2016/11/30 by Yun-Hua Chen, Yunhua Chen, Martin Cleven +9 · 40 citations
Mathematics · Physics and Astronomy · #Distribution (mathematics) #Geometry #High-Energy Particle Collisions Research #Invariant mass #Mathematical analysis #Mathematics #Meson #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pi #Pion #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Spectral line #hep-ex #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.95.034022
published in Physical review. D/Physical review. D. 95(3) (American Physical Society) · 25 pages, 8 figures, predictions of the decay width and the dikaon mass distribution of the $Υ(4S) \rightarrow Υ(1S) K^+ K^-$ process added, more discussions added
openalex created_date 2016/11/11 · openalex publication_date 2017/02/21 · arxiv created 2017/02/22 · arxiv updated 2017/02/27 · openalex updated_date 2026/08/05
We study the dipion transitions \mathrm\ensuremathΥ(4S)\ensuremath→\mathrm\ensuremathΥ(nS)\ensuremathπ+\ensuremathπ^\ensuremath-(n=1,2). In particular, we consider the effects of the two intermediate bottomoniumlike exotic states Zb(10610) and Zb(10650) as well as bottom meson loops. The strong pion-pion final-state interactions, especially including channel coupling to KK in the S wave, are taken into account model independently by using dispersion theory. Based on a nonrelativistic effective field theory we find that the contribution from the bottom meson loops is comparable to those from the chiral contact terms and the Zb-exchange terms. For the \mathrm\ensuremathΥ(4S)\ensuremath→\mathrm\ensuremathΥ(2S)\ensuremathπ+\ensuremathπ^\ensuremath- decay, the result shows that including the effects of the Zb exchange and the bottom meson loops can naturally reproduce the two-hump behavior of the \ensuremathπ\ensuremathπ mass spectra. Future angular distribution data are decisive for the identification of different production mechanisms. For the \mathrm\ensuremathΥ(4S)\ensuremath→\mathrm\ensuremathΥ(1S)\ensuremathπ+\ensuremathπ^\ensuremath- decay, we show that there is a narrow dip around 1 GeV in the \ensuremathπ\ensuremathπ invariant mass distribution, caused by the final-state interactions. The distribution is clearly different from that in similar transitions from lower \mathrm\ensuremathΥ states, and needs to be verified by future data with high statistics. Also we predict the decay width and the dikaon mass distribution of the \mathrm\ensuremathΥ(4S)\ensuremath→\mathrm\ensuremathΥ(1S)K+K^\ensuremath- process.