The decays τ → (K,K(1460))ντ and the value of the weak decay constants FK and FK′ in the extended NJL model

Abstract

In the extended Nambu–Jona-Lasinio (NJL) model, the decay widths of [Formula: see text], [Formula: see text] are calculated. The contributions from intermediate axial-vector mesons [Formula: see text], [Formula: see text] and the first radially excited state [Formula: see text] are taken into account. Estimates for the weak decay constants [Formula: see text] and [Formula: see text] are given. Predictions are made for the width of [Formula: see text] decay and [Formula: see text] constant.

The decay τ → K∗0(892)K−ντ in the extended NJL model

“…M a 1 (1260) = 1299(+12, −28) MeV, M K 1 (1270) = 1272 ± 7 MeV, M K 1 (1400) = 1403 ± 7 MeV are the mass of axial-vector mesons [3,11]. The splitting of the K 1A state into two physical mesons K 1 (1270) and K 1 (1400) is taken into account in the expression for Z K , α = 57 • [12,13].…”

“…The terms in the curly brackets (12) are the contributions of the contact diagram and diagrams with intermediate mesons in the ground and first radially excited states. M µν…”

Low-energy interactions of mesons with participation of the first radially excited states in $U(3) \times U(3)$ NJL model

“…where β = 57 • [30]. Equation ( 22) can be used to determine the mass of the s quark m s = 420 MeV, which leads to agreement of the charged kaon mass with the experimental value [31]. For the s quark current mass we obtain the value m 0 s = 76 MeV.…”

“…The matrices λ u and λ s are defined in (31), the matrices λ K are defined in (38) and the matrices λ π are defined in (58).…”

“…describe the transitions of intermediate mesons to the kaon [31]. The value M 2 K 1A is defined as follows:…”