56519732
Search for a permanent EDM using laser cooled radioactive atom
The search for the electric-dipole moment (EDM) of laser-cooled francium (Fr) atoms could lead to a measurement for the electron EDM. It is predicted that the electron EDM would be enhanced by approximately three orders of magnitude in heavy atoms such as Fr. Laser-cooling and trapping techniques are expected to suppress statistical and systematic errors in precision measurements. The magneto-optical trap was achieved using stable rubidium in a developing factory of laser-cooled radioactive atoms. In light of the results from the rubidium experiments, we found that an upgrade of each apparatus is preferred for Fr trapping.
122001891
Development of the measurement system for the search of an electric dipole moment of the electron with laser-cooled francium atoms
We plan to measure the permanent electric dipole moment (EDM) of the elec- tron, which has the sensitivity to the CP violation in theories beyond the standard model by using the laser-cooled francium (Fr) atom. This paper reports the present status of the EDM measurement system. A high voltage application system was constructed in order to produce the strong electric field (100 kV /cm) needed for the experiment. After condi- tioning, the leakage current was 10 pA when a high voltage of 43 kV was applied. Also, a drift of an environmental field was measured at the planned location of the Fr-EDM experiment. The drift is suppressed at present down to the level of 10 pT by installing a 4-layer magnetic shield. Improvements are still needed to reach the required field stability of 1 fT.
119162632
Non-Abelian Discrete Symmetries in Particle Physics
We review pedagogically non-Abelian discrete groups, which play an important role in the particle physics. We show group-theoretical aspects for many concrete groups, such as representations, their tensor products. We explain how to derive, conjugacy classes, characters, representations, and tensor products for these groups (with a finite number). We discussed them explicitly for $S_N$, $A_N$, $T'$, $D_N$, $Q_N$, $\Sigma(2N^2)$, $\Delta(3N^2)$, $T_7$, $\Sigma(3N^3)$ and $\Delta(6N^2)$, which have been applied for model building in the particle physics. We also present typical flavor models by using $A_4$, $S_4$, and $\Delta (54)$ groups. Breaking patterns of discrete groups and decompositions of multiplets are important for applications of the non-Abelian discrete symmetry. We discuss these breaking patterns of the non-Abelian discrete group, which are a powerful tool for model buildings. We also review briefly about anomalies of non-Abelian discrete symmetries by using the path integral approach.
54183358
Calculation of Single Top Quark Production in Electron-Positron Scattering
55566134
Current status of the LHCf experiment and future plan
The Large Hadron Collider forward (= LHCf) experiment has successfully finished the first phase of data taking at LHC √ s = 0.9 and 7 TeV proton-proton collisions in 2010. As current status, we concentrate on analyzing the obtained data. As the first result, the energy spectra of photon measured by LHCf during = 7 TeV p-p collision has been published recently. Also the study of the upgraded version of LHCf detector for future = 14TeV run scenario is developed with the GSO scintillator. Another possible plan of p-A(nuclear) collision in LHC is also studied. In this paper, as the current status of the experiment, analyses, and works for foreseen detector upgrade are summarized.
118633837
Like-Sign Dimuon Asymmetry of B0 Meson and LFV in SU(5) SUSY GUT with S4 Flavor Symmetry
The like-sign dimuon charge asymmetry of the B meson, which was reported in the DO Collaboration, is studied in the SU(5) SUSY GUT model with S4 flavor symmetry. Additional CP violating effects from the squark sector are discussed in Bs- ¯ Bs mixing process. The predicted like-sign charge asymmetry is in the 2σ range of the combined result of DO and CDF measurements. Since the SUSY contributions in the quark sector affect to the lepton sector because of the SU(5) GUT relation, two predictions are given in the leptonic processes: (i) both BR(μ → eγ) and the electron EDM are close to the present upper bound, (ii) the decay ratios of τ decays, τ → μγ and τ → eγ, are related to each other via the Cabibbo angle λc :B R( τ → eγ)/BR(τ → μγ) � λ 2. These are testable at future experiments. Subject Index: 142, 151, 152, 154, 158
119265355
Tetrahedral symmetry in Zr nuclei: calculations of low-energy excitations with Gogny interaction
We report on the results of the calculations of the low energy excitation patterns for three Zirconium isotopes, viz 80Zr40, 96Zr56 and 110Zr70, reported by other authors to be doubly-magic tetrahedral nuclei (with tetrahedral magic numbers Z = 40 and N = 40, 56 and 70). We employ the realistic Gogny effective interactions using three variants of their parametrization and the particle-number, parity and the angular-momentum projection techniques. We confirm quantitatively that the resulting spectra directly follow the pattern expected from the group theory considerations for the tetrahedral symmetric quantum objects. We also find out that, for all the nuclei studied, the correlation energy obtained after the angular momentum projection is very large for the tetrahedral deformation as well as other octupole deformations. The lowering of the energies of the resulting configurations is considerable, i.e. by about 10 MeV or even more, once again confirming the significance of the angular-momentum projections techniques in the mean-field nuclear structure calculations.