TY - JOUR AU - Krasznahorkay, Attila AU - Begala, Marcell AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Gulyás, János AU - Krakó, Attila AU - Krasznahorkay, Attila AU - Nyakó, Barna Mátyás AU - Rajta, István AU - Sas, Nándor AU - Timár, János AU - Vajda, István K. TI - A new light particle is being born JF - JOURNAL OF PHYSICS-CONFERENCE SERIES J2 - J PHYS CONF SER VL - 2391 PY - 2022 IS - 1 SN - 1742-6588 DO - 10.1088/1742-6596/2391/1/012007 UR - https://m2.mtmt.hu/api/publication/33541847 ID - 33541847 N1 - Institute for Nuclear Research (ATOMKI), P.O. Box 51, Debrecen, H-4001, Hungary University of Debrecen, PO Box 105, Debrecen, 4010, Hungary Export Date: 15 November 2023 AB - A few years ago we observed anomalous electron-positron angular correlations for the 18.15 MeV M1 transition of 8 Be. This was interpreted as the creation and decay of an intermediate bosonic particle with a mass of m 0 c 2 =16.70±0.35(stat )±0.5(sys) MeV, which is now called X17. The possible relation of the X17 boson to the dark matter problem triggered an enormous interest in the wider physics community. We also observed a similar anomaly in 4 He, which could be described also by the creation and subsequent decay of the same X17 particle. Very recently, the 11 B proton capture reaction was used for exciting the 17.2 MeV broad (Γ=1.15 MeV) resonance in 12 C and studying their internal pair creation decay. Anomalies were observed in the angular correlation of the electron-positron pairs, which together with the 8 Be and 4 He data provides kinematic evidence for the X17 particle and supports their vector boson and fifth force explanation. LA - English DB - MTMT ER - TY - JOUR AU - Krasznahorkay, Attila AU - Krasznahorkay, Attila AU - Begala, Marcell AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Gulyás, János AU - Krakó, Attila AU - Timár, János AU - Rajta, István AU - Vajda, István K. AU - Sas, Nándor TI - New anomaly observed in C 12 supports the existence and the vector character of the hypothetical X17 boson JF - PHYSICAL REVIEW C J2 - PHYS REV C VL - 106 PY - 2022 IS - 6 SN - 2469-9985 DO - 10.1103/PhysRevC.106.L061601 UR - https://m2.mtmt.hu/api/publication/33327781 ID - 33327781 N1 - Institute for Nuclear Research (ATOMKI), P.O. Box 51, Debrecen, H-4001, Hungary University of Debrecen, Faculty of Science and Technology, Physics Institute, PO Box 105, Debrecen, 4010, Hungary Export Date: 5 March 2023 LA - English DB - MTMT ER - TY - JOUR AU - Krasznahorkay, Attila AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Gulyás, János AU - Krasznahorkay, Attila AU - Nyakó, Barna Mátyás AU - Rajta, István AU - Timár, János AU - Vajda, István K. AU - Sas, Nándor TI - New anomaly observed in 4He supports the existence of the hypothetical X17 particle JF - PHYSICAL REVIEW C J2 - PHYS REV C VL - 104 PY - 2021 IS - 4 SN - 2469-9985 DO - 10.1103/PhysRevC.104.044003 UR - https://m2.mtmt.hu/api/publication/32461516 ID - 32461516 N1 - Institute for Nuclear Research (ATOMKI), P.O. Box 51, Debrecen, H-4001, Hungary University of Debrecen, 4010 Debrecen, PO Box 105, Hungary Export Date: 3 January 2023 LA - English DB - MTMT ER - TY - JOUR AU - Krasznahorkay, Attila AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Gulyás, János AU - Koszta, M. AU - Szihalmi, B. AU - Timár, János AU - Firak, D.S. AU - Nagy, Ádám AU - Sas, Nándor AU - Krasznahorkay, Attila TI - A new anomaly observed in 4 He supporting the existence of the hypothetical X17 particle JF - JOURNAL OF PHYSICS-CONFERENCE SERIES J2 - J PHYS CONF SER VL - 1643 PY - 2020 IS - 1 SN - 1742-6588 DO - 10.1088/1742-6596/1643/1/012001 UR - https://m2.mtmt.hu/api/publication/31795368 ID - 31795368 N1 - WoS:hiba:000686763400001 2022-12-21 20:19 típus nem egyezik LA - English DB - MTMT ER - TY - JOUR AU - Firak, D. S. AU - Krasznahorkay, Attila AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Gulyás, János AU - Koszta, M. AU - Szihalmi, B. AU - Timár, János AU - Nagy, Ádám AU - Sas, Nándor AU - Krasznahorkay, Attila TI - Confirmation of the existence of the X17 particle JF - EPJ WEB OF CONFERENCES J2 - EPJ WEB CONF VL - 232 PY - 2020 SN - 2101-6275 DO - 10.1051/epjconf/202023204005 UR - https://m2.mtmt.hu/api/publication/31400226 ID - 31400226 LA - English DB - MTMT ER - TY - JOUR AU - Nagy, Ádám AU - Krasznahorkay, Attila AU - Ciemala, M. AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Gácsi, Zoltán AU - Hunyadi, Mátyás AU - Klaus, T. AU - Kmiecik, M. AU - Maj, A. AU - Pietralla, N. AU - Revay, Zs AU - Sas, Nándor AU - Stieghorst, C. AU - Timár, János AU - Tornyi, Tamás Gábor AU - Wasilewska, B. TI - Searching for the double gamma-decay of the X(17) particle JF - NUOVO CIMENTO C-COLLOQUIA AND COMMUNICATIONS IN PHYSICS J2 - NUOVO CIMENTO C-COLLOQ COMMUN PHYS VL - 42 PY - 2019 IS - 2-3 PG - 4 SN - 2037-4909 DO - 10.1393/ncc/i2019-19124-8 UR - https://m2.mtmt.hu/api/publication/31103967 ID - 31103967 N1 - University of Debrecen, University square 1, Debrecen, 4032, Hungary Institute for Nuclear Research, Hungarian Academy of Sciences, Bem ter 18/c, Debrecen, H-4026, Hungary Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, Krakow, 31-342, Poland Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 9, Darmstadt, 64289, Germany Technical University Munich, Heinz Maier-Leibnitz Centrum (FRM II), Lichtenberg str. 1, Garching, D-85748, Germany Export Date: 1 January 2023 AB - The e(-)e(+) decay of the candidate new particle X(17) has already been confirmed by previous experiments. However, theoretical models give different predictions for the spin and the parity of this particle. The double gamma-decay process could be an appropriate probe to shed light on such properties. Thus, for the first time, we searched for the gamma gamma decay of X(17) created in nuclear transitions. In this paper, we report preliminary results of two experiments on the J(pi) = 0(-) -> 0(+) transition in He-4. LA - English DB - MTMT ER - TY - JOUR AU - Krasznahorkay, Attila AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Firak, D. AU - Gulyás, János AU - Nagy, Ádám AU - Sas, Nándor AU - Timár, János AU - Tornyi, Tamás Gábor AU - Krasznahorkay, Attila TI - On the X17 Light-particle Candidate Observed in Nuclear Transitions JF - ACTA PHYSICA POLONICA B J2 - ACTA PHYS POL B VL - 50 PY - 2019 IS - 3 SP - 675 EP - 684 PG - 10 SN - 0587-4254 DO - 10.5506/APhysPolB.50.675 UR - https://m2.mtmt.hu/api/publication/30655939 ID - 30655939 N1 - Institute for Nuclear Research, Hungarian Academy of Sciences (MTA Atomki), P.O. Box 51, Debrecen, 4001, Hungary CERN, Geneva, Switzerland Export Date: 1 January 2023 CODEN: APOBB LA - English DB - MTMT ER - TY - JOUR AU - Krasznahorkay, Attila AU - Véghné Csatlós, Margit AU - Csige, Lóránt AU - Gácsi, Zoltán AU - Gulyás, János AU - Nagy, Ádám AU - Sas, Nándor AU - Timár, János AU - Tornyi, Tamás Gábor AU - Vajda, István K. AU - Krasznahorkay, Attila TI - New results on the 8 Be anomaly JF - JOURNAL OF PHYSICS-CONFERENCE SERIES J2 - J PHYS CONF SER VL - 1056 PY - 2018 IS - 1 SN - 1742-6588 DO - 10.1088/1742-6596/1056/1/012028 UR - https://m2.mtmt.hu/api/publication/3411216 ID - 3411216 AB - 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°. 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 8 Be 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 ). LA - English DB - MTMT ER -