Attila J. Krasznahorkay
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
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Attila J. Krasznahorkay has a total of 252 co-authors. Here are the top co-authors by number of shared publications:
L. Csige
13 shared publicationsJ. Gulyás
Institute for Nuclear Research (Atomki), P.O. Box 51, H-4001 Debrecen, Hungary
11 shared publicationsJ. Timár
Institute for Nuclear Research (Atomki)
11 shared publicationsM. Csatlós
Institute for Nuclear Research (Atomki)
11 shared publicationsA. Krasznahorkay
Institute for Nuclear Research (ATOMKI) University of Debrecen P.O. Box 51 PO Box 105 H-4001 4010 Debrecen Debrecen Hungary
6 shared publications- János Timár
HUN-REN Institute for Nuclear Research
6 shared publications
Latest Publications
- 11 December 2025
- Published by American Physical Society (APS) in Physical Review C
- Vol. 112 (6)
Negative-parity high-spin structure of Pd 105
- 11 December 2025
- Published by American Physical Society (APS) in Physical Review C
- Vol. 112 (6)
Negative-parity high-spin structure of Pd 105
- Open Access
- 1 April 2025
- Published by Jagiellonian University in Acta Physica Polonica B Proceedings Supplement
- Vol. 18 (4)
Experiments to Detect the Hypothetical X17 Particle
Recently, when examining the differential internal pair creation coefficients of \(^8\)Be, \(^4\)He, and \(^{12}\)C nuclei, we observed peak-like anomalies in the angular correlation of the \(e^+e^-\) pairs. This was interpreted as the creation and immediate decay of an intermediate bosonic particle with a mass of \(m_{X}c^2\approx 17\) MeV, receiving the name X17 in subsequent publications. In this paper, I will give a mini-review of the experiments related to X17 the results of which are already published, and the ones closest to being published. Published by the Jagiellonian University 2025 authors- 1 April 2025
- Published by Jagiellonian University in Acta Physica Polonica B Proceedings Supplement
- Vol. 18 (4)
Open AccessExperiments to Detect the Hypothetical X17 Particle
Recently, when examining the differential internal pair creation coefficients of \(^8\)Be, \(^4\)He, and \(^{12}\)C nuclei, we observed peak-like anomalies in the angular correlation of the \(e^+e^-\) pairs. This was interpreted as the creation and immediate decay of an intermediate bosonic particle with a mass of \(m_{X}c^2\approx 17\) MeV, receiving the name X17 in subsequent publications. In this paper, I will give a mini-review of the experiments related to X17 the results of which are already published, and the ones closest to being published. Published by the Jagiellonian University 2025 authors - Open Access
An Update of the Hypothetical X17 Particle
Recently, when examining the differential internal pair creation coefficients of 8Be, 4He and 12C nuclei, we observed peak-like anomalies in the angular correlation of the e+e− pairs. This was interpreted as the creation and immediate decay of an intermediate bosonic particle with a mass of 17 MeV, receiving the name X17 in subsequent publications. In this paper, our latest results obtained for the X17 particle are presented by investigating the e+e− pair correlations in the decay of the Giant Dipole Resonance (GDR) of 8Be. Our results initiated a significant number of new experiments all over the world to detect the X17 particle and determine its properties. In this paper, we will also conduct a mini-review of the experiments whose results are already published, as well as the ones closest to being published.Open AccessAn Update of the Hypothetical X17 Particle
Recently, when examining the differential internal pair creation coefficients of 8Be, 4He and 12C nuclei, we observed peak-like anomalies in the angular correlation of the e+e− pairs. This was interpreted as the creation and immediate decay of an intermediate bosonic particle with a mass of 17 MeV, receiving the name X17 in subsequent publications. In this paper, our latest results obtained for the X17 particle are presented by investigating the e+e− pair correlations in the decay of the Giant Dipole Resonance (GDR) of 8Be. Our results initiated a significant number of new experiments all over the world to detect the X17 particle and determine its properties. In this paper, we will also conduct a mini-review of the experiments whose results are already published, as well as the ones closest to being published. - 18 May 2024
- Published by Springer Nature
- p. 71-80
A New Particle is Suggested by Anomalies Observed in Internal e$ ^+ $e$ ^- $ Pair Creation- 18 May 2024
- Published by Springer Nature
- p. 71-80
A New Particle is Suggested by Anomalies Observed in Internal e$ ^+ $e$ ^- $ Pair Creation- Open Access
Checking the 8Be Anomaly with a Two-Arm Electron Positron Pair Spectrometer
We have repeated the experiment performed recently by ATOMKI Laboratory (Debrecen, Hungary), which may indicate a new particle called X17 in the literature. In order to obtain a reliable and independent result, we used a different structure of the electron–positron pair spectrometer at the VNU University of Science. The spectrometer has two arms and simpler acceptance and efficiency as a function of the correlation angle, but the other conditions of the experiment were very similar to the published ones. We could confirm the presence of the anomaly measured at Ep = 1225 keV, which is above the Ep = 1040 keV resonance.
