### Speaker

### Description

Tau-based finite-energy sum rule (FESR) analyses often assume that scales

s_0~m_tau^2 are large enough that (i) integrated duality violations (DVs)

can be neglected, and (ii) contributions from non-perturbative OPE

condensates of dimension D scale as ~(Lambda_{QCD}/m_tau )^D, allowing the

OPE series to be truncated at low dimension. The latter assumption is not

true in general since the OPE series is not convergent, while the former

is open to question given experimental results for the electromagnetic,

I=1 vector (V), I=1 axial vector (A) and I=1 V+A current spectral functions,

which show clear DV oscillations with amplitudes comparable in size to the

corresponding alpha_s-dependent perturbative contributions at hadronic

invariant mass-squareds s~2-3 GeV^2. In this talk, we (1) introduce, and

illustrate the utility of, a new strategy for assessing the numerical

relevance of omitted higher-D OPE and/or residual DV contributions, (2) use

large N_c and analyticity arguments to derive the expected large-s form for

DV contribution to the I=1, V spectral function, under the assumption that

the leading behavior is Regge-like at large s, and (3) use this form to

explore the level of suppression of residual integrated DV contributions

in I=1, V channel FESRs.

What is your topic? | Hadronic decays |
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