9,889 research outputs found
CP violation and limits on New Physics including recent measurements
We analyse present constraints on the SM parameter space and derive, in a
model independent way, various bounds on New Physics contributions to
-- and -- mixings. Our analyses include
information on a large set of asymmetries, leading to the measurement of the
CKM phases and , as well as recent data from D0 and CDF
related to the -- system such as the measurement of , and . We examine in detail several
observables such as the asymmetries , , the width differences
and and discuss the r\^ole they play
in establishing the limits on New Physics. The present data clearly favour the
SM, with the New Physics favoured region placed around the SM solution. A New
Physics solution significantly different from the SM is still allowed, albeit
quite disfavoured (2.6% probability). We analyse the presently available
indirect knowledge on the phase entering in --
mixing and study the impact of a future measurement of to be
achieved at LHC, through the measurement of the time-dependent CP asymmetry in
decays.Comment: 29 pages, 31 figures; updated analyses and reference
Nonleptonic charmless two-body decays
In this work we have studied hadronic charmless two-body B decays involving
p-wave mesons in final state. We have calculated branching ratios of
decays (where and denotes a axial-vector and a tensor meson,
respectively), using form factors obtained in the covariant
light-front (CLF) approach, and the full effective Hamiltonian. We have
obtained that ,
,
(with ) for ,
with
, for
where . It seems that these decays can be measured
in experiments at factories. Additionally, we have found that
and
ratios could be useful to determine numerical values of mixing angles
and , respectively.Comment: 12 page
An Improved Standard Model Prediction Of BR(B -> tau nu) And Its Implications For New Physics
The recently measured B -> tau nu branching ratio allows to test the Standard
Model by probing virtual effects of new heavy particles, such as a charged
Higgs boson. The accuracy of the test is currently limited by the experimental
error on BR(B -> tau nu) and by the uncertainty on the parameters fB and |Vub|.
The redundancy of the Unitarity Triangle fit allows to reduce the error on
these parameters and thus to perform a more precise test of the Standard Model.
Using the current experimental inputs, we obtain BR(B -> tau nu)_SM = (0.84 +-
0.11)x10^{-4}, to be compared with BR(B -> tau nu)_exp = (1.73 +-
0.34)x10^{-4}. The Standard Model prediction can be modified by New Physics
effects in the decay amplitude as well as in the Unitarity Triangle fit. We
discuss how to disentangle the two possible contributions in the case of
minimal flavour violation at large tan beta and generic loop-mediated New
Physics. We also consider two specific models with minimal flavour violation:
the Type-II Two Higgs Doublet Model and the Minimal Supersymmetric Standard
Model.Comment: 7 pages, 13 figures, 1 table. v2: added references and discussion of
B -> D tau nu in the 2HDM. v3: added Bs->mumu in the 2HDM. Final version to
appear in PL
Perspectives on IT Outsourcing Success: Covariance Structure Modelling of a Survey of Outsourcing in Australia
Australia has been at the forefront of the adoption of outsourcing as a means for delivering IT services, but the success of IT outsourcing in Australia has been mixed. With two hundred and forty one responses from the top 1000 IT users in the country, the survey reported in this paper is one of the largest and most representative IT outsourcing studies in the world. Covariance structure modelling and confirmatory factor analysis has shed new light on the concept of outsourcing success, highlighting its complex, multidimensional nature. It has also confirmed many insights gained to date from qualitative research. Analysis also emphasises the importance to the outsourcing relationship of the management processes adopted by the client organization.
L'Australie a Ă©tĂ© un pionnier dans l'adoption de l'impartition pour les services informatiques. Toutefois, les rĂ©sultats ont Ă©tĂ© mitigĂ©s. Avec plus de deux cent rĂ©pondants, provenant des 1000 plus grandes entreprises australiennes, cette Ă©tude et une des plus larges et reprĂ©sentatives faites jusqu'Ă 0501ntenant. Une analyse des structure de co-variance, de mĂȘme qu'une anlayse factorielle confirmatoire jettent un regard neuf sur la notion de succĂšs de l'impartition. L'Ă©tude met en lumiĂšre le caractĂšre complexe et multi-dimensionel de ce succĂšs.Outsourcing, Australia, survey research, success, information systems, Impartition, Australie, enquĂȘte, succĂšs, services informatiques
Radiative and Semileptonic B Decays Involving Higher K-Resonances in the Final States
We study the radiative and semileptonic B decays involving a spin-
resonant with parity for and for
in the final state. Using the large energy effective theory (LEET)
techniques, we formulate transition form factors in the large
recoil region in terms of two independent LEET functions
and , the values of
which at zero momentum transfer are estimated in the BSW model. According to
the QCD counting rules, exhibit a dipole
dependence in . We predict the decay rates for ,
and . The
branching fractions for these decays with higher -resonances in the final
state are suppressed due to the smaller phase spaces and the smaller values of
. Furthermore, if the spin of
becomes larger, the branching fractions will be further suppressed due to the
smaller Clebsch-Gordan coefficients defined by the polarization tensors of the
. We also calculate the forward backward asymmetry of the decay, for which the zero is highly insensitive to the
-resonances in the LEET parametrization.Comment: 27 pages, 4 figures, 7 tables;contents and figures corrected, title
and references revise
Initial Conditions for Large Cosmological Simulations
This technical paper describes a software package that was designed to
produce initial conditions for large cosmological simulations in the context of
the Horizon collaboration. These tools generalize E. Bertschinger's Grafic1
software to distributed parallel architectures and offer a flexible alternative
to the Grafic2 software for ``zoom'' initial conditions, at the price of large
cumulated cpu and memory usage. The codes have been validated up to resolutions
of 4096^3 and were used to generate the initial conditions of large
hydrodynamical and dark matter simulations. They also provide means to generate
constrained realisations for the purpose of generating initial conditions
compatible with, e.g. the local group, or the SDSS catalog.Comment: 12 pages, 11 figures, submitted to ApJ
What can we learn from phi_1 and B_d^0 -> pi^+ pi^- ?
We discuss what we can understand from and
decay mode. Using a convention without weak phases and , we
can solve the parameters from the time-depended CP asymmetry. If we can put a
condition the contribution from penguin except for the CKM factor including in
the diagram is small, then we can lead the allowed region of or
by using the convention.Comment: 7 pages, 4 figures, references and comments adde
The UTfit Collaboration Average of D meson mixing data: Spring 2012
We derive constraints on the parameters , and
that describe meson mixing using all available data, allowing
for CP violation. We also provide posterior distributions and predictions for
observable parameters appearing in physics.Comment: 5 pages, 3 figure
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