Tetraquark-based analysis and predictions of the cross sections and distributions for the processes e^+ e^- --> Upsilon(1S) (pi^+ pi^-, K^+ K^-, eta pi^0) near Upsilon(5S)

TL;DR

This paper uses a tetraquark model to analyze and predict cross sections and distributions for specific e+ e- to Upsilon(1S) final states near the Upsilon(5S) resonance, fitting existing data and proposing new tests.

Contribution

It introduces a tetraquark-based approach to calculate and predict cross sections and distributions for these processes, providing a new framework for understanding the data.

Findings

Good fits to existing Upsilon(1S) pi+ pi- and K+ K- data

Dominance of light scalar and tensor states in spectra

Predicted ratio of cross sections for charged and neutral K Kbar states

Abstract

We calculate the cross sections and final state distributions for the processes e^+ e^- --> Upsilon(1S) (pi^+ pi^-, K^+ K^-, eta pi^0) near the Upsilon(5S) resonance based on the tetraquark hypothesis. This framework is used to analyse the data on the Upsilon(1S) pi^+ pi^- and Upsilon(1S) K^+ K^- final states [K.F. Chen et al. (Belle Collaboration), Phys. Rev. Lett. 100, 112001 (2008); I. Adachi et al. (Belle Collaboration), arXiv:0808.2445], yielding good fits. Dimeson invariant mass spectra in these processes are shown to be dominated by the corresponding light scalar and tensor states. The resulting correlations among the cross sections are worked out. We also predict sigma(e^+ e^- --> Upsilon(1S) K^+ K^-)/sigma(e^+ e^- --> Upsilon(1S) K^0 Kbar^0) = 1/4. These features provide crucial tests of the tetraquark framework and can be searched for in the currently available and forthcoming data from the B factories.