243 research outputs found
The Landau Pole and decays in the 331 bilepton model
We calculate the decay widths and branching ratios of the extra neutral boson
predicted by the 331 bilepton model in the framework of two
different particle contents. These calculations are performed taken into
account oblique radiative corrections, and Flavor Changing Neutral Currents
(FCNC) under the ansatz of Matsuda as a texture for the quark mass matrices.
Contributions of the order of are obtained in the branching
ratios, and partial widths about one order of magnitude bigger in relation with
other non- and bilepton models are also obtained. A Landau-like pole arise at
3.5 TeV considering the full particle content of the minimal model (MM), where
the exotic sector is considered as a degenerated spectrum at 3 TeV scale. The
Landau pole problem can be avoid at the TeV scales if a new leptonic content
running below the threshold at TeV is implemented as suggested by other
authors.Comment: 20 pages, 5 figures, LaTeX2
Semiseparable integral operators and explicit solution of an inverse problem for the skew-self-adjoint Dirac-type system
Inverse problem to recover the skew-self-adjoint Dirac-type system from the
generalized Weyl matrix function is treated in the paper. Sufficient conditions
under which the unique solution of the inverse problem exists, are formulated
in terms of the Weyl function and a procedure to solve the inverse problem is
given. The case of the generalized Weyl functions of the form
, where is a strictly proper rational
matrix function and is a diagonal matrix, is treated in greater
detail. Explicit formulas for the inversion of the corresponding semiseparable
integral operators and recovery of the Dirac-type system are obtained for this
case
Cerebral perfusion in sepsis
This article is one of ten reviews selected from the Yearbook of Intensive Care and Emergency Medicine 2010 (Springer Verlag) and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/yearbook. Further information about the Yearbook of Intensive Care and Emergency Medicine is available from http://www.springer.com/series/2855
Search for and Using Genetic Programming Event Selection
We apply a genetic programming technique to search for the double Cabibbo
suppressed decays and .
We normalize these decays to their Cabibbo favored partners and find
\Lambda_c^+ \to p K^+ \pi^-\Lambda_c^+ \to p K^-
\pi^+ and D_s^+ \to K^+ K^+
\pi^-D_s^+ \to K^+ K^- \pi^+ where
the first errors are statistical and the second are systematic. Expressed as
90% confidence levels (CL), we find and respectively.
This is the first successful use of genetic programming in a high energy
physics data analysis.Comment: 10 page
Measurement of the branching ratio of the decay D^0 -> \pi^-\mu^+\nu relative to D^0 -> K^-\mu^+\nu
We present a new measurement of the branching ratio of the Cabibbo suppressed
decay D^0\to \pi^-\mu^+\nu relative to the Cabibbo favored decay D^0\to
K^-\mu^+\nu and an improved measurement of the ratio
|\frac{f_+^{\pi}(0)}{f_+^{K}(0)}|. Our results are 0.074 \pm 0.008 \pm 0.007
for the branching ratio and 0.85 \pm 0.04 \pm 0.04 \pm 0.01 for the form factor
ratio, respectively.Comment: 13pages, 3 figure
Study of the decay asymmetry parameter and CP violation parameter in the Lambdac+ --> Lambda pi+ decay
Using data from the FOCUS (E831) experiment at Fermilab, we present a new
measurement of the weak decay-asymmetry parameter alpha(Lambdac) in Lambdac -->
Lambda pi decay. Comparing particle with antiparticle decays, we obtain the
first measurement of the CP violation parameter : A =
[alpha(Lambdac)+alpha(antiLambda_c)]/[alpha(Lambdac)-alpha(antiLambda_c)]. We
obtain alpha(Lambdac)=-0.78+-0.16+-0.13 and A = -0.07+-0.19+-0.12 where errors
are statistical and systematic.Comment: 18 pages, to be submitted to Phys. Lett. B For a list of the FOCUS
collaboration, see http://www-focus.fnal.gov/authors.htm
Search for T Violation in Charm Meson Decays
Using data from the FOCUS (E831) experiment, we have searched for T violation
in charm meson decays using the four-body decay channels , , and . The T violation asymmetry is obtained using triple-product
correlations and assuming the validity of the CPT theorem. We find the
asymmetry values to be
,
, and
.
Each measurement is consistent with no T violation. New measurements of the
CP asymmetries for some of these decay modes are also presented.Comment: 17 pages,6 figures,submitted to Phys.Lett.
Hadronic Mass Spectrum Analysis of D+ into K- pi+ mu+ nu Decay and Measurement of the K*(892)^0 Mass and Width
We present a Kpi mass spectrum analysis of the four-body semileptonic charm
decay D+ into K- pi+ mu+ nu in the range of 0.65 GeV < mKpi < 1.5 GeV. We
observe a non-resonant contribution of 5.30 +- 0.74 +0.99 -0.51 % with respect
to the total D+ into K- pi+ mu+ nu decay. For the K*(892)^0 resonance, we
obtain a mass of 895.41 +- 0.32 +0.35 -0.36 MeV, a width of 47.79 +- 0.86 +1.3
-1.1 MeV, and a Blatt-Weisskopf damping factor parameter of 3.96 +- 0.54 +0.72
-0.90 GeV^(-1). We also report 90 % CL upper limits of 4 % and 0.64 % for the
branching ratios of D+ into K*(1680)^0 mu+ nu with respect to D+ into K- pi+
mu+ nu and D+ into K*(1430)^0 mu+ nu with respect to D+ into K- pi+ mu+ nu,
respectively.Comment: 14 page
Study of Lambda/c+ Cabibbo Favored Decays Containing a Lambda Baryon in the Final State
Using data from the FOCUS experiment (FNAL-E831), we study the decay of
baryons into final states containing a hyperon. The
branching fractions of into , and relative to that into are
measured to be , and
, respectively. We also report new measurements of
, and . Further, an analysis of the subresonant structure for the
decay mode is presented.Comment: 14 pages, 6 figures, 3 tables, Submitted to Physics Letter
Measurement of the branching fraction
The branching fraction is measured in a data sample
corresponding to 0.41 of integrated luminosity collected with the LHCb
detector at the LHC. This channel is sensitive to the penguin contributions
affecting the sin2 measurement from The
time-integrated branching fraction is measured to be . This is the most precise measurement to
date
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