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We investigate the viability of observing charged Higgs bosons () produced in association with bosons at the CERN large hadron collider, using the leptonic decay and hadronic 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 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 and intermediate masses () when using softer cuts (, 50 GeV), whereas for harder cuts (, 100 GeV) we only find a viable signal for very large (). 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 -violating phases. Even so we find that the signal after cuts remains small except for small masses () when using the softer cuts. Finally, in all the scenarios we have investigated we have only found small -asymmetries.

The Monte Carlo program, PYBBWH, is an implementation of the associated production of a charged Higgs and a W boson from fusion in a general Two-Higgs-Doublet model for both CP-conserving and CP-violating couplings.It is implemented as a external process to Pythia 6.The code can be downloaded from http://www.isv.uu.se/thep/MC/pybbwh.

To properly discover a charged Higgs Boson (H^±) requires its spin and couplings to be determined. We investigate how to utilize t spin correlations to analyze the H^± couplings in the decay t → bH⁺ → bτ⁺ν_τ. 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 tan β. Using a Monte Carlo approach to simulate full hadron-level events, we evaluate systematically how the H^± → τ^±ν_τ decay mode can be used for spin analysis. The most promising observables are obtained from azimuthal angle correlations in the transverse rest frames of t(). This method is particularly useful for determining the coupling structure of H^± in the large tan β limit, where differences from the SM are most significant.

We discuss the phenomenology of charged Higgs bosons in the MSSM with minimal flavor violation. In addition to the constrained MSSM (CMSSM) with universal soft supersymmetry breaking mass parameters at the GUT scale, we explore non-universal Higgs mass models (NUHM) where this universality condition is relaxed. To identify the allowed parameter space regions, we apply constraints from direct searches, low energy observables, and cosmology. We find that values of the charged Higgs mass as low as m_H⁺ 135 GeV can be accommodated in the NUHM models, but that several flavor physics observables disfavor large H⁺ contributions, associated with high tan β, quite independently of MSSM scenario. We confront the constrained scenarios with the discovery potentials reported by ATLAS and CMS, and find that the current exclusion by indirect constraints is similar to the expected LHC discovery reach with 30 fb⁻¹ of data. Finally, we evaluate the sensitivity of the presented discovery potential to the choice of MSSM benchmark scenario. This sensitivity is found to be higher in the case of a light (m_H⁺ < m_t) charged Higgs.

Wepresent a new model, based on color rearrangements, which atthe same time can describe both hidden and open charmproduction in B-meson decays. The model is successfully compared toboth inclusive decays, such as B-->J/psiX and B-->D_sX, as wellas exclusive ones, such as B-->J/psiK^(*) and B-->D^(*)D^(*)K. It alsogives a good description of the momentum distribution of directJ/psi's, especially in the low-momentum region, which earlier has beenclaimed as a possible signal for new exotic states.

We describe the public C++ code 2HDMC which can be used to perform calculations in a general, CP-conserving, two-Higgs-doublet model (2HDM). The program features simple conversion between different parametrizations of the 2HDM potential, a flexible Yukawa sector specification with choices of different Z_2-symmetries or more general couplings, a decay library including all two-body - and some three-body - decay modes for the Higgs bosons, and the possibility to calculate observables of interest for constraining the 2HDM parameter space, as well as theoretical constraints from positivity and unitarity. The latest version of the 2HDMC code and full documentation is available from: http://www.isv.uu.se/thep/MC/2HDMC.