Charged Higgs-boson production in association with an electron and a neutrino at electron-positron colliders

We present results of a calculation of the cross section for the production of a charged Higgs boson in association with an electron and a neutrino at electron-positron colliders (e+ e- -> H+ e- nu_e-bar, H- e+ nu_e). We study predictions for the cross section in the Minimal Supersymmetric Standard Model (MSSM) and the Two Higgs Doublet Model (THDM), highlighting possible differences. The process is effectively loop-induced in both models. Hence, the cross section is expected to be strongly model-dependent. Most notably, due to the presence of superpartners, the MSSM amplitude contains Feynman graphs of pentagon-type, which are not present in the THDM. This is the first complete one-loop calculation of the cross section for this process in the THDM and the MSSM. For both models, so far, only approximate results with limited ranges of validity were available. Our main aim here is to clarify several open questions in the existing literature on this process. Specifically, we will discuss the validity of the Heavy Fermion loop approximation in both models, and of the Fermion/Sfermion loop approximation in the MSSM.Comment: 21 pages, 8 figures, 1 tabl

Themed project case study: Quadruple tanks control with PLCs^†

A themed project based on the control of a quadruple tank rig using PLCs has been successfully carried out as part of the MSc in Advanced Control and Systems Engineering at the University of Manchester. The themed project involves ten students who address a single multivariable control challenge under the supervision of two academics and four PhD students. As every student is required to write their own MSc dissertation, the key point is the possibility of using different control techniques to be implemented on different hardware platforms. </jats:p

On MSSM charged Higgs boson production in association with an electroweak W boson at electron positron colliders

We present a calculation of the cross section for the process e+ e- --> W+/- H-/+ in the minimal supersymmetric standard model (MSSM) and the Two Higgs Doublet Model (THDM). We study the basic features of the MSSM prediction for some distinctive parameter scenarios. We find large effects from virtual squarks for scenarios with large mixing in the stop sector which can lead to a cross section vastly different from a THDM with identical Higgs sector parameters. We investigate this interesting behaviour in more detail by thoroughly scanning the MSSM parameter space for regions of large cross section. For a charged Higgs boson too heavy to be pair-produced at such a machine, it turns out that a large MSSM cross section with a good chance of observation is linked to a squark mass scale below 600 GeV and a considerable amount of mixing in either the stop and sbottom sector.Comment: 25 pages, 10 figures (two in colour). Substantially improved on the MSSM parameter restrictions taken into account. Added some reference