# Search for the Decay $\tau^- \rightarrow 3\pi^- 2\pi^+2\pi^0 \nu_\tau$

### Description

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{sup +}e{sup -} collider. The analysis uses 232 fb{sup -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{sub -1.4}{sup +2.0} events. In the absence of a signal, we set the limit on the branching ratio {Beta}({tau}{sup -} {yields} 3{pi}{sup -}2{pi}{sup +}2{pi}{sup 0}{nu}{sub {tau}}) &lt; 3.4 x 10{sup -6} at the 90% confidence level. This is a significant improvement ... continued below

8 pages

### Creation Information

Aubert, B. April 10, 2006.

### Context

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### Description

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{sup +}e{sup -} collider. The analysis uses 232 fb{sup -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{sub -1.4}{sup +2.0} events. In the absence of a signal, we set the limit on the branching ratio {Beta}({tau}{sup -} {yields} 3{pi}{sup -}2{pi}{sup +}2{pi}{sup 0}{nu}{sub {tau}}) &lt; 3.4 x 10{sup -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}{sup -} {yields} 2{omega}{pi}{sup -}{nu}{sub {tau}}. We observe 1 event with an expected background of 0.4{sub -0.4}{sup +1.0} events and calculate the upper limit {Beta}({tau}{sup -} {yields} 2{omega}{pi}{sup -}{nu}{sub {tau}}) &lt; 5.4 x 10{sup -7} at the 90% confidence level. This is the first upper limit for this mode.

8 pages

### Identifier

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• Report No.: SLAC-PUB-11804
• Grant Number: AC02-76SF00515
• DOI: 10.2172/881120 | External Link
• Office of Scientific & Technical Information Report Number: 881120

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#### Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

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### Creation Date

• April 10, 2006

### Added to The UNT Digital Library

• Sept. 21, 2016, 2:29 a.m.

### Description Last Updated

• Dec. 8, 2016, 10:51 p.m.

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Aubert, B. Search for the Decay $\tau^- \rightarrow 3\pi^- 2\pi^+2\pi^0 \nu_\tau$, report, April 10, 2006; [Menlo Park, California]. (digital.library.unt.edu/ark:/67531/metadc885590/: accessed December 16, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.