Measurement of the Principal Quantum Number Distribution in a Beam of Antihydrogen Atoms

TL;DR

This paper reports the first measurement of the quantum state distribution of antihydrogen atoms in a low magnetic field, crucial for precision CPT symmetry tests, and discusses machine learning methods for event identification.

Contribution

It introduces the first measurement of antihydrogen quantum state distribution and applies data-driven machine learning techniques for event identification.

Findings

Quantum state distribution of antihydrogen measured in low magnetic field

Machine learning methods effectively identify antihydrogen events

Results support the feasibility of high-precision CPT tests

Abstract

The ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) collaboration plans to measure the ground-state hyperfine splitting of antihydrogen in a beam at the CERN Antiproton Decelerator with initial relative precision of 10-6 or better, to test the fundamental CPT (combination of charge conjugation, parity transformation and time reversal) symmetry between matter and antimatter. This challenging goal requires a polarised antihydrogen beam with a sufficient number of antihydrogen atoms in the ground state. The first measurement of the quantum state distribution of antihydrogen atoms in a low magnetic field environment of a few mT is described. Furthermore, the data-driven machine learning analysis to identify antihydrogen events is discussed.