Measurement of the spectral functions of vector current hadronic tau decays

• Main Authors: BARATE, R., THULASIDAS, M.
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 1997
• Subjects: Computer Engineering; Databases and Information Systems
• Online Access: https://ink.library.smu.edu.sg/sis_research/5847; https://ink.library.smu.edu.sg/context/sis_research/article/6850/viewcontent/ppe_97_013.pdf
• Institution: Singapore Management University

A measurement of the spectral functions of non-strange τ vector current final states is presented, using 124 358 τ pairs recorded by the ALEPH detector at LEP during the years 1991 to 1994. The spectral functions of the dominant two- and four-pion τ decay channels are compared to published results of e + e - annihilation experiments via isospin rotation. A combined fit of the pion form factor from τ decays and e + e - data is performed using different parametrizations. The mass and the width of the ρ ±(770) and the ρ 0(770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M ρ ± (770) - M ρ 0 (770) = (0.0 ± 1.0) MeV/c 2 and Γ ρ ± (770) - Γ ρ 0 (770) = (0.1 ± 1.9) MeV/c 2.