349 research outputs found
NMSPEC: A Fortran code for the sparticle and Higgs masses in the NMSSM with GUT scale boundary conditions
NMSPEC is a Fortran code that computes the sparticle and Higgs masses, as
well as Higgs decay widths and couplings in the NMSSM, with soft SUSY breaking
terms specified at MGUT. Exceptions are the soft singlet mass m_s^2 and the
singlet self coupling kappa, that are both determined in terms of the other
parameters through the minimization equations of the Higgs potential. We
present a first analysis of the NMSSM parameter space with universal SUSY
breaking terms at MGUT -- except for m_s and A_kappa -- that passes present
experimental constraints on sparticle and Higgs masses. We discuss in some
detail a region in parameter space where a SM-like Higgs boson decays
dominantly into two CP odd singlet-like Higgs states.Comment: 21 pages, 3 figure
Masses and Couplings of the Lightest Higgs Bosons in the (M+1)SSM
We study the upper limits on the mass of the lightest and second lightest CP
even Higgs bosons in the (M+1)SSM, the MSSM extended by a gauge singlet. The
dominant two loop contributions to the effective potential are included, which
reduce the Higgs masses by 10 GeV. Since the coupling R of the lightest Higgs
scalar to gauge bosons can be small, we study in detail the relations between
the masses and couplings of both lightest scalars. We present upper bounds on
the mass of a 'strongly' coupled Higgs (R > 1/2) as a function of lower
experimental limits on the mass of a 'weakly' coupled Higgs (R < 1/2). With the
help of these results, the whole parameter space of the model can be covered by
Higgs boson searches.Comment: Changed notation and added explanations; to appear in European
Journal of Physics
A 750 GeV Diphoton Signal from a Very Light Pseudoscalar in the NMSSM
The excess of events in the diphoton final state near 750 GeV observed by
ATLAS and CMS can be explained within the NMSSM near the R-symmetry limit. Both
scalars beyond the Standard Model Higgs boson have masses near 750 GeV, mix
strongly, and share sizeable production cross sections in association with
b-quarks as well as branching fractions into a pair of very light
pseudoscalars. Pseudoscalars with a mass of ~ 210 MeV decay into collimated
diphotons, whereas pseudoscalars with a mass of ~ 500-550 MeV can decay either
into collimated diphotons or into three pi^0 resulting in collimated photon
jets. Various such scenarios are discussed; the dominant constraints on the
latter scenario originate from bounds on radiative Upsilon decays, but they
allow for a signal cross section up to 6.7 fb times the acceptance for
collimated multiphotons to pass as a single photon.Comment: Major update, 21 pages, scenarios with M_A ~ 210 MeV and M_A ~ 550
MeV added, references and output files from NMSSMTools added, section and
figure on Delta_eta of diphotons added. To appear in JHE
Higgs Sector of Non-minimal Supersymmetric Models at Future Hadron Colliders
We investigate the potential of current and planned hadron colliders
operating at the TeV scale in disentangling the structure of the Higgs sector
of non-minimal Supersymmetric extensions of the Standard Model with an extra
gauge singlet. We assume universality of the soft Supersymmetry breaking terms
at the GUT scale as well as a CP-even Higgs boson with mass around 115 GeV, as
suggested by LEP. We find that mixing angles between the doublet and singlet
Higgs states are always small. However, concrete prospects exist at both the
Tevatron (Run II) and the Large Hadron Collider of detecting at least one
neutral Higgs state with a dominant singlet component, in addition to those
available from a doublet Higgs sector which is similar to the one of the
Minimal Supersymmetric Standard Model.Comment: 4 pages, 2 figures, latex, contribution to the APS/DPF/DPB Summer
Study on the `Future of Particle Physics (Snowmass 2001)', Snowmass,
Colorado, 30 June - 21 July 200
The semi-constrained NMSSM satisfying bounds from the LHC, LUX and Planck
We study the parameter space of the semi-constrained NMSSM, compatible with
constraints on the Standard Model like Higgs mass and signal rates, constraints
from searches for squarks and gluinos, a dark matter relic density compatible
with bounds from WMAP/Planck, and direct detection cross sections compatible
with constraints from LUX. The remaining parameter space allows for a
fine-tuning as low as about 100, an additional lighter Higgs boson in the
