Semileptonic decays of the light $J^P=1/2^{+}$ ground state baryon octet

We calculate the semileptonic baryon octet-octet transition form factors using a manifestly Lorentz covariant quark model approach based on the factorization of the contribution of valence quarks and chiral effects. We perform a detailed analysis of SU(3)-breaking corrections to the hyperon semileptonic decay form factors. We present complete results on decay rates and asymmetry parameters including lepton mass effects for the rates.

Figure 1

Baryon mass operator. Bold and thin lines refer to the baryons and quarks, respectively. Quarks are labeled by the indices $k=1$, 2, 3.

Figure 2

Diagrams contributing to the matrix elements of the bare quark operators $V_{\mu ,k}^{ij}(0)$ and $A_{\mu ,k}^{ij}(0)$, $k=1$, 2, 3: triangle (a), bubbles (b) and (c). Bold, thin, and wiggly lines refer to the baryons, quarks, and external weak field, respectively. Quarks participating in the quark flavor transition $q_i\to q_j$ are labeled by the indices $1i$ and $1j$, while the spectator quarks—by the indices 2 and 3. Initial and final baryons are labeled by the indices $i$ and $j$.