R-parity violating resonant stop production at the Large Hadron Collider

We have investigated the resonant production of a stop at the Large Hadron Collider, driven by baryon number violating interactions in supersymmetry. We work in the framework of minimal supergravity models with the lightest neutralino being the lightest supersymmetric particle which decays within the detector. We look at various dilepton and trilepton final states, with or without b-tags. A detailed background simulation is performed, and all possible decay modes of the lighter stop are taken into account. We find that higher stop masses are sometimes easier to probe, through the decay of the stop into the third or fourth neutralino and their subsequent cascades. We also comment on the detectability of such signals during the 7 TeV run, where, as expected, only relatively light stops can be probed. Our conclusion is that the resonant process may be probed, at both 10 and 14 TeV, with the R-parity violating coupling {\lambda}"_{312} as low as 0.05, for a stop mass of about 1 TeV. The possibility of distinguishing between resonant stop production and pair-production is also discussed.Comment: 20 pages, 4 figures, 6 tables; Version accepted by JHE

Avatars of Eurocentrism in the critique of the liberal peace

Recent scholarly critiques of the so-called liberal peace raise important political and ethical challenges to practices of postwar intervention in the global South. However, their conceptual and analytic approaches have tended to reproduce rather than challenge the intellectual Eurocentrism underpinning the liberal peace. Eurocentric features of the critiques include the methodological bypassing of target subjects in research, the analytic bypassing of subjects through frameworks of governmentality, the assumed ontological split between the ‘liberal’ and the ‘local’, and a nostalgia for the liberal subject and the liberal social contract as alternative bases for politics. These collectively produce a ‘paradox of liberalism’ that sees the liberal peace as oppressive but also the only true source of emancipation. However, the article suggests that a repoliticization of colonial difference offers an alternative ‘decolonizing’ approach to critical analysis through repositioning the analytic gaze. Three alternative research strategies for critical analysis are briefly developed

Non-overshooting stabilisation via state and output feedback

The concept of “strong stability” of LTI systems has been introduced in a recent paper [KHP2]. This is a stronger notion of stability compared to alternative definitions (e.g. stability in the sense of Lyapunov, asymptotic stability), which allows the analysis and design of control systems with non-overshooting response in the state-space for arbitrary initial conditions. The paper reviews the notion of “strong stability” [KHP2] and introduces the problem of non-overshooting stabilization. It is shown that non-overshooting stabilization under dynamic and static output feedback are, in a certain sense, equivalent problems. Thus, we turn our attention to static non-overshooting stabilization problems under state-feedback, output injection and output feedback. After developing a number of preliminary results, we give a geometric interpretation to the problem in terms of the intersection of an affine hyperplane and the interior of an open convex cone. A solution to the problem is finally obtained via Linear Matrix Inequalities, along with the complete parametrization of the optimal solution set

Supersymmetric Monojets at the Large Hadron Collider

Supersymmetric monojets may be produced at the Large Hadron Collider by the process qg -> squark neutralino_1 -> q neutralino_1 neutralino_1, leading to a jet recoiling against missing transverse momentum. We discuss the feasibility and utility of the supersymmetric monojet signal. In particular, we examine the possible precision with which one can ascertain the neutralino_1-squark-quark coupling via the rate for monojet events. Such a coupling contains information on the composition of the neutralino_1 and helps bound dark matter direct detection cross-sections and the dark matter relic density of the neutralino_1. It also provides a check of the supersymmetric relation between gauge couplings and gaugino-quark-squark couplings.Comment: 46 pages, 10 figures. The appendix has been rewritten to correct an error that appears in all previous versions of the appendix. This error has no effect on the results in the main body of the pape

Cost-effectiveness of initiating extrafine- or standard size-particle inhaled corticosteroid for asthma in two health-care systems: a retrospective matched cohort study

Data acquisition and analyses were funded by Teva Pharmaceuticals

Strong interface-induced spin-orbit coupling in graphene on WS2

Interfacial interactions allow the electronic properties of graphene to be modified, as recently demonstrated by the appearance of satellite Dirac cones in the band structure of graphene on hexagonal boron nitride (hBN) substrates. Ongoing research strives to explore interfacial interactions in a broader class of materials in order to engineer targeted electronic properties. Here we show that at an interface with a tungsten disulfide (WS2) substrate, the strength of the spin-orbit interaction (SOI) in graphene is very strongly enhanced. The induced SOI leads to a pronounced low-temperature weak anti-localization (WAL) effect, from which we determine the spin-relaxation time. We find that spin-relaxation time in graphene is two-to-three orders of magnitude smaller on WS2 than on SiO2 or hBN, and that it is comparable to the intervalley scattering time. To interpret our findings we have performed first-principle electronic structure calculations, which both confirm that carriers in graphene-on-WS2 experience a strong SOI and allow us to extract a spin-dependent low-energy effective Hamiltonian. Our analysis further shows that the use of WS2 substrates opens a possible new route to access topological states of matter in graphene-based systems.Comment: Originally submitted version in compliance with editorial guidelines. Final version with expanded discussion of the relation between theory and experiments to be published in Nature Communication

Protein Profile Changes during Porcine Oocyte Aging and Effects of Caffeine on Protein Expression Patterns

It has been shown that oocyte aging critically affects reproduction and development. By using proteomic tools, in the present study, changes in protein profiles during porcine oocyte aging and effects of caffeine on oocyte aging were investigated. By comparing control MII oocytes with aging MII oocytes, we identified 23 proteins that were up-regulated and 3 proteins that were down-regulated during the aging process. In caffeine-treated oocytes, 6 proteins were identified as up-regulated and 12 proteins were identified as down-regulated. A total of 38 differentially expressed proteins grouped into 5 regulation patterns were determined to relate to the aging and anti-aging process. By using the Gene Ontology system, we found that numerous functional gene products involved in metabolism, stress response, reactive oxygen species and cell cycle regulation were differentially expressed during the oocyte aging process, and most of these proteins are for the first time reported in our study, including 2 novel proteins. In addition, several proteins were found to be modified during oocyte aging. These data contribute new information that may be useful for future research on cellular aging and for improvement of oocyte quality

Precise measurement of the W-boson mass with the CDF II detector

We have measured the W-boson mass MW using data corresponding to 2.2/fb of integrated luminosity collected in proton-antiproton collisions at 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO