Probing unparticle theory via lepton flavor violating process $J/\psi\to ll'$ at BESIII

TL;DR

This paper explores the potential of the BESIII experiment to detect lepton flavor violating decays of $J/\psi$ as a test for unparticle physics, which predicts larger effects than the Standard Model.

Contribution

It provides a detailed analysis of how $J/\psi\to ll'$ decays can serve as probes for unparticle theory, highlighting the experimental feasibility and theoretical implications.

Findings

Unparticle effects could enhance $J/\psi\to ll'$ decay rates.

BESIII's data could potentially observe or constrain unparticle contributions.

Leptonic decay backgrounds are low, making detection cleaner.

Abstract

The lepton flavor violating process $J/\psi\to ll' (l\neq l')$ serves as an ideal place to probe the unparticle theory. Such process can only occur at loop level in the Standard model (SM), so that should be very suppressed, by contrast in unparticle scenario, it happens at tree level and its contribution may be sizable for practical measurement. Moreover, the BESIII will offer the largest database on $J/\psi$ which makes more accurate measurements possible. Furthermore, for such purely leptonic decays background is relatively low and signal would be cleaner. Our work carefully investigates the possibility of observing such processes from both theoretical and experimental aspects.