A search for the decay of the tau lepton to seven charged pions and one or zero pi(0) mesons was performed using the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider. The analysis uses 232.2 fb(-1) of data at center-of-mass energies on or near the Upsilon(4S) resonance. We observe 24 events with an expected background of 21.6 +/- 1.3 events. Without evidence for a signal, we calculate an upper limit of B(tau(-)-> 4 pi(-)3 pi(+)(pi(0))nu(tau))< 3.0 x 10(-7) at 90% confidence level. This is an improvement by nearly an order of magnitude over the previously established limit. In addition, we set upper limits for the exclusive decays tau(-)-> 4 pi(-)3 pi(+)nu(tau) and tau(-)-> 4 pi(-)3 pi(+)pi(0)nu(tau).
Search for the decay tau(-->)4 pi(-)3 pi(+)(pi(0))nu(tau) RID C-2728-2008 RID C-5223-2009 RID C-5719-2008 RID D-1055-2009
LUSIANI, Alberto;
2005
Abstract
A search for the decay of the tau lepton to seven charged pions and one or zero pi(0) mesons was performed using the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider. The analysis uses 232.2 fb(-1) of data at center-of-mass energies on or near the Upsilon(4S) resonance. We observe 24 events with an expected background of 21.6 +/- 1.3 events. Without evidence for a signal, we calculate an upper limit of B(tau(-)-> 4 pi(-)3 pi(+)(pi(0))nu(tau))< 3.0 x 10(-7) at 90% confidence level. This is an improvement by nearly an order of magnitude over the previously established limit. In addition, we set upper limits for the exclusive decays tau(-)-> 4 pi(-)3 pi(+)nu(tau) and tau(-)-> 4 pi(-)3 pi(+)pi(0)nu(tau).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
