Cold antihydrogen: a new frontier in fundamental physics

Abstract

The year 2002 heralded a breakthrough in antimatter research when the first low energy antihydrogen atoms were produced. Antimatter has inspired both science and fiction writers for many years, but detailed studies have until now eluded science. Antimatter is notoriously difficult to study as it does not readily occur in nature, even though our current understanding of the laws of physics have us expecting that it should make up half of the universe. The pursuit of cold antihydrogen is driven by a desire to solve this profound mystery. This paper will motivate the current effort to make cold antihydrogen, explain how antihydrogen is currently made, and how and why we are attempting to trap it. It will also discuss what kind of measurements are planned to gain new insights into the unexplained asymmetry between matter and antimatter in the universe.

Simulation of an aperture-based antihydrogen gravity experiment

“…One simulation (e.g., with a given set of values for R, a, T, L, and N s or N) provides a single value for N ζ . Twenty (20) simulations are carried out for each set of parameter values, and the average N ζ and standard deviation SD of the values obtained for N ζ are reported in Table I. The correlation between statistical results for N ζ and calculated values for P is shown by providing values for the quotients N ζ /P and SD/P.…”

“…13 Antihydrogen research may ultimately provide experimental tests of CPT (charge conjugation, parity, time reversal) and gravity symmetries. [14][15][16][17][18][19][20] There exist numerous conflicting issues associated with using nested Penning traps to produce antiatoms with sufficiently low energies and also in sufficient numbers for conducting high precision CPT and gravity measurements. 3,21 Many of the issues are being addressed, as indicated by recent advances.…”

Matter-Antimatter Asymmetry and States in the Universe

“…Although one would expect solutions with the similar profile for both ψ,ψ it is perfectly reasonable that their momentum dependences may have different or even opposite behavior. Besides that the particle/antiparticle effective masses may become different dynamically by a solution such as those resulting from expressions (6). The hermiticity of Dirac Hamiltonian is not necessarily kept in curved spacetimes due to the time dependence of the metrics that brings time dependence of the spatial position eigenstates (53).…”

Aperture-based antihydrogen gravity experiment: Parallel plate geometry

“…Antihydrogen research may ultimately provide experimental tests of CPT (charge conjugation, parity, time reversal) symmetry and the weak equivalence principle of general relativity. [12][13][14][15][16][17] Aperture-based antihydrogen gravity experiments have been previously considered that use a horizontal, cylindrical drift tube with a single or multiple aperture setup. 18,19 The present work represents a third iteration of study on a possible aperture-based antimatter gravity experiment.…”