Review on Proton Radioactivity in the Actinide Region: Experimental status, Theoretical Approaches and Future perspectives

Proton radioactivity is one of the most distinctive manifestations of quantum tunnelling in atomic nuclei and provides a powerful probe of nuclear structure beyond the proton drip line. Since its theoretical prediction by Goldanskii in 1960 and subsequent experimental confirmation, proton emission has become an important spectroscopic tool for investigating single-particle configurations, shell evolution, nuclear deformation, and the interplay between nuclear and Coulomb interactions in proton-rich systems. While proton radioactivity has been extensively studied in light, medium-mass, and rare-earth nuclei, comparatively little attention has been devoted to the actinide region despite its unique structural and decay properties.This review presents a comprehensive overview of proton radioactivity in actinide nuclei (89 ≤ Z ≤ 103), with emphasis on recent theoretical developments and future experimental prospects. The historical evolution of the field, experimental status, theoretical models, and decay systematics are critically discussed. Particular attention is given to the prediction of proton-emitting actinides, the influence of proton-decay energy and quantum tunnelling on half-lives, Geiger–Nuttall-type correlations, and the competition between proton emission, α decay, β decay, spontaneous fission, and cluster radioactivity. The predictive performance of widely used theoretical approaches, including the Coulomb and Proximity Potential Model (CPPM), Generalized Liquid Drop Model (GLDM), Effective Liquid Drop Model (ELDM), Density-Dependent Michigan 3-Yukawa (DDM3Y) interaction, Jeukenne–Lejeune–Mahaux (JLM) interaction, and related microscopic models, is also evaluated.The review highlights the most promising candidate proton emitters in the actinide region and discusses the prospects for their experimental observation using next-generation rare-isotope facilities. By integrating current theoretical predictions with available experimental knowledge, this article provides a comprehensive assessment of proton radioactivity in heavy nuclei and underscores its importance for understanding the limits of nuclear stability and the structure of proton-rich actinides.

Proton radioactivity; Actinides; Proton drip line; Quantum tunneling; Nuclear structure

1. V.I. Goldanskii,“On neutron-deficient isotopes of light nuclei and the phenomena of proton and two-proton radioactivity”, Nucl. Phys. 19 (1960) 482–495. [Google Scholar] [Crossref]

2. K.P. Jackson, C.U. Cardinal, H.C. Evans, N.A. Jelley, J. Cerny, “53mCo: A proton-unstable isomer”,Phys. Lett. B 33 (1970) 281–283. [Google Scholar] [Crossref]

3. J. Cerny,“Proton radioactivity”,Annu. Rev. Nucl. Part. Sci. 28 (1978) 301–340. [Google Scholar] [Crossref]

4. S. Hofmann et al.,“Proton radioactivity of 151Lu”,Z. Phys. A 305 (1982) 111–123. [Google Scholar] [Crossref]

5. P.J. Woods, C.N. Davids,“Proton Radioactivity”,Annu. Rev. Nucl. Part. Sci. 47 (1997) 541–590. [Google Scholar] [Crossref]

6. C.N. Davids et al.,“Observation of proton radioactivity from 141Ho”,Phys. Rev. Lett. 80 (1998) 1849–1852. [Google Scholar] [Crossref]

7. P. Sellin et al.,“Fine structure in proton radioactivity of 151Lu”,Phys. Rev. C 47 (1993) 1933–1937. [Google Scholar] [Crossref]

8. K. Rykaczewski et al.,“Proton radioactivity studies near the proton drip line”,Phys. Rev. C 52 (1995) R2310–R2314. [Google Scholar] [Crossref]

9. B. Blank et al.,“First observation of two-proton radioactivity in 45Fe”,Phys. Rev. Lett. 94 (2005) 232501. [Google Scholar] [Crossref]

10. M. Pfützner et al.,“First evidence for two-proton decay of 45Fe”,Eur. Phys. J. A 14 (2002) 279–285. [Google Scholar] [Crossref]

11. M. Pfützner, M. Karny, L.V. Grigorenko, K. Riisager,“Radioactive decays at limits of nuclear stability”,Rev. Mod. Phys. 84 (2012) 567–619. [Google Scholar] [Crossref]

12. L.V. Grigorenko et al.,“Theory of two-proton radioactivity”,Phys. Rev. Lett. 85 (2000) 22–25. [Google Scholar] [Crossref]

13. M. Mukha et al.,“Observation of two-proton radioactivity of 94Ag isomer”,Nature 439 (2006) 298–302. [Google Scholar] [Crossref]

14. M. Mukha et al.,“Two-proton emission studies in proton-rich nuclei”,Phys. Rev. Lett. 99 (2007) 182501. [Google Scholar] [Crossref]

15. R. Giovinazzo et al.,“Two-proton radioactivity of 45Fe”,Phys. Rev. Lett. 89 (2002) 102501. [Google Scholar] [Crossref]

