- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Letters

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access

O16(p,γ)F17 Reaction and the C and O Isotopic Ratios in Red Giant Branch Stars

D. Robb1, P. McGlynn2, M. Aliotta1, C. Ananna3,4,*, F. Barile5,6, L. Barbieri1, D. Bemmerer7, A. Best3,4, R. Biasissi8,9 et al. (LUNA Collaboration)

R. Biasissi8,9, A. Boeltzig7, R. Bonnell1, C. Broggini9, C. G. Bruno1, A. Caciolli8,9, M. Campostrini10, F. Casaburo11,12, F. Cavanna13, G. F. Ciani6, T. Chillery14, P. Colombetti15,13, A. Compagnucci1, P. Corvisiero11,12, L. Csedreki16, T. Davinson1, R. Depalo17,18,†, A. Di Leva3,4, Z. Elekes16, F. Ferraro14, A. Formicola19, Zs. Fülöp16, G. Gervino15,13, R. M. Gesuè20,14, G. Gosta17,18, Gy. Gyürky16, A. Guglielmetti17,18, C. Gustavino21, C. Hebborn22, G. Imbriani3,4, M. Junker14, M. Lugaro23, J. Marsh1, E. Masha7, R. Menegazzo9, D. Mercogliano3,4, V. Paticchio6, D. Piatti8,9, P. Prati11,12, D. Rapagnani3,4, V. Rigato10, M. Rossi12, R. Sariyal13, R. S. Sidhu1,‡, J. Skowronski8,9, O. Straniero24,19, T. Szücs16, S. Turkat8,9,§, M. Vagnoni25,19, and S. Zavatarelli12 (LUNA Collaboration)

  • 1SUPA, School of Physics and Astronomy, University of Edinburgh, EH9 3FD Edinburgh, United Kingdom
  • 2Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
  • 3Università degli Studi di Napoli “Federico II,” 80125 Naples, Italy
  • 4Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, 80125 Naples, Italy
  • 5Università degli Studi di Bari “A. Moro,” 70125 Bari, Italy
  • 6Istituto Nazionale di Fisica Nucleare, Sezione di Bari, 70125 Bari, Italy
  • 7Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
  • 8Dipartimento di Fisica, Università degli Studi di Padova, 35131 Padova, Italy
  • 9Istituto Nazionale di Fisica Nucleare, Sezione di Padova, 35131 Padova, Italy
  • 10Laboratori Nazionali di Legnaro, 35020 Legnaro, Italy
  • 11Università degli Studi di Genova, 16146 Genova, Italy
  • 12Istituto Nazionale di Fisica Nucleare, Sezione di Genova, 16146 Genova, Italy
  • 13Istituto Nazionale di Fisica Nucleare, Sezione di Torino, 10125 Torino, Italy
  • 14Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso, 67100 Assergi, Italy
  • 15Dipartimento di Fisica, Università degli Studi di Torino, 10125 Torino, Italy
  • 16HUN-REN Institute for Nuclear Research (ATOMKI), PO Box 51, H-4001 Debrecen, Hungary
  • 17Università degli Studi di Milano, 20133 Milano, Italy
  • 18Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano, Italy
  • 19Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Piazzale A. Moro 2, 00185 Roma, Italy
  • 20Gran Sasso Science Institute, 67100 L’Aquila, Italy
  • 21Istituto Nazionale di Fisica Nucleare, Sezione di Roma, 00185 Roma, Italy
  • 22CNRS - IJCLab, 91405 Orsay, France
  • 23Konkoly Observatory, Research Centre for Astronomy and Earth Sciences (HUN-REN CSFK), 1121 Budapest, Hungary
  • 24Istituto Nazionale di Astrofisica, Osservatorio Astronomico d’Abruzzo, Via Mentore Maggini, 64100 Teramo, Italy
  • 25Università degli Studi della Campania “Luigi Vanvitelli,” 81100 Caserta, Italy

  • *Present address: Università del Salento, 73100 Lecce, Italy.
  • †Contact author: rosanna.depalo@unimi.it
  • ‡Present address: University of Surrey, Guildford GU2 7XH, United Kingdom.
  • §Present address: Technische Universität Dresden, 01069 Dresden, Germany.
PDF

