New results on the 8Be anomaly

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

Research output: Contribution to journalConference article

5 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 - Jul 19 2018
EventConference on Neutrino and Nuclear Physics 2017, CNNP 2017 - Catania, Italy
Duration: Oct 15 2017Oct 21 2017


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

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