Electroweak Precision Observables in the MSSM with Non-Minimal Flavor Violation

The leading corrections to electroweak precision observables in the MSSM with non-minimal flavor violation (NMFV) are calculated and the effects on M_W and sin^2 theta_eff are analyzed. The corrections are obtained by evaluating the full one-loop contributions from the third and second generation scalar quarks, including the mixing in the scalar top and charm, as well as in the scalar bottom and strange sector. Furthermore the leading corrections to the mass of the lightest MSSM Higgs boson, m_h, is obtained. The electroweak one-loop contribution to M_W can amount up to 140 MeV and up to 70x10^{-5} for sin^2 theta_eff, allowing to set limits on the NMFV parameters. The corrections for m_h are not significant for moderate generation mixing.Comment: LaTeX, 21 pages, 8 figures. Complete one-loop effects from scalar quark generation mixing (beyond Delta rho) included for M_W and sin^2 theta_ef

Bulk fields with general brane kinetic terms

We analyse the effect of general brane kinetic terms for bulk scalars, fermions and gauge bosons in theories with extra dimensions, with and without supersymmetry. We find in particular a singular behaviour when these terms contain derivatives orthogonal to the brane. This is brought about by $\delta(0)$ divergences arising at second and higher order in perturbation theory. We argue that this behaviour can be smoothed down by classical renormalization.Comment: 31 pages, v2 few typos correcte

MSSM Higgs Boson Phenomenology at the Tevatron Collider

The Higgs sector of the minimal supersymmetric standard model (MSSM) consists of five physical Higgs bosons, which offer a variety of channels for their experimental search. The present study aims to further our understanding of the Tevatron reach for MSSM Higgs bosons, addressing relevant theoretical issues related to the SUSY parameter space, with special emphasis on the radiative corrections to the down--quark and lepton couplings to the Higgs bosons for large $\tan\beta$. We performed a computation of the signal and backgrounds for the production processes $W\phi$ and $b \bar{b} \phi$ at the upgraded Tevatron, with $\phi$ being the neutral MSSM Higgs bosons. Detailed experimental information and further higher order calculations are demanded to confirm/refine these predictions.Comment: 47 pages, REVTex format, 15 figures; spacing changed to reduce length, references added or moved within manuscript for clarity, some rewording, labelling corrected on two figures, results unchange

Detecting a light Higgs boson at the Fermilab Tevatron through enhanced decays to photon pairs

We analyze the prospects of the Tevatron for finding a Higgs boson in the two photon decay mode. We conclude that the Standard Model (SM) Higgs boson will likely not be discovered in this mode. However, we motivate several theories beyond the SM, including the MSSM, that predict a Higgs boson with enhanced branching fractions into photons, and calculate the luminosity needed to discover a general Higgs boson at the Tevatron by a two-photon invariant mass peak at large transverse momentum. We find that a high luminosity Tevatron will play a significant role in discovering or constraining these theories.Comment: 20 pages, latex, 5 figure

Physics Opportunities at mu+mu- Higgs Factories

We update theoretical studies of the physics opportunities presented by mu+mu- Higgs factories. Interesting measurements of the Standard Model Higgs decays into {\bar b}b, tau+tau- and WW* may be possible if the Higgs mass is less than about 160 GeV, as preferred by the precision electroweak data, the mass range being extended by varying appropriately the beam energy resolution. A suitable value of the beam energy resolution would also enable the uncertainty in the b-quark mass to be minimized, facilitating measurements of parameters in the MSSM at such a first mu+mu- Higgs factory. These measurements would be sensitive to radiative corrections to the Higgs-fermion-antifermion decay vertices, which may violate CP. Radiative corrections in the MSSM may also induce CP violation in Higgs-mass mixing, which can be probed via various asymmetries measurable using polarized mu+mu- beams. In addition, Higgs-chargino couplings may be probed at a second mu+mu- Higgs factory.Comment: Report of the Higgs factory working group of the ECFA-CERN study on Neutrino Factory & Muon Storage Rings at CERN. 28 p

