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New evidence supporting the existence of the hypothetic X17 particle
We observed electron-positron pairs from the electro-magnetically forbidden M0 transition depopulating the 21.01 MeV 0$^-$ state in $^4$He. A peak was observed in their $e^+e^-$ angular correlations at 115$^\circ$ with 7.2$\sigma$ significance, and could be described by assuming the creation and sub...
| Autores principales: | , , , , , , , , , , |
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| Lenguaje: | eng |
| Publicado: |
2019
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| Materias: | |
| Acceso en línea: | http://cds.cern.ch/record/2702353 |
| _version_ | 1780964546606792704 |
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| author | Krasznahorkay, A.J. Csatlós, M. Csige, L. Gulyás, J. Koszta, M. Szihalmi, B. Timár, J. Firak, D.S. Nagy, Á Sas, N.J. Cern, Geneva |
| author_facet | Krasznahorkay, A.J. Csatlós, M. Csige, L. Gulyás, J. Koszta, M. Szihalmi, B. Timár, J. Firak, D.S. Nagy, Á Sas, N.J. Cern, Geneva |
| author_sort | Krasznahorkay, A.J. |
| collection | CERN |
| description | We observed electron-positron pairs from the electro-magnetically forbidden M0 transition depopulating the 21.01 MeV 0$^-$ state in $^4$He. A peak was observed in their $e^+e^-$ angular correlations at 115$^\circ$ with 7.2$\sigma$ significance, and could be described by assuming the creation and subsequent decay of a light particle with mass of $m_\mathrm{X}c^2$=16.84$\pm0.16 (stat) \pm 0.20 (syst)$ MeV and $\Gamma_\mathrm{X}$= $3.9\times 10^{-5}$ eV. According to the mass, it is likely the same X17 particle, which we recently suggested [Phys. Rev. Lett. 116, 052501 (2016)] for describing the anomaly observed in $^8$Be. |
| id | cern-2702353 |
| institution | Organización Europea para la Investigación Nuclear |
| language | eng |
| publishDate | 2019 |
| record_format | invenio |
| spelling | cern-27023532021-11-09T07:06:30Zhttp://cds.cern.ch/record/2702353engKrasznahorkay, A.J.Csatlós, M.Csige, L.Gulyás, J.Koszta, M.Szihalmi, B.Timár, J.Firak, D.S.Nagy, ÁSas, N.J.Cern, GenevaNew evidence supporting the existence of the hypothetic X17 particlenucl-exNuclear Physics - ExperimentWe observed electron-positron pairs from the electro-magnetically forbidden M0 transition depopulating the 21.01 MeV 0$^-$ state in $^4$He. A peak was observed in their $e^+e^-$ angular correlations at 115$^\circ$ with 7.2$\sigma$ significance, and could be described by assuming the creation and subsequent decay of a light particle with mass of $m_\mathrm{X}c^2$=16.84$\pm0.16 (stat) \pm 0.20 (syst)$ MeV and $\Gamma_\mathrm{X}$= $3.9\times 10^{-5}$ eV. According to the mass, it is likely the same X17 particle, which we recently suggested [Phys. Rev. Lett. 116, 052501 (2016)] for describing the anomaly observed in $^8$Be.arXiv:1910.10459oai:cds.cern.ch:27023532019-10-23 |
| spellingShingle | nucl-ex Nuclear Physics - Experiment Krasznahorkay, A.J. Csatlós, M. Csige, L. Gulyás, J. Koszta, M. Szihalmi, B. Timár, J. Firak, D.S. Nagy, Á Sas, N.J. Cern, Geneva New evidence supporting the existence of the hypothetic X17 particle |
| title | New evidence supporting the existence of the hypothetic X17 particle |
| title_full | New evidence supporting the existence of the hypothetic X17 particle |
| title_fullStr | New evidence supporting the existence of the hypothetic X17 particle |
| title_full_unstemmed | New evidence supporting the existence of the hypothetic X17 particle |
| title_short | New evidence supporting the existence of the hypothetic X17 particle |
| title_sort | new evidence supporting the existence of the hypothetic x17 particle |
| topic | nucl-ex Nuclear Physics - Experiment |
| url | http://cds.cern.ch/record/2702353 |
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