1,990 research outputs found
Baryogenesis in the MSSM, nMSSM and NMSSM
We compare electroweak baryogenesis in the MSSM, nMSSM and NMSSM. We comment
on the different sources of CP violation, the phase transition and constraints
from EDM measurements.Comment: 6 pages, 4 figures. To appear in the proceedings of the 7th
Conference on Strong and Electroweak Matter (SEWM06), Brookhaven National
Laboratory, May 10-13, 200
Does early intervention improve outcomes in physiotherapy management of lumbar radicular syndrome? A mixed-methods study protocol.
INTRODUCTION: Lumbar radicular syndrome (LRS) can be a painful and debilitating condition. The optimum management strategies and their timing remain elusive despite extensive research. Surgery provides good short-term outcomes but has concomitant risks and costs. Physiotherapy is commonly practised for patients with LRS but its effects remain equivocal and there is a lack of consensus on the type, duration and timing of physiotherapy intervention. There is a lack of high-quality evidence into new and innovative management strategies and the timings of those strategies for LRS. This pilot trial is an essential preliminary to a definitive randomised controlled trial (RCT) assessing the effectiveness and cost-effectiveness of early physiotherapy intervention for patients with LRS. The study will test the protocol, the intervention, the use of outcome measures and the ability to set-up and run the trial to enable refinement of a future definitive RCT. METHODS AND ANALYSIS: This is a mixed-methods study encompassing an external pilot RCT with integrated qualitative interviews with patients, clinicians and other key stakeholders. 80 patients will be recruited from primary care and randomised, after consent into 1 of 2 groups. Both groups will receive individually tailored, goal orientated physiotherapy. The usual care group will begin their physiotherapy 6 weeks after randomisation and the intervention group at 2 weeks after randomisation. Outcome measures will primarily be feasibility parameters including the ability to recruit and retain patients and to deliver the intervention. Data will be collected at baseline, and 6, 12 and 26 weeks following randomisation. ETHICS AND DISSEMINATION: The study has received favourable ethical review from the East of Scotland Research Ethics Service (EoSRES) on the 20 August 2015 (15/ES/0130). Recruitment began on the 1 March 2016 and is expected to close in January 2017. Data collection is anticipated to be complete in July 2017. The study results will be made available to participants, clinicians involved in the study and the wider clinical community through publication in a peer reviewed journal and at conference presentations. TRIAL REGISTRATION NUMBER: ISRCTN: 25018352, Pre-results; Clinical Trials.Gov: NCT02618278 Document version V1.1 23.9.2016
Geometry, Scaling and Universality in the Mass Distributions in Heavy Ion Collisions
Various features of the mass yields in heavy ion collisions are studied. The
mass yields are discussed in terms of iterative one dimensional discrete maps.
These maps are shown to produce orbits for a monomer or for a nucleus which
generate the mass yields and the distribution of cluster sizes. Simple
Malthusian dynamics and non-linear Verhulst dynamics are used to illustrate the
approach. Nuclear cobwebbing, attractors of the dynamics, and Lyapanov
exponents are discussed for the mass distribution. The self-similar property of
the Malthusian orbit offers a new variable for the study of scale invariance
using power moments of the mass distribution. Correlation lengths, exponents
and dimensions associated with scaling relations are developed. Fourier
transforms of the mass distribution are used to obtain power spectra which are
investigated for a behavior.Comment: 29 pages in REVTEX, 9 figures (available from the authors), RU-92-0
ON THE INTRINSIC CHARM COMPONENT OF THE NUCLEON
Using a meson cloud model we calculate the squared charm radius
of the nucleon . The ratio between this squared radius and the ordinary baryon
squared radius is identified with the probability of ``seeing'' the intrinsic
charm component of the nucleon. Our estimate is compatible with those used to
successfully describe the charm production phenomenology.Comment: 9 pages, 2 figures not included, avaiable from the author
The Four-Fermi Model in Three Dimensions at Non-Zero Density and Temperature
The Four Fermi model with discrete chiral symmetry is studied in three
dimensions at non-zero chemical potential and temperature using the Hybrid
Monte Carlo algorithm. The number of fermion flavors is chosen large
to compare with analytic results. A first order chiral symmetry restoring
transition is found at zero temperature with a critical chemical potential
in good agreement with the large calculations. The critical index
of the correlation length is measured in good agreement with analytic
calculations. The two dimensional phase diagram (chemical potential vs.