Open AccessChecking the 8Be Anomaly with a Two-Arm Electron Positron Pair Spectrometer
We have repeated the experiment performed recently by ATOMKI Laboratory (Debrecen, Hungary), which may indicate a new particle called X17 in the literature. In order to obtain a reliable and independent result, we used a different structure of the electron–positron pair spectrometer at the VNU University of Science. The spectrometer has two arms and simpler acceptance and efficiency as a function of the correlation angle, but the other conditions of the experiment were very similar to the published ones. We could confirm the presence of the anomaly measured at Ep = 1225 keV, which is above the Ep = 1040 keV resonance.
- Open Access
- 5 March 2024
- Published by MDPI AG in Preprints.org
Checking the 8Be Anomaly with a Two-Arm Electron Positron Pair Spectrometer
We have repeated the experiment performed recently by Krasznahorkay et al., (Phys. Rev. Lett. 116, 042501 (2016)), which may indicate a new particle called X17 in the literature. In order to get a reliable, and independent result, we used a different type of electron-positron pair spectrometer which have a more simple acceptance/efficiency as a function of the correlation angle, but the other conditions of the experiment were very similar to the published ones. We could confirm the presence of the anomaly measured at the Ex=18.15 MeV resonance, and also confirm their absence at the Ex=17.6 MeV resonance, and at Ep= 800 keV off resonance energies.
- 5 March 2024
- Published by MDPI AG in Preprints.org
Open AccessChecking the 8Be Anomaly with a Two-Arm Electron Positron Pair Spectrometer
We have repeated the experiment performed recently by Krasznahorkay et al., (Phys. Rev. Lett. 116, 042501 (2016)), which may indicate a new particle called X17 in the literature. In order to get a reliable, and independent result, we used a different type of electron-positron pair spectrometer which have a more simple acceptance/efficiency as a function of the correlation angle, but the other conditions of the experiment were very similar to the published ones. We could confirm the presence of the anomaly measured at the Ex=18.15 MeV resonance, and also confirm their absence at the Ex=17.6 MeV resonance, and at Ep= 800 keV off resonance energies.
- Open Access
Observation of the X17 anomaly in the decay of the Giant Dipole Resonance of $^8$Be
Angular correlation spectra of $e^+e^-$ pairs produced in the $^{7}$Li($p$,$γ$)$^{8}$Be nuclear reaction were studied at a proton beam energy of $E_p$~=~4.0~MeV, which corresponds to the excitation energy of the Giant Dipole Resonance (GDR) in $^8$Be. The spectra measured show a peak like anomaly at 120$^\circ$ and a broader anomaly also above 140$^\circ$. Both anomalies could consistently be described by assuming that the same hypothetical X17 particle was created both in the ground-state transition and in the transition going to the broad ($Γ$=1.5~MeV), first excited state in $^8$Be. The invariant mass of the particle, which was derived to be $m_Xc^2 = 16.95 \pm 0.48$(stat.)~MeV, agrees well with our previously published values.Open AccessObservation of the X17 anomaly in the decay of the Giant Dipole Resonance of $^8$Be
Angular correlation spectra of $e^+e^-$ pairs produced in the $^{7}$Li($p$,$γ$)$^{8}$Be nuclear reaction were studied at a proton beam energy of $E_p$~=~4.0~MeV, which corresponds to the excitation energy of the Giant Dipole Resonance (GDR) in $^8$Be. The spectra measured show a peak like anomaly at 120$^\circ$ and a broader anomaly also above 140$^\circ$. Both anomalies could consistently be described by assuming that the same hypothetical X17 particle was created both in the ground-state transition and in the transition going to the broad ($Γ$=1.5~MeV), first excited state in $^8$Be. The invariant mass of the particle, which was derived to be $m_Xc^2 = 16.95 \pm 0.48$(stat.)~MeV, agrees well with our previously published values. - 12 December 2022
- Published by American Physical Society (APS) in Physical Review C
- Vol. 106 (6) , L061601
