632 research outputs found
The structure and mode of growth of bacterial colonies
(1) The structure of e morphologically "rough" colony
of e bacillus or vibrio is essentially similar to that
of trie "Medusa head" colony of the anthrax bacillus.
The bacteria are closely attached end to end in the
form of threads.(2) The bacteria composing a smooth colony tend to be
separate from one another and show no characteristic
arrangement.(3) Between these extremes are e number of intermediate
forms.(4) These variations are paralleled by similar forms
found among the streptococci and pneumococci.(5) The structure of e colony depends ultimately upon
physical factors and varies mainly with the degree of
attachment of the component organisms.(6) The division of the filamentous forms composing
rough colonies is much less regular in occurrence and
position than is that of the individual bacteria
composing smooth colonies.(7) The usually described S â» R variation appears to
consist of two separate changes, one affecting the
morphology of the organism, the other connected solely
with the nature of its capsular material or other
antigenic constituents, These may occur separately,
though a considerable degree of relationship appears
to exist.(8) The biological significance of the morphological
variations are discussed
Wedgebox analysis of four-lepton events from neutralino pair production at the LHC
`Wedgebox' plots constructed by plotting the di-electron invariant mass
versus the di-muon invariant mass from pp -> e^+e^- mu^+ mu^- + missing energy
signature LHC events. Data sets of such events are obtained across the MSSM
input parameter space in event-generator simulations, including cuts designed
to remove SM backgrounds. Their study reveals several general features:
(1)Regions in the MSSM input parameter space where a sufficient number of
events are expected so as to be able to construct a clear wedgebox plot are
delineated. (2)The presence of box shapes on a wedgebox plot either indicates
the presence of heavy Higgs bosons decays or restricts the location to a quite
small region of low \mu and M_2 values \lsim 200 GeV, a region denoted as the
`lower island'. In this region, wedgebox plots can be quite complicated and
change in pattern rather quickly as one moves around in the (\mu, M_2) plane.
(3)Direct neutralino pair production from an intermediate Z^{0*} may only
produce a wedge-shape since only \widetilde{\chi}_2^0\widetilde{\chi}_3^0
decays can contribute significantly. (4)A double-wedge or
wedge-protruding-from-a-box pattern on a wedgebox plot, which results from
combining a variety of MSSM production processes, yields three distinct
observed endpoints, almost always attributable to \widetilde{\chi}_{2,3,4}^0
\to \widetilde{\chi}_1^0 \ell^+\ell^- decays, which can be utilized to
determine a great deal of information about the neutralino and slepton mass
spectra and related MSSM input parameters. Wedge and double-wedge patterns are
seen in wedgebox plots in another region of higher \mu and M_2 values, denoted
as the`upper island.' Here the pattern is simpler and more stable as one moves
across the (\mu, M_2) input parameter space.Comment: 28 pages (LaTeX), 8 figures (encapsulated postscript
One-loop Neutron Electric Dipole Moment from Supersymmetry without R-parity
We present a detailed analysis together with exact numerical calculations on
one-loop contributions to neutron electric dipole moment from supersymmetry
without R-parity, focusing on the gluino, chargino, and neutralino
contributions. Apart from the neglected family mixing among quarks, complete
formulae are given for the various contributions, through the quark dipole
operators, to which the present study is restricted. We discuss the structure
and main features of the R-parity violating contributions and the interplay
between the R-parity conserving and violating parameters. In particular, the
parameter combination , under the optimal
parametrization adopted, is shown to be solely responsible for the R-parity
violating contributions in the supersymmetric loop diagrams. While
could bear a complex phase, the latter is not
necessary to have a R-parity violating contribution.Comment: 43 pages Revtex with 15 eps- and 4 ps- figure files incoporated;
proofread version to be published in Phys. Rev.
On Measuring Split-SUSY Neutralino and Chargino Masses at the LHC
In Split-Supersymmetry models, where the only non-Standard Model states
produceable at LHC-energies consist of a gluino plus neutralinos and charginos,
it is conventionally accepted that only mass differences among these latter are
measureable at the LHC. The present work shows that application of a simple
`Kinematic Selection' technique allows full reconstruction of neutralino and
chargino masses from one event, in principle. A Monte Carlo simulation
demonstrates the feasibilty of using this technique at the LHC.Comment: 17 pages, 4 figures; EPJC versio
Disease Status and Pubertal Stage Predict Improved Growth in Anti-TNF Therapy for Pediatric Inflammatory Bowel Disease
Background: Growth failure is well-recognised in pediatric Inflammatory Bowel Disease (PIBD; <18 years). We aimed to examine whether anti-Tumor Necrosis Factor (TNF) therapy improves growth in a PIBD population-based cohort. Methods: A retrospective review of all Scottish children receiving anti-TNF (infliximab (IFX) and adalimumab (ADA)) from 2000-2012 was performed; height was collected at: 12 months before anti-TNF (T-12), start (T0) and 12 (T+12) months after anti-TNF. Results: 93/201 treated with IFX and 28/49 for ADA had satisfactory growth data; 66 had full pubertal data. Univariate analysis demonstrated early pubertal stages (Tanner 1-3 n = 44 vs. T4-5 n = 22), disease remission, disease duration >=2 years and duration of IFX >=12 months were associated with improved linear growth for IFX; for ADA only improvement was seen in Tanner 1-3. For IFX, Tanner 1-3 median [DELTA] ht SDS -0.3 (-0.7,0.2) at T0 changed to 0.04 (-0.5, 0.7) at T+12 (p < 0.001) vs -0.01 (-0.5, 0.9) at T0 in T4-5 changed to -0.01 (-0.4, 0.2) at T+12 (p > 0.05). For IFX disease duration >=2 year, median [DELTA] ht SDS was -0.13 (-0.6, 0.3) at T0 then 0.07 (-0.3, 0.6) at T+12 (p < 0.001). Remission improved [DELTA] ht SDS (median [DELTA] ht SDS -0.14 (-0.6, 0.3) at T0 to 0.17 (-0.2, 0.7) at T+12 (p > 0.001)). Multiple regression analysis demonstrated corticosteroid usage at T0 predicted improved [DELTA] ht SDS at T+12 for IFX and ADA. Conclusions: Anti-TNF therapy is more likely to be associated with growth improvement when used at earlier stages of puberty with remission a key growth-promoting strategy in Paediatric Crohn's disease
Signals of neutralinos and charginos from gauge boson fusion at the CERN Large Hadron Collider
We point out that interesting signals of the non-strongly interacting sector
of the supersymmetric standard model arise from the production of charginos and
neutralinos via vector boson fusion (VBF) at the Large Hadron Collider (LHC).
