1,442 research outputs found
Hunting the CKM weak phase with time-integrated Dalitz analyses of Bs -> K pi pi decays
We present a new technique to extract information on the Unitarity Triangle
from the study of Bs -> K pi pi Dalitz plot. Using isospin symmetry and the
possibility to access the decay amplitudes from Dalitz analyses, we propose a
new strategy to extract the weak phase gamma from Bs to K pi pi.Comment: 2 pages. v2: Discussion of interference on Dalitz plot clarified. Bs
-> K K pi channels removed. v3: Improved discussion of experimental aspects.
Final version to appear in Phys. Lett.
CP violation in supersymmetric theories
We review the present status of CP violating problem in supersymmetric
extensions of the standard model. We analyze the constraints imposed by the
experimental limits of the electron, neutron, and mercury electric dipole
moments on the supersymmetric CP phases and show that only the scenarios with
flavour-off- diagonal CP violation remain attractive. These scenarios require
hermitian Yukawa matrices which naturally arise in models with left-right
symmetry or a SU(3) flavour symmetry. In this case, epsilon_K and
epsilon'/epsilon can be saturated by a small non-universality of the soft
scalar masses through the gluino and chargino contributions respectively. The
model also predicts a strong correlation between A_{CP}(b-> s gamma) and the
neutron electric dipole moment. In this framework, the standard model gives a
the leading contribution to the CP asymmetry in B ->psi K_S decay, while the
dominant chargino contribution to this asymmetry is < 0.2. Thus, no constraint
is set on the non-universality of this model by the recent BaBar and Belle
measureets.Comment: 34 pages, 10 figures. Invited review article for International
Journal of Modern Physics
Theoretical status of epsilon'/epsilon
We review the theory of epsilon'/epsilon and present an updated
phenomenological analysis using hadronic matrix elements from lattice QCD. The
present status of the computation of epsilon'/epsilon, considering various
approaches to the matrix-element evaluation, is critically discussed.Comment: 22 pages, 2 eps figures, based on the talks given by M.C. at "Les
Rencontres de Physique de la Vallee d'Aoste", La Thuile (Italy), 27
February-4 March 2000 and by G.M. at the "XXXVth Rencontres de Moriond", Les
Arcs 1800 (France), 11-18 March 200
NLO corrections to Delta F=2 effective Hamiltonians and SUSY contribution to FCNC
The most general QCD-NLO Anomalous-Dimension Matrix of all four-fermion
dimension six Delta F=2 operators is presented. Two applications of this
Anomalous-Dimension Matrix to the study of SUSY contribution to K- Kbar mixing
are also discussed.Comment: 4 pages. Talk given at International Euroconference on Quantum
Chromodynamics (QCD98), Montpellier, France, 2-8 july 1998. Submitted to
Nucl. Phys. B (Proc. Suppl.
Opportunities From Precision Flavour Physics
The possible role of precision flavour physics, and particularly of B
physics, in the next decade is briefly discussed. Few 2--3 deviations
from the Standard Model found in present data are reviewed as potential
forerunners of new physics signals to be looked for in next-generation
experiments. The perspectives for theoretical calculations, in particular those
based on lattice QCD, to match the expected progress in experimental precision
are also discussed.Comment: 10 pages, 7 figures, proceedings of the 12th International Conference
on B-Physics at Hadron Machines - BEAUTY 2009, September 07-12, 2009,
Heidelberg, German
Status of the CKM matrix
An updated determination of the parameters of the Cabibbo-Kobayashi-Maskawa
matrix is presented.Comment: 8 pages, 9 figures, uses espcrc2.sty. Talk given at the "7th Topical
Seminar on the Legacy of LEP and SLC", 8-11 October 2001, Siena (Italy
Charming penguin and direct CP-violation in charmless B decays
In the study of two-body charmless B decays as a mean of looking for direct
CP-violation and measuring the CKM mixing parameters in the Standard Model, the
short-distance penguin contribution with its absorptive part generated by charm
quark loop seems capable of producing sufficient decays rates, as
obtained in factorization and QCD-improved factorization models. However there
are also long-distance charming penguin contributions which could give rise to
a strong phase due to the rescattering etc. In this
talk, I would like to discuss recent works on the charming penguin contribution
as a different approach to the calculation of these contributions in two-body
charmless B decays. We find that the charming penguin contribution is
significant for decays and, together with the tree and penguin
terms, produces large branching ratios in agreement with data, though the
analysis is affected by large theoretical uncertainties. The absorptive part
due to the charmed meson intermediate states is found to produce large CP
asymmetries for decays.Comment: Talk given at the QCD Euroconference 2002, Montpellier 2-9 July 2002,
LaTex, 7 pages, Misprint in the Tables correcte
The Chromomagnetic Dipole Operator and the B Semileptonic Branching Ratio
We consider the possibility of having a large branching ratio for the decay
coming from an enhanced Wilson coefficient of the chromomagnetic
dipole operator. We show that values of up to or
more are compatible with the constraints coming from the CLEO experimental
results on and . Such large values can
reconcile the predictions of both the semileptonic branching ratio and the
charm counting with the present experimental results. We also discuss a
supersymmetric model with gluino-mediated flavour violations, which can account
for such large values of .Comment: 19 pages, 3 eps figures included, replacement with minor change
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