3,946 research outputs found
Neutral Higgs production at proton colliders in the CP-conserving NMSSM
We discuss neutral Higgs boson production through gluon fusion and
bottom-quark annihilation in the CP-conserving -invariant
Next-to-Minimal Supersymmetric Standard Model (NMSSM) at proton colliders. For
gluon fusion we adapt known asymptotic expansions in supersymmetric particles
for the inclusion of next-to-leading order contributions of squarks and gluinos
from the Minimal Supersymmetric Standard Model (MSSM) and include electro-weak
corrections involving light quarks. Together with the resummation of higher
order sbottom contributions in the bottom-quark Yukawa coupling for both
production processes we thus present accurate cross section predictions
implemented in a new release of the code SusHi. We elaborate on the new
features of an additional SU singlet in the production of CP-even and
-odd Higgs bosons with respect to the MSSM and include a short discussion of
theory uncertainties.Comment: 33 pages, 8 figures; minor corrections, updated references, matches
published versio
Off-shell effects in Higgs decays to heavy gauge bosons and signal-background interference in Higgs decays to photons at a linear collider
We discuss off-shell contributions in Higgs decays to heavy gauge bosons
with for a standard model (SM)
Higgs boson for both dominant production processes and at a (linear) collider. Dependent on the
centre-of-mass energy off-shell effects are sizable and important for the
understanding of the electroweak symmetry breaking mechanism. Moreover we
shortly investigate the effects of the signal-background interference in
decays for the Higgsstrahlung initiated process
, where we report a similar shift in the
invariant mass peak of the two photons as found for the LHC. For both effects
we discuss the sensitivity to the total Higgs width.Comment: 11 pages, 9 figures, talk presented at the International Workshop on
Future Linear Colliders (LCWS14), Belgrade, Serbia, 6-10 October 201
CP violation in bilinear R-parity violation and its consequences for the early universe
Supersymmetric models with bilinear R-parity violation (BRpV) provide a
framework for neutrino masses and mixing angles to explain neutrino oscillation
data. We consider CP violation within the new physical phases in BRpV and
discuss their effect on the generation of neutrino masses and the decays of the
lightest supersymmetric particle (LSP), being a light neutralino with mass
GeV, at next-to-leading order. The decays affect the lepton and via
sphaleron transitions the baryon asymmetry in the early universe. For a rather
light LSP, asymmetries generated before the electroweak phase transition via
e.g. the Affleck-Dine mechanism are reduced up to two orders of magnitude, but
are still present. On the other hand, the decays of a light LSP themselves can
account for the generation of a lepton and baryon asymmetry, the latter in
accordance to the observation in our universe, since the smallness of the BRpV
parameters allows for an out-of-equilibrium decay and sufficiently large CP
violation is possible consistent with experimental bounds from the
non-observation of electric dipole-moments.Comment: 26 pages, 13 figure
Phenomenology of on-shell Higgs production in the MSSM with complex parameters
A computation of inclusive cross sections for neutral Higgs boson production
through gluon fusion and bottom-quark annihilation is presented in the MSSM
with complex parameters. The predictions for the gluon-fusion process are based
on an explicit calculation of the leading-order cross section for arbitrary
complex parameters which is supplemented by higher-order corrections: massive
top- and bottom-quark contributions at NLO QCD, in the heavy top-quark
effective theory the top-quark contribution up to NLO QCD including a soft
expansion for the -even component of the light Higgs boson. For
its -odd component and the heavy Higgs bosons the contributions
are incorporated up to NNLO QCD. Two-loop electroweak effects are also
incorporated, and SUSY QCD corrections at NLO are interpolated from the MSSM
with real parameters. Finite wave function normalisation factors ensuring
correct on-shell properties of the external Higgs bosons are incorporated from
the code . For the typical case of a strong admixture of
the two heavy Higgs bosons it is demonstrated that squark effects are strongly
dependent on the phases of the complex parameters. The remaining theoretical
uncertainties for cross sections are discussed. The results have been
implemented into an extension of the numerical code called
.Comment: 37 pages, 12 figures, minor clarifications, updated references,
matches published versio
Interference contributions to gluon initiated heavy Higgs production in the Two-Higgs-Doublet Model
We discuss the production of a heavy neutral Higgs boson of a CP-conserving
Two-Higgs-Doublet Model in gluon fusion and its decay into a four-fermion final
state, .
We investigate the interference contributions to invariant mass distributions
of the four-fermion final state and other relevant kinematical observables. The
relative importance of the different contributions is quantified for the
process in the on-shell approximation, . We show that
interferences of the heavy Higgs with the light Higgs boson and background
contributions are essential for a correct description of the differential cross
section. Even though they contribute below to those heavy
Higgs signal cross sections, to which the experiments at the Large Hadron
Collider were sensitive in its first run, we find that they are sizeable in
certain regions of the parameter space that are relevant for future heavy Higgs
boson searches. In fact, the interference contributions can significantly
enhance the experimental sensitivity to the heavy Higgs boson.Comment: 24 pages, 13 figures; minor clarifications, updated references,
matches published versio
and the wrong-sign limit of the Two-Higgs-Doublet Model
We point out the importance of the decay channels and in
the wrong-sign limit of the Two-Higgs-Doublet Model (2HDM) of type II. They can
be the dominant decay modes at moderate values of , even if the
(pseudo)scalar mass is above the threshold where the decay into a pair of top
quarks is kinematically open. Accordingly, large cross sections
and are obtained and currently probed by the LHC experiments,
yielding conclusive statements about the remaining parameter space of the
wrong-sign limit. In addition, mild excesses - as recently found in the ATLAS
analysis - could be explained. The wrong-sign limit makes
other important testable predictions for the light Higgs boson couplings.Comment: 19 pages, 6 figures, v2: journal versio
Characterization and modification of cavitation pattern in shock wave lithotripsy
The temporal and spatial dynamics of cavitation bubble cloud growth and collapse in extracorporeal shock wave lithotripsy (ESWL) is studied experimentally. The first objective is obtaining reproducible cloud patterns experimentally and comparing them with FDTD-calculations. Second, we describe a method to modify the cavitation pattern by timing two consecutive pressure waves at variable delays. It is found that the spatial and temporal dynamics of the cavitation bubble can be varied in large ranges. The ability to control cavitation dynamics allows discussing strategies for improvement of medical and biological applications of shock waves such as cell membrane poration and stone fragmentation
Higgs Strahlung at the Large Hadron Collider in the 2-Higgs-Doublet Model
We present a calculation of all relevant contributions to associated
production of a Higgs boson with a weak gauge boson in the 2-Higgs-Doublet
Model (2HDM) at the LHC, , with and
. While for the mode, this mostly amounts to a simple
rescaling of the Standard Model (SM) cross section, the cross section
depends on several 2HDM parameters. The ratio ,
for which we present the currently most complete SM prediction, therefore
appears to be a sensitive probe of possible New Physics effects. We study its
numerical dependence on the top and bottom Yukawa couplings, including their
sign. Furthermore, we consider the ratio in exemplary 2HDM
scenarios and briefly address the effects in the boosted regime. Analogous
studies for other 2HDM scenarios will become possible with an upcoming version
of the program vh@nnlo which incorporates the 2HDM effects.Comment: 32 pages, 18 figures; v2: discussion of boosted regime added, typos
corrected, references added, version published in JHE
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