h→Υγh \to \Upsilon \gamma Decay: Smoking Gun Signature of Wrong-Sign hbbˉhb\bar{b} Coupling

We analyze in a model-independent way the potential to probe new physics using Higgs decay to $\Upsilon \gamma$. The $h \to \Upsilon \gamma$ decay width is unusually small in the Standard Model because of an accidental cancellation among the direct and indirect decay diagrams. Thus, any new physics that can modify the direct or the indirect decay amplitudes disrupts the accidental Standard Model cancellation and can potentially lead to a relatively large decay width for $h \to \Upsilon \gamma$. Here, we carry out a detailed model-independent analysis of the possible new physics that can disrupt this cancellation. We demonstrate that after taking into account all possible constraints on Higgs production and decay processes from experimental measurements, the wrong-sign $h b \bar{b}$ coupling is the only scenario in which the $h \to \Upsilon \gamma$ decay width can be changed by almost two orders of magnitude. We conclude that an observation of a significantly enhanced $h \to \Upsilon \gamma$ decay width at the LHC or any future collider will be a conclusive evidence of a wrong-sign $h b \bar{b}$ coupling.Comment: 39 pages, 30 figures, 12 table

A study on premenstrual syndrome among adolescent girl students in an urban area of West Bengal

Background: Previous studies in India reported a prevalence of premenstrual syndrome to be 20% in a general population and severe symptoms in 8%. The present study was conducted to study the socio-demographic characteristics of adolescent school girls, to estimate the proportion of premenstrual syndrome among them and to find out factors associated with premenstrual syndrome, if any.Methods: It was a cross-sectional descriptive study conducted at a Kolkata city. Data were collected from the students of Class IX to XII in the classroom using pre-tested pre-designed self-administered questionnaire. Total 278 students were included in the study. Data analysis was done with the help of SPSS version 20.0.Results: The mean age of the students was 15.61 years ± 1.3. 54% of girls reported to have PMS. Out of the affective symptoms in ACOG criteria depression was by 45.7%, anger by 61.2%, irritability by 88.1%, anxiety by 51.8%, confusion by 46.4%, rejection by 24.8, breast pain by 22.7, abdominal distension by 37.5%, headache by 40.6% and swelling of limbs by 5% of girls.Conclusions: Proper medical care and psychological counselling should be sought earlier for increased blood flow during menstruation and dysmenorrhoea to get rid of PMS in adolescent girls

Electrorheology of a dilute emulsion of surfactant-covered drops

The effects of surfactant coating on a deformable viscous drop under the combined action of a shear flow and a uniform electric field, are investigated by solving the coupled equations of electrostatics, fluid flow and surfactant transport. Employing a comprehensive three-dimensional solution technique, the non-Newtonian shearing response of the bulk emulsion is analyzed in the dilute suspension regime. The present results reveal that the surfactant non-uniformity creates significant alterations in the flow disturbance around the drop, thereby influencing the viscous dissipation from the flowing emulsion. This, in effect, triggers changes in the bulk shear viscosity. It is striking to observe that the balance between electrical and hydrodynamic stresses is affected in such a way that surface tension gradient on the drop surface vanishes for some specific shear rates and the corresponding effective change in the bulk viscosity becomes negligible too. This critical condition hugely depends on the electrical permittivity and conductivity ratios of the two fluids and orientation of the applied electric field. Also the physical mechanisms of charge convection of surface deformation play their role in determining this critical shear rate. The charge convection instigated shear thinning or shear thickening behavior of the emulsion gets reversed due to a coupled interaction of the charge convection and Marangoni stress. In addition, the electrically created anisotropic normal stresses in the bulk rheology, get reduced due to the presence of surfactants, especially when the drop viscosity is much lesser than the continuous fluid. A thorough description of the drop-level flow physics and its connection to the bulk rheology of a dilute emulsion, may provide a fundamental understanding of a more complex emulsion system