On electroweak baryogenesis in the littlest Higgs model with T parity

We study electroweak baryogenesis within the framework of the littlest Higgs model with T parity. This model has shown characteristics of a strong first-order electroweak phase transition, which is conducive to baryogenesis in the early Universe. In the T parity symmetric theory, there are two gauge sectors, viz., the T-even and the T-odd ones. We observe that the effect of the T-parity symmetric interactions between the T-odd and the T-even gauge bosons on gauge-higgs energy functional is quite small, so that these two sectors can be taken to be independent. The T-even gauge bosons behave like the Standard Model gauge bosons, whereas the T-odd ones are instrumental in stabilizing the Higgs mass. For the T-odd gauge bosons in the symmetric and asymmetric phases and for the T-even gauge bosons in the asymmetric phase, we obtain, using the formalism of Arnold and McLerran, very small values of the ratio, (Baryon number violation rate/Universe expansion rate). We observe that this result, in conjunction with the scenario of inverse phase transition in the present work and the value of the ratio obtained from the lattice result of sphaleron transition rate in the symmetric phase, can provide us with a plausible baryogenesis scenario.Comment: 13 pages, 2 figures, published version, references modifie

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Friedel-crafts alkylation of diphenyl oxide with 1-decene over sulfated zirconia as catalyst

Friedel-Crafts alkylation and acylation reactions, using highly polluting homogeneous Lewis and Bronsted acids, are ubiquitous in a variety of organic process industries. In many cases very high conversions and selectivities can be achieved with aluminum chloride as catalyst and nitrobenzene as a solvent. However, environmental concerns associated with aluminum chloride-nitrobenzene or BF3-HF or mineral acids catalysts have encouraged development of solid acids, which not only intensify the rates of reactions but also offer better product selectivity. Amongst these catalysts, sulfated zirconia has gained a considerable importance due to its super-acidity under certain conditions. The alkylation of diphenyl oxide with 1-decene was studied over sulfated zirconia catalyst and it leads to industrially important products. The surface reaction between chemisorbed 1-decene diphenyl oxide from the liquid phase, in the absence of any mass transfer resistance, was found to be the rate determining step with Eley-Rideal type of mechanism

Study of flow unsteadiness in a bifurcated Y-Shaped duct for a typical combat aircraft model

Aircraft intake which operates at supersonic speed encounters a flow instability phenomenon called “Buzz”. In this study wind tunnel tests have been carried out on a typical combat aircraft model for air intake studies. An attempt has been made towards qualitative and quantitative assessment of buzz characteristics. The present study is intended to study the qualitative and quantitative aspects of the buzz characteristics. In quantitative study unsteady pressures measured by rake, fuselage ports, duct pressures have been analyzed and Schlieren technique has been used to study the qualitative aspect of the buzz characteristics. It is observed that the pressure recovery is decreasing and pulse level is increasing during the onset of buzz at supersonic speed regime

Efficient Extraction of Sulfur and Nitrogen Mustards from Nonpolar Matrix and an Investigation on Their Sorption Behavior on Silica

Extraction of vesicant class of chemical warfare agents (CWAs) such as sulfur mustard and nitrogen mustards from the environmental matrices is of prime importance, from a forensic and verification viewpoint of the Chemical Weapons Convention (CWC). For extraction of Convention Related Compounds from nonpolar organic medium, commercially available silica cartridges are used extensively, but silica cartridges exhibit limited efficiency toward vesicant classes of compounds. It is expected that sulfur mustard being nonpolar does not retain sufficiently on silica surface, and nitrogen mustards (being basic) are strongly adsorbed on acidic silica surface, resulting in their poor recoveries. Contrary to the expected higher recovery of sulfur mustard over nitrogen mustards, it was observed that the recovery of sulfur mustard was lower than that of nitrogen mustards with the silica based sorbent. The reason for this typical behavior of these agents on silica was investigated. This study was aimed to develop an analytical method for efficient extraction and enrichment of sulfur and nitrogen mustards from hydrophobic matrices. In this work, the polymeric sorbent was synthesized with polar methacrylic acid (MAA) as monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker and used for solid phase extraction (SPE) of sulfur mustard and nitrogen mustards. The extraction efficiency of the polymeric sorbent was optimized and compared with that of silica cartridges. Both classes of analytes were recovered in good amounts from the polymeric sorbent compared to silica. The extraction parameters were optimized for the proposed method which included extraction solvent ethyl acetate and washing solvent <i>n</i>-hexane (1 mL). The recoveries of the analytes ranged from 75 to 87% with relative standard deviations (RSDs) lower than 9%. The limit of detection (LOD) was found to be in the range of 0.075–0.150 μg mL^–1, and limit of quantification (LOQ) was >0.25 μg mL^–1. The linear dynamic range of optimized method was found to be 0.50–20 μg mL^–1 (<i>r</i>² = 0.9994) for sulfur mustard and 0.25–20 μg mL^–1 (<i>r</i>² = 0.9897–0.9987) for nitrogen mustards, respectively

Polymeric Sorbent with Controlled Surface Polarity: An Alternate for Solid-Phase Extraction of Nerve Agents and Their Markers from Organic Matrix

Extraction and identification of lethal nerve agents and their markers in complex organic background have a prime importance from the forensic and verification viewpoint of the Chemical Weapons Convention (CWC). Liquid–liquid extraction with acetonitrile and commercially available solid phase silica cartridges are extensively used for this purpose. Silica cartridges exhibit limited applicability for relatively polar analytes, and acetonitrile extraction shows limited efficacy toward relatively nonpolar analytes. The present study describes the synthesis of polymeric sorbents with tunable surface polarity, their application as a solid-phase extraction (SPE) material against nerve agents and their polar as well as nonpolar markers from nonpolar organic matrices. In comparison with the acetonitrile extraction and commercial silica cartridges, the new sorbent showed better extraction efficiency toward analytes of varying polarity. The extraction parameters were optimized for the proposed method, which included ethyl acetate as an extraction solvent and <i>n</i>-hexane as a washing solvent. Under optimized conditions, method linearity ranged from 0.10 to 10 μg mL^–1 (<i>r</i>² = 0.9327–0.9988) for organophosphorus esters and 0.05–20 μg mL^–1 (<i>r</i>² = 0.9976–0.9991) for nerve agents. Limits of detection (S:N = 3:1) in the SIM mode were found in the range of 0.03–0.075 μg mL^–1 for organophosphorus esters and 0.015–0.025 μg mL^–1 for nerve agents. Limits of quantification (S:N = 10:1) were found in the range of 0.100–0.25 μg mL^–1 for organophosphorus esters and 0.05–0.100 μg mL^–1 for nerve agents in the SIM mode. The recoveries of the nerve agents and their markers ranged from 90.0 to 98.0% and 75.0 to 95.0% respectively. The repeatability and reproducibility (with relative standard deviations (RSDs) %) for organophosphorus esters were found in the range of 1.35–8.61% and 2.30–9.25% respectively. For nerve agents, the repeatability range from 1.00 to 7.75% and reproducibility were found in the range of 2.17–6.90%