17,154 research outputs found
Natural NMSSM with a Light Singlet Higgs and Singlino LSP
Supersymmetry (SUSY) is an attractive extension of the Standard Model (SM) of
particle physics which solves the SM hierarchy problem. Motivated by the
theoretical -term problem of the Minimal Supersymmetric Model (MSSM), the
Next-to MSSM (NMSSM) can also account for experimental deviations from the SM
like the anomalous muon magnetic moment and the dark matter relic density.
Natural SUSY, motivated by naturalness considerations, exhibits small fine
tuning and a characteristic phenomenology with light higgsinos, stops and
gluinos. We describe a scan in NMSSM parameter space motivated by Natural SUSY
and guided by the phenomenology of an NMSSM with a slightly broken Peccei-Quinn
symmetry and a lightly coupled singlet. We identify a scenario which survives
experimental constraints with a light singlet Higgs and a singlino lightest
SUSY particle. We then discuss how the scenario is not presently excluded by
searches at the Large Hadron Collider (LHC) and which channels are promising
for discovery at the LHC and International Linear Collider.Comment: Added results of checks on LHC Run 1 exclusion with CheckMAT
ATLAS Searches for Beyond the Standard Model Higgs Bosons
The present status of ATLAS searches for Higgs bosons in extensions of the
Standard Model (SM) is presented. This includes searches for the Higgs bosons
of the Two-Higgs-Doublet Model (2HDM), the Minimal Supersymmetric Model (MSSM),
the Next-to-Minimal Supersymmetric Model (NMSSM) and models with an invisibly
decaying Higgs boson. A review of the phenomenology of the Higgs sectors of
these models is given together with the search strategy and the resulting
experimental constraints.Comment: Presentation at the DPF 2013 Meeting of the American Physical Society
Division of Particles and Fields, Santa Cruz, California, August 13-17, 201
Saturation of interband absorption in graphene
The transient response of an intrinsic graphene, which is caused by the
ultrafast interband transitions, is studied theoretically for the range of
pumping correspondent to the saturated absorption regime. Spectral and temporal
dependencies of the photoexcited concentration as well as the transmission and
relitive absotption coefficients are considered for mid-IR and visible (or
near-IR) spectral regions at different durations of pulse and broadening
energies. The characteristic intencities of saturation are calculated and the
results are compared with the experimental data measured for the near-IR lasers
with a saturable absorber. The negative absorption of a probe radiation during
cascade emission of optical phonons is obtained.Comment: 7 pages, 7 figure
Classification of interacting electronic topological insulators in three dimensions
A fundamental open problem in condensed matter physics is how the dichotomy
between conventional and topological band insulators is modified in the
presence of strong electron interactions. We show that there are 6 new
electronic topological insulators that have no non-interacting counterpart.
Combined with the previously known band-insulators, these produce a total of 8
topologically distinct phases. Two of the new topological insulators have a
simple physical description as Mott insulators in which the electron spins form
spin analogs of the familiar topological band-insulator. The remaining are
obtained as combinations of these two `topological paramagnets' and the
topological band insulator. We prove that these 8 phases form a complete list
of all possible interacting topological insulators, and are classified by a
Z_2^3 group-structure. Experimental signatures are also discussed for these
phases.Comment: New version contains more results on experimental signatures and a
more rigorous proof of a key statement (see Appendix D,E), with references
reorganize
Gapped Symmetry Preserving Surface-State for the Electron Topological Insulator
It is well known that the 3D electronic topological insulator (TI) with
charge-conservation and time-reversal symmetry cannot have a trivial insulating
surface that preserves symmetry. It is often implicitly assumed that if the TI
surface preserves both symmetries then it must be gapless. Here we show that it
is possible for the TI surface to be both gapped and symmetry-preserving, at
the expense of having surface-topological order. In contrast to analogous
bosonic topological insulators, this symmetric surface topological order is
intrinsically non-Abelian. We show that the surface-topological order provides
a complete non-perturbative definition of the electron TI that transcends a
free-particle band-structure picture, and could provide a useful perspective
for studying strongly correlated topological Mott insulators.Comment: 12 pages, 2 figures, (published version
An improved human display model for occupant crash simulation programs
An improved three-dimensional display model of a human being which can be used to display the results of three-dimensional simulation programs that predict the positions of an occupant during impact of a vehicle was presented. The model allows the user to view the occupant from any orientation in any position during the crash. The display model assumes the usual break up of the body into rigid segments which is normal for occupant crash simulation programs, but the shape of the segments in the display model are not necessarily the same as those used in the crash simulation. The display model is proportioned so as to produce a realistic drawing of the human body in any position. Joints connecting the segments are also drawn to improve realism
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