1.
|
Observation of Anomalous Internal Pair Creation in $^8$Be
/ Krasznahorkay, A J (KLTE-ATOMKI) ; Csatlós, M (KLTE-ATOMKI) ; Csige, L (KLTE-ATOMKI) ; Gácsi, Z (KLTE-ATOMKI) ; Gulyás, J (KLTE-ATOMKI) ; Hunyadi, M (KLTE-ATOMKI) ; Ketel, T J (NIKHEF, Amsterdam) ; Krasznahorkay, A (KLTE-ATOMKI ; CERN) ; Kuti, I (KLTE-ATOMKI) ; Nyakó, B M (KLTE-ATOMKI) et al.
The electron–positron angular correlation was measured for the isoscalar magnetic dipole 18.15 MeV transition in 8Be. Significant, peak-like deviation was observed from the internal pair creation at Θ ≈ 140° in the angular correlation. [...]
2015 - 8 p.
- Published in : Acta Phys. Pol. Suppl. 8 (2015) 597
Acta Physica Polonica: PDF;
In : 22nd Nuclear Physics Workshop 'Marie & Pierre Curie': Essential Problems in Nuclear Physics, Kazimierz Dolny, Poland, 22 - 27 Sep 2015, pp.597
|
|
2.
|
Observation of Anomalous Internal Pair Creation in $^8$Be: A Possible Signature of a Light, Neutral Boson
/ Krasznahorkay, A. J. (Debrecen, Inst. Nucl. Res.) ; Csatlós, M. (KLTE-ATOMKI) ; Csige, L. (KLTE-ATOMKI) ; Gácsi, Z. (KLTE-ATOMKI) ; Gulyás, J. (KLTE-ATOMKI) ; Hunyadi, M. (KLTE-ATOMKI) ; Ketel, T.J. (NIKHEF, Amsterdam) ; Krasznahorkay, A. (KLTE-ATOMKI ; CERN) ; Kuti, I. (KLTE-ATOMKI) ; Nyakó, B.M. (KLTE-ATOMKI) et al.
Electron-positron angular correlations were measured for the isovector magnetic dipole 17.6 MeV state ($J^\pi=1^+$, $T=1$) $\rightarrow$ ground state ($J^\pi=0^+$, $T=0$) and the isoscalar magnetic dipole 18.15 MeV ($J^\pi=1^+$, $T=0$) state $\rightarrow$ ground state transitions in $^{8}$Be. Significant deviation from the internal pair creation was observed at large angles in the angular correlation for the isoscalar transition with a confidence level of $> 5\sigma$. [...]
arXiv:1504.01527.-
2016-01-26 - 5 p.
- Published in : Phys. Rev. Lett. 116 (2016) 042501
APS Open Access article: PDF; Fulltext: PDF; External link: Symmetry Magazine article
|
|
3.
|
A new anomaly observed in $^4$He supporting the existence of the hypothetical X17 particle
/ Krasznahorkay, A J (KLTE-ATOMKI) ; Csatlós, M (KLTE-ATOMKI) ; Csige, L (KLTE-ATOMKI) ; Gulyás, J (KLTE-ATOMKI) ; Koszta, M (KLTE-ATOMKI) ; Szihalmi, B (KLTE-ATOMKI) ; Timár, J (KLTE-ATOMKI) ; Firak, D S (Debrecen U.) ; Nagy, Á (Debrecen U.) ; Sas, N J (Debrecen U.) et al.
Recently, we observed an anomalous peak-like excess of internal $e^+e^-$ pairs at around 140° for the M1 transition depopulating the 18.15 MeV isoscalar $1^+$ state in $^8$Be. The deviation from the theoretical prediction can be described by GEANT simulations assuming the creation and subsequent decay of a new, light boson with a mass of 16.7 MeV/$c^2$. [...]
2020 - 6 p.
