Recently, we observed an anomalous internal pair creation for the M1 transition depopulating the 18.15 MeV isoscalar 1+ state in 8Be. The deviation from the theoretical prediction can be described by assuming the creation and subsequent decay of a new, light boson with a mass of 16.7 MeV/c2. 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 (m0c2= 17.01(16) MeV) and branching ratio compared to the γ-decay (Bx=6(1)x10−6). We investigated also the high-energy (21 MeV) J=0−->0+ transition in 4He and got a consistent result for the X(17) particle
We observed electron-positron pairs from the electro-magnetically forbidden M0 transition depopulati...
Electron-positron angular correlations were remeasured for the 17.6 MeV (Jπ = 1+ → 0+) ground state ...
Electron-positron angular correlations were remeasured for the 17.6 MeV $(J^π = 1^+ \to 0^+)$ ground...
In a 2016 paper, an anomaly in the internal pair creation on theM1transition depopulating the 18....
The e−e+ decay of the candidate new particle X(17) has already been confirmed by previous experiment...
The e−e+ decay of the candidate new particle X(17) has already been confirmed by previous experiment...
The improved results on a direct search for a new X(16.7 MeV) boson that could explain the anomalou...
Recently, we observed anomalous internal pair creation for the M1 transition depopulating the 18.15 ...
The existence of a light neutral boson, possible mediator of a new fundamental interaction, has been...
Recently, we measured the e+e− angular correlations in internal pair creation (IPC) for the M1 trans...
The improved results on a direct search for a new X ( 16.7 MeV ) boson that could expl...
The 6.8σ anomaly in excited 8Be nuclear decays via internal pair creation is fit well by a new parti...
The improved results on a direct search for a new X(16.7 MeV) boson that could explain the anomalou...
In a measurement of the angular correlation of e(+)e(-) pairs in the isovector M1 decay from 1(+) le...
Electron-positron angular correlations were remeasured for the 17.6 MeV (Jπ = 1+ → 0+) ground state ...
We observed electron-positron pairs from the electro-magnetically forbidden M0 transition depopulati...
Electron-positron angular correlations were remeasured for the 17.6 MeV (Jπ = 1+ → 0+) ground state ...
Electron-positron angular correlations were remeasured for the 17.6 MeV $(J^π = 1^+ \to 0^+)$ ground...
In a 2016 paper, an anomaly in the internal pair creation on theM1transition depopulating the 18....
The e−e+ decay of the candidate new particle X(17) has already been confirmed by previous experiment...
The e−e+ decay of the candidate new particle X(17) has already been confirmed by previous experiment...
The improved results on a direct search for a new X(16.7 MeV) boson that could explain the anomalou...
Recently, we observed anomalous internal pair creation for the M1 transition depopulating the 18.15 ...
The existence of a light neutral boson, possible mediator of a new fundamental interaction, has been...
Recently, we measured the e+e− angular correlations in internal pair creation (IPC) for the M1 trans...
The improved results on a direct search for a new X ( 16.7 MeV ) boson that could expl...
The 6.8σ anomaly in excited 8Be nuclear decays via internal pair creation is fit well by a new parti...
The improved results on a direct search for a new X(16.7 MeV) boson that could explain the anomalou...
In a measurement of the angular correlation of e(+)e(-) pairs in the isovector M1 decay from 1(+) le...
Electron-positron angular correlations were remeasured for the 17.6 MeV (Jπ = 1+ → 0+) ground state ...
We observed electron-positron pairs from the electro-magnetically forbidden M0 transition depopulati...
Electron-positron angular correlations were remeasured for the 17.6 MeV (Jπ = 1+ → 0+) ground state ...
Electron-positron angular correlations were remeasured for the 17.6 MeV $(J^π = 1^+ \to 0^+)$ ground...
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