Top transport in electroweak baryogenesis

In non-supersymmetric models of electroweak baryogenesis the top quark plays a crucial role. Its CP-violating source term can be calculated in the WKB approximation. We point out how to resolve certain discrepancies between computations starting from the Dirac equation and the Schwinger--Keldysh formalism. We also improve on the transport equations, keeping the W-scatterings at finite rate. We apply these results to a model with one Higgs doublet, augmented by dimension-6 operators, where our refinements lead to an increase in the baryon asymmetry by a factor of up to about 5.Comment: 17 pages, 3 figures, references adde

Edge Illumination X-Ray Phase Contrast Imaging and Ultrasonic Attenuation for Porosity Quantification in Composite Structures

Carbon fiber reinforced composites are widely used in the aerospace industry, due to their low weight and high strength. Porosity often occurs during the manufacturing of composite structures, which can compromise the structural integrity of the part and affect its mechanical properties. In the aerospace industry a typical requirement for structural components is for the porosity content to be kept below 2%. Non-destructive evaluation (NDE) techniques are used to estimate the porosity content in composite components, the most common being ultrasonic attenuation and X-ray computed tomography (CT). Planar Edge Illumination X-ray Phase Contrast Imaging (EI XPCI) was used to quantify the porosity content in woven carbon fiber reinforced composite plates with porosity ranging between 0.7% and 10.7%. A new metric was introduced, the standard deviation of the differential phase (STDVDP) signal, which represents the variation of inhomogeneity in the plates for features of a scale equal to or above the system resolution (here 12µm). The SDTVDP was found to have a very high correlation with porosity content estimated from matrix digestion and ultrasonic attenuation, hence providing a promising new methodology to quantify porosity in composite plates

Baryogenesis in the Two-Higgs Doublet Model

We consider the generation of the baryon asymmetry in the two-Higgs doublet model. Investigating the thermal potential in the presence of CP violation, as relevant for baryogenesis, we find a strong first-order phase transition if the extra Higgs states are heavier than about 300 GeV. The mass of the lightest Higgs can be as large as about 200 GeV. We compute the bubble wall properties, including the profile of the relative complex phase between the two Higgs vevs. The baryon asymmetry is generated by top transport, which we treat in the WKB approximation. We find a baryon asymmetry consistent with observations. The neutron electric dipole moment is predicted to be larger than about 10^{-27}ecm and can reach the current experimental bound. Low values of tan\beta are favored.Comment: 25 pages, 7 figure

Electroweak Baryogenesis with dimension-6 Higgs interactions

We present the computation of the baryon asymmetry in the SM amplified by dimension-6 Higgs interactions using the WKB approximation. Analyzing the one-loop potential it turns out that the phase transition is strongly first order in a wide range of the parameters. It is ensured not to wash out the net baryon number gained previously even for Higgs masses up to at least 170 GeV. In addition dimension-6 operators induce new sources of CP violation. Novel source terms which enhance the generated baryon asymmetry emerge in the transport equations. This model predicts a baryon to entropy ratio close to the observed value for a large part of the parameter space.Comment: 10 pages, 4 figures, Talk given at the 8th International Moscow School of Physic

VITESS 3 Virtual Instrumentation Tool for the European Spallation Source

VITESS is a software widely used for simulation of neutron scattering experiments. Although originally motivated by instrument design for the European Spallation Source, all major neutron sources are available. Existing as well as future instruments on reactor or spallation sources can be designed and optimized, or simulated in a virtual experiment to prepare a measurement, including basic data evaluation. This note gives an overview of the VITESS software concept and usage. New developments are presented, including a 3D visualization of instruments and neutron trajectories, a numerical optimization routine and a parallelization tool allowing to split VITESS simulations on a computer cluste

Effect of an upper temperature threshold on heat unit calculations, defoliation timing, lint yield, and fiber quality in cotton

Crop managers need to determine the most profitable time to defoliate cotton (Gossypium hirsutum L.) in a high rainfall environment such as the coastal region of Texas. In cotton production, delaying defoliation exposes open bolls to a higher probability of rainfall, and thus, reduces lint yield and fiber quality. Premature defoliation, however, has detrimental affects on lint yield and fiber quality. A more recent method to determine defoliation is based on heat-unit (HU or DD15) accumulation after physiological cutout or five nodes above white flower (NAWF=5). Results have been inconsistent across a wide range of field environments when utilizing HU accumulation past cutout; therefore, adoption of this method has been limited. Many regions of the Cotton Belt have maximum day time temperatures during the growing season that are above optimum for maximum growth. Field studies were conducted for three consecutive growing seasons in the Brazos River Valley and Upper Gulf Coast regions of Texas. The purpose of this research was to identify an upper temperature threshold (UTT) for calculating degree days for defoliation timing. The experimental design consisted of a split-plot design with four replications. The main plots consisted of three upper temperature thresholds (32°C, 35°C, and no upper limit) and the subplots were five HU timings (361, 417, 472, 528, and 583) accumulated from date of cutout. Utilizing an UTT to calculate daily HU failed to explain differences in the optimum time to defoliate based on accumulated HU from cutout for the upper thresholds investigated. Accumulated HU had a significant impact, however, on defoliation timing. Comparison of the two locations showed that maximum lint yield was obtained at 472 HU and 52% open boll at Wharton County versus a maximum of 528 HU and 62% open boll for the Burleson County location. Employing the NACB=4 method to time defoliation at both locations would have resulted in premature application of harvest aids and reduced lint yields. No differences were observed in adjusted gross income values at Wharton County among the 417, 472, 528, and 583 HU treatments. For Burleson County, adjusted gross income peaked in value at 528 HU