Antihydrogen studies in ALPHA

N Madsen

doi:10.1088/1742-6596/770/1/012021

Abstract

The ALPHA experiment studies antihydrogen as a means to investigate the symmetry of matter and antimatter. Spectroscopic studies of the anti-atom hold the promise of the most precise direct comparisons of matter and antimatter possible. ALPHA was the first to trap antihydrogen in a magnetic trap, allowing the first ever detection of atomic transitions in an anti-atom. More recently, through stochastic heating, we have also been able to put a new limit on the charge neutrality of antihydrogen. ALPHA is currently preparing to perform the first laser-spectroscopy of antihydrogen, hoping to excite the 2s state using a two-photon transition from the 1s state. We discuss the recent results as well as the key developments that led to these successes and discuss how we are preparing to perform the first laser-spectroscopy. We will also discuss plans to use our novel technique for gravitational tests on antihydrogen for a direct measurement of the sign of the gravitational force on antihydrogen.

Highlights

Antihydrogen, the bound state of an antiproton and a positron, is a promising test-bed for high precision comparisons of matter and antimatter and for testing fundamental symmetries
In recent years the ALPHA experiment has noted a number of breakthroughs that are helping pave the way for such comparisons
We here presented the latest results of the ALPHA antihydrogen experiment and discussed some exciting upcoming directions

Summary

Introduction

Antihydrogen, the bound state of an antiproton and a positron, is a promising test-bed for high precision comparisons of matter and antimatter and for testing fundamental symmetries. In recent years the ALPHA experiment has noted a number of breakthroughs that are helping pave the way for such comparisons These include the trapping and holding of antihydrogen for extended periods [1, 2], the first observation of atomic transitions in the from of a positron spin-flip (hyperfine transition) in the ground state [3], demonstration of a novel technique for studying the effects of gravity [4] and measurements of the charge neutrality of antihydrogen [5]. These feats have put ALPHA at the lead of the

ALPHA collaboration

Findings

Conclusions