TY - JOUR AU - Psaltis, A. AU - Arcones, A. AU - Avila, M.L. AU - Hansen, C.J. AU - Jacobi, M. AU - Lombardo, L. AU - Meisel, Z. AU - Mohr, Péter AU - Montes, F. AU - Ong, W.J. AU - Schatz, H. TI - Using (α,xn) reaction rates and abundance ratios to constrain the weak r-process JF - INTERNATIONAL JOURNAL OF MODERN PHYSICS: CONFERENCE SERIES J2 - INT J MOD PHYS CONF SER VL - 2586 PY - 2023 IS - 1 PG - 4 SN - 2010-1945 DO - 10.1088/1742-6596/2586/1/012105 UR - https://m2.mtmt.hu/api/publication/34470128 ID - 34470128 N1 - Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstr. 2, Darmstadt, 64289, Germany GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, Darmstadt, 64291, Germany Physics Division, Argonne National Laboratory, Argonne, IL 60439, United States Institute for Applied Physics, Goethe University Frankfurt, Max-von-Laue-Str. 12, Frankfurt am Main, 60438, Germany GEPI, Observatoire de Paris, Université PSL, CNRS, 5 place Jules Janssen, Meudon, 92195, France Institute of Nuclear & Particle Physics, Department of Physics & Astronomy, Ohio University, Athens, OH 45701, United States Institute for Nuclear Research (ATOMKI), Bem tér 18/c, Debrecen, H-4001, Hungary National Superconducting Cyclotron Laboratory, East Lansing, MI 48824, United States Joint Institute for Nuclear Astrophysics, Center for the Evolution of the Elements, Michigan State University, East Lansing, MI 48824, United States Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States Export Date: 1 January 2024 LA - English DB - MTMT ER - TY - JOUR AU - Jayatissa, H. AU - Avila, M. L. AU - Rehm, K. E. AU - Mohr, Péter AU - Meisel, Z. AU - Chen, J. AU - Hoffman, C. R. AU - Liang, J. AU - Müller-Gatermann, C. AU - Neto, D. AU - Ong, W. J. AU - Psaltis, A. AU - Santiago-Gonzalez, D. AU - Tang, T. L. AU - Ugalde, C. AU - Wilson, G. TI - Study of the Mg 22 Waiting Point Relevant for X-Ray Burst Nucleosynthesis via the Mg 22 ( α , p ) Al 25 Reaction JF - PHYSICAL REVIEW LETTERS J2 - PHYS REV LETT VL - 131 PY - 2023 IS - 11 SN - 0031-9007 DO - 10.1103/PhysRevLett.131.112701 UR - https://m2.mtmt.hu/api/publication/34143154 ID - 34143154 N1 - Physics Division, Argonne National Laboratory, Lemont, IL 60439, United States Institute for Nuclear Research (Atomki), P.O. Box 51, Debrecen H, 4001, Hungary Institute of Nuclear and Particle Physics, Ohio University, Athens, OH 45701, United States Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada Department of Physics, University of Illinois Chicago, 845 W. Taylor St., Chicago, IL 60607, United States Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, United States Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt D, 64289, Germany Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, United States Export Date: 8 October 2023 LA - English DB - MTMT ER - TY - JOUR AU - Roberti, Lorenzo AU - Pignatari, Marco AU - Psaltis, A. AU - Sieverding, A. AU - Mohr, Péter AU - Fülöp, Zsolt AU - Lugaro, Maria TI - The γ -process nucleosynthesis in core-collapse supernovae JF - ASTRONOMY & ASTROPHYSICS J2 - ASTRON ASTROPHYS VL - 677 PY - 2023 SN - 0004-6361 DO - 10.1051/0004-6361/202346556 UR - https://m2.mtmt.hu/api/publication/34110878 ID - 34110878 N1 - Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), Konkoly-Thege Miklós út 15-17, Budapest, 1121, Hungary Csfk, Mta Centre of Excellence, Budapest, Konkoly-Thege Miklós út 15-17, Budapest, 1121, Hungary INAF- Osservatorio Astronomico di Roma, Via Frascati 33, Monteporzio Catone, 00040, Italy E. A. Milne Centre for Astrophysics, University of Hull, Hull, HU6 7RX, United Kingdom Department of Physics, North Carolina State University, Raleigh, NC 27695, United States Triangle Universities Nuclear Laboratory, Duke University, Durham, NC 27710, United States Max-Planck Institute for Astrophysics, Postfach 1317, Garching, 85741, Germany Institute for Nuclear Research (ATOMKI), Debrecen, 4001, Hungary Eötvös Loránd University, Institute of Physics, Pázmány Péter sérány 1/A, Budapest, 1117, Hungary School of Physics and Astronomy, Monash UniversityVIC 3800, Australia Export Date: 1 January 2024 CODEN: AAEJA AB - Context. The γ -process nucleosynthesis in core-collapse supernovae is generally accepted as a feasible process for the synthesis of neutron-deficient isotopes beyond iron. However, crucial discrepancies between theory and observations still exist: the average yields of γ -process nucleosynthesis from massive stars are still insufficient to reproduce the solar distribution in galactic chemical evolution calculations, and the yields of the Mo and Ru isotopes