- Published in : J. Phys. : Conf. Ser. 1643 (2020) 012001
Fulltext: PDF;
In : International Nuclear Physics Conference 2019, Glasgow, United Kingdom, 29 Jul - 2 Aug 2019, pp.012001
|
|
4.
|
New results on the $^8$Be anomaly
/ Krasznahorkay, A J (Debrecen, Inst. Nucl. Res.) ; Csatlós, M (Debrecen, Inst. Nucl. Res.) ; Csige, L (Debrecen, Inst. Nucl. Res.) ; Gácsi, Z (Debrecen, Inst. Nucl. Res.) ; Gulyás, J (Debrecen, Inst. Nucl. Res.) ; Nagy, Á (Debrecen, Inst. Nucl. Res.) ; Sas, N (Debrecen, Inst. Nucl. Res.) ; Timár, J (Debrecen, Inst. Nucl. Res.) ; Tornyi, T G (Debrecen, Inst. Nucl. Res.) ; Vajda, I (Debrecen, Inst. Nucl. Res.) et al.
Recently, we observed anomalous internal pair creation for the M1 transition depopulating the 18.15 MeV isoscalar 1$^+$ state in $^8$Be. We observed a significant (σ = 7.37) peak-like deviation from the predicted angular correlation of the e+ e pairs at θ = 140°. [...]
2018 - 7 p.
- Published in : J. Phys.: Conf. Ser. 1056 (2018) 012028
Fulltext: pdf - PDF; 10.1088_1742-6596_1056_1_012028 - PDF;
In : Conference on Neutrino and Nuclear Physics, Catania, Italy, 15 - 21 Oct 2017
|
|
5.
|
New results on the Be-8 anomaly
/ Krasznahorkay, A J (Debrecen, Inst. Nucl. Res.) ; Csatlós, M (Debrecen, Inst. Nucl. Res.) ; Csige, L (Debrecen, Inst. Nucl. Res.) ; Gulyás, J (Debrecen, Inst. Nucl. Res.) ; Hunyadi, M (Debrecen, Inst. Nucl. Res.) ; Ketel, T J (NIKHEF, Amsterdam) ; Krasznahorkay, A (CERN) ; Kuti, I (Debrecen, Inst. Nucl. Res.) ; Nagy, Á (Debrecen, Inst. Nucl. Res.) ; Nyakó, B M (Debrecen, Inst. Nucl. Res.) et al.
Recently, we measured the e+e− angular correlations in internal pair creation (IPC) for the M1 transitions depopulating the 17.6 and 18.15 MeV states in 8Be, and observed a peak-like deviation from the predicted IPC for the 18.15 MeV transition, but not for the 17.6 MeV one. To the best of our knowledge no nuclear physics related description of such deviation can be made. [...]
SISSA, 2017 - 10 p.
- Published in : PoS BORMIO2017 (2017) 036
Fulltext: PDF; External link: PoS server
In : 55th International Winter Meeting on Nuclear Physics, Bormio, Italy, 23 - 27 Jan 2017, pp.036
|
|
6.
|
|
7.
|
On the creation of the 17 MeV X boson in the 17.6 MeV M1 transition of $^8Be$
/ Krasznahorkay, A J (Debrecen, Inst. Nucl. Res.) ; Csatlós, M (Debrecen, Inst. Nucl. Res.) ; Csige, L (Debrecen, Inst. Nucl. Res.) ; Gulyás, J (Debrecen, Inst. Nucl. Res.) ; Ketel, T J (NIKHEF, Amsterdam) ; Krasznahorkay, A (CERN ; MIT) ; Kuti, I (Debrecen, Inst. Nucl. Res.) ; Nagy, Á (Debrecen, Inst. Nucl. Res.) ; Nyakó, B M (Debrecen, Inst. Nucl. Res.) ; Sas, N (Debrecen, Inst. Nucl. Res.) et al.
Electron-positron angular correlations were remeasured for the 17.6 MeV $(J^π = 1^+ \to 0^+)$ ground state transition in $^8Be$ using an improved setup compared to one we used previously. Significant deviations from the internal pair creation was observed at large angles in the angular correlations, which supports that, in an intermediate step, a neutral isoscalar particle with a mass of 17.0±0.5 (stat)±0.5 (sys) $MeV/c^2$ and $J^π = 1^+$ was created..
