2020/03/04 by David McKeen, McKeen, David, Maxim Pospelov +1 · 5 citations
Chemistry · Pharmacology, Toxicology and Pharmaceutics · Physics and Astronomy · #Atom (system on chip) #Chemical Reactions and Isotopes #Computer science #FOS: Physical sciences #Group (periodic table) #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Hydrogen #Hydrogen atom #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Parallel computing #Physics #Quantum mechanics #Various Chemistry Research Topics #hep-ex #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.48550/arxiv.2003.02270
6 pages, 4 figures
arxiv created 2020/03/04 · openalex publication_date 2020/03/04 · arxiv updated 2020/03/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is possible that the proton is stable while atomic hydrogen is not. This is the case in models with new particles carrying baryon number which are light enough to be stable themselves but heavy enough so that proton decay is kinematically blocked. Models of new physics that explain the neutron lifetime anomaly generically have this feature, allowing for atomic hydrogen to decay through electron capture on a proton. We calculate the radiative hydrogen decay rate involving the emission of a few hundred keV photon, which makes this process detectable in experiment. In particular, we show that the low energy part of the Borexino spectrum is sensitive to radiative hydrogen decay, and turn this into a limit on the hydrogen lifetime of order 1030~\rm s or stronger. For models where the neutron mixes with a dark baryon, χ, this limits the mixing angle to roughly 10-11, restricting the n→χγ branching to 10-4, over a wide range of parameter space.