Sensitivity of the SHiP experiment to light dark matter

TL;DR

The paper evaluates the SHiP experiment's potential to detect light dark matter particles in the sub-GeV range, showing it can improve current limits and probe the thermal relic parameter space.

Contribution

It provides a detailed sensitivity analysis of SHiP for light dark matter detection, focusing on a specific benchmark scenario with dark photon decay.

Findings

SHiP can improve current limits for dark matter masses 1 MeV to 300 MeV.

SHiP can probe the thermal target for Majorana dark matter candidates.

SHiP can reach the Pseudo-Dirac thermal relic parameter space.

Abstract

Dark matter is a well-established theoretical addition to the Standard Model supported by many observations in modern astrophysics and cosmology. In this context, the existence of weakly interacting massive particles represents an appealing solution to the observed thermal relic in the Universe. Indeed, a large experimental campaign is ongoing for the detection of such particles in the sub-GeV mass range. Adopting the benchmark scenario for light dark matter particles produced in the decay of a dark photon, with $\alpha_D=0.1$ and $m_{A'}=3m_{\chi}$, we study the potential of the SHiP experiment to detect such elusive particles through its Scattering and Neutrino detector (SND). In its 5-years run, corresponding to $2\cdot 10^{20}$ protons on target from the CERN SPS, we find that SHiP will improve the current limits in the mass range for the dark matter from about 1 MeV to 300 MeV. In particular, we show that SHiP will probe the thermal target for Majorana candidates in most of this mass window and even reach the Pseudo-Dirac thermal relic.