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R. Kowalewski

Publications and source records attributed to R. Kowalewski.

4 recordsLinked to original sources

Track Finding Efficiency in BaBar

We describe several studies to measure the charged track reconstruction efficiency and asymmetry of the BaBar detector. The first two studies measure the tracking efficiency of a charged particle using $τ$ and initial state radiation decays. The third uses the $τ$ decays to study the asymmetry in tracking, the fourth measures the tracking efficiency for low momentum tracks, and the last measures the reconstruction efficiency of $K_S^0$ particles. The first section also examines the stability of the measurements vs BaBar running periods.

hep-ex

Averages of b-hadron and c-hadron Properties at the End of 2007

This article reports world averages for measurements of b-hadron and c-hadron properties obtained by the Heavy Flavor Averaging Group (HFAG) using the results available at the end of 2007. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, and parameters of semileptonic decays.

hep-ex

Dark matter pair-production in b -> s transitions

The flavour-changing neutral current transition b \to s can serve as a sensitive probe of WIMP dark matter models, if the WIMP mass is under 2 GeV. In this work we extend our earlier analysis to a generic class of models where the interaction between the dark matter sector and the Standard Model matter sector is mediated by the Higgs boson(s). We show that experimental limits on the decays of B-mesons to K(K^*) and missing energy provide stringent constraints on the parameter space of such models, but do not rule out sub-GeV WIMPs in a model-independent way. We find that in the context of the NMSSM with light pseudoscalar Higgs, the WIMP masses under a few hundred MeV are generically excluded with the exception of few highly tuned points in the parameter space.

hep-ph

Averages of b-hadron Properties at the End of 2005

This article reports world averages for measurements on b-hadron properties obtained by the Heavy Flavor Averaging Group (HFAG) using the available results as of at the end of 2005. In the averaging, the input parameters used in the various analyses are adjusted (rescaled) to common values, and all known correlations are taken into account. The averages include lifetimes, neutral meson mixing parameters, parameters of semileptonic decays, branching fractions of B meson decays to final states with open charm, charmonium and no charm, and measurements related to CP asymmetries.

hep-ex