Unveiling the $K_1(1270)$ double-pole structure in the $\bar{B}\to J/\psi \rho\bar{K}$ and $\bar{B}\to J/\psi \bar{K}^*\pi$ decays

TL;DR

This paper investigates the double-pole structure of the $K_1(1270)$ resonance in specific B meson decays using the Chiral Unitary approach, predicting how this structure influences meson spectra for future experimental verification.

Contribution

It introduces a theoretical model employing the Chiral Unitary approach to reveal the double-pole nature of the $K_1(1270)$ resonance in B meson decay spectra.

Findings

The $K_1(1270)$ appears as a dynamically generated double-pole in the model.

The resonance significantly affects the invariant mass distributions in the studied decays.

Model predictions can be tested in future experimental analyses.

Abstract

By looking at the pseudoscalar-vector meson spectra in the $\bar{B}\to J/\psi \rho\bar{K}$ and $\bar{B}\to J/\psi \bar{K}^*\pi$ weak decays, we theoretically investigate the double-pole structure of the $K_1(1270)$ resonance by using the Chiral Unitary approach to account for the final state interactions between the pseudoscalar and vector mesons. The $K_1(1270)$ resonance appears as dynamically generated through these interactions in coupled channels and influence the shape of the invariant mass distributions under consideration. We show how those shapes are affected by the $K_1(1270)$ double-pole structure to confront the results from our model with future experiments that might investigate the $PV$ spectra in these decays.