Unveiling the K1(1270) double-pole structure in the B¯→J/ψρK¯ and B¯→J/ψK¯*π decays

J M Dias,E Oset,G Toledo,L Roca

doi:10.1103/physrevd.103.116019

J M Dias, E Oset + Show 2 more

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https://doi.org/10.1103/physrevd.103.116019

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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.

Highlights

The observation of the axial-vector mesons K1ð1270Þ and K1ð1400Þ [1,2] were identified as the expected 1þ strange mesons from the quark model
By looking at the pseudoscalar-vector meson spectra in the B → J=ψρKand B → J=ψK Ãπ weak decays, we theoretically investigate the double-pole structure of the K1ð1270Þ resonance by using the chiral unitary approach to account for the final-state interactions between the pseudoscalar (P) and vector (V) mesons
The two-pole structure for the K1ð1270Þ resonance is not unique: there are several cases where two poles were found for hadronic resonances, and a recent review can be seen in Ref. [8]

Summary

INTRODUCTION

The observation of the axial-vector mesons K1ð1270Þ and K1ð1400Þ [1,2] were identified as the expected 1þ strange mesons from the quark model. While the dominant K1ð1270Þ decay channel is ρK, the K1ð1400Þ is observed to decay mostly through the KÃð892Þπ one. These states have usually been studied in terms of the mixing of the strange states of the JPC 1⁄4 1þþ and JPC 1⁄4 1þ− nonets Another study considered the Dþ → νlþK1ð1270Þ decay [10], identifying the signatures in the invariant-mass distributions of the decaying K1ð1270Þ. In this work we provide an additional reaction, considering decays of the form B 0 → J=ψVP, where VP are the vector and pseudoscalar meson pairs, ρKand K Ãπ, using the chiral unitary approach, and we look for signatures of the two K1ð1270Þ states. Invariant-mass distribution for the VP pair and its structure in terms of the individual poles, and identify the regions where the signature of such poles can be extracted

VP pseudoscalar and vector meson production

Final-state interaction and the K1ð1270Þ resonance

RESULTS

CONCLUSIONS