Bubble wall dynamics, generalised Yukawa couplings and adequate electroweak baryogenesis in two-Higgs-doublet model

Baryogenesis at the electroweak scale depends on divers but identifiable details of bubble wall dynamics and the particle physics. We show that inclusion of the dynamics of relative phase in two-Higgs-doublet model (2HDM) enhances the adiabatic order of the mechanism proposed by McLerran-Shaposhnikov-Turok-Voloshin where the scalar-scalar-vector triangle diagram with top quark in the loop gives rise to a significant contribution to the effective chemical potential biasing the Chern-Simons number. We also show that in 2HDM with less stringent constraints on Yukawa couplings than those imposed by natural flavour conservation, there are additional diagrams contributing to the effective chemical potential. These two effects can combine with several others to produce adequate baryon asymmetry at the electroweak scale.Comment: 7 pages, Latex, figures available upon reques

Cosmic Strings at the Electroweak Phase Transition

If cosmic strings are present at the electroweak phase transition, they can act as seeds on which bubbles of true vacuum nucleate. We explore the nature of such a phase transition, in particular the wall velocity and thickness of the bubbles. {}From the viewpoint of electroweak baryogenesis, adiabatic conditions exist in the expanding bubble walls, and such models of baryogenesis can be successfully applied. In the present mechanism, the nature of the electroweak phase transition is insensitive to the other details of the model, thus reducing the uncertainties in the estimate of net baryon asymmetry.Comment: 11 Pages (figure available on request

Discontinuous precipitation of Co3V in a complex Co-based alloy

Discontinuous precipitation of chromium-rich Co3V lamellae has been found in a Co-based alloy containing 2 wt% V after prolonged ageing at 800 {\degr}C. This discontinuous precipitation is associated with a noticeable redistribution of alloying elements in the alloy relative to those parts of the aged alloy that preserve the c.c.p.-L12 microstructure found in the as-cast and homogenized condition. The orientation relationship between the c.c.p. Co-rich matrix and these hexagonal phase chromium-rich Co3V precipitates is shown to be || and [1 1 1]Co || , i.e. || and [1 1 1]Co || in the four-index notation. 3 × 3 transformation matrices relating directions and planes in the two phases have been established. The observed orientation relationship between the two phases is consistent with low lattice misfit between the two phases.We would also like to acknowledge the EPSRC/Rolls-Royce plc Strategic Partnership (EP/H500375/1) for funding this work.This is the author accepted manuscript. The final version can be found on the publisher's website at: http://www.tandfonline.com/doi/abs/10.1080/14786435.2013.861946#.U8fYa_ldXH

Shell model study of the pairing correlations

A systematic study of the pairing correlations as a function of temperature and angular momentum has been performed in the sd-shell region using the spherical shell model approach. The pairing correlations have been derived for even-even, even-odd and odd-odd systems near N=Z and also for the asymmetric case of N=Z+4. The results indicate that the pairing content and the behavior of pair correlations is similar in even-even and odd-mass nuclei. For odd-odd N=Z system, angular momentum I=0 state is an isospin, t=1 neutron-proton paired configuration. Further, these t=1 correlations are shown to be dramatically reduced for the asymmetric case of N=Z+4. The shell model results obtained are qualitatively explained within a simplified degenerate model

On the entropic stabilisation of an Al<inf>0.5</inf>CrFeCoNiCu high entropy alloy

The extent to which configurational entropy can stabilise a single solid solution in an Al0.5CrFeCoNiCu high entropy alloy has been assessed through characteristion of samples following casting and heat treatment at 1000 C. At temperatures between 1000 C and the onset of melting, the alloy was shown to be within a two phase field and these phases were stable following prolonged exposure at elevated temperature. X-ray and transmission electron diffraction indicated that both constituent phases had an fcc structure. Therefore, these phases share a Gibbs energy curve that must contain two local minima at the solidus temperature, rather than the single minimum required for a continuous solid solution. These observations indicate that there is no temperature at which this material is in a stable, solid state single phase field and that therefore, the configurational complexity is insufficient to stabilise a solid solution phase against enthalpic effects.EPSRC/Rolls-Royce Strategic partnership for funding (NGJ, AB and HJS under EP/H500375/1, JWA and BDC under EP/H022309/1).This is the final published manuscript distributed under a Creative Commons Attribution License 2.0 UK. This article can also be viewed on the publisher's website at: http://www.sciencedirect.com/science/article/pii/S0966979514001848

Observation of a γ\gamma-band based on two-quasiparticle configuration in 70^{70}Ge

The structure of $^{70}$Ge has been studied through in-beam gamma ray spectroscopy. A new band structure is identified that leads to forking of the ground-state band into two excited bands. Band structures have been investigated using the microscopic triaxial projected shell model approach. The observed forking is demonstrated to result from almost simultaneous band crossing of the two neutron aligned and the \gamma-band built on this two-quasiparticle configuration with the ground-state band.Comment: 9 pages, 13 figures, Accepted for publication as a Regular Article in PRC. in Physical Review C, 24th Feb 201

Effect of paclobutrazol and sucrose on in vitro cormel formation in gladiolus

Studies with excised shoots of six gladiolus cultivars viz., Bellariana, Blue Moon, Cream White, Friendship, Her Majesty and Top Brass indicated that paclobutrazol enhanced early cormel initiation and development. The interaction between paclobutrazol and sucrose was significant for cormel size. Supplementation of 10 mg L–1 paclobutrazol and 120 g L–1 sucrose to Murashige and Skoog’s medium favored formation of bigger cormels. Among the cultivars response to exogenous sucrose supplementation varied significantly and absence of paclobutrazol produced longer leaves, roots and smaller cormels