Flavour physics constraints in the BMSSM

We study the implications of the presence of the two leading-order, non-renormalizable operators in the Higgs sector of the MSSM to flavour physics observables. We identify the constraints of flavour physics on the parameters of the BMSSM when we: a) focus on a region of parameters for which electroweak baryogenesis is feasible, b) use a CMSSM-like parametrization, and c) consider the case of a generic NUHM-type model. We find significant differences as compared to the standard MSSM case.Comment: 22 pages, 7 figure

The Effective Lagrangian for Bulk Fermions in Models with Extra Dimensions

We compute the dimension 6 effective Lagrangian arising from the tree level integration of an arbitrary number of bulk fermions in models with warped extra dimensions. The coefficients of the effective operators are written in terms of simple integrals of the metric and are valid for arbitrary warp factors, with or without an infrared brane, and for a general Higgs profile. All relevant tree level fermion effects in electroweak and flavor observables can be computed using this effective Lagrangian.Comment: 22 pages. V2: typos corrected, matches published versio

Dark Matter, Light Stops and Electroweak Baryogenesis

We examine the neutralino relic density in the presence of a light top squark, such as the one required for the realization of the electroweak baryogenesis mechanism, within the minimal supersymmetric standard model. We show that there are three clearly distinguishable regions of parameter space, where the relic density is consistent with WMAP and other cosmological data. These regions are characterized by annihilation cross sections mediated by either light Higgs bosons, Z bosons, or by the co-annihilation with the lightest stop. Tevatron collider experiments can test the presence of the light stop in most of the parameter space. In the co-annihilation region, however, the mass difference between the light stop and the lightest neutralino varies between 15 and 30 GeV, presenting an interesting challenge for stop searches at hadron colliders. We present the prospects for direct detection of dark matter, which provides a complementary way of testing this scenario. We also derive the required structure of the high energy soft supersymmetry breaking mass parameters where the neutralino is a dark matter candidate and the stop spectrum is consistent with electroweak baryogenesis and the present bounds on the lightest Higgs mass.Comment: 24 pages, 8 figures; version published in Phys.Rev.

The Usage of ROOT for Online Monitoring in the ALICE DATE System

Presentation for CHEP2000Data Acquisition systems for HEP applications need constant monitoring (online and offline) of their data streams to accomplish several tasks: quality checking, tuning, statistics, pre-analysis. Monitoring tasks can and should use the same tools as data analysis products (conventions, libraries, environments) to reduce training, installation, development and support efforts and -at the same time - to strengthen the liaison between the online and the offline worlds. The ALICE DATE Data Acquisition system available today for R&D and for test beams is fully integrated with the ROOT environment. A simple DAQ-oriented approach and a more complex OO-based model have been developed to allow a variety of programming paradigms and to validate the complete life cycle of monitoring tools, both for online and offline environments

The Light Stop Scenario from Gauge Mediation

In this paper we embed the light stop scenario, a MSSM framework which explains the baryon asymmetry of the universe through a strong first order electroweak phase transition, in a top-down approach. The required low energy spectrum consists in the light SM-like Higgs, the right-handed stop, the gauginos and the Higgsinos while the remaining scalars are heavy. This spectrum is naturally driven by renormalization group evolution starting from a heavy scalar spectrum at high energies. The latter is obtained through a supersymmetry-breaking mix of gauge mediation, which provides the scalars masses by new gauge interactions, and gravity mediation, which generates gaugino and Higgsino masses. This supersymmetry breaking also explains the \mu\ and B_\mu\ parameters necessary for electroweak breaking and predicts small tri-linear mixing terms A_t in agreement with electroweak baryogenesis requirements. The minimal embedding predicts a Higgs mass around its experimental lower bound and by a small extension higher masses m_H\lesssim 127 GeV can be accommodated.Comment: 20 pages, 3 figures; v2: changes in the conventions; v3: more details on the Higgs mass prediction, version published in JHE