# Dual MeV Gamma-Ray and Dark Matter Observatory -- GRAMS Project

## TL;DR

GRAMS is a novel, cost-effective observatory designed to improve MeV gamma-ray detection and search for dark matter via antimatter, especially low-energy antideuterons, surpassing previous experiments in sensitivity.

## Contribution

It introduces a dual-purpose, large-scale LArTPC detector that advances MeV gamma-ray astronomy and dark matter indirect detection with antimatter.

## Key findings

- Enhanced sensitivity in MeV gamma-ray detection by over an order of magnitude.
- Potential to detect background-free low-energy antideuterons as dark matter signatures.
- Next-generation experiment surpassing GAPS in antimatter survey capabilities.

## Abstract

GRAMS (Gamma-Ray and AntiMatter Survey) is a novel project that can simultaneously target both astrophysical observations with MeV gamma rays and an indirect dark matter search with antimatter. The GRAMS instrument is designed with a cost-effective, large-scale LArTPC (Liquid Argon Time Projection Chamber) detector surrounded by plastic scintillators. The astrophysical observations at MeV energies have not yet been well-explored (the so-called "MeV-gap") and GRAMS can improve the sensitivity by more than an order of magnitude compared to previous experiments. While primarily focusing on MeV gamma-ray observations, GRAMS is also optimized for cosmic ray antimatter surveys to indirectly search for dark matter. In particular, low-energy antideuterons will provide an essentially background-free dark matter signature. GRAMS will be a next generation experiment beyond the current GAPS (General AntiParticle Spectrometer) project for antimatter survey.