102 research outputs found
Charged Higgs Observability Through Associated Production With W at a Muon Collider
The observability of a charged Higgs boson produced in association with a W
boson at future muon colliders is studied. The analysis is performed within the
MSSM framework. The charged Higgs is assumed to decay to tb and a fully
hadronic final state is analyzed, i.e., mu+mu- \rightarrow H\pmW\mp \rightarrow
tbW \rightarrow WbbW \rightarrow jjjjbb. The main background is tt production
in fully hadronic final state which is an irreducible background with very
similar kinematic features. It is shown that although the discovery potential
is almost the same for a charged Higgs mass in the range 200 GeV < mH\pm < 400
GeV, the signal significance is about 1sigma for tanbeta = 50 at integrated
luminosity of 50 fb-1. The signal rate is well above that at e+e- linear
colliders with the same center of mass energy and enough data (O(1 ab-1)) will
provide the same discovery potential for all heavy charged Higgs masses up to
mH\pm \sim 400 GeV, however, the muon collider cannot add anything to the LHC
findings.Comment: 18 pages, 11 figure
Avaliacao preliminar da cultura do aspargo no norte de Minas Gerais.
Introducao de uma colecao de hibridos e cultivares de aspargo, objetivando avaliar seu comportamento nas condicoes da regiao Norte de Minas Gerais, sob irrigacao
Associated charged Higgs and W boson production in the MSSM at the CERN Large Hadron Collider
We investigate the viability of observing charged Higgs bosons (H^+/-)
produced in association with W bosons at the CERN Large Hadron Collider, using
the leptonic decay H^+ -> tau^+ nu_tau and hadronic W-decay, within different
scenarios of the Minimal Supersymmetric Standard Model (MSSM) with both real
and complex parameters. Performing a parton level study we show how the
irreducible Standard Model background from W+2 jets can be controlled by
applying appropriate cuts and find that the size of a possible signal depends
on the cuts needed to suppress QCD backgrounds and misidentifications. In the
standard maximal mixing scenario of the MSSM we find a viable signal for large
tan(beta) and intermediate H^+/- masses (~m_t) when using optimistic cuts
whereas for more pessimistic ones we only find a viable signal for very large
tan(beta) (>~50). We have also investigated a special class of MSSM scenarios
with large mass-splittings among the heavy Higgs bosons where the cross-section
can be resonantly enhanced by factors up to one hundred, with a strong
dependence on the CP-violating phases. Even so we find that the signal after
cuts remains small except for small masses (~< m_t) with optimistic cuts.
Finally, in all the scenarios we have investigated we have only found small
CP-asymmetries.Comment: 28 pages, 12 figures, version to appear in Euro. Phys. J.
Corrections to at the CERN Large Hadron Collider
The corrections to the cross section for at the LHC are calculated in the minimal supersymmetric
standard model (MSSM) in the and OS (on-mass-shell) renormalization
schemes. The results in two schemes are in good agreement. In the
scheme, the QCD corrections are negative and within for
charged Higgs mass up to 1 TeV and . For , the
magnitude of the QCD corrections can be greater than 30%.Comment: Initial-gluon contribution added, version to appear in PR
Charged Higgs- and R-Parity-Violating Slepton-Strahlung at Hadron Colliders
It is shown that the radiation of a charged Higgs boson off a
third-generation quark (charged-Higgs-strahlung) provides an important channel
for the discovery of the charged Higgs at hadron colliders. Equivalently, in
supersymmetric models with explicit lepton-number (R-parity) violation,
sleptons may also be produced in association with quarks (slepton-strahlung).
Higgs- and slepton-strahlung production cross sections are given for both the
Tevatron and the LHC. The LHC cross sections imply that heavy (TeV)
charged Higgs bosons can be produced via charged-Higgs-strahlung and that
strahlung production of charged sleptons is possible even for small R-parity
violating couplings. The possible discovery of sleptons through this channel
offers a surprising handle on models of neutrino masses.Comment: 23 pages, LaTex + RevTex, 11 figures (included). Title modified.
(Published version.
Higgs-Boson Production Induced by Bottom Quarks
Bottom quark-induced processes are responsible for a large fraction of the
LHC discovery potential, in particular for supersymmetric Higgs bosons.
Recently, the discrepancy between exclusive and inclusive Higgs boson
production rates has been linked to the choice of an appropriate bottom
factorization scale. We investigate the process kinematics at hadron colliders
and show that it leads to a considerable decrease in the bottom factorization
scale. This effect is the missing piece needed to understand the corresponding
higher order results. Our results hold generally for charged and for neutral
Higgs boson production at the LHC as well as at the Tevatron. The situation is
different for single top quark production, where we find no sizeable
suppression of the factorization scale. Turning the argument around, we can
specify how large the collinear logarithms are, which can be resummed using the
bottom parton picture.Comment: 18 page
H^+ -> W^+ l_i^- l_j^+$ decay in the two Higgs doublet model
We study the lepton flavor violating H^+ -> W^+ l_i^- l_j^+ and the lepton
flavor conserving $H^+ -> W^+ l_i^- l_i^+ (l_i=\tau, l_j=\mu) decays in the
general 2HDM, so called model III. We estimate the decay width \Gamma for LFV
(LFC) at the order of the magnitude of (10^{-11}-10^{-5}) GeV
((10^{-9}-10^{-4}) GeV), for 200 GeV\leq m_{H^\pm}\leq 400
GeV, and the intermediate values of the coupling
\bar{\xi}^{E}_{N,\tau \mu}\sim 5 GeV (\bar{\xi}^{E}_{N,\tau
\tau}\sim 30 GeV). We observe that the experimental result of the process
under consideration can give comprehensive information about the physics beyond
the standard model and the existing free parameters.Comment: 8 pages, 7 Figure
Charged and Pseudoscalar Higgs production at a Muon Collider
We consider single charged Higgs () and pseudoscalar Higgs ()
production in association with a gauge boson at colliders. We find
that the tree-level t-channel and s-channel contributions to are enhanced for large values of , allowing
sizeable cross-sections whose analogies at colliders would be very
small. These processes provide attractive new ways of producing such particles
at colliders and are superior to the conventional methods in
regions of parameter space.Comment: 11 pages Latex, 5 figures, formulae added in sections 2.2 and 2.3,
extra discussion in section 2.3, references adde
Protein Pattern Formation
Protein pattern formation is essential for the spatial organization of many
intracellular processes like cell division, flagellum positioning, and
chemotaxis. A prominent example of intracellular patterns are the oscillatory
pole-to-pole oscillations of Min proteins in \textit{E. coli} whose biological
function is to ensure precise cell division. Cell polarization, a prerequisite
for processes such as stem cell differentiation and cell polarity in yeast, is
also mediated by a diffusion-reaction process. More generally, these functional
modules of cells serve as model systems for self-organization, one of the core
principles of life. Under which conditions spatio-temporal patterns emerge, and
how these patterns are regulated by biochemical and geometrical factors are
major aspects of current research. Here we review recent theoretical and
experimental advances in the field of intracellular pattern formation, focusing
on general design principles and fundamental physical mechanisms.Comment: 17 pages, 14 figures, review articl
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