30 research outputs found
Constraints on the two-Higgs-doublet model
The two-Higgs-doublet model provides a simple, yet interesting,
generalization of the SM Higgs sector. We study the CP-conserving version of
this model with general, flavor-diagonal, Yukawa couplings. Indirect
constraints are obtained from flavor physics on the charged Higgs boson mass
and couplings. The relation of these bounds to those for the more specialized
two-Higgs-doublet model types with a symmetry is discussed.Comment: 4 pages, 3 figures. Talk given at SUSY09, Boston (MA), June 200
Improved prediction for the mass of the W boson in the NMSSM
Electroweak precision observables, being highly sensitive to loop
contributions of new physics, provide a powerful tool to test the theory and to
discriminate between different models of the underlying physics. In that
context, the boson mass, , plays a crucial role. The accuracy of the
measurement has been significantly improved over the last years, and
further improvement of the experimental accuracy is expected from future LHC
measurements. In order to fully exploit the precise experimental determination,
an accurate theoretical prediction for in the Standard Model (SM) and
extensions of it is of central importance. We present the currently most
accurate prediction for the boson mass in the Next-to-Minimal
Supersymmetric extension of the Standard Model (NMSSM), including the full
one-loop result and all available higher-order corrections of SM and SUSY type.
The evaluation of is performed in a flexible framework, which facilitates
the extension to other models beyond the SM. We show numerical results for the
boson mass in the NMSSM, focussing on phenomenologically interesting
scenarios, in which the Higgs signal can be interpreted as the lightest or
second lightest CP-even Higgs boson of the NMSSM. We find that, for both Higgs
signal interpretations, the NMSSM prediction is well compatible with the
measurement. We study the SUSY contributions to in detail and investigate
in particular the genuine NMSSM effects from the Higgs and neutralino sectors.Comment: 43 pages, 21 figure
Prospects for GMRT to Observe Radio Waves from UHE Particles Interacting with the Moon
Ultra high energy (UHE) particles of cosmic origin impact the lunar regolith
and produce radio signals through Askaryan effect, signals that can be detected
by Earth based radio telescopes. We calculate the expected sensitivity for
observation of such events at the Giant Metrewave Radio Telescope (GMRT), both
for UHE cosmic rays (CR) and UHE neutrino interactions. We find that for 30
days of observation time a significant number of detectable events is expected
above eV for UHECR or neutrino fluxes close to the current limits.
Null detection over a period of 30 days will lower the experimental bounds on
UHE particle fluxes by magnitudes competitive to both present and future
experiments at the very highest energies.Comment: 21 pages, 9 figure
New angles on top quark decay to a charged Higgs
To properly discover a charged Higgs Boson () requires its spin and
couplings to be determined. We investigate how to utilize \ttbar spin
correlations to analyze the couplings in the decay . Within the framework of a general Two-Higgs-Doublet Model, we
obtain results on the spin analyzing coefficients for this decay and study in
detail its spin phenomenology, focusing on the limits of large and small values
for . Using a Monte Carlo approach to simulate full hadron-level
events, we evaluate systematically how the decay
mode can be used for spin analysis. The most promising observables are obtained
from azimuthal angle correlations in the transverse rest frames of
. This method is particularly useful for determining the coupling
structure of in the large limit, where differences from the
SM are most significant.Comment: 28 pages, 13 figures. Uses JHEP forma