Unparticle-Induced Lepton Flavor Violating Decays \tau^- ->l^- (V^0, ~P^0)

TL;DR

This paper evaluates lepton flavor violating tau decays into mesons within unparticle physics, finding some modes could have detectable branching ratios at future colliders, constrained by current experimental data.

Contribution

It systematically constrains unparticle coupling parameters using experimental data and predicts potentially observable tau decay modes in future experiments.

Findings

$ au o au V^0$ modes can reach branching ratios of $10^{-10}$ to $10^{-8}$

$ au o au P^0$ modes are too small to detect

Parameter space constraints align with experimental limits

Abstract

We make an evaluation of the lepton flavor violating (LFV) decays $\tau \to \ell (V^0, P^0)$, where $\ell=e$ or $\mu$ and $V^0(P^0)$ is a neutral vector (pseudo-scalar) meson, in the context of unparticle physics. The constraints are investigated systematically on the related coupling parameters from all the available experimental data, and the parameter values are specified appropriately. The results show that whereas over the whole parameter space allowed by experiments all the $\tau \to \ell P^0$ modes have a branching ratio too small to be measurable experimentally, in a large subspace as observed all of the $\tau \to \ell V^0$ modes get simultaneously a branching ratio as high as ${\cal O}(10^{-10}-10^{-8})$, which is reachable at the LHC and super B factory. The important implications are drawn.