@misc{10481/74795,
year = {2022},
month = {4},
url = {http://hdl.handle.net/10481/74795},
abstract = {Recently, the Belle Collaboration reported the first measurements of the τ−→ντπ−e+e− branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle’s results, we evaluated this branching fraction which turned out to be compatible with that reported by Belle, although with a large uncertainty. This is the motivation to seek for improvement on our previous evaluation of τ−→ντπ−ℓ+ℓ− decays (ℓ=e, μ). In this paper we improve our calculation of the WP−γ∗ vertex by including flavor-symmetry breaking effects in the framework of the resonance chiral theory. We impose QCD short-distance behavior to constrain most parameters and data on the π−e+e− spectrum reported by the Belle Collaboration to fix the remaining free ones. As a result, improved predictions for the branching ratios and hadronic/leptonic spectra are reported, which are in good agreement with observations. Analogous calculations for the strangeness-changing τ−→ντK−ℓ+ℓ− transitions are reported for the first time. Albeit one expects the mπμ+μ− spectrum to be measured in Belle-II and the observables with ℓ=e can be improved, it is rather unlikely that the K channels can be measured due to the suppression factor |Vud/Vus|2=0.05.},
organization = {Ciencia de Frontera Conacyt
	162336, 428218},
organization = {Cátedras Marcos Moshinsky},
organization = {SEP-Cinvestav Fund
	142, MCIN/AEI/10.13039/501100011033, PID2020–114473 GB-I00},
organization = {Fundación Marcos Moshinsky

319395},
organization = {Consejo Nacional de Ciencia y Tecnología},
organization = {Ministerio de Economía y Competitividad},
organization = {Generalitat Valenciana

Prometeo/2017/053},
organization = {European Regional Development Fund

FIS2017-85053-C2-1-P},
organization = {Junta de Andalucía

FQM-225},
publisher = {American Physical Society},
title = {Improved description of dilepton production in τ − → ντP− decays},
doi = {10.1103/PhysRevD.105.076007},
author = {Guevara, Adolfo and López Castro, Gabriel and Roig, P.},
}