16. D.S. Delion,“Theory of Particle and Cluster Emission”,Springer, Berlin (2010). [Google Scholar] [Crossref]

17. B. Blank, M. Ploszajczak,“Two-proton radioactivity”,Rep. Prog. Phys. 71 (2008) 046301. [Google Scholar] [Crossref]

18. K. Riisager,“Halos and proton-rich nuclei”,Phys. Scr. T152 (2013) 014001. [Google Scholar] [Crossref]

19. N.K. Timofeyuk,“Proton emitters and nuclear structure”,J. Phys. G 29 (2003) R59–R92. [Google Scholar] [Crossref]

20. G. Royer,“Alpha decay and exotic decay within GLDM”,J. Phys. G 26 (2000) 1149–1170. [Google Scholar] [Crossref]

21. J.M. Dong, H.F. Zhang, G. Royer,“Proton radioactivity in generalized liquid drop model”,Phys. Rev. C 81 (2010) 064309. [Google Scholar] [Crossref]

22. D.S. Delion,R.J. Liotta,R. Wyss,“Unified description of proton radioactivity”,Phys. Rev. Lett. 96 (2006) 072501. [Google Scholar] [Crossref]

23. G. Gangopadhyay,“Proton radioactivity using DDM3Y interaction”,Phys. Rev. C 71 (2005) 027601. [Google Scholar] [Crossref]

24. G. Gangopadhyay,“Microscopic proton radioactivity calculations”,J. Phys. G 34 (2007)799–810. [Google Scholar] [Crossref]

25. K.P. Santhosh,R.K. Biju,Sabina Sahadevan,“Proton radioactivity using CPPM”,Nucl. Phys. A 850 (2011) 34–50. [Google Scholar] [Crossref]

26. K.P. Santhosh,Sabina Sahadevan,“Ground-state proton emitters with Z > 50”Phys. Rev. C 84 (2011) 064611. [Google Scholar] [Crossref]

27. E. Maglione,L.S. Ferreira,R.J. Liotta,“Proton emission from deformed nuclei”Phys. Rev. Lett. 81 (1998) 538–541. [Google Scholar] [Crossref]

28. E. Maglione,L.S. Ferreira,R.J. Liotta,“Structure effects in proton radioactivity”,Rep. Prog. Phys. 63 (2000) 471–537. [Google Scholar] [Crossref]

29. M. Patial et al.,“Deformation effects in proton radioactivity”Nucl. Phys. A 859 (2011) 25–37. [Google Scholar] [Crossref]

30. D.S. Delion,R.J. Liotta,R. Wyss,“Spectroscopic factors in proton emission”,Phys. Rev. C 76 (2007) 044301. [Google Scholar] [Crossref]

31. C. Qi et al.,“Universal decay law for proton emission”,Phys. Rev. C 80 (2009) 044326. [Google Scholar] [Crossref]

32. H.F. Zhang et al.,“Proton radioactivity within RMF framework”,Phys. Rev. C 80 (2009) 057301. [Google Scholar] [Crossref]

33. L.S. Ferreira et al.,“Covariant density functional theory of proton emitters”,Phys. Lett. B 767 (2017) 34–39. [Google Scholar] [Crossref]

34. J.M. Dong et al.,“Microscopic calculations of proton decay half-lives”,Nucl. Phys. A 832 (2010) 198–208. [Google Scholar] [Crossref]

35. M.G. Srinivas et al.,“Proton decay of actinide nuclei” ,Nucl. Phys. A 995 (2020) 121689. [Google Scholar] [Crossref]

36. M.G. Srinivas et al.,“Systematics of proton decay of actinides”,Indian J. Pure Appl. Phys. 58 (2020) 255–262. [Google Scholar] [Crossref]

37. H.C. Manjunatha et al.,“Proton radioactivity of heavy nuclei of atomic number range 72 < Z < 88”,Phys. Part. Nucl. Lett. 17 (2020) 909–915. [Google Scholar] [Crossref]

38. M.G. Srinivas et al.,“Semi-empirical formulae for one- and two-proton radioactivity”,Indian J. Phys. 97 (2023) 1161–1178. [Google Scholar] [Crossref]

39. M.G. Srinivas et al.,“A systematic analysis for one proton radioactivity of ground state nuclei”,Nucl. Phys. A 1036 (2023) 122673. [Google Scholar] [Crossref]

40. M.G. Srinivas et al.,“A systematic study of proton decay in superheavy elements”,Ukr. J. Phys. 67 (2022) 631–638. [Google Scholar] [Crossref]

41. Jänecke, J.,“Masses and proton stability of light nuclei”,Nucl. Phys. 61 (1965) 326–344. [Google Scholar] [Crossref]

42. Brown, B.A.,“Proton drip-line nuclei and nuclear masses”,Phys. Rev. C 43 (1991) R1513–R1516. [Google Scholar] [Crossref]

43. Dobaczewski, J., Nazarewicz, W.,“Mean-field description of proton-rich nuclei”,Phil. Trans. R. Soc. Lond. A 356 (1998) 2007–2025. [Google Scholar] [Crossref]