Phys. Rev. Lett. 137, 162701 – Published 14 October, 2026

DOI: https://doi.org/10.1103/tclf-b44m

Abstract

The O16:O17 isotopic ratio is a widely used tracer of nucleosynthesis and mixing processes in red giant stars. Its value depends on the rates of the proton-capture reactions responsible for the production and destruction of O16 and O17 among which the O16(p,γ)F17 reaction plays a central role, as it involves both isotopes. This work reports on a new measurement of the O16(p,γ)F17 cross section carried out at the Laboratory for Underground Nuclear Astrophysics (LUNA) over a center-of-mass energy range of 200–380 keV, a region previously unexplored by experimental studies. Two complementary techniques were employed: prompt gamma-ray detection and activation. The results obtained with the two techniques are consistent within experimental uncertainties. From the measured cross sections and existing literature data, we evaluate a new thermonuclear reaction rate, which is then used to demonstrate how simultaneous measurements of stellar carbon and oxygen isotopic ratios constrain the initial mass and the extent of the mixing events in red giant branch stars. In particular, we demonstrate how the C12:C13 abundance ratio is primarily sensitive to the temperature Tmax attained during mixing, whereas the O16:O17 abundance ratio is highly sensitive to the initial stellar mass Mi. Therefore, simultaneous measurements of these isotopic ratios can disentangle and place stringent constraints on Mi and Tmax, and the remaining uncertainty is now dominated by stellar abundance measurements rather than nuclear-physics inputs.

View figure in article

Physics Subject Headings (PhySH)

Article Text

Supplemental Material

References (42)

