Related papers: Resolving a discrepancy between experimental and t…
When a hydrogen atom trapped in finite space formed by two parallel perfectly conducting plates, the transition rates can be modified. Life-time of the hydrogen $2P_{1/2}$-state is estimated to be shorter as much as $56.3ps $ with a…
The energy interval between the ground and the P-wave excited states of the recently discovered positronium molecule Ps_2 is evaluated, including the relativistic and the leading logarithmic radiative corrections, E_P-E_S = 0.181 586 7(8)…
Relativistic coupled-cluster(RCC) theory has been employed to calculate the life time of the $6 ^2P_{3/2}$ state of single ionized lead($^{207}Pb$) to an accurac y of 3% and compared with the corresponding value obtained using second order…
The energy levels and transition rates of promising laser-cooling candidate thorium anion Th^- have been experimentally obtained in the current work. Three new excited states between the bound-bound electric dipole (E1) transition of Th^-…
A method and results of an experimental test of the time stability of the half-life of alpha-decay Po-214 nuclei are presented. Two underground installations aimed at monitoring the time stability have been constructed. Time of measurement…
Highly charged ions (HCIs) offer many opportunities for next-generation clock research due to the vast landscape of available electronic transitions in different charge states. The development of XUV frequency combs has enabled the search…
A new, more precise measurement of the $\Lambda$ hyperon lifetime is performed using a large data sample of Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with ALICE. The $\Lambda$ and $\overline{\Lambda}$ hyperons are reconstructed…
The life-time of $^{133}Cs$ in the first excited state has been measured with the M\"ossbauer method by placing the absorber, CsCl, between two parallel flat plates and the gamma-ray source, Ba^*TiO_3, in the free space. The result is 9.37…
Fe II radiative lifetimes were measured applying the time-resolved nonlinear laser-induced fluoresence technique. We investigated 21 levels of up to 47000 1/cm. The uncertainties are typically 2-3%. The lifetimes provide an improved…
Metastability and long-range interactions of Mg, Ca, and Sr in the lowest-energy metastable $^3P_2$ state are investigated. The calculated lifetimes are 38 minutes for Mg*, 118 minutes for Ca*, and 17 minutes for Sr*, supporting feasibility…
The expression for the $(\pi^+\pi^-)$ atom lifetime is derived within the Bethe-Salpeter approach. First-order perturbative corrections due to the contribution of strong interactions are taken into account. It is demonstrated that the atom…
The kinetic energy distribution of ground state muonic hydrogen atoms mu-p(1S) is determined from time-of-flight spectra measured at 4, 16, and 64 hPa H2 room-temperature gas. A 0.9 keV-component is discovered and attributed to…
We report a precise determination of the 19Ne half-life to be $T_{1/2} = 17.262 \pm 0.007$ s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that…
We excite the 717 nm electric quadrupole 6$D_{3/2} $ $\leftrightarrow$ 7$S_{1/2}$ transition in a laser-cooled $^{232}$Th$^{3+}$ ion crystal. The transition frequency and the lifetime of the metastable 7$S_{1/2}$ level are measured to be…
Lifetimes of $2^+_1$ and $4^+_1$ states, as well as some negative-parity and non-yrast states, in $^{188-200}$Hg were measured using $\gamma-\gamma$ electronic fast timing techniques with the LaBr$_3$(Ce) detector array of the GRIFFIN…
We report a measurement of the lifetime of the cesium $7s\,^2S_{1/2}$ state using time-correlated single-photon counting spectroscopy in a vapor cell. We excite the atoms using a Doppler-free two-photon transition from the $6s\,^2S_{1/2}$…
We present a measurement of the lifetime of the metastable 3d 2D5/2 state in the 40Ca+ ion, using the so-called shelving technique on a string of five Doppler laser-cooled ions in a linear Paul trap. A detailed account of the data analysis…
Radiative deexcitation (RD) of the metastable 2S state of muonic protium and deuterium atoms has been observed. In muonic protium, we improve the precision on lifetime and population (formation probability) values for the short-lived…
This work reports new experimental radiative lifetimes and calculated oscillator strengths for transitions of astrophysical interest in singly ionized cobalt. More precisely, nineteen radiative lifetimes in Co+ have been measured with the…
We report the results of a precise measurement of the Ds meson lifetime based on 1662 +/- 56 fully reconstructed Ds -> phi pi decays, from the charm hadroproduction experiment E791 at Fermilab. Using an unbinned maximum likelihood fit, we…