# 2019 Meeting of the Division of Particles & Fields of the American Physical Society

July 29, 2019 to August 2, 2019
Northeastern University
US/Eastern timezone

## Revisiting the Dark Photon Interpretation of the Muon Anomalous Magnetic Moment

Jul 30, 2019, 2:00 PM
18m
Shillman 335 (Northeastern University)

### Shillman 335

#### Northeastern University

Oral Presentation Beyond Standard Model Physics

### Speaker

Gopolang Mohlabeng (Brookhaven National Laboratory)

### Description

A massive U(1)′ gauge boson known as a “dark photon” or A′, has long been proposed as a potential explanation for the discrepancy observed between the experimental measurement and theoretical determination of the anomalous magnetic moment of the muon ($g_μ$ − 2) anomaly. Recently, experimental results have excluded this possibility for a dark photon exhibiting exclusively visible or invisible decays. In this work, we revisit this idea and consider a model where A′ couples inelastically to dark matter and an excited dark sector state, leading to a more exotic decay topology we refer to as a semi-visible decay. We show that for large mass splittings between the dark sector states this decay mode is enhanced, weakening the previous invisibly decaying dark photon bounds. As a consequence, A′ resolves the $g_μ$ − 2 anomaly in a region of parameter space the thermal dark matter component of the Universe is readily explained. Interestingly, it is possible that the semi-visible events we discuss may have been vetoed by experiments searching for invisible dark photon decays. A re-analysis of the data and future searches may be crucial in uncovering this exotic decay mode or closing the window on the dark photon explanation of the $g_μ$ − 2 anomaly.

### Primary author

Gopolang Mohlabeng (Brookhaven National Laboratory)