Probing invisible vector meson decay mode with hadronic beam in the NA64 experiment at SPS/CERN

TL;DR

This paper proposes a novel fixed-target experimental method using a pion beam to search for invisible vector meson decays, providing new bounds and a promising approach to explore sub-GeV Dark Matter.

Contribution

It introduces a new experimental approach with a pion beam to search for invisible meson decays, expanding the methods for probing Dark Matter.

Findings

Derived bounds for invisible vector ρ meson decay

Compared new bounds with existing Dark Matter search limits

Showed effectiveness of the approach in probing sub-GeV Dark Matter

Abstract

We test a novel idea of using a $\pi^-$ beam in the fixed-target experiments to search for New Physics in the events with missing energy. Bounds for invisible vector $\rho$ meson decay were derived, analyzed, and compared with the current limits on searching Dark Matter in the accelerator based experiments. We demonstrate that the new approach can be effective tool to probe sub-GeV Dark Matter parameter space.