Study of T decays involving kaons, spectral functions and determination of the strange quark mass

• Main Authors: BARATE, R., THULASIDAS, M.
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 1999
• Subjects: Computer Sciences; Databases and Information Systems
• Online Access: https://ink.library.smu.edu.sg/sis_research/5862; https://ink.library.smu.edu.sg/context/sis_research/article/6865/viewcontent/ep_99_026.pdf
• Institution: Singapore Management University

All ALEPH measurements of branching ratios of ττ decays involving kaons are summarized including a combination of results obtained with K0SKS0 and K0LKL0 detection. The decay dynamics are studied, leading to the determination of contributions from vector K∗(892)K∗(892) and K∗(1410)K∗(1410), and axial-vector K1(1270)K1(1270) and K1(1400)K1(1400) resonances. Agreement with isospin symmetry is observed among the different final states. Under the hypothesis of the conserved vector current, the spectral function for the KK¯¯¯¯¯πKK¯π mode is compared with the corresponding cross section for low energy e+e−e+e− annihilation, yielding an axial-vector fraction of (94+6−8)%(94−8+6)% for this mode. The branching ratio for ττ decay into all strange final states is determined to be B(τ−→X−(S=−1)ντ)=(28.7±1.2)×10−3B(τ−→X−(S=−1)ντ)=(28.7±1.2)×10−3. The measured mass spectra of the strange ττ decay modes are exploited to derive the S=−1S=−1 spectral function. A combination of strange and nonstrange spectral functions is used to determine the strange quark mass and nonperturbative contributions to the strange hadronic width. A method is developed to avoid the bad convergence of the spin zero hadronic component, with the result ms(M2τ)=(176+46−57)ms(Mτ2)=(176−57+46) MeV/c2c2. The evolution down to 1 GeV gives ms(1GeV2)=(234+61−76)MeV/c2ms(1GeV2)=(234−76+61)MeV/c2.