temperature) is mapped out quantitatively. Finite size effects on relatively
small lattices and non-zero fermion mass effects are seen to smooth out the
chiral transition dramatically.Comment: 21 pages, sorry, no figure
Semiclassical force for electroweak baryogenesis: three-dimensional derivation
We derive a semiclassical transport equation for fermions propagating in the
presence of a CP-violating planar bubble wall at a first order electroweak
phase transition. Starting from the Kadanoff-Baym (KB) equation for the
two-point (Wightman) function we perform an expansion in gradients, or
equivalently in the Planck constant h-bar. We show that to first order in h-bar
the KB equations have a spectral solution, which allows for an on-shell
description of the plasma excitations. The CP-violating force acting on these
excitations is found to be enhanced by a boost factor in comparison with the
1+1-dimensional case studied in a former paper. We find that an identical
semiclassical force can be obtained by the WKB method. Applications to the MSSM
are also mentioned.Comment: 19 page
Detection of NMR signals with a radio-frequency atomic magnetometer
We demonstrate detection of proton NMR signals with a radio frequency atomic
magnetometer tuned to the NMR frequency of 62 kHz. High-frequency operation of
the atomic magnetometer makes it relatively insensitive to ambient magnetic
field noise. We obtain magnetic field sensitivity of 7 fT/Hz using only
a thin aluminum shield. We also derive an expression for the fundamental
sensitivity limit of a surface inductive pick-up coil as a function of
frequency and find that an atomic rf magnetometer is intrinsically more
sensitive than a coil of comparable size for frequencies below about 50 MHz.Comment: 7 page
Electroweak Baryogenesis: Concrete in a SUSY Model with a Gauge Singlet
SUSY models with a gauge singlet easily allow for a strong first order
electroweak phase transition (EWPT) if the vevs of the singlet and Higgs fields
are of comparable size. We discuss the profile of the stationary expanding
bubble wall and CP-violation in the effective potential, in particular
transitional CP-violation inside the bubble wall during the EWPT. The
dispersion relations for charginos contain CP-violating terms in the WKB
approximation. These enter as source terms in the Boltzmann equations for the
(particle--antiparticle) chemical potentials and fuel the creation of a baryon
asymmetry through the weak sphaleron in the hot phase. This is worked out for
concrete parameters.Comment: 46 pages, LaTeX, 11 figures, discussion of source terms and transport
equations modified, version to appear in Nucl. Phys.
Quantum Monte Carlo Calculations of Pion Scattering from Li
We show that the neutron and proton transition densities predicted by recent
quantum Monte Carlo calculations for A=6,7 nuclei are consistent with pion
scattering from 6Li and 7Li at energies near the Delta resonance. This has
provided a microscopic understanding of the enhancement factors for quadrople
excitations, which were needed to describe pion inelastic scattering within the
nuclear shell model of Cohen and Kurath.Comment: 10 pages, REVTeX, 3 postscript figures; added calculation of elastic
and inelastic pion scattering from 6Li at multiple energie
K* nucleon hyperon form factors and nucleon strangeness
A crucial input for recent meson hyperon cloud model estimates of the nucleon
matrix element of the strangeness current are the nucleon-hyperon-K* (NYK*)
form factors which regularize some of the arising loops. Prompted by new and
forthcoming information on these form factors from hyperon-nucleon potential
models, we analyze the dependence of the loop model results for the
strange-quark observables on the NYK* form factors and couplings. We find, in
particular, that the now generally favored soft N-Lambda-K* form factors can
reduce the magnitude of the K* contributions in such models by more than an
order of magnitude, compared to previous results with hard form factors. We
also discuss some general implications of our results for hadronic loop models.Comment: 9 pages, 8 figures, new co-author, discussion extended to the
momentum dependence of the strange vector form factor
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