Same-sign W pair production as a probe of double parton scattering at the LHC

We study the production of same-sign W boson pairs at the LHC in double parton interactions. Compared with simple factorised double parton distributions (dPDFs), we show that the recently developed dPDFs, GS09, lead to non-trivial kinematic correlations between the W bosons. A numerical study of the prospects for observing this process using same-sign dilepton signatures, including same-sign WWjj, di-boson and heavy flavour backgrounds, at 14 TeV centre-of-mass energy is then performed. It is shown that a small excess of same-sign dilepton events from double parton scattering over a background dominated by single scattering WZ(gamma*) production could be observed at the LHC.Comment: 14 pages, 8 figures. Added references, slight changes in the text

Modeling of Ti-W Solidification Microstructures Under Additive Manufacturing Conditions

Additive manufacturing (AM) processes have many benefits for the fabrication of alloy parts, including the potential for greater microstructural control and targeted properties than traditional metallurgy processes. To accelerate utilization of this process to produce such parts, an effective computational modeling approach to identify the relationships between material and process parameters, microstructure, and part properties is essential. Development of such a model requires accounting for the many factors in play during this process, including laser absorption, material addition and melting, fluid flow, various modes of heat transport, and solidification. In this paper, we start with a more modest goal, to create a multiscale model for a specific AM process, Laser Engineered Net Shaping (LENS™), which couples a continuum-level description of a simplified beam melting problem (coupling heat absorption, heat transport, and fluid flow) with a Lattice Boltzmann-cellular automata (LB-CA) microscale model of combined fluid flow, solute transport, and solidification. We apply this model to a binary Ti-5.5 wt pct W alloy and compare calculated quantities, such as dendrite arm spacing, with experimental results reported in a companion paper

Prompt K_short production in pp collisions at sqrt(s)=0.9 TeV

The production of K_short mesons in pp collisions at a centre-of-mass energy of 0.9 TeV is studied with the LHCb detector at the Large Hadron Collider. The luminosity of the analysed sample is determined using a novel technique, involving measurements of the beam currents, sizes and positions, and is found to be 6.8 +/- 1.0 microbarn^-1. The differential prompt K_short production cross-section is measured as a function of the K_short transverse momentum and rapidity in the region 0 < pT < 1.6 GeV/c and 2.5 < y < 4.0. The data are found to be in reasonable agreement with previous measurements and generator expectations.Comment: 6+18 pages, 6 figures, updated author lis

In-vitro evaluation of certain Egyptian traditional medicinal plants against Propionibacterium acnes

ArticleMany plant species are reported in Egyptian traditional medicine for the treatment of different types of skin infections. The present study was designed to screen the methanolic extracts of twenty five Egyptian plants used in traditional medicine for the treatment of skin infections for their antibacterial activities against Propionibacterium acnes, and to isolate the bioactive compound(s) from the most active extract. The results showed that Myrtus communis, Curcuma longa and Myristica fragrans exhibited inhibition on P. acnes growth in which M. communis demonstrated the highest antibacterial effect with an MIC of 7.8 μg/ml. A phytochemical analysis of the extract of M. communis leads to the isolation of eight compounds viz., 5-acetoxy-4-hydroxy-4-isobutyl-2,2,6,6-tetramethylcyclohexan-1,3-dione (1), β-sitosterol (2), isomyrtucommulone-B (3), endoperoxide-G-3-hormone (4), gallic acid (5), myricetin-3-O-α-l-rhamnoside (6), myricetin-3-O-β-d-glucoside (7), and myricetin-3-O-β-d-galactoside-6″-O-gallate (8). Compounds 1 and 3 showed strong inhibition against P. acnes with MIC values of 6.3 and 0.8 μg/ml, respectively. This is the first report on the isolation of compound 3 from M. communis and the validation in the use of Egyptian herbal medicines against P. acnes.Mr. James SwezeyProf. I. Green, SU, South Afric