1,756 research outputs found
Comparison of SUSY spectrum calculations and impact on the relic density constraints from WMAP
We compare results of four public supersymmetric (SUSY) spectrum codes,
Isajet, Softsusy, Spheno and Suspect to estimate the present-day uncertainty in
the calculation of the relic density of dark matter in mSUGRA models. We find
that even for mass differences of about 1% the spread in the obtained relic
densities can be 10%. In difficult regions of the parameter space, such as
large tan(beta) or large m_0, discrepancies in the relic density are much
larger. We also find important differences in the stau co-annihilation region.
We show the impact of these uncertainties on the bounds from WMAP for several
scenarios, concentrating on the regions of parameter space most relevant for
collider phenomenology. We also discuss the case of non-zero A_0 and the stop
co-annihilation region. Moreover, we present a web application for the online
comparison of the spectrum codes.Comment: 26 pages, 6 figures, 10 tables; version to appear in PR
Feebly-interacting dark matter
We briefly review scenarios with feebly interacting particles (FIMPs) as dark
matter candidates. The discussion covers issues with dark matter production in
the early universe as well as signatures of FIMPs at the high energy and high
intensity frontier as well as in astroparticle and cosmology.Comment: 6 pages, 2 captioned figures. Review article for EPJ ST Special
Issue: Frontier 23: Elementary particle physics, dark matter and
astroparticle physic
Spousal support and relationship happiness in adults with type 2 diabetes and their spouses
Objectives
The purpose of this study was to examine the association between the perceptions of spousal support self-efficacy in terms of dietary self-care and relationship happiness.
Methods
Forty-six couples, in which only one spouse has type 2 diabetes, completed questionnaires on perceptions of spousal support self-efficacy and relationship happiness.
Results
Using an actor-partner interdependence model, we found that when persons with type 2 diabetes were more confident in their spouse’s ability to provide them with support regarding their dietary self-care, they reported more relationship happiness. We also found that when their spouse without diabetes was more confident in their own abilities to provide such support to their partner, they reported more relationship happiness. However, the person with diabetes’ confidence in their spouse’s support abilities and the spouse’s confidence in their own support abilities were not associated with the other partner’s relationship happiness.
Conclusions
This study offers a unique dyadic perspective on the determinants of happiness for couples in which one spouse has type 2 diabetes. The perceived quality of spousal support appears to be associated with relationship happiness in committed couples managing diabetes, regardless of the actual support received or provided
Indirect search for dark matter with micrOMEGAs2.4
We present a new module of micrOMEGAs devoted to the computation of indirect
signals from dark matter annihilation in any new model with a stable weakly
interacting particle. The code provides the mass spectrum, cross-sections,
relic density and exotic fluxes of gamma rays, positrons and antiprotons. The
propagation of charged particles in the Galactic halo is handled with a new
module that allows to easily modify the propagation parameters.Comment: 24 pages, 6 figures, typos corrected, acknowledgements modifie
Relic density of neutralino dark matter in the MSSM with CP violation
We calculate the relic density of dark matter in the MSSM with CP violation.
We analyse various scenarios of neutralino annihilation: the cases of a bino,
bino-wino and bino-Higgsino LSP, annihilation through Higgs, as well as
sfermion coannihilation scenarios. Large phase effects are found, on the one
hand due to shifts in the masses, on the other hand due to modifications of the
couplings. Taking special care to disentangle the effects in masses and
couplings, we demonstrate that the presence of CP phases can have a significant
influence on the neutralino relic abundance. Typical variations in \Omega h^2
solely from modifications in the couplings are O(10%-100%), but can reach an
order of magnitude in some cases.Comment: 36 pages, 21 figures (low resolution). A version with high-resolution
figures can be downloaded from http://cern.ch/kraml/papers/omc
A single hollow beam optical trap for cold atoms
We present an optical trap for atoms that we have developed for precision
spectroscopy measurements. Cold atoms are captured in a dark region of space
inside a blue-detuned hollow laser beam formed by an axicon. We analyze the
light potential in a ray optics picture and experimentally demonstrate trapping
of laser-cooled metastable xenon atoms.Comment: 12 pages, 8 figure
Recommended from our members
Echocardiographic evaluation of velocity ratio, velocity time integral ratio, and pulmonary valve area in dogs with pulmonary valve stenosis.
