Conveners
Session I: Vus
- Juliet Lee-Franzini (LNF-INFN, Frascati)
- Matthew Moulson (LNF-INFN, Frascati)
Session I: Vus and Vud
- Mario Antonelli (LNF-INFN, Frascati)
Dr
Vincenzo Cirigliano
(Los Alamos)
5/21/07, 2:30 PM
Vus and Vud
Swagato Banerjee
(University of Victoria)
5/21/07, 3:30 PM
Vus and Vud
We report measurements of branching fractions for several
hadronic tau decays to
final states including kaons, which can be used to determine the
strange quark mass
and the element |Vus| of the CKM quark mixing matrix. The results
are collected with
the Babar detector at PEP-II, the SLAC asymmetric-energy e+e-
collider.
Andreas Juettner
(Univ. of Southampton)
5/21/07, 3:50 PM
Vus and Vud
We present the latest results from UKQCD/RBC collaborations for
the Kl3 form factor
with 2+1 flavours of dynamical domain wall quarks. Simulations
are performed on
16^3x32x16 and 24^3x64x16 lattices with three values of the light
quark mass,
allowing for an extrapolation to the chiral limit
Ms
Anne Dabrowski
(Department of Physics and Astronomy, Northwestern University)
5/21/07, 4:10 PM
Vus and Vud
Measured ratios of decay rates for ${\cal R}_{K e 3 / K2\pi}$,
${\cal R}_{K \mu 3
/ K2\pi}$ and
${\cal R}_{K \mu 3 / Ke3}$ are presented, based
on $K^\pm$ decays collected in a dedicated run in
2003 by the NA48/2 experiment at CERN. The results obtained are
$ {\cal R}_{K e 3 / K2\pi} = 0.2470\pm 0.0009 (stat)\pm 0.0004
(syst)$ and
$ {\cal R}_{K \mu 3 / K2\pi} = 0.1637\pm 0.0006...
Emilie Passemar
(IPN Orsay)
5/21/07, 5:00 PM
Vus and Vud
In this talk we will introduce an accurate dispersive
parametrization of the two K_{l3} form factors and discuss three
applications to the analysis of K_{e3} and K_{mu3} measurements:
the prediction of the branching ratios K_{mu3}/K_{e3}, the
extraction of |f_+(0)V_{us}| and finally the possible measurement
of m_d - m_u induced isospin breaking asymmetry.
Jan Stern
(IPN Orsay)
5/21/07, 5:20 PM
Vus and Vud
The recent dedicated analysis of K^L_{$\mu$ 3} Dalitz plot by
NA48 reveals a 5
$\sigma$ deviation from the Callan-Treiman low-energy theorem ,
provided standard
electroweak
couplings of quarks are assumed. QCD can hardly tolerate such a
huge violation of its
$ SU(2) X SU(2) $ chiral symmetry. We suggest that , instead, the
observed
discrepancy reflects a small admixture of right -...
Dr
Barbara Sciascia
(LNF - INFN, Frascati)
5/21/07, 5:50 PM
Vus and Vud
The semileptonic BR's are relevant for the evaluation of the CKM
matrix element |Vus|. The measurement of the branching ratios for
the charged K semileptonic decays uses four independent samples
tagged by the following kaon decays: K+ -> mu2, K+ -> pi2, K- ->
mu2, and K- -> pi2. Using 410 pb-1 of total integrated luminosity
(2.5 fb-1), about 60 million tag decays have been identified...
Mr
Viacheslav Duk
(INR RAS)
5/21/07, 6:10 PM
Vus and Vud
We review recent results on charged kaon decays obtained by
ISTRA+ collaboration. The
obtained branching fractions are compared with theoretical
predictions. For Kl3
radiative
decays the estimations of T-odd asymmetry are given.
Dr
Claudio Gatti
(LNF - INFN, Frascati)
5/21/07, 6:30 PM
Vus and Vud
Semileptonic kaon decays offer possibly the cleanest way to
obtain an
accurate value of the Cabibbo angle, or better, $V_{us}$. At
present,
the largest uncertainty in calculating $V_{us}$ from the decay
rate, is due to
the difficulties in computing the matrix element of the $K
\rightarrow \pi$ transition.
The matrix element of $K_L \rightarrow \pi \mu \nu$ decay is
expressed in...
Paolo Massarotti
(Naples University & INFN)
5/21/07, 6:50 PM
Vus and Vud
The charged K lifetime, is an experimental input to the
determination of Vus. The present fractional uncertainty is about
0.2%,
however the available data show large discrepancies between the
measurements done using charged kaon decays in-flight and at-rest.
At KLOE two different methods have been developed: one based on
the measurement of the charged kaon decay length
and the other...
Prof.
Takashi Kaneko
(KEK, Tsukuba)
5/22/07, 9:00 AM
Vus and Vud
Dr
Matteo Palutan
(LNF -INFN)
5/22/07, 10:00 AM
Vus and Vud
At present, the first-row constraint, $|V_{ud}|^2 + |V_{us}|^2 +
|V_{ub}|^2$ = 1 (with $|V_{ub}|^2$ negligible), offers the most
precise test of CKM unitarity.
Up until 2002 (and for the 2004 PDG evaluation), the evaluation
of $|V_{us}$ from older $K_{l3}$ data gave 2.3$\sigma$ hint of
unitarity violation in the first-row test. The 2003 measurement
of BR($K^+_{e2}$) by BNL E865 gave a...
