Search results for "PARITY"
showing 10 items of 513 documents
Coupling of single atom with localized modes associated to defects in one-dimensional photonic crystals
1998
Abstract The Hamiltonian model describing the interaction between a two-level atom with two electromagnetic localized modes in an imperfect one-dimensional photonic crystals is introduced. The possibility of generating Schroedinger-cat-like states of these defect modes is reported. The physical origin of this dynamical behaviour is pointed out.
Structure of the Triplet of low-lying states in101Mo
1991
The properties of the triplet of low-lying states in101Mo have been studied through spectroscopy of theγ radiation following thermal neutron capture in100Mo and β− decay of101Nb and through a measurement of the proton angular distributions in the100Mo(d,p) reaction with 14 MeV deuteron energy. The half-lives of the 13.5 keV state and the 57.0 keV 5/2+ state have been measured as 226(7) and 133(7)ns, respectively. These values and the quadrupole/dipole mixing ratios of the 13.5 keV and 43.5 keV transitions yield spin and parity 3/2+ for the 13.5 keV level. The E2 components in the 13.5 (3/2+ →1/2+) and 43.5 keV (5/2+→3/2+) transitions are ≦ 8·10−4 and 54(9)%, respectively. The possibility of…
The nuclear structure of $^{223}$Fr
1991
Abstract The γ-rays following the β− decay of 223Rn have been investigated by means of γ-ray singles including multispectrum analysis, and γγ-coincidence measurements using Ge detectors. Multipolarities of 38 transitions in 223Fr have been established by measuring conversion electrons with a mini-orange electron spectrometer. Most of the observed transitions could be placed in a level scheme comprising 53 excited states of 223Fr. The level structure is interpreted in terms of K π = 3 2 ± and 1 2 ± parity doublet bands, and a second K π = 3 2 ± higher-lying parity doublet. The experimental data are compared with the theoretical predictions of the reflection-asymmetric rotor model.
The nuclear structure of 229Th
2002
Abstract The γ -rays following the β − decay of 229 Ac have been investigated by means of γ -ray singles and γγ -coincidence measurements using Ge detectors. Multipolarities of 40 transitions in 229 Th have been established by measuring conversion electrons with a mini-orange electron spectrometer. The half-lives of the 146.35, 164.53 and 261.96 keV levels have been measured using the advanced time delayed βγγ (t) method. The low-lying states in 229 Th and observed transition rates have been interpreted within the quasiparticle–phonon model with inclusion of Coriolis coupling. Two octupole correlated parity partner bands, with K π =5/2 ± and K π =3/2 ± , were identified in 229 Th.
Polarization corrections to single-particle energies studied within the energy-density-functional and quasiparticle random-phase approximation approa…
2014
Background: Models based on using perturbative polarization corrections and mean-field blocking approximation give conflicting results for masses of odd nuclei. Purpose: We systematically investigate the polarization and mean-field models, implemented within self-consistent approaches that use identical interactions and model spaces, to find reasons for the conflicts between them. Methods: For density-dependent interactions and with pairing correlations included, we derive and study links between the mean-field and polarization results obtained for energies of odd nuclei. We also identify and discuss differences between the polarization-correction and full particle-vibration-coupling (PVC) …
Prolate yrast cascade in183Tl
2000
The yrast sequence in ${}^{183}\mathrm{Tl}$ has been studied for the first time in recoil-mass selected \ensuremath{\gamma}-ray spectroscopic measurements. A rotational-like cascade of seven transitions is established down to the band head with probable spin and parity ${(13/2}^{+}).$ Unlike in the adjacent odd-mass Tl nuclei, prompt \ensuremath{\gamma} decay from the yrast band to a lower lying weakly deformed (oblate) structure is not observed. These features are consistent with the predicted drop of the prolate band head in ${}^{183}\mathrm{Tl}$ compared to ${}^{185}\mathrm{Tl}.$ The implications for the prolate energy minimum in odd-mass Tl nuclei at the neutron ${i}_{13/2}$ midshell $(…
Nature of93Rb levels studied in IBFM
1989
The structure of the low-lying states with negative parity of3793Rb56 has been studied in the framework of the Interacting Boson-Fermion Model (IBFM) using the even-even neighbour3894Sr56 as a core. A good description of the properties of the levels has been obtained. A sensitive test of the quality of the theoretical studies is the decay pattern of the second excited state at 267 keV with a half-life of 2.0(2) ns. The calculations givet1/2=2.26 ns and they predict the existence of a 13 keV transition into the first excited state, the existence of which has been confirmed afterwards by experiments.
Left-right symmetry breaking in NJL approach
1995
We study left-right symmetric models which contain only fermion and gauge boson fields and no elementary scalars. The Higgs bosons are generated dynamically through a set of gauge- and parity-invariant 4-fermion operators. It is shown that in a model with a composite bi-doublet and two triplet scalars there is no parity breaking at low energies, whereas in the model with two doublets instead of two triplets parity is broken automatically regardless of the choice of the parameters of the model. For phenomenologically allowed values of the right-handed scale a tumbling symmetry breaking mechanism is realized in which parity breaking at a high scale $\mu_R$ propagates down and eventually cause…
Supersymmetry with spontaneous R-parity breaking in Z0 decays: the case of an additional Z
1991
Single production of SUSY particles in the decays of the Z0 may proceed with large rates in models with spontaneously broken R-parity. We focus on the case where there is a lepton number symmetry as part of the gauge group. In the simplest of such models there is a single additional neutral gauge boson and the strength of Rp-violating interactions is related with that of the new gauge force. We study the phenomenological implications of the model for Z0 decays, including the study of the rates for single chargino production in Z0 decays, i.e. Z0→ξ±τ±, as well as for the so-called Zen events, and find that they may be measurable at LEP. The first process, characteristics of spontaneously bro…
O(αs2) corrections to high-qT polarized gauge boson production at hadron colliders
1991
Abstract We report first results on O(αs2) corrections to the parity conserving structure functions that describe high-qT polarized gauge boson production in hadron collisions. We present some numerical results for polarized W+ production at the Tevatron p p collider. In particular we find that the relation A0=A2 between the longitudinal and transverse interference structure functions no longer holds true at next-to-leading order (NLO). We calculate the NLO corrections to this relation.