Recently, a peak in the light fermion pair spectrum at invariant q)2 ≈ (16.7MeV)2 has been observed in the bombardment of 7Li by protons. This peak has been interpreted in terms of a protophobic interaction of fermions with a gauge boson (X boson) of invariant mass ≈16.7MeV which couples mainly to neutrons. High-precision atomic physics experiments aimed at observing the protophobic interaction need to separate the X boson effect from the nuclear-size effect, which is a problem because of the short range of the interaction (11.8 fm), which is commensurate with a "nuclear halo." Here we analyze the X boson in terms of its consequences for both electronic atoms as well as muonic hydrogen and deuterium. We find that the most promising atomic systems where the X boson has an appreciable effect, distinguishable from a finite-nuclear-size effect, are muonic atoms of low and intermediate nuclear charge numbers.
U. D. Jentschura and I. Nandori, "Atomic Physics Constraints on the X Boson," Physical Review A, vol. 97, no. 4, American Physical Society (APS), Apr 2018.
The definitive version is available at https://doi.org/10.1103/PhysRevA.97.042502
Keywords and Phrases
Atoms, Atomic system; Gauge bosons; High-precision; Invariant mass; Muonic hydrogen; Nuclear charge numbers; Nuclear sizes; Physics experiments, Bosons
International Standard Serial Number (ISSN)
Article - Journal
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