arXiv subjects
Publications and source records attributed to F. M. Borzumati.
We point out that charged Higgs bosons can decay into final states different than $τ^+ ν_τ$ and $c \bar{s}$, even when they are light enough to be produced at LEPII or at the Tevatron, through top-quark decays. These additional decay modes are overlooked in ongoing searches even though they alter the existing lower bounds on the mass of charged Higgs bosons that are present in supersymmetric and two Higgs doublets models.
The possibility of radiative generation of fermion masses from soft supersymmetry breaking chiral flavor violation is explored. Consistent models are identified and classified. Phenomenological implications for electric dipole moments and magnetic moments, as well as collider probes -- in particular those relevant at the Higgs resonance -- are discussed. It is shown that partial widths $Γ_{h^{0} \to ff}$ are enhanced compared with the minimal supersymmetric standard model.
We calculate the inclusive production of charged hadrons in $\pbp$ collisions to next-to-leading order (NLO) in the QCD improved parton model using a new set of NLO fragmentation functions for charged pions and kaons. We predict transverse-momentum distributions and compare them with experimental data from the CERN S$\pbp$S Collider and the Fermilab Tevatron.
It is shown that the minimal supersymmetric SO(10) model with electroweak radiative breaking and universal soft mass terms at the GUT scale is strongly disfavoured by the combination of constraints from the $b\to s γ$ decay and the condition $Ωh^2 < 1$ for the lightest (stable) neutralino. The constraints are, however, easily satisfied for certain class of supersymmetric SO(10) models with non--universal scalar masses which gives small supersymmetric corrections to the bottom quark mass and light higgsino--like neutralinos.
The supersymmetric decays of the top quark into charged Higgs plus bottom, $\thb$, and into the supersymmetric partner of the top (${\wti u}_1$) plus the lightest neutralino (${\wti χ}_1^0$), $\tstopneu$, are discussed within the framework of the Minimal Supersymmetric Standard Model with radiatively induced breaking of the gauge group $SU(2)\times U(1)$. The possibility of detecting these decays at present, i.e. given the available bounds on supersymmetric parameters, is compared with the situation a Next $e^+e^-$ Linear Collider would face if supersymmetric particles were still undiscovered at LEP~II. The indirect implications for $\thb$ and $\tstopneu$ of a measurement of the bottom quark decay $\bsgamma$ at the Standard Model level are taken into account. }}
We present a re-analysis of the decay $\bsgamma$ in the Minimal Supersymmetric Standard Model with radiatively induced breaking of $SU(2) \times U(1)$. We extend this analysis to regions of the supersymmetric parameter space wider than those previously studied. Results are explicitly presented for $m_t=150\GeV$. We emphasize the consequences for future searches of charged Higgs and charginos from a measurement of the branching ratio for this decay compatible with the Standard Model prediction. In spite of the strong sensitivity of this decay to the effects of supersymmetry, we find that, at the moment, no lower limit on the mass of these particles can be obtained. The large chargino contributions to the branching ratio for $\bsgamma$, for large values of $\tan β$, are effectively reduced by pushing the lightest eigenvalue of the up-squark mass matrix closer to the electroweak scale, i.e. by increasing the degree of degeneracy among the up-squarks.
{Two supersymmetric decays of the top quark, $\thb$ and $\tstopneu$, are discussed within the framework of the Minimal Supersymmetric Standard Model with radiatively induced breaking of $SU(2)\times U(1)$. The present possibility of detecting these decays, given the available bounds on supersymmetric parameters, is compared with the situation a Next $e^+e^-$ Linear Collider would face if supersymmetric particles were still undiscovered after LEP~II. The indirect implications for $\thb$ and $\tstopneu$ of a possible detection of the bottom quark decay $\bsgamma$ at the Standard Model level are taken into account. } % Invited talk presented to the {\it Workshop on Physics and Experiments with Linear $e^+e^-$ Colliders}, Waikoloa, Hawaii, April 1993
We calculate in next-to-leading order inclusive cross sections of single-particle production via resolved photons in $ep$ collisions at HERA. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with first experimental data from the H1 Collaboration at HERA.
Inclusive single-particle production cross sections have been calculated including higher-order QCD corrections. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with experimental data from the CERN S(p anti-p)S Collider and the Fermilab Tevatron.