60-120 GeV mass range detectable in the diphoton mode or in decays into a pair
of lighter CP-odd Higgs bosons, and dominantly singlino like dark matter with a
mass down to 1 GeV, but possibly a very small direct detection cross section.Comment: 19 pages, 13 Figure
Neutralino Cascades in the (M+1)SSM
In the (M+1)SSM an additional gauge singlet Weyl spinor appears in the
neutralino sector. For a large part of the parameter space this approximative
eigenstate is the true LSP. Then most sparticle decays proceed via an
additional cascade involving the NLSP -> LSP transition, where the NLSP is the
non-singlet next-to-lightest neutralino. We present a comprehensive list of all
processes, which contribute to the NLSP -> LSP transition, the partial widths
and the total NLSP decay rate. We perform a scan of the parameters of the model
compatible with universal soft terms, and find that the NLSP life time can be
quite large, leading to macroscopically displaced vertices. Our results imply
that the signatures for sparticle production in the (M+1)SSM can be very
different from the MSSM, and are important for calculations of the abundance of
dark matter in this model.Comment: 25 pages (LaTeX2e), 8 figs., explanations adde
Topologies of the (M+1)SSM with a Singlino LSP at LEP2
We study the possible signals of the (M+1)SSM with a singlino LSP at LEP2.
First we identify regions of the parameter space which are ruled out by
negative results of sparticle searches in the context of the MSSM. In the
remaining kinematically accessible regions we present total event rates for
topologies which require further studies, i.e. estimations of the corresponding
efficiencies: various 4 charged fermion final states with missing energy,
possibly with displaced vertices due to a long lifetime of the NLSP, the second
lightest neutralino. Searches for these unconventional signatures are essential
in order to cover the entire kinematically accessible parameter space of the
(M+1)SSM with a singlino LSP at LEP2.Comment: 21 pages (LaTeX2e), 2 figs., table with all possible final states
adde
Los aprendizajes en geografía propuestos a los alumnos de entre 11 y 16 años: actividades básicas
Una investigación referente a las actividades de aprendizaje en geografía propuestas a alumnos de edades comprendidas entre los 11 y los 16 años pone de manifiesto que las actividades predominantes son muy básicas y que se centran en un vocabulario y en situaciones elementales. El enfoque que se utiliza es más analítico que sintético o sistémico. Los docentes lo justifican basándose en una concepción analítica de la construcción del saber en general y del saber geográfico en particular.A research into on activities of learning in geography the pupils of 11 to 16 in French secondary schools shows that dominant activities are very elementary, aimed at basic vocabulary and locations, in an approach more analytic than synthetic or systemic. Teachers justify their choices basing them on an analytic idea of the construction of general knowledge and of geographical knowledge in particular.Una investigación referente a las actividades de aprendizaje en geografía propuestas a alumnos de edades comprendidas entre los 11 y los 16 años pone de manifiesto que las actividades predominantes son muy básicas y que se centran en un vocabulario y en situaciones elementales. El enfoque que se utiliza es más analítico que sintético o sistémico. Los docentes lo justifican basándose en una concepción analítica de la construcción del saber en general y del saber geográfico en particular
NMHDECAY: A Fortran Code for the Higgs Masses, Couplings and Decay Widths in the NMSSM
The Fortran code NMHDECAY computes the masses, couplings and decay widths of
all Higgs bosons of the NMSSM in terms of its parameters at the electroweak
(SUSY breaking) scale: the Yukawa couplings lambda and kappa, the soft
trilinear terms A_lambda and A_kappa, and tan(beta) and mu_eff = lambda*.
The computation of the spectrum includes leading two loop terms, electroweak
corrections and propagator corrections. The computation of the decay widths is
carried out as in HDECAY, but (for the moment) without three body decays. Each
point in parameter space is checked against negative Higgs bosons searches at
LEP, including unconventional channels relevant for the NMSSM. One version of
the program uses generalized SLHA conventions for input and output.Comment: Typos corrected, references added, radiative corrections written out
explicitely in new appendix
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