1,313 research outputs found
Probing Supersymmetry With Third-Generation Cascade Decays
Full text linkThe chiral structure of supersymmetric particle couplings involving third
generation Standard Model fermions depends on left-right squark and slepton
mixings as well as gaugino-higgsino mixings. The shapes and intercorrelations
of invariant mass distributions of a first or second generation lepton with
bottoms and taus arising from adjacent branches of SUSY cascade decays are
shown to be a sensitive probe of this chiral structure. All possible cascade
decays that can give rise to such correlations within the MSSM are considered.
For bottom-lepton correlations the distinctive structure of the invariant mass
distributions distinguishes between decays originating from stop or sbottom
squarks through either an intermediate chargino or neutralino. For decay
through a chargino the spins of the stop and chargino are established by the
form of the distribution. When the bottom charge is signed through soft muon
tagging, the structure of the same-sign and opposite-sign invariant mass
distributions depends on a set function of left-right and gaugino-higgsino
mixings, as well as establishes the spins of all the superpartners in the
sequential two-body cascade decay. Tau-lepton and tau-tau invariant mass
distributions arising from MSSM cascade decays are likewise systematically
considered with particular attention to their dependence on tau polarization.
All possible tau-lepton and tau-tau distributions are plotted using a
semi-analytic model for hadronic one-prong taus. Algorithms for fitting tau-tau
and tau-lepton distributions to data are suggested.Comment: 35 pages, 17 .eps figure
Experience as Evidence: The Dialogic Construction of Health Professional Knowledge through Patient Involvement
Get PDFThis article investigates how healthcare professionals articulate the relationship between patient experience and ‘evidence’, creating hybrid forms of knowledge. We propose a Bakhtinian dialogical framework to theorise this process. Drawing on ethnographic work from patient involvement initiatives in England, we show how patient experiences are re-articulated by professionals who add their own intentions and accents in a dialogical process which incorporates diverse forms of knowledge and the conflicting demands of healthcare services. In this process, patient experiences become useful epistemic commodities, helping professionals to respond to workplace pressures by abstracting experiences from patients’ biographies, instrumentalising experiences and privileging ‘disembodied’ forms of involvement. Understanding knowledge as relational and hybrid helps move beyond the assumption that there is a clear dichotomy between ‘objective science’ and ‘subjective experience’. This article illuminates how new knowledge is produced when professionals engage with ‘lay’ patient knowledge, and helps inform the sociology of knowledge production more widely
Governing researchers through public involvement
Get PDFThis paper focuses on recent developments in UK health research policy, which place new pressures on researchers to address issues of accountability and impact through the implementation of patient and public involvement (PPI). We draw on an in-depth interview study with 20 professional researchers, and we analyse their experiences of competing for research funding, focusing on PPI as a process of professional research governance. We unearth dominant professional narratives of scepticism and alternative identifications in their enactment of PPI policy. We argue that such narratives and identifications evidence a resistance to ways in which patient involvement has been institutionalised and to the resulting subject-positions researchers are summoned to take up. We show that the new subjectivities emerging in this landscape of research governance as increasingly disempowered, contradictory and fraught with unresolved tensions over the ethical dimensions of the researchers' own professional identities
Strongly-Coupled Quarks and Colorful Black Holes
Full text linkWe use the AdS/CFT correspondence to study the behavior of strongly-coupled
quarks in a black hole background. The supergravity background consists of a
six-dimensional Schwarzschild-black string AdS soliton, for which the bulk
horizon extends from the AdS boundary down to an infra-red floor. By going to
higher energy scales, the regime of validity of the classical supergravity
background can be extended closer to the singularity than might be expected
from the four-dimensional perspective. Small black holes potentially created by
the Large Hadron Collider could typically carry color charges inherited from
their parton progenitors. The dynamics of quarks near such a black hole depends
on the curved spacetime geometry as well as the strong interaction with the
color-charged black hole. We study the resulting behavior of quarks and compute
the rate at which a quark rotating around the black hole loses energy. We also
investigate how the interaction between a quark and an antiquark is altered by
the presence of the black hole, which results in a screening length.Comment: Proceedings of the DPF-2011 Conference, 8 pages, 5 figures, added
reference
Colibacillosis in poultry: A disease overview and the new perspectives for its control and prevention
Get PDFΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗEscherichia coli (E.coli) is a common bacterium that can be naturally found in the intestinal tract of birds and as a result in their environment. However, it can cause clinical disease called colibacillosis which is regarded as one of the most common and important diseases in poultry. Strains of E.coli that have the ability to cause clinical disease are described as Avian Pathogenic Escherichia Coli (APEC). Colibacillosis can affect birds of all ages and different types of poultry production including broiler and commercial layers and breeders. The ability of E.coli to cause colibacillosis is not always the same; that is why its role as primary or secondary pathogen triggered by various predisposing factors is contradictory and differs from case to case. Antibiotics have been used as the main tool against colibacillosis for many decades. However, the emergence of increased antibiotic resistance has posed the need of alternative treatment to colibacillosis as well as emphasizing on preventive measures to avoid disease. Τhe scope of this article is to assess recent scientific literature data on avian colibacillosis emphasizing on disease characteristics and recent data on prevention and control of the disease
Testing Gluino Spin with Three-Body Decays
Full text linkWe examine the possibility of distinguishing a supersymmetric gluino from a
Kaluza-Klein gluon of universal extra dimensions (UED) at the Large Hadron
Collider (LHC). We focus on the case when all kinematically allowed tree-level
decays of this particle are 3-body decays into two jets and a massive daughter
(typically weak gaugino or Kaluza-Klein weak gauge boson). We show that the
shapes of the dijet invariant mass distributions differ significantly in the
two models, as long as the mass of the decaying particle mA is substantially
larger than the mass of the massive daughter mB. We present a simple analysis
estimating the number of events needed to distinguish between the two models
under idealized conditions. For example, for mA/mB=10, we find the required
number of events to be of order several thousand, which should be available at
the LHC within a few years. This conclusion is confirmed by a parton level
Monte Carlo study which includes the effects of experimental cuts and the
combinatoric background.Comment: 19 pages, 10 figure
Using Higher Moments of Fluctuations and their Ratios in the Search for the QCD Critical Point
Full text linkThe QCD critical point can be found in heavy ion collision experiments via
the non-monotonic behavior of many fluctuation observables as a function of the
collision energy. The event-by-event fluctuations of various particle
multiplicities are enhanced in those collisions that freeze out near the
critical point. Higher, non-Gaussian, moments of the event-by-event
distributions of such observables are particularly sensitive to critical
fluctuations, since their magnitude depends on the critical correlation length
to a high power. We present quantitative estimates of the contribution of
critical fluctuations to the third and fourth moments of the pion, proton and
net proton multiplicities, as well as estimates of various measures of
pion-proton correlations, all as a function of the same five non-universal
parameters, one of which is the correlation length that parametrizes proximity
to the critical point. We show how to use nontrivial but parameter independent
ratios among these more than a dozen fluctuation observables to discover the
critical point. We also construct ratios that, if the critical point is found,
can be used to overconstrain the values of the non-universal parameters.Comment: 16 pages, 5 figures. Version to appear in PRD. Footnote and reference
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