In particular, if R-parity is violated, the hadronically quiet signals of
charginos and neutralinos through direct production get considerably
suppressed. We show that in such cases, the VBF channel can be useful in
identifying this sector through clean and background-free final states.Comment: 10 pages Latex, 8 figures, minor changes in text and few references
added, to be published in Phys. Rev.
WMAP-Compliant Benchmark Surfaces for MSSM Higgs Bosons
We explore `benchmark surfaces' suitable for studying the phenomenology of
Higgs bosons in the minimal supersymmetric extension of the Standard Model
(MSSM), which are chosen so that the supersymmetric relic density is generally
compatible with the range of cold dark matter density preferred by WMAP and
other observations. These benchmark surfaces are specified assuming that
gaugino masses m_{1/2}, soft trilinear supersymmetry-breaking parameters A_0
and the soft supersymmetry-breaking contributions m_0 to the squark and slepton
masses are universal, but not those associated with the Higgs multiplets (the
NUHM framework). The benchmark surfaces may be presented as M_A-tan_beta planes
with fixed or systematically varying values of the other NUHM parameters, such
as m_0, m_{1/2}, A_0 and the Higgs mixing parameter mu. We discuss the
prospects for probing experimentally these benchmark surfaces at the Tevatron
collider, the LHC, the ILC, in B physics and in direct dark-matter detection
experiments. An Appendix documents developments in the FeynHiggs code that
enable the user to explore for her/himself the WMAP-compliant benchmark
surfaces.Comment: Minor corrections, references added. 43 pages, 10 figures. Version to
appear in JHE
Spontaneous R-Parity violation bounds
We investigate bounds from tree-level and one-loop processes in generic
supersymmetric models with spontaneous R-parity breaking in the superpotential.
We analyse the bounds from a general point of view. The bounds are applicable
both for all models with spontaneous R-parity violation and for explicit
bilinear R-parity violation based on general lepton-chargino and
neutrino-neutralino mixings. We find constraints from semileptonic B, D and K
decays, leptonic decays of the mu and tau, electric dipole moments, as well as
bounds for the anomalous magnetic moment of the muon.Comment: 22 page
Supersymmetry without R-parity : Constraints from Leptonic Phenomenology
R-parity conservation is an {\it ad hoc} assumption in the most popular
version of the supersymmetric standard model. Most studies of models which do
allow for R-parity violation have been restricted to various limiting
scenarios. The single-VEV parametrization used in this paper provides a
workable framework to analyze phenomenology of the most general theory of SUSY
without R-parity. We perform a comprehensive study of leptonic phenomenology at
tree-level. Experimental constraints on various processes are studied
individually and then combined to yield regions of admissible parameter space.
In particular, we show that large R-parity violating bilinear couplings are not
ruled out, especially for large .Comment: 56 pages Revtex with figures incorporated; typos (including
transcription typo in Table II) and minor corrections; proof-read version, to
appear in Phys. Rev.
Detecting Higgs Boson Decay to Neutralinos at Hadron Supercolliders
We examine prospects for detecting the neutral Higgs bosons of minimal
supersymmetric models (MSSM) when their decays into neutralino pairs are
kinematically allowed. The best signature appears to be
H_h,H_p\to\tz_2\tz_2\to 4\ell +\eslt. We argue that Standard Model
contributions to this signature are negligible, and examine regions of MSSM
parameter space where the four lepton mode should be observable at the Large
Hadron Collider. The same signal can also come from continuum neutralino pair
production. We propose a set of cuts to illustrate that the neutralino decay
mode of the Higgs bosons provides a viable signal over a substantial range of
model parameters, and show that it may be separable from continuum neutralino
production if sufficient integrated luminosity can be accumulated.Comment: 15 pages (REVTEX), 7 figures available by regular mail,
FSU-HEP-940204, UH-511-781-9
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