are a factor of ten lower than the yields of the other γ -process nuclei. LA - English DB - MTMT ER - TY - JOUR AU - Mohr, Péter TI - Comment on ‘Alpha decay of thermally excited nuclei’ JF - JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS J2 - J PHYS G NUCL PARTIC VL - 50 PY - 2023 IS - 9 PG - 3 SN - 0954-3899 DO - 10.1088/1361-6471/ace63a UR - https://m2.mtmt.hu/api/publication/34076236 ID - 34076236 N1 - Export Date: 14 August 2023 Correspondence Address: Mohr, P.; Institute for Nuclear Research (Atomki), POB. 51, Hungary; email: mohr@atomki.hu AB - In a recent study, Perez Velasquez, Caballero, and Kelkar report a dramatically enhanced α decay rate of the nucleus 212 Po at high temperatures which reaches almost five orders of magnitude at a temperature of 2 Giga-Kelvin. Contrary to that finding, only a moderate enhancement by a factor of three is found in the present comment which is based on a careful study of the properties of excited states in 212 Po. LA - English DB - MTMT ER - TY - JOUR AU - Mohr, Péter TI - α-decay half-life of 212Po at stellar temperatures JF - JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS J2 - J PHYS G NUCL PARTIC VL - 50 PY - 2023 IS - 7 PG - 11 SN - 0954-3899 DO - 10.1088/1361-6471/acd39a UR - https://m2.mtmt.hu/api/publication/34022942 ID - 34022942 N1 - Export Date: 19 June 2023 Correspondence Address: Mohr, P.; Institute for Nuclear Research (Atomki), POB. 51, Hungary; email: mohr@atomki.hu LA - English DB - MTMT ER - TY - JOUR AU - Tsantiri, A. AU - Palmisano-Kyle, A. AU - Spyrou, A. AU - Mohr, Péter AU - Berg, H.C. AU - Deyoung, P.A. AU - Dombos, A.C. AU - Gastis, P. AU - Good, E.C. AU - Harris, C.M. AU - Liddick, S.N. AU - Lyons, S.M. AU - Olivas-Gomez, O. AU - Owens-Fryar, G. AU - Pereira, J. AU - Richard, A.L. AU - Simon, A. AU - Smith, M.K. AU - Zegers, R.G.T. TI - Cross-section measurement of the Kr 82 (p,γ) Rb 83 reaction in inverse kinematics JF - PHYSICAL REVIEW C J2 - PHYS REV C VL - 107 PY - 2023 IS - 3 SN - 2469-9985 DO - 10.1103/PhysRevC.107.035808 UR - https://m2.mtmt.hu/api/publication/33742439 ID - 33742439 N1 - Export Date: 31 October 2023 LA - English DB - MTMT ER - TY - JOUR AU - Psaltis, Athanasios AU - Arcones, Almudena AU - Avila, Melina L. AU - Jacobi, Maximilian AU - Hansen, Camilla Juul AU - Lombardo, Linda AU - Meisel, Zach AU - Mohr, Péter AU - Montes, Fernando AU - Ong, Wei Jia AU - Schatz, Hendrik TI - Constraining nucleosythesis in neutrino-driven winds using the impact of ( α , xn) reaction rates JF - EPJ WEB OF CONFERENCES J2 - EPJ WEB CONF VL - 279 PY - 2023 PG - 3 SN - 2101-6275 DO - 10.1051/epjconf/202327908002 UR - https://m2.mtmt.hu/api/publication/33720220 ID - 33720220 AB - The lighter heavy elements of the first r-process peak, between strontium and silver, can be synthesized in the moderately neutron-rich neutrino–driven ejecta of either core–collapse supernovae or neutron star mergers via the weak r–process. This nucleosynthesis scenario exhibits uncertainties from the absence of experimental data from ( α , xn ) reactions on neutron–rich nuclei, which are currently based on statistical model estimates. We have performed a new impact study to identify the most important ( α , xn ) reactions that can affect the production of the lighter heavy elements under different astrophysical conditions using new, constrained ( α , xn ) reaction rates based on the Atomki-V2 α OMP. Our results show how when reducing the nuclear physics uncertainties, we can use abundance ratios to constrain the astrophysical conditions/environment. This can be achieved in the near future, when the key ( α , xn ) reaction rates will be measured experimentally in radioactive beam facilities. LA - English DB - MTMT ER - TY - JOUR AU - Gyürky, György AU - Mohr, Péter AU - Angyal, Anikó AU - Halász, Zoltán AU - Kiss, Gábor Gyula AU - Mátyus, Zsolt AU - Szegedi, Tibor Norbert AU - Szücs, Tamás AU - Fülöp, Zsolt TI - Cross section measurement of the 144 Sm ( α , n ) 147 Gd reaction for studying the α -nucleus optical potential at astrophysical energies JF - PHYSICAL REVIEW C J2 - PHYS REV C VL - 107 PY - 2023 IS - 02 PG - 8 SN - 2469-9985 DO - 10.1103/PhysRevC.107.025803 UR - https://m2.mtmt.hu/api/publication/33630192 ID - 33630192 N1 - Institute for Nuclear Research (ATOMKI), Debrecen, H-4001, Hungary University of Debrecen, Doctoral School of Physics, Egyetem tér 1., Debrecen, H-4032, Hungary Export Date: 20 March 2023 AB - Background: Nuclear reactions involving α particles play an important role in various astrophysical processes such as the γ process of heavy element nucleosynthesis. The poorly known low-energy α-nucleus optical potential is a key parameter to estimate the rates of these reactions. Purpose: The α-nucleus optical potential can be tested by measuring the cross section of α scattering as well as α-induced reactions. Low energy elastic α scattering on Sm144 has recently been measured with high precision. The aim of the present work was to complement that work by measuring the (α,n) cross sections on Sm144 at low energies. The experimental data shall be used to constrain the α-nucleus optical model potential. From this potential the Sm144(α,γ)Gd148 reaction rate can be derived with reduced uncertainties. Method: The Sm144(α,n)Gd147 reaction was studied by bombarding Sm targets with α beams provided by the cyclotron accelerator of Atomki. The cross section was determined using the activation method. The γ radiation following the decay of the Gd147 reaction product was measured with a high-purity germanium (HPGe) detector. The experimental data are analyzed within the statistical model. Results: The cross section was measured in the α-energy range between 13 and 20 MeV in 1 MeV steps, i.e., from close above the (α,n) threshold. The results were compared with statistical model calculations using various approaches and parametrizations for the α-nucleus optical potential, and excellent agreement was obtained for two recent potentials. However, these potentials cannot reproduce literature data for the Sm144(α,γ)Gd148 reaction with the same accuracy. Conclusions: Constraints for the α-nucleus potential were derived from an analysis of the new Sm144(α,n)Gd147 data and literature data for Sm144(α,γ)Gd148. These constraints enable a determination of the reaction rate of the Sm144(α,γ)Gd148 reaction with significantly reduced uncertainties of less than a factor of 2. LA - English DB - MTMT ER - TY - JOUR AU - Ong, W.-J. AU - Avila, M.L. AU - Mohr, Péter AU - Rehm, K.E. AU - Santiago-Gonzalez, D. AU - Chen, J. AU - Hoffman, C.R. AU - Meisel, Z. AU - Montes, F. AU - Pereira, J. TI - Measurement of the Mo 100 (α,xn) cross section at weak r -process energies JF - PHYSICAL REVIEW C J2 - PHYS REV C VL - 105 PY - 2022 IS - 5 PG - 1 SN - 2469-9985 DO - 10.1103/PhysRevC.105.055803 UR - https://m2.mtmt.hu/api/publication/33607710 ID - 33607710 N1 - Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States Physics Division, Argonne National Laboratory, Lemont, IL 60439, United States Joint Institute for Nuclear Astrophysics, Center for the Evolution of the Elements, Michigan State University, East Lansing, MI 48824, United States Institute for Nuclear Research (MTA Atomki), Debrecen, H-4001, Hungary Department of Physics and Astronomy, Ohio University, Athens, OH 45701, United States National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, United States Export Date: 15 November 2023 LA - English DB - MTMT ER - TY - JOUR AU - Psaltis, A. AU - Arcones, A. AU - Montes, F. AU - Mohr, Péter AU - Hansen, C. J. AU - Jacobi, M. AU - Schatz, H. TI - Constraining Nucleosynthesis in Neutrino-driven Winds: Observations, Simulations, and Nuclear Physics JF - ASTROPHYSICAL JOURNAL J2 - ASTROPHYS J VL - 935 PY - 2022 IS - 1 SN - 1538-4357 DO - 10.3847/1538-4357/ac7da7 UR - https://m2.mtmt.hu/api/publication/33051452 ID - 33051452 N1 - Export Date: 15 November 2023 AB - A promising astrophysical site to produce the lighter heavy elements of the first r -process peak ( Z = 38 − 47) is the moderately neutron-rich (0.4 < Y e < 0.5) neutrino-driven ejecta of explosive environments, such as core-collapse supernovae and neutron star mergers, where the weak r -process operates. This nucleosynthesis exhibits uncertainties from the absence of experimental data from ( α , xn ) reactions on neutron-rich nuclei, which are currently based on statistical model estimates. In this work, we report on a new study of the nuclear reaction impact using a Monte Carlo approach and improved ( α , xn ) rates based on the Atomki-V2 α optical model potential. We compare our results with observations from an up-to-date list of metal-poor stars with [Fe/H] < −1.5 to find conditions of the neutrino-driven wind where the lighter heavy elements can be synthesized. We identified a list of ( α , xn ) reaction rates that affect key elemental ratios in different astrophysical conditions. Our study aims to motivate more nuclear physics experiments on ( α , xn ) reactions using the current and new generation of radioactive beam facilities and also more observational studies of metal-poor stars. LA - English DB - MTMT ER -