Tests of the Atomki anomaly in lepton pair decays of heavy mesons

The anomalies recently reported in lepton pair transitions of Be-8* and He-4 nuclei may be attributed to the existence of a feebly interacting light vector boson X17. We study the effects of this hypothetic particle in the semileptonic H* -> He(+)e(-) decays (H a Q (q) over bar meson) in the framework of the HQET + VMD model. Using current bounds and the universality assumption of the X17 boson to quarks, we find that decays of D*(+) and D-s*(+) mesons can be importantly enhanced relative to the dominant photon-mediated contributions. Dedicated experimental searches at current heavy meson factories may confirm the existence of this light boson or set stronger bounds of their couplings to ordinary matter.

Automated summary

Researchers studied the effects of the X17 boson on semileptonic decays within the HQET + VMD model, finding significant enhancements in the decays of D*(+) and D-s*(+) mesons. Dedicated experimental searches at heavy meson factories may confirm the existence of this light boson or establish stronger bounds on its couplings to ordinary matter.