2026-04-14T08:39:42Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1313922025-12-05T16:39:31Zcom_2072_1057col_2072_478823col_2072_478917

00925njm 22002777a 4500 dc Graugés Pous, Eugeni author BABAR Collaboration author 2019-04-04T11:39:44Z 2019-04-04T11:39:44Z 2006-06-09 2019-04-04T11:39:44Z search for the decay of the τ lepton to five charged and two neutral pions is performed using data collected by the BABAR detector at the PEP-II asymmetric-energy e + e − collider. The analysis uses 232     fb − 1 of data at center-of-mass energies on or near the Υ ( 4 S ) resonance. We observe 10 events with an expected background of 6.5 + 2.0 − 1.4 events. In the absence of a signal, we set the limit on the branching ratio B ( τ − → 3 π − 2 π + 2 π 0 ν τ ) < 3.4 × 10 − 6 at the 90% confidence level. This is a significant improvement over the previously established limit. In addition, we search for the decay mode τ − → 2 ω π − ν τ . We observe 1 event with an expected background of 0.4 + 1.0 − 0.4 events and calculate the upper limit B ( τ − → 2 ω π − ν τ ) < 5.4 × 10 − 7 at the 90% confidence level. This is the first upper limit for this mode. Física de partícules Experiments Particle physics Experiments Search for the decay τ− → 3π−2π+2π0ντ