174 research outputs found
Supersymmetric Musings on the Predictivity of Family Symmetries
We discuss the predictivity of family symmetries for the soft supersymmetry
breaking parameters in the framework of supergravity. We show that unknown
details of the messenger sector and the supersymmetry breaking hidden sector
enter into the soft parameters, making it difficult to obtain robust
predictions. We find that there are specific choices of messenger fields which
can improve the predictivity for the soft parameters.Comment: 20 pages, 5 figure
Complete genome sequences of two Citrobacter rodentium bacteriophages, CR8 and CR44b
© 2014 Toribio et al. The complete genomes of two virulent phages infecting Citrobacter rodentium are reported here for the first time. Both bacteriophages were isolated from local sewage treatment plant effluents. Genome analyses revealed a close relationship between both phages and allowed their classification as members of the Autographivirinae subfamily in the T7-like genus
Impact of DM direct searches and the LHC analyses on branon phenomenology
Dark Matter direct detection experiments are able to exclude interesting
parameter space regions of particle models which predict an important amount of
thermal relics. We use recent data to constrain the branon model and to compute
the region that is favored by CDMS measurements. Within this work, we also
update present colliders constraints with new studies coming from the LHC.
Despite the present low luminosity, it is remarkable that for heavy branons,
CMS and ATLAS measurements are already more constraining than previous analyses
performed with TEVATRON and LEP data.Comment: 17 pages, 2 figure
The Gravitino-Stau Scenario after Catalyzed BBN
We consider the impact of Catalyzed Big Bang Nucleosynthesis on theories with
a gravitino LSP and a charged slepton NLSP. In models where the gravitino to
gaugino mass ratio is bounded from below, such as gaugino-mediated SUSY
breaking, we derive a lower bound on the gaugino mass parameter m_1/2. As a
concrete example, we determine the parameter space of gaugino mediation that is
compatible with all cosmological constraints.Comment: 1+14 pages, 6 figures; v2: minor clarifications, 1 reference added,
matches version to appear in JCA
Phenomenology of heterotic M-theory with five-branes
We analyze some phenomenological implications of heterotic M-theory with
five-branes. Recent results for the effective 4-dimensional action are used to
perform a systematic analysis of the parameter space, finding the restrictions
that result from requiring the volume of the Calabi-Yau to remain positive.
Then the different scales of the theory, namely, the 11-dimensional Planck
mass, the compactification scale and the orbifold scale, are evaluated.
The expressions for the soft supersymmetry-breaking terms are computed and
discussed in detail for the whole parameter space. With this information we
study the theoretical predictions for the supersymmetric contribution to the
muon anomalous magnetic moment, using the recent experimental result as a
constraint on the parameter space. We finally analyze the neutralino as a dark
matter candidate in this construction. In particular, the neutralino-nucleon
cross-section is computed and compared with the sensitivities explored by
present dark matter detectors.Comment: Final version to appear in Phys. Rev. D. Some comments and references
added. 37 pages, 19 figure
Entropy production by Q-ball decay for diluting long-lived charged particles
The cosmic abundance of a long-lived charged particle such as a stau is
tightly constrained by the catalyzed big bang nucleosynthesis. One of the ways
to evade the constraints is to dilute those particles by a huge entropy
production. We evaluate the dilution factor in a case that non-relativistic
matter dominates the energy density of the universe and decays with large
entropy production. We find that large Q balls can do the job, which is
naturally produced in the gauge-mediated supersymmetry breaking scenario.Comment: 8 pages, 1 figur
Les Houches 2011: Physics at TeV Colliders New Physics Working Group Report
We present the activities of the "New Physics" working group for the "Physics
at TeV Colliders" workshop (Les Houches, France, 30 May-17 June, 2011). Our
report includes new agreements on formats for interfaces between computational
tools, new tool developments, important signatures for searches at the LHC,
recommendations for presentation of LHC search results, as well as additional
phenomenological studies.Comment: 243 pages, report of the Les Houches 2011 New Physics Group; fix
three figure
Results from the Super Cryogenic Dark Matter Search (SuperCDMS) experiment at Soudan
We report the result of a blinded search for Weakly Interacting Massive
Particles (WIMPs) using the majority of the SuperCDMS Soudan dataset. With an
exposure of 1690 kg days, a single candidate event is observed, consistent with
expected backgrounds. This analysis (combined with previous Ge results) sets an
upper limit on the spin-independent WIMP--nucleon cross section of () cm at 46 GeV/. These results set the
strongest limits for WIMP--germanium-nucleus interactions for masses 12
GeV/
Does Solar Physics Provide Constraints to Weakly Interacting Massive Particles?
We investigate whether present data on helioseismology and solar neutrino
fluxes may constrain WIMP--matter interactions in the range of WIMP parameters
under current exploration in WIMP searches. We find that, for a WIMP mass of 30
GeV, once the effect of the presence of WIMPs in the Sun's interior is
maximized, the squared isothermal sound speed is modified, with respect to the
standard solar model, by at most 0.4% at the Sun's center. The maximal effect
on the Boron-8 solar neutrino flux is a reduction of 4.5%. Larger masses lead
to smaller effects. These results imply that present sensitivities in the
measurements of solar properties, though greatly improved in recent years, do
not provide information or constraints on WIMP properties of relevance for dark
matter. Furthermore, we show that, when current bounds from direct WIMP
searches are taken into account, the effect induced by WIMPs with dominant
coherent interactions are drastically reduced as compared to the values quoted
above. The case of neutralinos in the minimal supersymmetric standard model is
also discussed.Comment: 31 pages, 2 tables and 9 figures, typeset with ReVTeX4. The paper may
also be found at http://www.to.infn.it/~fornengo/papers/helio.ps.gz or
through http://www.to.infn.it/astropart/index.htm
Lower limit on the neutralino mass in the general MSSM
We discuss constraints on SUSY models with non-unified gaugino masses and R_P
conservation. We derive a lower bound on the neutralino mass combining the
direct limits from LEP, the indirect limits from gmuon, bsgamma, Bsmumu and the
relic density constraint from WMAP. The lightest neutralino (mneutralino=6GeV)
is found in models with a light pseudoscalar with MA<200GeV and a large value
for . Models with heavy pseudoscalars lead to mneutralino>18(29)GeV
for . We show that even a very conservative bound from the
muon anomalous magnetic moment can increase the lower bound on the neutralino
mass in models with mu<0 and/or large values of . We then examine
the potential of the Tevatron and the direct detection experiments to probe the
SUSY models with the lightest neutralinos allowed in the context of light
pseudoscalars with high . We also examine the potential of an e+e-
collider of 500GeV to produce SUSY particles in all models with neutralinos
lighter than the W. In contrast to the mSUGRA models, observation of at least
one sparticle is not always guaranteed.Comment: 37 pages, LateX, 16 figures, paper with higher resolution figures
available at
http://wwwlapp.in2p3.fr/~boudjema/papers/bound-lsp/bound-lsp.htm
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