A search for the decay of the tau 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 Upsilon(4S) resonance. We observe 10 events with an expected background of 6.5(-1.4)(+2.0) events. In the absence of a signal, we set the limit on the branching ratio B(tau(-)-> 3 pi(-)2 pi(+)2 pi(0)nu(tau))< 3.4x10(-6) at the 90% confidence level. This is a significant improvement over the previously established limit. In addition, we search for the decay mode tau(-)-> 2 omega pi(-)nu(tau). We observe 1 event with an expected background of 0.4(-0.4)(+1.0) events and calculate the upper limit B(tau(-)-> 2 omega pi(-)nu(tau))< 5.4x10(-7) at the 90% confidence level. This is the first upper limit for this mode.
Search for the decay tau(-)-> 3 pi(-)2 pi(+)2 pi(0)nu(tau) RID A-8798-2012 RID C-2728-2008 RID C-5223-2009 RID C-5719-2008 RID D-1055-2009 RID A-2675-2009
LUSIANI, Alberto;
2006
Abstract
A search for the decay of the tau 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 Upsilon(4S) resonance. We observe 10 events with an expected background of 6.5(-1.4)(+2.0) events. In the absence of a signal, we set the limit on the branching ratio B(tau(-)-> 3 pi(-)2 pi(+)2 pi(0)nu(tau))< 3.4x10(-6) at the 90% confidence level. This is a significant improvement over the previously established limit. In addition, we search for the decay mode tau(-)-> 2 omega pi(-)nu(tau). We observe 1 event with an expected background of 0.4(-0.4)(+1.0) events and calculate the upper limit B(tau(-)-> 2 omega pi(-)nu(tau))< 5.4x10(-7) at the 90% confidence level. This is the first upper limit for this mode.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
