相关论文: First observation of long-lived $\pi^+ \pi^-$ atom…
Long-lived isomers in 212Bi have been studied following 238U projectile fragmentation at 670 MeV per nucleon. The fragmentation products were injected as highly charged ions into the GSI storage ring, giving access to masses and half-lives.…
The COMPASS experiment at the CERN SPS features good charged particle tracking and coverage by electromagnetic calorimetry, and our data provide excellent opportunity for simultaneous observation of new states in two different decay modes…
Preliminary results of the strong interaction shift and width in pionic hydrogen ($\pi H$) using an X-ray spectrometer with spherically bent crystals and CCDs as X-ray detector are presented. In the experiment at the Paul Scherrer Institute…
Employing two state-of-the-art methods, multiconfiguration Dirac--Hartree--Fock and second-order many-body perturbation theory, the excitation energies and lifetimes for the lowest 200 states of the $2s^2 2p^4$, $2s 2p^5$, $2p^6$, $2s^2…
The COMPASS experiment at CERN is designed for light hadron spectroscopy with emphasis on the detection of new states, in particular the search for exotic states and glue-balls. After a short pilot run in 2004 (190 GeV/c negative pion beam,…
We report a precise determination of the lifetime of the (4p)$^2$P$_{3/2}$ state of $^{40}$Ca$^+$, $\tau_{\textrm{P}_{3/2}}=6.639(42)$ ns, using a combination of measurements of the induced light shift and scattering rate on a single…
The discovery of naturally occurring long-lived isomeric states (t_1/2 > 10^8 yr) in the neutron-deficient isotopes 211,213,217,218Th [A. Marinov et al., Phys. Rev. C 76, 021303(R) (2007)] was reexamined using accelerator mass spectrometry…
The relationship between the pionium lifetime and the $\pi\pi$ scattering lengths is established, including the sizable electromagnetic corrections. The bound state formalism that is used is that of constraint theory which provides a…
The partial widths of the decays $D^+_s \to \phi \pi^+$ and $D^+_s \to \pi^+ \pi^+ \pi^-$ - nonresonant are computed within the effective quark model with chiral symmetry involving Heavy quark effective theory (HQET) and Chiral perturbation…
We study the process e+e- -> pi+pi-pi+pi-gamma, with a photon emitted from the initial-state electron or positron, using 454.3 fb^-1 of data collected with the BABAR detector at SLAC, corresponding to approximately 260,000 signal events. We…
We report measurements of the lifetimes of the 3d $^2$D$_{5/2}$ and 3d $^2$D$_{3/2}$ metastable states of a single laser-cooled $^{40}$Ca$^+$ ion in a linear Paul trap. We introduce a new measurement technique based on high-efficiency…
The hitherto unexplored two-photon doubly-excited states [Ne$^{*}$($2p^{-1}3s$)]$_{2}$ were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These states undergo ultrafast…
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…
The recent discoveries of the long-lived high spin super- and hyperdeformed isomeric states and their unusual radioactive decay properties are described. Based on their existence a consistent interpretation is given to the production of the…
The electric quadrupole transition from the first 2+ state to the ground 0+ state in 18C was studied through lifetime measurement by an upgraded recoil shadow method applied to inelastically scattered radioactive 18C nuclei. The measured…
As an important step towards an atomic parity violation experiment in one single trapped Ra$^+$ ion, laser spectroscopy experiments were performed with on-line produced short-lived $^{212,213,214}$Ra$^+$ ions. The isotope shift of the…
We report the results from a study of ~23 Million K+- ==> pi+- pizero pizero decays recorded by the NA48/2 experiment at the CERN SPS, showing an anomaly in the pizero pizero invariant mass distribution in the region around 2m+, where m+ is…
A systematic study of the $\pi^-/\pi^+$ ratio in heavy-ion collisions with the same neutron/proton ratio but different masses can help single out effects of the nuclear mean field on pion production. Based on simulations using the IBUU04…
The spectrum of the (L_i^3 + p-bar + 2e) four-body system was calculated in an adiabatic approach. The two-electron energies were approximated by a sum of two single-electron effective charge two-center energies as suggested in [6]. While…
The reaction 28Si + 181Ta has been studied at E(Lab) = 125 and 135 MeV. Coincidences between high energy particles and various X- and gamma-rays from abnormally long-lived states were observed. e.g. 7.8 - 8.6 MeV alpha-particles with…