The contribution of Bc mesons to the search for B → τ ντ decays at LEP

We study the contribution of B_c mesons to the search for B → τν_τ decays. We find that at LEP the contributions from B_u and B_c mesons can be comparable. This observation can have a relevant impact on the extraction of constraints on new physics (such as charged-Higgs contributions) from current LEP limits on B → τν final states. Inclusion of the B_c contribution can reduce the current L3 limit on tan β/M_H from 0.38 GeV⁻¹ (90% CL) down to 0.27 GeV⁻¹ (90% CL).     

Application of capillary electrophoresis at low pH to oligonucleotides quality control.

A method for oligonucleotides analysis by using capillary electrophoresis at low pH in free solution is described. It may be considered an alternative to classical analytical techniques which use basic buffers and require the presence of sieving media to separate oligonucleotides as a function of their length. On the contrary, at low pH oligo nucleotides can be separated only depending on their base composition. A large set of samples consisting of 72 synthetic oligonucleotides bearing a 5'-alkylamine moiety and designed for HLA genotyping were analysed. The quality of these synthetic oligos was easily assessed, and a single base difference in oligonucleotides of equal sequence was detected. The results suggest the application of this method to the emerging field of mutation detection and single nucleotide polymorfism analysis.     

Standard model backgrounds to supersymmetry searches

This work presents a review of the standard model sources of backgrounds to the search of supersymmetry signals. Depending on the specific model, typical signals may include jets, leptons, and missing transverse energy due to the escaping lightest supersymmetric particle. We focus on the simplest case of multijets and missing energy, since this allows us to expose most of the issues common to other more complex cases. The review is not exhaustive, and it is aimed at collecting a series of general comments and observations, to serve as a guideline for the process that will lead to a complete experimental determination of size and features of such SM processes.