Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2608.28047

Doppler-shift attenuation method (DSAM) lifetimes in $^{54}$Cr - a re-evaluation

Andrew E. Stuchbery
View original source ↗Read source document ↗Export metadata ↓

Abstract

Background: Contemporary stopping powers for fp-shell nuclei slowing in tantalum can differ by a factor of two from the 1963 Lindhard, Scharff and Schi{\o}tt (LSS) theory [Mat. Fys. Medd. Dan. Vid. Selsk. 33 no. 14, (1963)] used in Doppler-shift attenuation method (DSAM) lifetime measurements dating back to the 1970s. In recent work [Phys. Rev. C 113, 044306 (2026)], it was found that anomalously high collectivity in the $4^+_1 \rightarrow 2^+_1$ transition of 58Fe given in the literature [Nucl. Data Sheets 111, 897 (2010)] could be traced back as due to the use of these historical stopping powers in the Doppler-shift lifetime measurements. Satisfactory agreement with shell-model calculations was obtained from a re-analysis of the measurement of Bolotin et al. [Nucl. Phys. A 311, 75 (1978)] once the stopping powers were replaced by up-to-date values. Purpose: The DSAM measurement on 54Cr by the same group [Nucl. Phys. A 337, 1 (1980)], which used the same experimental methods and procedures, is re-examined. Method: The computer code used in the original DSAM analysis has been rebuilt and upgraded with the capacity to use contemporary stopping powers. E2 transition strengths derived from the revised lifetimes are compared with shell-model calculations. Results: The lifetimes increase by 16% to 27%, with the larger increase generally corresponding to shorter lifetimes where electronic stopping dominates. Conclusions: Revised lifetimes, based on current stopping powers, imply E2 transition rates between states up to the 6$^+_1$ state in 54Cr that compare well with shell-model calculations. The lifetime data together with branching ratios and the shell-model calculations strongly suggest revision of the spins assigned to the levels at 3.786 (currently (4)$^+$) and 4.043 MeV (currently 5$^+$). These levels are suggested to be the 5$^+_1$ and 6$^+_2$ states, respectively.

Explore related subjects

nucl-exnucl-th

Keep this discovery

BibTeXRIS

Andrew E. Stuchbery. 2026-08-28. Doppler-shift attenuation method (DSAM) lifetimes in $^{54}$Cr - a re-evaluation. https://arxiv.org/abs/2608.28047

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Reinvestigation of the Yield of the Trinity Device

Previous published analyses of trinitite to determine the yield of the Trinity nuclear explosion used various estimates of the fraction of fission products that became incorporated in trinitite. Furthermore, these studies utilized nuclear data that has subsequently been revised. Utilizing a planar germanium detector, we observed gamma rays produced by the decays of both 137Cs and 239Pu from four samples of trinitite. From the observed 137Cs/239Pu ratios of and a simple analysis method based on current nuclear data and weapons debris studies, we find an average yield of 9.1+-4.5 kilotons from our four samples. While this result is substantially lower than the established total yield of 21 kilotons, it is in reasonable agreement that attributable to fissions in the 239Pu core alone.

nucl-ex↗
arXiv2026

Search for neutrinoless quadruple beta decay of $^{136}$Xe in PandaX-4T detector

The observation of neutrinoless quadruple beta decay (0$\nu$4$\beta$) in the absence of neutrinoless double beta decay (0$\nu$2$\beta$) has been argued to provide a strong indication that neutrinos are Dirac particles. We report a search for 0$\nu$4$\beta$ decay of $^{136}\text{Xe}$ using a total $^{136}\text{Xe}$ exposure of 148.4 kg$\cdot$yr, collected during the commissioning and the first science runs of the PandaX-4T experiment. No significant excess of events over the background is observed. A lower limit on the 0$\nu$4$\beta$ decay half-life of $^{136}\text{Xe}$ is set at 6.01 x $10^{24}$ yr at the 90% confidence level. This result establishes the most stringent constraint on this process in xenon, demonstrating the unique capability of the PandaX-4T detector in probing lepton number violation and shedding light on the fundamental nature of neutrinos.

nucl-ex↗
arXiv2026

Island of Inversion in neutron-rich cobalt isotopes revealed from mass measurements

Mass measurements of the ground and isomeric states of $^{68-70}$Co have been performed using the JYFLTRAP Penning-trap mass spectrometer at the IGISOL facility. The masses were measured, either for the first time for the isomeric states of $^{68}$Co and $^{70}$Co, or with greatly improved precision for the others, removing ambiguities in the mass surface beyond $N=40$. The ordering of the low and high-spin states in $^{68}$Co and $^{70}$Co has also been established. The results, supported by Large-Scale Shell Model and Discrete Non-Orthogonal Shell-Model calculations, show a gradual lowering of intruder states with increasing neutron number, eventually leading to an inversion in $^{70}$Co. These findings clarify previously proposed contradictory interpretations. Finally, we demonstrate the importance of including induced effective 3N forces for a consistent description of binding energies in the island of inversion near $N=40$.

nucl-ex↗