Search results for "nuclear physics"
showing 10 items of 5307 documents
Decay properties of exoticN≃28 S and Cl nuclei and theCa48/46Ca abundance ratio
1993
Beta-decay half-lives and \ensuremath{\beta}-delayed neutron-emission probabilities of the very neutron-rich nuclei $^{44}\mathrm{S}$ and $^{45--47}\mathrm{Cl}$ have been measured. These isotopes, which lie at or close to the N=28 magic shell, were produced in interactions of a 60 MeV/u $^{48}\mathrm{Ca}$ beam from GANIL (Grand Acc\'el\'erateur National d'Ions Lourds) with a $^{64}\mathrm{Ni}$ target, and were separated by the doubly achromatic spectrometer LISE (Ligne d'Ions Super Epluch\'es). Their decay was studied by a \ensuremath{\beta}-n time correlation measurement. The results are compared to recent model predictions and indicate a rapid weakening of the N=28 shell effect below $_{2…
Description of πp→Δ(1232)π and πp→Δ(1232)ρ(770) reaction proceeding via baryon exchange mechanism
1991
We analyze the available experimental data on the backward production processes πN→Δπ and πN→ Δπ in the framework of the strong-cut Reggeized absorption model, which is based on the exchange of the baryon Regge trajectoriesNα and Δδ with the associated cuts. The model describes rather well the data on the differential cross sections at incident π momenta ranging from 2.15 to 20 GeV/c. An essential contribution of Δδ exchange even at small energies (Elab of the order of a few GeV) is found. A model-independent analysis of data confirms this fenomena.
Observation of charmless baryonic decays B(s)0→pp¯h+h′−
2017
Decays of B0 and Bs0 mesons to the charmless baryonic final states pp¯h+h′-, where h and h′ each denote a kaon or a pion, are searched for using the LHCb detector. The analysis is based on a sample of proton-proton collision data collected at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. Four-body charmless baryonic Bs0 decays are observed for the first time. The decays Bs0→pp¯K+K-, Bs0→pp¯K±π∓, B0→pp¯K±π∓ and B0→pp¯π+π- are observed with a significance greater than 5 standard deviations; evidence at 4.1 standard deviations is found for the B0→pp¯K+K- decay and an upper limit is set on the branching fraction for Bs0→pp¯π+π-. Branching fraction…
Der Zerfall des94Sr
1973
The nuclide94Sr was isolated by chemical separation methods after thermal neutron induced fission of235U. Its decay properties were investigated employing semi-conductor spectrometers and coincidence techniques. A half-life of 74.1±0.3 sec was found. Besides the 1428.3 keV γ-ray we found 4 new γ-rays which could be placed in a decay scheme comprising three excited states of94Y. The 1+ states in theuu-nuclides90,92,94Y and88,90,92Rb are compared.
Development of nuclear chemistry at Mainz and Darmstadt
2018
Abstract This review describes some key accomplishments of Günter Herrmann such as the establishment of the TRIGA Mark II research reactor at Mainz University, the identification of a large number of very neutron-rich fission products by fast, automated chemical separations, the study of their nuclear structure by spectroscopy with modern detection techniques, and the measurement of fission yields. After getting the nuclear chemistry group, the target laboratory, and the mass separator group established at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, a number of large international collaborations were organized exploring the mechanism of deeply inelastic multi-nucleon trans…
DETERMINATION OF NUCLEAR GROUND STATE PROPERTIES FAR FROM STABILITY BY OPTICAL PUMPING
1973
The possibilities of determining nuclear spin, moments and variation in charge volume by optical pumping of on line masseparated isotopes are described for the example of the isotopic chain lY1Hg-205Hg. The variation in nuclear charge volume (6 ) along this chain and in particular its abrupt change for the lightest Hg-isotopes, indicating a phase transition in nuclear structure, are discussed. 1. Introduction. - This talk is based on expe- riments (I), (2), (3) performed recently by a visiting team (*) at the ISOLDE facility at CERN with the members : J. Bonn, G. Huber, H.-J. Kluge, U. Kopf, L. Kugler, J. Rodriguez, and E. W. Otten. The investigation of the hyperfine structure (hfs) and iso…
On-line laser spectroscopy of refractory radioisotopes at the JYFL IGISOL facility
1998
A major objective of the laser-IGISOL program has been realized with the first ever on-line observation of collinear laser induced fluorescence from an ion of a refractory element. The measurements demonstrate that the IGISOL can be operated in a mode that produces ion beams of good emittance with reasonable extraction efficiency. The technique has been used to study the neutron-deficient Hf isotopes.
Muon states in uniaxially strained iron
1984
Effects of lattice relaxation, quantum motion, and uniaxial strain on the internal field at a positive-muon site in iron have been calculated. The uniaxial strain gives rise to a statistical shift of the muon population at interstitial sites. The effect of the population shift is found to be primarily responsible for the observed changes in the muon-precession frequency. The theory also predicts a 1T temperature dependence of the frequency shifts. Peer reviewed
Evidence for violation of the Gallagher-Moszkowski rules in154Pm
1972
The existence of two radioactive species of154Pm (1.8 min ground state and 2.65 min isomer) is established. The Nilsson model configurations assigned to these states give evidence against the validity of the Gallagher-Moszkowski coupling rules in154Pm.
Study ofe+e−→pp¯π0in the vicinity of theψ(3770)
2014
The process e(+)e(-) -> p (p) over bar pi(0) has been studied by analyzing data collected at root s = 3.773 GeV, root s = 3.650 GeV, and during a psi(3770) line shape scan with the BESIII detector at the BEPCII collider. The Born cross section of p (p) over bar pi(0) in the vicinity of the psi(3770) is measured, and the Born cross section of psi(3770) -> p (p) over bar pi(0) is extracted considering interference between resonant and continuum production amplitudes. Two solutions with the same probability and a significance of 1.5 sigma are found. The solutions for the Born cross section of psi(3770) -> p (p) over bar pi(0) are 33.8 +/- 1.8 +/- 2.1 pb and 0.06(-0.04-0.01)(+0.10+0.01) pb ( ->…