Custodial SO(4) symmetry and CP violation in N-Higgs-doublet potentials

We study the implementation of global $SO(4)\sim SU(2)_L\otimes SU(2)_R$ symmetry in general potentials with N-Higgs-doublets in order to obtain models with custodial $SO(3)_C$ symmetry. We conclude that any implementation of the custodial SO(4) symmetry is equivalent, by a basis transformation, to a canonical one if $SU(2)_L$ is the gauge factor, $U(1)_Y$ is embedded in $SU(2)_R$ and we require $N$ copies of the doublet representation of $SU(2)_R$. The invariance by SO(4) automatically leads to a CP invariant potential and the basis of the canonical implementation of SO(4) is aligned to a basis where CP-symmetry acts in the standard fashion. We show different but equivalent implementations for the 2HDM, including an implementation not previously considered.Comment: 22pp, REVTeX4. Published versio

REPLY TO HEP-PH/0211241 "On the extra factor of two in the phase of neutrino oscillations"

Arguments continue to appear in the literature concerning the validity of the standard oscillation formula. We point out some misunderstandings and try to explain in simple terms our viewpoint.Comment: 4 pages [1 colored LaTex-fig], AMS-Te

Wave packets and quantum oscillations

We give a detailed analysis of the oscillation formula within the context of the wave packet formalism. Particular attention is made to insure flavor eigenstate creation in the physical cases (Delta p not equal 0). This requirement imposes non instantaneous particle creation in all frames. It is shown that the standard formula is not only exact when the mass wave packets have the same velocity, but it is a good approximation when minimal slippage occurs. For more general situations the oscillation formula contains additional arbitrary parameters, which allows for the unknown form of the wave packet envelope.Comment: 15 pages [8 figs], AMS-Te

On the Decelerating Shock Instability of Plane-Parallel Slab with Finite Thickness

Dynamical stability of the shock compressed layer with finite thickness is investigated. It is characterized by self-gravity, structure, and shock condition at the surfaces of the compressed layer. At one side of the shocked layer, its surface condition is determined via the ram pressure, while at the other side the thermal pressure supports its structure. When the ram pressure dominates the thermal pressure, we expect deceleration of the shocked layer. Especially, in this paper, we examine how the stratification of the decelerating layer has an effect on its dynamical stability. Performing the linear perturbation analysis, a {\it more general} dispersion relation than the previous one obtained by one of the authors is derived. It gives us an interesting information about the stability of the decelerating layer. Importantly, the DSI (Decelerating Shock Instability) and the gravitational instability are always incompatible. We also consider the evolution effect of the shocked layer. In the early stages of its evolution, only DSI occurs. On the contrary, in the late stages, it is possible for the shocked layer to be unstable for the DSI (in smaller scale) and the gravitational instability (in larger scale). Furthermore, we find there is a stable range of wavenumbers against both the DSI and the gravitational instability between respective unstable wavenumber ranges. These stable modes suggest the ineffectiveness of DSI for the fragmentation of the decelerating slab.Comment: 17 pages, 6 figures. The Astrophysical Journal Vol.532 in pres

Fano-Kondo effect in a two-level system with triple quantum dots: shot noise characteristics

We theoretically compare transport properties of Fano-Kondo effect with those of Fano effect. We focus on shot noise characteristics of a triple quantum dot (QD) system in the Fano-Kondo region at zero temperature, and discuss the effect of strong electric correlation in QDs. We found that the modulation of the Fano dip is strongly affected by the on-site Coulomb interaction in QDs.Comment: 4 pages, 6figure

Effect of the thyroid status in pregnant patients on the outcome in medical abortion