  1. C. Abia, R. P. Hedrosa, I. Domínguez, and O. Straniero, The puzzle of the CNO isotope ratios in asymptotic giant branch carbon stars, Astron. Astrophys. 599, A39 (2017).
  2. N. Lagarde et al., The gaia-ESO survey: Impact of extra mixing on C and N abundances of giant stars, Astron. Astrophys. 621, A24 (2019).
  3. C. McCormick, S. R. Majewski, V. V. Smith, C. R. Hayes, K. Cunha, T. Masseron, A. Weiss, M. Shetrone, A. Almeida, P. M. Frinchaboy, D. A. García-Hernández, and C. Nitschelm, An investigation of non-canonical mixing in red giant stars using apogee 12c/13c ratios observed in open cluster stars, Mon. Not. R. Astron. Soc. 524, 4418 (2023).
  4. M. Lugaro, A. I. Karakas, L. R. Nittler, C. M. O’D. Alexander, P. Hoppe, C. Iliadis, and J. C. Lattanzio, On the asymptotic giant branch star origin of peculiar spinel grain OC2, Astron. Astrophys. 461, 657 (2007).
  5. M. Lugaro, A. I. Karakas, C. G. Bruno, M. Aliotta, L. R. Nittler, D. Bemmerer, A. Best, A. Boeltzig, C. Broggini, A. Caciolli et al., Origin of meteoritic stardust unveiled by a revised proton-capture rate of O17, Nat. Astron. 1, 0027 (2017).
  6. C. Iliadis, C. Angulo, P. Descouvemont, M. Lugaro, and P. Mohr, New reaction rate for O16(p,γ)17F and its influence on the oxygen isotopic ratios in massive AGB stars, Phys. Rev. C 77, 045802 (2008).
  7. C. Iliadis, V. Palanivelrajan, and R. S. de Souza, Bayesian estimation of the s factor and thermonuclear reaction rate for O16(p,γ)17F, Phys. Rev. C 106, 055802 (2022).
  8. B. Acharya et al., Solar fusion III: New data and theory for hydrogen-burning stars, Rev. Mod. Phys. 97, 035002 (2025).
  9. E. Tursunov and S. Turakulov, Study of the direct O16(p,γ)17F astrophysical capture reaction within a potential model approach, Nucl. Phys. A1051, 122931 (2024).
  10. R. E. Hester, R. E. Pixley, and W. A. S. Lamb, Radiative capture of protons in oxygen at 140 to 170 keV, Phys. Rev. 111, 1604 (1958).
  11. A. Formicola, G. Imbriani, M. Junker, D. Bemmerer, R. Bonetti, C. Broggini, C. Casella, P. Corvisiero, H. Costantini, Gervino, Gianpiero et al., The LUNA II 400 kV accelerator, Nucl. Instrum. Methods Phys. Res., Sect. A 507, 609 (2003).
  12. A. Caciolli, D. Scott, A. Di Leva, A. Formicola, M. Aliotta, M. Anders, A. Bellini, D. Bemmerer, C. Broggini et al., Preparation and characterisation of isotopically enriched Ta2O5 targets for nuclear astrophysics studies, Eur. Phys. J. A 48, 1 (2012).
  13. C. Ananna, L. Barbieri, A. Boeltzig, M. Campostrini, F. Casaburo, G. F. Ciani, A. Compagnucci, R. M. Gesuè, J. Marsh, E. Masha et al., Recent results and future perspectives with solid targets at LUNA, Front. Astron. Space Sci. 10, 1325053 (2024).
  14. M. Brodeur, C. Nicoloff, T. Ahn, J. Allen, D. W. Bardayan, F. D. Becchetti, Y. K. Gupta, M. R. Hall, O. Hall, J. Hu, J. M. Kelly, J. J. Kolata, J. Long, P. Omalley, and B. E. Schultz, Precision half-life measurement of F17, Phys. Rev. C 93, 025503 (2016).
  15. J. Skowronski, R. M. Gesuè, A. Boeltzig, G. F. Ciani, D. Piatti, D. Rapagnani, M. Aliotta, C. Ananna, F. Barile, D. Bemmerer et al., Advances in radiative capture studies at LUNA with a segmented BGO detector, J. Phys. G 50, 045201 (2023).
  16. J. Skowronski et al. (LUNA Collaboration), Proton-capture rates on carbon isotopes and their impact on the astrophysical C12/C13 ratio, Phys. Rev. Lett. 131, 162701 (2023).
  17. A. Boeltzig et al., Improved background suppression for radiative capture reactions at LUNA with HPGe and BGO detectors, J. Phys. G Nucl. Phys. 45, 025203 (2018).
  18. S. Agostinelli et al. (GEANT4 Collaboration), GEANT4—a simulation toolkit, Nucl. Instrum. Methods Phys. Res., Sect. A 506, 250 (2003).
  19. J. Long, C. R. Nicoloff, D. W. Bardayan, F. D. Becchetti, D. Blankstein, C. Boomershine, D. P. Burdette, M. A. Caprio, L. Caves, P. J. Fasano, B. Frentz, S. L. Henderson, J. M. Kelly, J. J. Kolata, B. Liu, P. D. OMalley, S. Y. Strauss, R. Zite, and M. Brodeur, Precision half-life determination for the β+ emitter N13, Phys. Rev. C 106, 045501 (2022).
  20. D. P. Burdette, M. Brodeur, D. W. Bardayan, F. D. Becchetti, D. Blankstein, C. Boomershine, L. Caves, S. L. Henderson, J. J. Kolata, B. Liu, J. Long, P. D. OMalley, and S. Y. Strauss, Precise half-life determination of the mixed-mirror β-decaying O15, Phys. Rev. C 101, 055504 (2020).
