https://doi.org/10.1140/epjd/s10053-021-00145-0
Regular Article – Atomic Physics
Electron capture nuclear decay rate under compression in a confined environment
1
Variable Energy Cyclotron Center, 1/AF, Bidhannagar, 700064, Kolkata, India
2
Homi Bhabha National Institute Training School Hostel, Anushaktinagar, 400094, Mumbai, India
3
Departmento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco186, C.P. 09340, Mexico, DF, Mexico
4
CONACYT - Universidad Autónoma Metropolitana-Cuajimalpa, Av. Vasco de Quiroga 4871, Santa Fe Cuajimalpa, C.P. 05300, Mexico, DF, Mexico
5
Institute of Physics and CINSaT, University of Kassel, Heinrich-Plett-St. 40, 34132, Kassel, Germany
Received:
21
December
2020
Accepted:
2
April
2021
Published online:
27
April
2021
We have calculated the effect of compressing the radioactive atoms in the crystal lattice environments on their electron capture nuclear decay rates. The electronic structure calculations of solids using the density functional techniques have been used to calculate the change of electron density at the nuclei and the corresponding change of electron capture nuclear decay rate of the radioactive atoms confined to the interstitial spaces of different crystal lattices. The effects of finite nuclear size and vacuum polarization were considered in the calculations. It has been found that the calculations significantly underpredict the experimentally measured increase of electron capture nuclear decay rate under compression. The increase of decay rate due to compression-induced quantum anti-Zeno effect is generally believed to be very small because of very short duration of initial nonexponential decay time for the nuclear decays. However, this effect could be observable for the electron capture nuclear decay of 
Ho, because of its very low decay energy. Moreover, certain models of quantum measurement indicate much longer initial nonexponential decay time and the corresponding implication on the increase of decay rate under compression is still not known. It is important to understand the large discrepancy between the measured and calculated increase of electron capture nuclear decay rate under compression and the associated role of quantum anti-Zeno effect because of their possible implications in various astrophysical and geophysical calculations.
Contribution to the Topical Issue “Atoms and Molecules in a Confined Environment” edited by C. N. Ramachandran, Vincenzo Aquilanti, Henry Ed Montgomery, Narayanasami Sathyamurthy.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021
