16298898
Landau pole effects and the parameter space of the minimal supergravity model.
It is shown that analyses at the electroweak scale can be significantly affected due to Landau pole effects in certain regions of the parameter space. This phenomenon arises due to a large magnification of errors of the input parameters $m_t$, $\alpha_G$ which have currently a 10 percent uncertainty in their determination. The influence of the Landau pole on the constraint that the scalar SUSY spectrum be free of tachyons is also investigated.It is found that this constraint is very strong and eliminates a large portion of the parameter space.Under the above constraint the trilinear soft SUSY breaking term at the electroweak scale is found to lie in a restricted domain.
44568977
Is the Gepner three generation model phenomenologically viable?
The low-energy spectrum of the Gepner three generation model constructed from the discrete series of the [ital N]=2 superconformal theory below the intermediate scale is studied. It is found that, aside from the usual standard model leptons and quarks, there appear four Higgs doublets, six exotic light neutral particles, and a pair of light color Higgs triplets. Although the proton is stable, the presence of these new particles and the difficulty for the up and down quarks and the first two lepton generations to grow nonzero masses may rule out this model phenomenologically. Despite this discouraging result we do find that the nonrenormalizable interactions can provide a viable mechanism to solve the lepton-quark mass hierarchy problem, due to the large VEV growth of the standard model singlet fields at the intermediate symmetry-breaking scale.
38924798
Constraints on the minimal supergravity model from the b-->s gamma decay.
The constraints on the minimal supergravity model from the b → s decay are studied. A large domain in the parameter space for the model satisfies the CLEO bound, BR(b → s) 0, however, the branching ratio � � ,
26505270
Decoupling and anomalous bandcrossings in odd-proton nuclei.
The anomalous bandcrossing observed in the [541] [down arrow] bands of odd-[ital Z] nuclei from the rare-earth region was investigated in the framework of the particle-rotor model. The participation of the decoupling term in the [ital K]=1/2 band will give rise to a significant shift of the bandcrossing frequency, with an amplitude comparable to the observed values.
7640052
Spin determination and calculation of nuclear superdeformed bands in A~190 region.
Using the two-parameter expression for rotational spectra, {ital E}({ital I})={ital a}( {radical}1+{ital bI}({ital I}+1) {minus}1), derived from the Bohr Hamiltonian, the spins of 22 superdeformed bands observed in the {ital A}{similar to}190 region were determined. The calculated transition energies depend sensitively on the prescribed spins. The agreement between the calculated and observed transition energies is incredibly well when a correct spin assignment is made. The kinematic and dynamic moments of inertia were extracted from the observed transition energies and their variation with rotational frequency was investigated.
5308245
Yrast-yrare interaction strength.
An accurate particle-number-conserving calculation shows that in a single-{ital j} ({ital j}=13/2) model the yrast-yrare interaction {ital V} is always strong and no periodic oscillation of {ital V} with Fermi energy {lambda} is obtained. However, in a two-{ital j} model or realistic nuclei sharp backcrossings do occur for appropriate single-particle level distribution and oscillation of {ital V} with increasing {lambda} is found. The occupation-number distribution for the high-{ital j} shell plays a key role in understanding the backcrossing properties.
18651854
Sources of CP violation in the two-Higgs-doublet model.
Assuming $\mathrm{CP}$ violation arises solely through the Higgs potential, we develop the most general two-Higgs-doublet model. There is no discrete symmetry that distinguishes the two Higgs bosons. It is assumed that an approximate global family symmetry sufficiently suppresses flavor-changing neutral scalar interactions. In addition to a Cabibbo-Kobayashi-Maskawa phase, neutral boson mixing, and superweak effects, there can be significant $\mathrm{CP}$ violation due to charged Higgs boson exchange. The value of $\frac{{\ensuremath{\epsilon}}^{\ensuremath{'}}}{\ensuremath{\epsilon}}$ due to this last effect could be as large as in the standard model.
29674729
Relation between the kinematic and dynamic moments of inertia in superdeformed nuclei.
The relation between the kinematic and dynamic moments of inertia, {ital scrJ}{sup (1)} and {ital scrJ}{sup (2)}, was analyzed for the normally deformed and superdeformed rotational bands. According to the {ital ab} expression for rotational spectrum, {ital E}({ital I})={ital a}( {radical}1+{ital bI}({ital I}+1) {minus}1), the ratio {ital R}= {radical}({ital scrJ}{sup (1)}){sup 3}/{ital scrJ}{sup (2)} should be {ital I} independent. Extensive analyses for the normally deformed rotational bands in the rare-earth and actinide nuclei show that the {ital R}'s do remain {ital I} independent. The same relation holds well for the superdeformed bands observed in the {ital A}{similar to}190 region, and seems also to hold for those in the {ital A}{similar to}150 region, if spin assignments are made correctly. The {ital I} independence of {ital R} provides an additional support to the spin assignments.