Jul 24 – 30, 2016
Highfield Campus, University of Southampton
Europe/London timezone

Vus from inclusive determinations based on hadronic tau data

Jul 28, 2016, 3:20 PM
Building 67 Room 1003 (Highfield Campus, University of Southampton)

Building 67 Room 1003

Highfield Campus, University of Southampton

Highfield Campus, Southampton SO17 1BJ, UK
Talk Weak Decays and Matrix Elements Weak Decays and Matrix Elements


Kim Maltman (York University)


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)


Hiroshi Ohki (BNL) James Zanotti (University of ADelaide) Randy Lewis (York University) Dr Renwick Hudspith (York University) Taku Izubuchi (BNL)

Presentation materials