BackgroundVelocity ratio, velocity time integral (VTI) ratio, and pulmonary valve area indexed to body surface area (iPVA) are methods of assessment of pulmonary valve stenosis (PS) severity that are less dependent on blood flow. Studies evaluating these methods are limited.ObjectivesTo determine the effects of butorphanol, atenolol, and balloon valvuloplasty (BV) on velocity ratio, VTI ratio, iPVA, mean PG, and max PG.AnimalsTwenty-seven dogs with PS (max PG >50 mm Hg).MethodsProspective study. All dogs underwent an echocardiogram at baseline, 5-minutes after administration of butorphanol (0.2-0.25 mg/kg IV), and 2-to-4 weeks after atenolol (1-1.5 mg/kg q12h). Twenty-one of these were evaluated 24-hours after BV.ResultsThere were no significant differences (P > .05) amongst any of the methods of assessment of PS severity after butorphanol. After atenolol, mean (SD) of mean (57.0 [21.0] mm Hg) and max PG (93.1 [33.8] mm Hg) were significantly decreased (P ≤ .047) compared with baseline (65.2 [26.2] mm Hg and 108 [44.4] mm Hg, respectively). After atenolol, there were no significant (P ≥ .12) differences in velocity ratio (0.29 [0.09]), VTI ratio (0.18 [0.05]), or iPVA (0.43 [0.16] cm2 /m2 ) compared with baseline (0.30 [0.09], 0.19 [0.09], 0.44 [0.17] cm2 /m2 , respectively).Conclusions and clinical importanceAtenolol might reduce mean and max PG but does not alter less flow-dependent methods of assessment of PS severity (velocity ratio, VTI ratio, and iPVA) in dogs with PS. Results support an integrative approach to assessment of PS severity that includes less flow-dependent methods, particularly in states of altered flow or right ventricular function
Rare kaon decays in SUSY with non-universal A terms
We study the rare kaon decays in the framework of general SUSY models. Unlike
the results in the literature, we find the contributions from the gluino
exchange to the branching ratio of can reach the
central value () of the new E787 data while the
predicted value of standard model is less than . We also find that
the same effects also enhance the decays of ,
and .Comment: 9 pages, references added, revised version to appear in J. Phys.
Light Sneutrino Dark Matter at the LHC
In supersymmetric (SUSY) models with Dirac neutrino masses, a weak-scale
trilinear A-term that is not proportional to the small neutrino Yukawa
couplings can induce a sizable mixing between left and right-handed sneutrinos.
The lighter sneutrino mass eigenstate can hence become the lightest SUSY
particle (LSP) and a viable dark matter candidate. In particular, it can be an
excellent candidate for light dark matter with mass below ~10 GeV. Such a light
mixed sneutrino LSP has a dramatic effect on SUSY signatures at the LHC, as
charginos decay dominantly into the light sneutrino plus a charged lepton, and
neutralinos decay invisibly to a neutrino plus a sneutrino. We perform a
detailed study of the LHC potential to resolve the light sneutrino dark matter
scenario by means of three representative benchmark points with different
gluino and squark mass hierarchies. We study in particular the determination of
the LSP (sneutrino) mass from cascade decays involving charginos, using the mT2
variable. Moreover, we address measurements of additional invisible sparticles,
in our case the lightest neutralino, and the question of discrimination against
the MSSM.Comment: 25 pages, 16 figure
The generalised NMSSM at one loop: fine tuning and phenomenology
We determine the degree of fine tuning needed in a generalised version of the
NMSSM that follows from an underlying Z4 or Z8 R symmetry. We find that it is
significantly less than is found in the MSSM or NMSSM and extends the range of
Higgs mass that have acceptable fine tuning up to Higgs masses of mh ~ 130 GeV.
For universal boundary conditions analogous to the CMSSM the phenomenology is
rather MSSM like with the singlet states typically rather heavy. For more
general boundary conditions the singlet states can be light, leading to
interesting signatures at the LHC and direct detection experiments.Comment: 20 pages, 9 figures, matches published versio
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