional annotations such as GO annotation, protein signatures, protein best-hits in the <it>Arabidopsis </it>and rice genome are provided. In addition, pre-calculated transcription factor binding sites of each gene are generated and mutant information is incorporated into ProFITS. In short, ProFITS provides a user-friendly web interface for studies in signal transduction process in maize.</p> <p>Conclusion</p> <p>ProFITS, which utilizes both the B73 maize genome and full length cDNA (FLcDNA) datasets, provides users a comprehensive platform of maize annotation with specific focus on the categorization of families involved in the signal transduction process. ProFITS is designed as a user-friendly web interface and it is valuable for experimental researchers. It is freely available now to all users at <url>http://bioinfo.cau.edu.cn/ProFITS</url>.</p
Propagation and blocking in periodically hostile environments
We study the persistence and propagation (or blocking) phenomena for a
species in periodically hostile environments. The problem is described by a
reaction-diffusion equation with zero Dirichlet boundary condition. We first
derive the existence of a minimal nonnegative nontrivial stationary solution
and study the large-time behavior of the solution of the initial boundary value
problem. To the main goal, we then study a sequence of approximated problems in
the whole space with reaction terms which are with very negative growth rates
outside the domain under investigation. Finally, for a given unit vector, by
using the information of the minimal speeds of approximated problems, we
provide a simple geometric condition for the blocking of propagation and we
derive the asymptotic behavior of the approximated pulsating travelling fronts.
Moreover, for the case of constant diffusion matrix, we provide two conditions
for which the limit of approximated minimal speeds is positive
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
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