44. Blank, B.,“Nuclear structure at the proton drip line”,Eur. Phys. J. A 15 (2002) 121–127. [Google Scholar] [Crossref]

45. Riisager, K.,“Halos and related structures near drip lines”,Rev. Mod. Phys. 66 (1994) 1105–1116. [Google Scholar] [Crossref]

46. Nazarewicz, W.,“The nuclear landscape and drip lines”,Nature Physics 14 (2018) 537–541. [Google Scholar] [Crossref]

47. Ferreira, L.S., Maglione, E., Liotta, R.J.,“Proton emission as a spectroscopic tool”,Phys. Rev. Lett. 78 (1997) 1640–1643. [Google Scholar] [Crossref]

48. Delion, D.S., Liotta, R.J., Wyss, R.,“Systematics of proton-decay spectroscopic factors”,Phys. Rep. 424 (2006) 113–174. [Google Scholar] [Crossref]

49. Kruppa, A.T., Barmore, B., Nazarewicz, W.,“Single-particle resonances and proton emitters”,Phys. Rev. Lett. 84 (2000) 4549–4552. [Google Scholar] [Crossref]

50. Gamow, G.,“Zur Quantentheorie des Atomkernes”,Z. Phys. 51 (1928) 204–212. [Google Scholar] [Crossref]

51. Gurvitz, S.A., Kalbermann, G.,“Decay width and penetrability in quantum tunneling”,Phys. Rev. Lett. 59 (1987) 262–265. [Google Scholar] [Crossref]

52. Aberg, S., Semmes, P.B., Nazarewicz, W.,“Shell effects in proton emitters”, [Google Scholar] [Crossref]

53. Phys. Rev. C 56 (1997) 1762–1773. [Google Scholar] [Crossref]

54. Kruppa, A.T., Vertse, T.,“Resonances and proton radioactivity”,Phys. Rev. C 61 (2000) 034313. [Google Scholar] [Crossref]

55. Arumugam, P., Sherrill, B.M., Nazarewicz, W.,“Proton emission and deformation effects in 141Ho”,Phys. Rev. C 69 (2004) 054313. [Google Scholar] [Crossref]

56. Sonzogni, A.A.,“Nuclear structure information from proton emission”,Nucl. Data Sheets 95 (2002) 1–94. [Google Scholar] [Crossref]

57. Davids, C.N., Esbensen, H.,“Proton emission and nuclear deformation”,Phys. Rev. C 64 (2001) 034317. [Google Scholar] [Crossref]

58. Grigorenko, L.V., Zhukov, M.V.,“Two-proton radioactivity and three-body decay”,Phys. Rev. C 68 (2003) 054005. [Google Scholar] [Crossref]

59. Grigorenko, L.V.,“Theory of true two-proton decay”,Phys. Atom. Nucl. 72 (2009) 1870–1884. [Google Scholar] [Crossref]

60. Olsen, E., Pfutzner, M., Grigorenko, L.V.,“Two-proton radioactivity: status and perspectives” ,Prog. Part. Nucl. Phys. 59 (2013) 426–434. [Google Scholar] [Crossref]

61. Routray, T.R., Tripathy, S.K., Mishra, C.,“Proton radioactivity with Yukawa effective interaction”,Eur. Phys. J. A 47 (2011) 92. [Google Scholar] [Crossref]

62. Poenaru, D.N., Greiner, W.,“Cluster radioactivity and heavy-particle emission”,Springer, Berlin (1996). [Google Scholar] [Crossref]

63. Poenaru, D.N., Ivascu, M.,“Cluster decay and proton-rich nuclei”,J. Physique 44 (1983) 791–796. [Google Scholar] [Crossref]

64. Santhosh, K.P., Priyanka, B.,“Systematics of proton radioactivity in heavy nuclei”,Phys. Rev. C 92 (2015) 044603. [Google Scholar] [Crossref]

65. Deng, J.G., Zhang, H.F., Royer, G.,“Proximity potentials and proton radioactivity”,Phys. Rev. C 96 (2017) 024318. [Google Scholar] [Crossref]

66. Cui, Z.Y., Dong, T.K.,“Two-proton radioactivity within generalized liquid drop model”,Nucl. Phys. A 977 (2018) 41–54. [Google Scholar] [Crossref]

67. B Blank and MJG Borge, “Nuclear structure at the proton drip line:Advances with nuclear decay studies” Prog. Part. Nucl. Phys. 60 (2008) 403–483. [Google Scholar] [Crossref]

68. Basu, D. N., P. Roy Chowdhury, and C. Samanta. "Folding model analysis of proton radioactivity of spherical proton emitters." Physical Review C—Nuclear Physics 72.5 (2005): 051601. [Google Scholar] [Crossref]

69. Dong, J. M., H. F. Zhang, and Guy Royer. "Proton radioactivity within a generalized liquid drop model." Physical Review C—Nuclear Physics 79.5 (2009): 054330. [Google Scholar] [Crossref]

70. Qi, Chong, et al. "Universal decay law in charged-particle emission and exotic cluster radioactivity." Physical review letters 103.7 (2009): 072501. [Google Scholar] [Crossref]

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