τ → f1π−ντ decay in the extended Nambu–Jona-Lasinio model

Семинар «Физика адронов»

Дата и время: пятница, 22 декабря 2017 г., в 11:00

Место: Конференц-зал им. Блохинцева (4-й этаж), Лаборатория теоретической физики им. Н.Н. Боголюбова

Тема семинара: «τ → f₁π⁻ν_τ decay in the extended Nambu–Jona-Lasinio model»

Докладчик: А. А. Пивоваров

Авторы: М. К. Волков, А. А. Пивоваров, А. А. Осипов

Аннотация:

Within the framework of the extended Nambu–Jona-Lasinio model, we calculate the matrix element of the τ → f₁(1285)π⁻ν_τ decay and estimate the value of the branching ratio Br(τ → f₁π⁻ν_τ) = 4.0 × 10⁻⁴. The two types of contributions are considered: the contact interaction, and the axial-vector I^G(J^PC) = 1⁻(1⁺⁺) resonance exchange. The latter includes the ground a₁(1260) state, and its first radially excited state, a^|₁(1640). The corrections caused by the πa₁ transition are taken into account. The result is in a good agreement with known phenomenological data Br_exp(τ → f₁π⁻ν_τ) = (3.9 ± 0.5) × 10⁻⁴.