A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decay
Abstract We explore the potential of a combined analysis of the decays $$\tau ^{-}\rightarrow \pi ^{-}\pi ^{0}\nu _{\tau }$$ τ-→π-π0ντ and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ in the determination of the $$\rho (1450)$$ ρ(1450) and $$\rho (1700)$$ ρ(1700) resonance properties in...
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doaj-ef0826bf18584b7abc0a6dc4f9310e392020-11-25T03:17:19ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522019-05-0179511810.1140/epjc/s10052-019-6943-9A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decaySergi Gonzàlez-Solís0Pablo Roig1CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of SciencesDepartamento de Física, Centro de Investigación y Estudios Avanzados del IPNAbstract We explore the potential of a combined analysis of the decays $$\tau ^{-}\rightarrow \pi ^{-}\pi ^{0}\nu _{\tau }$$ τ-→π-π0ντ and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ in the determination of the $$\rho (1450)$$ ρ(1450) and $$\rho (1700)$$ ρ(1700) resonance properties in the frame of resonance Chiral Theory supplemented by dispersion relations. On the one hand, we take advantage of the very precise data on the modulus squared of the pion vector form factor $$|F_{V}^{\pi }|^{2}$$ |FVπ|2 obtained by Belle to carry out a very dedicated analysis of the region where these resonances come up into play. Our study provides an improved treatment of the systematic theoretical errors and, as a most important result, we conclude that they dominate over the fit uncertainties in the determination of the $$\rho (1450)$$ ρ(1450) and $$\rho (1700)$$ ρ(1700) pole parameters and tend to be larger than in other determinations quoted in the literature where these errors were ignored or underestimated. The results of our analysis are summarized in numerical tables for the form factor modulus and phase, including both statistical and systematic errors, that can be found as ancillary material of this paper. As a byproduct, we also determine the low-energy observables of the pion vector form factor and the $$\rho $$ ρ -pole position. On the other hand, we benefit from the recent experimental data for the transition $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ released by BaBar to perform a first analysis of its decay spectrum and discuss the role of these resonances in this decay. We point out that higher-quality data on the $$K^{-}K_{S}$$ K-KS decay channel will allow to compete with the $$|F_{V}^{\pi }|^{2}$$ |FVπ|2 ones and improve the determination of the $$\rho (1450)$$ ρ(1450) and $$\rho (1700)$$ ρ(1700) resonance parameters as a result of a combined analysis. We hope our study to be of interest for present and future experimental analysis of these decays.http://link.springer.com/article/10.1140/epjc/s10052-019-6943-9 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Sergi Gonzàlez-Solís Pablo Roig |
spellingShingle |
Sergi Gonzàlez-Solís Pablo Roig A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decay European Physical Journal C: Particles and Fields |
author_facet |
Sergi Gonzàlez-Solís Pablo Roig |
author_sort |
Sergi Gonzàlez-Solís |
title |
A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decay |
title_short |
A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decay |
title_full |
A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decay |
title_fullStr |
A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decay |
title_full_unstemmed |
A dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ decay |
title_sort |
dispersive analysis of the pion vector form factor and $$\tau ^{-}\rightarrow k^{-}k_{s}\nu _{\tau }$$ τ-→k-ksντ decay |
publisher |
SpringerOpen |
series |
European Physical Journal C: Particles and Fields |
issn |
1434-6044 1434-6052 |
publishDate |
2019-05-01 |
description |
Abstract We explore the potential of a combined analysis of the decays $$\tau ^{-}\rightarrow \pi ^{-}\pi ^{0}\nu _{\tau }$$ τ-→π-π0ντ and $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ in the determination of the $$\rho (1450)$$ ρ(1450) and $$\rho (1700)$$ ρ(1700) resonance properties in the frame of resonance Chiral Theory supplemented by dispersion relations. On the one hand, we take advantage of the very precise data on the modulus squared of the pion vector form factor $$|F_{V}^{\pi }|^{2}$$ |FVπ|2 obtained by Belle to carry out a very dedicated analysis of the region where these resonances come up into play. Our study provides an improved treatment of the systematic theoretical errors and, as a most important result, we conclude that they dominate over the fit uncertainties in the determination of the $$\rho (1450)$$ ρ(1450) and $$\rho (1700)$$ ρ(1700) pole parameters and tend to be larger than in other determinations quoted in the literature where these errors were ignored or underestimated. The results of our analysis are summarized in numerical tables for the form factor modulus and phase, including both statistical and systematic errors, that can be found as ancillary material of this paper. As a byproduct, we also determine the low-energy observables of the pion vector form factor and the $$\rho $$ ρ -pole position. On the other hand, we benefit from the recent experimental data for the transition $$\tau ^{-}\rightarrow K^{-}K_{S}\nu _{\tau }$$ τ-→K-KSντ released by BaBar to perform a first analysis of its decay spectrum and discuss the role of these resonances in this decay. We point out that higher-quality data on the $$K^{-}K_{S}$$ K-KS decay channel will allow to compete with the $$|F_{V}^{\pi }|^{2}$$ |FVπ|2 ones and improve the determination of the $$\rho (1450)$$ ρ(1450) and $$\rho (1700)$$ ρ(1700) resonance parameters as a result of a combined analysis. We hope our study to be of interest for present and future experimental analysis of these decays. |
url |
http://link.springer.com/article/10.1140/epjc/s10052-019-6943-9 |
work_keys_str_mv |
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