[Hps] [EXTERNAL] Result from 4He decay

[Andrea Celentano]

Dear HPS,
I point to you the following work: https://urldefense.proofpoint.com/v2/url?u=https-3A__arxiv.org_pdf_1910.10459.pdf&d=DwIFAg&c=CJqEzB1piLOyyvZjb8YUQw&r=ErLkbYGWd8oSAZ70ywHxhA&m=dFwrhuouOHKMqIKndYe1rdflD_3nU-h3lr6ytDZz_jE&s=zRH1OtqW_6gtA1vUtE2A3m-IBSlLoes2wQbwp2pVS4Q&e=  <https://urldefense.proofpoint.com/v2/url?u=https-3A__arxiv.org_pdf_1910.10459.pdf&d=DwIFAg&c=CJqEzB1piLOyyvZjb8YUQw&r=ErLkbYGWd8oSAZ70ywHxhA&m=dFwrhuouOHKMqIKndYe1rdflD_3nU-h3lr6ytDZz_jE&s=zRH1OtqW_6gtA1vUtE2A3m-IBSlLoes2wQbwp2pVS4Q&e= > recently uploaded to arXiv. The authors of the original 8Be search repeated their measurement exploiting a 3H target bombarded with a proton beam, and exciting a 20MeV level of 4He, decaying via internal pair creation. They do see a signal in the e+ e- spectrum compatible with the 8Be signal.
The mass of the hypothetic X boson they quote is 16.84 MeV. They do not put a limit on the coupling, but they quote a width of few 10-5 eV.

Bests,
Andrea
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