Probing charged lepton flavor violation with a positron beam at CEBAF (JLAB)

TL;DR

This paper proposes using a high-intensity polarized positron beam at CEBAF to search for Charged Lepton Flavor Violation, potentially surpassing current experimental limits and distinguishing between different new physics models.

Contribution

It introduces a novel experimental setup at CEBAF with a polarized positron beam and SoLID detector to significantly improve CLFV search sensitivity and differentiate between new physics scenarios.

Findings

Positron beam could improve CLFV limits by 100-1000 times.

Polarization enables distinguishing left- and right-handed leptoquark effects.

Feasibility of using existing CEBAF infrastructure for new physics searches.

Abstract

The addition of a high intensity 11 GeV polarized positron beam at the Continuous Electron Beam Accelerator Facility (CEBAF) at JLAB would allow for a search of Charged Lepton Flavor Violation (CLFV) via the process $e^+N \rightarrow \mu^+ X$. The proposed Solenoidal Large Intensity Detector (SoLID) spectrometer, in the configuration with muon chambers, would be ideal for such CLFV searches. Various new physics scenarios, including the phenomenologically convenient Leptoquark (LQ) framework, predict CLFV rates that are within reach of current or planned experiments. A positron beam with instantaneous luminosity, ${\cal L}\sim 10^{38}$ cm$^{-2}$s$^{-1}$, could improve on existing HERA limits by two or three orders of magnitude. The availability of positron beam polarization would also allow for distentangling CLFV effects mediated by left-handed vs. right-handed LQs.