2017 - 7 p.
- Published in : EPJ Web Conf. 142 (2017) 01019
Fulltext: PDF;
In : International Symposium Advances in Dark Matter and Particle Physics, Messina, Italy, 24 - 27 Oct 2016, pp.01019
|
|
8.
|
New experimental results for the 17 MeV particle created in $^8Be$
/ Krasznahorkay, A J (Debrecen, Inst. Nucl. Res.) ; Csatlós, M (Debrecen, Inst. Nucl. Res.) ; Csige, L (Debrecen, Inst. Nucl. Res.) ; Gulyás, J (Debrecen, Inst. Nucl. Res.) ; Hunyadi, M (Debrecen, Inst. Nucl. Res.) ; Ketel, T J (NIKHEF, Amsterdam) ; Krasznahorkay, A (CERN ; MIT) ; Kuti, I (Debrecen, Inst. Nucl. Res.) ; Nagy, Á (Debrecen, Inst. Nucl. Res.) ; Nyakó, B M (Debrecen, Inst. Nucl. Res.) et al.
Electron-positron angular correlations were remeasured for the 17.6 MeV $(J^π = 1^+ \to 0^+)$ ground state transition in $^8Be$ using an improved setup compared to the one we used previously. Significant deviations from the internal pair creation was observed at large angles in the angular correlations, which supports that, in an intermediate step, a neutral isoscalar particle with a mass of 17.0 ±0.2(stat) ±0.5(sys) $MeV/c^2$ and $J^π = 1^+$ was created..
2017 - 7 p.
- Published in : EPJ Web Conf. 137 (2017) 08010
Fulltext: PDF;
In : 12th Quark Confinement and the Hadron Spectrum, Thessaloniki, Greece, 29 Aug - 2 Sep 2016, pp.08010
|
|
9.
|
|
|
Observation of the X17 anomaly in the $^7$Li($p$,$e^+e^-$)$^8$Be direct proton-capture reaction
/ Sas, N.J. (KLTE-ATOMKI ; Debrecen U.) ; Krasznahorkay, A.J. (KLTE-ATOMKI ; CERN) ; Csatlós, M. (KLTE-ATOMKI) ; Gulyás, J. (KLTE-ATOMKI) ; Kertész, B. (KLTE-ATOMKI) ; Krasznahorkay, A. (KLTE-ATOMKI) ; Molnár, J. (KLTE-ATOMKI) ; Rajta, I. (KLTE-ATOMKI) ; Timár, J. (KLTE-ATOMKI) ; Vajda, I. (KLTE-ATOMKI) et al.
Angular correlation spectra of $e^+e^-$ pairs produced in the $^{7}$Li($p$,$\gamma$)$^{8}$Be nuclear reaction have been studied at the sharp $E_p$= 441 keV resonance as well as at $E_p$= 650 keV, 800 keV and 1100 keV proton beam energies. [...]
arXiv:2205.07744.
-
6 p.
Fulltext
|
|
10.
|
|
|
New evidence supporting the existence of the hypothetic X17 particle
/ Krasznahorkay, A.J. (KLTE-ATOMKI) ; Csatlós, M. (KLTE-ATOMKI) ; Csige, L. (KLTE-ATOMKI) ; Gulyás, J. (KLTE-ATOMKI) ; Koszta, M. (KLTE-ATOMKI) ; Szihalmi, B. (KLTE-ATOMKI) ; Timár, J. (KLTE-ATOMKI) ; Firak, D.S. (Debrecen U.) ; Nagy, Á (Debrecen U.) ; Sas, N.J. (Debrecen U.) et al.
We observed electron-positron pairs from the electro-magnetically forbidden M0 transition depopulating the 21.01 MeV 0$^-$ state in $^4$He. [...]
arXiv:1910.10459.
-
5 p.
Scientific American article - Phys.org article - Space.com article - Forbes Magazine article - Ars Technica article - Fulltext
|
|