  21. H. C. Chow, G. M. Griffiths, and T. H. Hall, The O16(p,γ)17F direct capture cross section with an extrapolation to astrophysical energies, Can. J. Phys. 53, 1672 (1975).
  22. C. R. Brune and D. B. Sayre, Energy deconvolution of cross-section measurements with an application to the C12(α,γ)16O reaction, Nucl. Instrum. Methods Phys. Res., Sect. A 698, 49 (2013).
  23. J. F. Ziegler, M. D. Ziegler, and J. P. Biersack, SRIM–The stopping and range of ions in matter (2010), Nucl. Instrum. Methods Phys. Res., Sect. B 268, 1818 (2010).
  24. See Supplemental Material at http://link.aps.org/supplemental/10.1103/tclf-b44m for experimental S factors in tabular form; for fit results from this work, compared to previous works.
  25. R. M. Gesuè et al. (LUNA Collaboration), First direct measurement of the 64.5 kev resonance strength in the O17(p,γ)18F reaction, Phys. Rev. Lett. 133, 052701 (2024).
  26. C. Rolfs, Spectroscopic factors from radiative capture reactions, Nucl. Phys. A217, 29 (1973).
  27. R. Christy and I. Duck, γ rays from an extranuclear direct capture process, Nucl. Phys. 24, 89 (1961).
  28. C. Rolfs, Spectroscopic factors from radiative capture reactions, Nucl. Phys. A217, 29 (1973).
  29. M. Wang, G. Audi, A. H. Wapstra, F. G. Kondev, M. MacCormick, X. Xu, and B. Pfeiffer, The ame2012 atomic mass evaluation, Chin. Phys. C 36, 1603 (2012).
  30. D. Tilley, H. Weller, and C. Cheves, Energy levels of light nuclei a = 16–17, Nucl. Phys. A564, 1 (1993).
  31. R. Morlock, R. Kunz, A. Mayer, M. Jaeger, A. Müller, J. W. Hammer, P. Mohr, H. Oberhummer, G. Staudt, and V. Kölle, Halo properties of the first 1/2+ state in F17 from the O16(p,γ)17F reaction, Phys. Rev. Lett. 79, 3837 (1997).
  32. C. D. Pruitt, A. E. Lovell, C. Hebborn, and F. M. Nunes, Role of the likelihood for elastic scattering uncertainty quantification, Phys. Rev. C 110, 064606 (2024).
  33. J. Skowronski et al. (LUNA Collaboration), Comparative analysis of R-matrix fitting: C12(p,γ)13N as a test case, Phys. Rev. C 111, 035802 (2025).
  34. C. A. Gagliardi, R. E. Tribble, A. Azhari, H. L. Clark, Y.-W. Lui, A. M. Mukhamedzhanov, A. Sattarov, L. Trache, V. Burjan, J. Cejpek, V. Kroha, i. c. v. Piskoř, and J. Vincour, Tests of transfer reaction determinations of astrophysical S factors, Phys. Rev. C 59, 1149 (1999).
  35. C. Abia, S. Palmerini, M. Busso, and S. Cristallo, Carbon and oxygen isotopic ratios in Arcturus and Aldebaran. Constraining the parameters for non-convective mixing on the red giant branch, Astron. Astrophys. 548, A55 (2012).
  36. A. I. Boothroyd and I.-J. Sackmann, The CNO isotopes: Deep circulation in red giants and first and second Dredge-up, Astrophys. J. 510, 232 (1999).
  37. O. Straniero et al., The impact of the revised O17(p,α)N14 reaction rate on O17 stellar abundances and yields, Astron. Astrophys. 598, A128 (2017).
  38. O. Straniero, I. Dominguez, L. Piersanti, M. Giannotti, and A. Mirizzi, The initial mass-final luminosity relation of type II supernova progenitors: Hints of new physics?, Astrophys. J. 881, 158 (2019).
  39. V. V. Smith, K. Cunha, M. D. Shetrone, S. Meszaros, C. Allende Prieto, D. Bizyaev, A. García Pérez, S. R. Majewski, R. Schiavon, J. Holtzman, and J. A. Johnson, Chemical abundances in field red giants from high-resolution H-band spectra using the APOGEE spectral linelist, Astrophys. J. 765, 16 (2013).
  40. A. L. Sallaska, C. Iliadis, A. E. Champange, S. Goriely, S. Starrfield, and F. X. Timmes, STARLIB: A next-generation reaction-rate library for nuclear astrophysics, Astrophys. J. 207, 18 (2013).
  41. D. Rapagnani et al. (LUNA Collaboration), Revision of the CNO cycle: Rate of O17 destruction in stars, Phys. Rev. C 111, 025805 (2025).
  42. K. Lodders, M. Bergemann, and H. Palme, Solar system elemental abundances from the solar photosphere and CI-chondrites, Space Sci. Rev. 221, 23 (2025).

Outline

Information

Phys. Rev. Lett. 137, 162701– Published 14 October, 2026
  • Received 4 February 2026
  • Revised 2 April 2026
  • Accepted 14 September 2026
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation