Professor Daniela Bortoletto

Abstract:

We report on a search for Λb0→pπ- and Λb0→pK- (and charge conjugate) decays in pp̄ collisions at s=1.96TeV using 193pb-1 of data collected by the CDF II experiment at the Fermilab Tevatron Collider. Data were collected using a track trigger that has been optimized to select tracks belonging to a secondary vertex that is typical of two-body charmless decays of b-flavored hadrons, including Λb0 baryons. As no Λb0 signal was observed, we set the upper limits on the branching fraction B(Λb0→ph-), where h is K or π, of 2.3×10-5 at 90% C.L. and 2.9×10-5 at 95% C.L. © 2005 The American Physical Society.

Abstract:

We present a search for long-lived doubly charged Higgs bosons (H±±), with signatures of high ionization energy loss and muonlike penetration. We use 292pb-1 of data collected in pp̄ collisions at s=1.96TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly charged particle production, we exclude HL±± and HR±± bosons with masses below 133GeV/c2 and 109GeV/c2, respectively. In the degenerate case we exclude H±± mass below 146GeV/c2. All limits are quoted at the 95% confidence level. © 2005 The American Physical Society.