New anomaly observed in supports the existence and the vector character of the hypothetical X17 bosonEmploying the nuclear reaction, the angular correlation of pairs was investigated in the angular range of for five different proton energies between –2.5 MeV. At small angles (), the results can be well interpreted by the internal pair creation process of electromagnetic radiations with and multipolarities and by the external pair creation in the target backing. However, at angles greater than , additional count excesses and anomalies were observed, which could be well accounted for by the existence of the previously suggested hypothetical X17 particle. Our results suggest that the X17 particle was generated mainly in radiation. The derived mass of the particle is MeV. According to the mass, and to the derived branching ratio [], this is likely the same X17 particle that we recently suggested for describing the anomaly observed in the decay of and .- 12 December 2022
- Published by American Physical Society (APS) in Physical Review C
- Vol. 106 (6) , L061601
New anomaly observed in supports the existence and the vector character of the hypothetical X17 bosonEmploying the nuclear reaction, the angular correlation of pairs was investigated in the angular range of for five different proton energies between –2.5 MeV. At small angles (), the results can be well interpreted by the internal pair creation process of electromagnetic radiations with and multipolarities and by the external pair creation in the target backing. However, at angles greater than , additional count excesses and anomalies were observed, which could be well accounted for by the existence of the previously suggested hypothetical X17 particle. Our results suggest that the X17 particle was generated mainly in radiation. The derived mass of the particle is MeV. According to the mass, and to the derived branching ratio [], this is likely the same X17 particle that we recently suggested for describing the anomaly observed in the decay of and .- Open Access
New anomaly observed in $^{12}$C supports the existence and the vector character of the hypothetical X17 boson
Employing the $^{11}$B(p,$\gamma$)$^{12}$C nuclear reaction, the angular correlation of $e^+e^-$ pairs was investigated in the angular range of $40^\circ\Theta\leq 175^\circ$ for five different proton energies between E$_p$ = 1.50 - 2.50 MeV. At small angles ($\Theta\leq 120^\circ$), the results can be well interpreted by the internal pair creation process of electromagnetic radiations with E1 and M1 multipolarities and by the external pair creation in the target backing. However, at angles greater than $120^\circ$, additional count excess and anomalies were observed, which could be well accounted for by the existence of the previously suggested hypotetical X17 particle. Our results show that the X17 particle was generated mainly in E1 radiation. The derived mass of the particle is $m_\mathrm{X}c^2$=17.03$\pm 0.11 (stat) \pm 0.20 (syst)$ MeV. According to the mass, and to the derived branching ratio ($B_x=3.6(3)\times10^{-6}$), this is likely the same X17 particle, which we recently suggested for describing the anomaly observed in the decay of $^8$Be and $^4$He.Open AccessNew anomaly observed in $^{12}$C supports the existence and the vector character of the hypothetical X17 boson
Employing the $^{11}$B(p,$\gamma$)$^{12}$C nuclear reaction, the angular correlation of $e^+e^-$ pairs was investigated in the angular range of $40^\circ\Theta\leq 175^\circ$ for five different proton energies between E$_p$ = 1.50 - 2.50 MeV. At small angles ($\Theta\leq 120^\circ$), the results can be well interpreted by the internal pair creation process of electromagnetic radiations with E1 and M1 multipolarities and by the external pair creation in the target backing. However, at angles greater than $120^\circ$, additional count excess and anomalies were observed, which could be well accounted for by the existence of the previously suggested hypotetical X17 particle. Our results show that the X17 particle was generated mainly in E1 radiation. The derived mass of the particle is $m_\mathrm{X}c^2$=17.03$\pm 0.11 (stat) \pm 0.20 (syst)$ MeV. According to the mass, and to the derived branching ratio ($B_x=3.6(3)\times10^{-6}$), this is likely the same X17 particle, which we recently suggested for describing the anomaly observed in the decay of $^8$Be and $^4$He.