New results on the 8Be anomaly

A. Krasznahorkay, M. Csatlós, L. Csige, Z. Gácsi, J. Gulyás, Nagy, N. Sas, J. Tímár, T. G. Tornyi, I. Vajda, A. Krasznahorkay

Research output: Conference article

2 Citations (Scopus)


Recently, we observed anomalous internal pair creation for the M1 transition depopulating the 18.15 MeV isoscalar 1+ state in 8Be. We observed a significant (σ = 7.37) peak-like deviation from the predicted angular correlation of the e+ e pairs at θ = 140°. To the best of our knowledge no nuclear physics related description of such deviation can be made. However, the deviation can be described by assuming the creation and subsequent decay of a boson with mass of ≈17 MeV. In order to clarify the interpretation, we re-investigated the 8Be anomaly with an improved, and independent setup. We have confirmed the signal of the assumed X(17) particle and constrained its mass (m 0 c 2 = 17.01(16) MeV) and branching ratio compared to the γ-decay (B x = 6(1) × 10-6).

Original languageEnglish
Article number012028
JournalJournal of Physics: Conference Series
Issue number1
Publication statusPublished - júl. 19 2018
EventConference on Neutrino and Nuclear Physics 2017, CNNP 2017 - Catania, Italy
Duration: okt. 15 2017okt. 21 2017


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Krasznahorkay, A., Csatlós, M., Csige, L., Gácsi, Z., Gulyás, J., Nagy, Sas, N., Tímár, J., Tornyi, T. G., Vajda, I., & Krasznahorkay, A. (2018). New results on the 8Be anomaly. Journal of Physics: Conference Series, 1056(1), [012028].