arXiv subjects
Publications and source records attributed to Sandra Malvezzi.
Interpretation of D-meson decay-dynamics has revealed itself to be strongly dependent on our understanding of the light-meson sector. The interplay becomes particularly evident in Dalitz plot analyses to study physics within and beyond the Standard Model. Experience and results from FOCUS are presented and discussed. A brief update of the pentaquark search in the experiment is also reported.
Progress in charm physics has been prodigious over the last twenty years; it comes both from fixed target and collider experiments, and can guide us toward future investigations. To fully exploit the power of flavor physics, complications coming from strong dynamics effects have to be dealt with. The role of charm in the search for New Physics, the lessons learnt so far and warnings for the future are briefly discussed.
The potentiality of interpreting the D-meson decay-dynamics has revealed itself to be strongly dependent on our understanding of the light-meson sector. The statistics collected by FOCUS is already at a level that manifests parametrization problems for scalar particles. In this paper the first application of the K-matrix approach in the charm sector is illustrated and preliminary results on the D+ and Ds decays to three pions are shown.
Recent results on Dalitz analysis of three-pseudoscalar decays are discussed in the context of probing charm hadronic-decay mechanisms: the role of FSI effects, which create phase shifts between the interfering resonant channels, can be studied in the different decay modes and the annihilation contribution measured in the charm sector through the $D^+_s \to π^+π^-π^+$ decay.
A review of the charmed meson and baryon lifetimes is presented. Our knowledge of charmed particle lifetimes has greatly improved over the past two years, a crucial rôle having been played by the E687 experiment at Fermilab, which has almost quadrupled the samples of $D$ mesons. The lifetime ratios $τ(D^+)/τ(D^0)$ and $τ(D_s^+)/τ(D^0)$ are now known with an accuracy of 1.7\% and 3.7\% respectively. In the baryon sector the statistics is still limited, but the experimental results on $Λ_c^+$, $Ξ_c^0$ and $Ξ_c^+$ exhibit a clear pattern of lifetime hierarchy, as expected from simple theoretical arguments. The first measurement of $τ(Ω_c^0)$ from E687 is also presented to complete the charmed baryon lifetime picture. The more accurate experimental scenario can provide information on non-perturbative QCD effects and the hadronic matrix elements.