Towards Antihydrogen Trapping and Spectroscopy at ALPHA

TL;DR

This paper discusses the development of techniques for trapping and spectroscopic analysis of antihydrogen at CERN, aiming to test fundamental symmetries and understand matter-antimatter asymmetry.

Contribution

It introduces new methods for directly measuring antiproton temperature, cooling them below 10 K, and utilizing a position-sensitive detector for effective annihilation identification.

Findings

Successful cooling of antiprotons below 10 K

Effective background rejection with position-sensitive detector

Preparation of antihydrogen samples for spectroscopy

Abstract

Spectroscopy of antihydrogen has the potential to yield high-precision tests of the CPT theorem and shed light on the matter-antimatter imbalance in the Universe. The ALPHA antihydrogen trap at CERN's Antiproton Decelerator aims to prepare a sample of antihydrogen atoms confined in an octupole-based Ioffe trap and to measure the frequency of several atomic transitions. We describe our techniques to directly measure the antiproton temperature and a new technique to cool them to below 10 K. We also show how our unique position-sensitive annihilation detector provides us with a highly sensitive method of identifying antiproton annihilations and effectively rejecting the cosmic-ray background.