Speaker
Kim Maltman
(York University)
Description
We discuss the current status of the determination of V_us based on
flavor-breaking finite energy sum rule analyses of non-strange and
strange hadronic tau decay data, highlighting the role of lattice
input in providing a means of investigating the reliability of the
OPE representation for the relevant flavor-breaking polarization
combination employed in this analysis, and in quantifying the associated
theoretical errors on V_us. We present results for V_us based on an
new implementation this approach motivated by continuum and lattice
studies and show that this resolves the long-standing problem of
V_us values more than 3 sigma low compared to 3-family unitarity
expectations obtained in earlier implementations of this approach.
We also discuss the practical limitations of this new implementation
given what near-term improvements are likely in the experimental
strange decay distributions, and, motivated by these limitations,
propose a new method for obtaining V_us which involves dispersive
analyses of the strange hadronic tau decay data alone in which
lattice results for the relevant combination of the flavor us
J=0 and 1 vector and axial vector polarizations can be used in place
of the OPE. Details of the practical implementation of this approach,
as well as preliminary results for V_us, will be presented in
the accompanying talk by Hiroshi Ohki.
Primary author
Kim Maltman
(York University)
Co-authors
Hiroshi Ohki
(BNL)
James Zanotti
(University of ADelaide)
Randy Lewis
(York University)
Dr
Renwick Hudspith
(York University)
Taku Izubuchi
(BNL)
