119426197
Nuclear wobbling motion and electromagnetic transitions
Abstract The nuclear wobbling motion is studied from a microscopic viewpoint. It is shown that the expressions not only of the excitation energy but also of the electromagnetic-transition rate in the microscopic RPA framework can be cast into the corresponding forms of the macroscopic rotor model. Criteria to identify the rotational band associated with the wobbling motion are given. Examples of realistic calculations are investigated and some theoretical predictions are presented.
14513100
MICROSCOPIC DESCRIPTION OF NUCLEAR WOBBLING MOTION ROTATION OF TRIAXIALLY DEFORMED NUCLEI
The nuclear wobbling motion in the Lu region is studied by the microscopic cranked mean-field plus RPA method. The Woods-Saxon potential is used as a mean-field with a new parameterization which gives reliable description of rapidly rotating nuclei. The prescription of symmetry-preserving residual interaction makes the calculation of the RPA step parameter-free, and we find the wobbling-like RPA solution if the triaxial deformation of the mean-field is suitably chosen. It is shown that the calculated out-of-band B(E2) of the wobbling-like solution depends on the triaxial deformation in the same way as in the macroscopic rotor model, and can be used to probe the triaxiality of the nuclear mean-field.
119961291
Octupole Vibrations with K =1 and 2 in Superconducting, Superdeformed Nuclei
We calculate the response functions for octupole vibrations in superdeformed nuclei by means of the RPA using a large configuration space composed of 9 major shells. The strongly collective octupole vibrations with K = 1 and 2 are predicted to appear very low in excitation energy, as well as those with K =0, if an appreciable amount of pairing correlation is present in superdeformed nuclei. Numerical examples are presented for 192Hg and 144Gd .
16280732
Microscopic calculation of transition intensities for vibrational bands and high- K isomers
We investigate the effect of the Coriolis coupling and the residual interactions upon the inter-band transition rates for the vibrational bands and the decay of two-quasiparticle high-K isomers.
16491530
Diabatic Mean-Field Description of Rotational Bands in Terms of the Selfconsistent Collective Coordinate Method
Diabatic description of rotational bands provides a clear-cut picture for understanding the back-bending phenomena, where the internal structure of the yrast band changes dramatically as a function of angular momentum. A microscopic framework to obtain the diabatic bands within the mean-field approximation is presented by making use of the selfconsistent collective coordinate method. Applying the framework, both the ground state rotational bands and the Stockholm bands are studied systematically for the rare-earth deformed nuclei. An overall agreement has been achieved between the calculated and observed rotational spectra. It is also shown that the inclusion of the double-stretched quadrupole-pairing interaction is crucial to obtain an overall agreement for the even-odd mass differences and the rotational spectra simultaneously.
122360678
Vacuum system for the SAMURAI spectrometer
Abstract The first commissioning experiment of the SAMURAI spectrometer and its beam line was performed in March, 2012. The vacuum system for the SAMURAI spectrometer includes its beam line and the SAMURAI vacuum chamber with the windows for detecting neutrons and charged particles. The window for neutrons was made of stainless steel with a thickness of 3 mm and was designed with a shape of partial cylinder to support itself against the atmospheric pressure. The window for charged particles was of the combination of Kevlar and Mylar with the thickness of 280 and 75 μm, respectively. The pressure in the vacuum system was at a few Pa throughout the commissioning experiment.
28690711
Deviations from tri-bimaximality and quark-lepton complementarity
We study deviations from tri-bimaximality (TBM) and quark-lepton complementarity (QLC) in a model-independent way. The current neutrino experimental data is well approximated by tri-bimaximal generation mixing but the QLC relations are not satisfied with each data of 1σ level. This means that there exist deviations from the complementarity. The same fact for the TBM might be checked in the future neutrino experiments. We discuss such deviations from the TBM and QLC, simultaneously. A new ratio between the deviations is introduced, and some interesting points are presented. We also show predicted correlations among leptonic mixing angles at the points.
453979
S4 Flavor Model of Quarks and Leptons
We present an S4 flavor model to unify quarks and leptons in the framework of the SU(5) GUT. Three generations of 5-plets in SU(5) are assigned to be 31 of S4 while the first and the second generations of 10-plets in SU(5) are assigned to be 2 of S4 ,a nd the third generation of 10-plet is to be 11 of S4. Right-handed neutrinos are also assigned to be 2 for the first and second generations and 11 for the third generation, respectively. Taking vacuum alignments of relevant gauge singlet scalars, we predict the quark mixing as well as the tri-bimaximal mixing of neutrino flavors. Especially, the Cabbibo angle is predicted to be 15 ◦ in the limit of the vacuum alignment. We can improve the model to predict observed CKM mixing angles.
8136589
Deviation from tri-bimaximal mixing and flavor symmetry breaking in a seesaw type A(4) model
Abstract We have studied the contribution of higher order corrections of the flavor symmetry breaking in the A 4 seesaw model with the supersymmetry. Taking account of possible higher dimensional mass operators, we predict the deviation from the tri-bimaximal lepton mixing for both normal hierarchy and inverted hierarchy of neutrino masses. We have found that the value of sin 2 2 θ 23 is larger than 0.96 and the upper bound of sin 2 θ 13 is 0.01. We have also examined the flavor changing neutral current of leptons from the soft SUSY breaking in slepton masses and A-terms within the framework of supergravity theory. Those magnitudes are enough suppressed to be consistent with experimental constraints.
121264816
Electroweak corrections to muon pair production in electron-positron annihilation at high energy
Abstract The lowest-order radiative corrections to the reaction e + + e − → μ + + μ − are analyzed in the standard SU(2) × U(1) electroweak theory. The virtual corrections are calculated in the on-shell renormalization scheme. The masses of the recently discovered Z-boson and W-boson are used to fix the weak coupling constants. The decay width of the Z-boson is also taken into account. By including the cross section of hard photon emission, various kinds of distribution are obtained both analytically and numerically. The magnitude of the effective axial vector coupling is confirmed to be quite different from that previously taken in the calculations within QED. This difference, which is due to the genuine electroweak corrections, reaches about 10% in angular distribution at the energy around the Z-boson mass, even if the reasonable effect of a hard photon is included.