Background: Medical abortion has the potential to expand abortion services, where surgical services are limited, and to expand women’s choice of abortion method and experience. Objective of present study was to compare the outcome after medical abortion in euthyroid and hypothyroid pregnant patients.Methods: A longitudinal study was carried out in pregnant patients before 9 weeks of pregnancy who wanted termination of pregnancy. Women were divided into two groups. Group I (n = 100) comprised euthyroid patients who acted as control group, whereas group II (n = 58) included patients having subclinical or overt hypothyroidism. All the patients were given 200 mg of mifepristone orally followed by 800 µg of misoprost vaginally 36 to 48 hours later. these patients were followed for 2 weeks. In all the patients, hemoglobin estimation and ultrasound were done during follow-up.Results: Average hemoglobin in the study group was 9.5 gm%, whereas in control group it was 11.1 gm%, which was statistically significant. the fall in hemoglobin after 2 weeks of the drug intake was also significant in control as well as the study group. About 13.79% patients in the study group had to undergo emergency evacuation of uterus within 24 hours for complaints of severe bleeding. In control group, no emergency curettage was done within 24 hours, the difference being highly significant. Mean duration of bleeding was also more in the study group. About 28.57% patients in the study group revealed products of conception on ultrasound after 2 weeks in comparison with 11.57% in the control group, which was also statistically significant (p = 0.008). A total of 41% patients in the study group had to undergo uterine curettage, which was highly significant (p = 0.000).Conclusions: Present study showed that patients having clinical or subclinical hypothyroidism have more failure rates, more chances of excessive bleeding, increased duration of bleeding, resulting in decrease in hemoglobin levels in already anemic patients. Also, the rate of operative intervention was unusually high in hypothyroid group

The Minimum Total Mass of MACHOs and Halo Models of the Galaxy

If the density distribution \rho (r) of MACHOs is spherically symmetric with respect to the Galactic center, it is shown that the minimal total mass M_{min}^{{ MACHO}} of the MACHOs is 1.7\times 10^{10}\sol \tau_{-6.7}^{{ LMC}} where \tau_{-6.7}^{{ LMC}} is the optical depth (\tau^{{ LMC}}) toward the Large Magellanic Cloud (LMC) in the unit of 2\times 10^{-7}. If \rho (r) is a decreasing function of r, it is proved that M_{min}^{{ MACHO}} is 5.6\times 10^{10}\sol \tau_{-6.7}^{{ LMC}}. Several spherical and axially symmetric halo models of the Galaxy with a few free parameters are also considered. It is found that M_{min}^{{ MACHO}} ranges from 5.6\times 10^{10}\sol \tau_{-6.7}^{{ LMC}} to \sim 3 \times 10^{11}\sol \tau_{-6.7}^{{ LMC}}. For general case, the minimal column density \Sigma_{min}^{{ MACHO}} of MACHOs is obtained as \Sigma_{min}^{{ MACHO}} =25 \sol { pc}^{-2}\tau_{-6.7}^{{ LMC}}. If the clump of MACHOs exist only halfway between LMC and the sun, M_{min}^{{ MACHO}} is 1.5\times 10^9\sol. This shows that the total mass of MACHOs is smaller than 5 \times 10^{10}\sol , i.e. \sim 10\% of the mass of the halo inside LMC, either if the density distribution of MACHOs is unusual or \tau^{{ LMC}}\ll 2\times 10^{-7}.Comment: 5 pages, 5 Encapsulated PostScript figures, Latex, Accepted for publication in Apj. Letter

Infrared spectroscopy under multi-extreme conditions: Direct observation of pseudo gap formation and collapse in CeSb

Infrared reflectivity measurements of CeSb under multi-extreme conditions (low temperatures, high pressures and high magnetic fields) were performed. A pseudo gap structure, which originates from the magnetic band folding effect, responsible for the large enhancement in the electrical resistivity in the single-layered antiferromagnetic structure (AF-1 phase) was found at a pressure of 4 GPa and at temperatures of 35 - 50 K. The optical spectrum of the pseudo gap changes to that of a metallic structure with increasing magnetic field strength and increasing temperature. This change is the result of the magnetic phase transition from the AF-1 phase to other phases as a function of the magnetic field strength and temperature. This result is the first optical observation of the formation and collapse of a pseudo gap under multi-extreme conditions.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev.