Strong decays of the lowest bottomonium hybrid within an extended Born–Oppenheimer framework

Abstract

AbstractWe analyze the decays of the theoretically predicted lowest bottomonium hybrid H(1P) to open bottom two-meson states. We do it by embedding a quark pair creation model into the Born–Oppenheimer framework which allows for a unified, QCD-motivated description of bottomonium hybrids as well as bottomonium. A new $$^{1}\!P_{1}$$ 1 P 1 decay model for H(1P) comes out. The same analysis applied to bottomonium leads naturally to the well-known $$^{3}\!P_{0}$$ 3 P 0 decay model. We show that H(1P) and the theoretically predicted bottomonium state $$\varUpsilon (5S)$$ Υ ( 5 S ) , whose calculated masses are close to each other, have very different widths for such decays. A comparison with data from $$\varUpsilon (10860)$$ Υ ( 10860 ) , an experimental resonance whose mass is similar to that of $$\varUpsilon (5S)$$ Υ ( 5 S ) and H(1P), is carried out. Neither a $$\varUpsilon (5S)$$ Υ ( 5 S ) nor a H(1P) assignment can explain the measured decay widths. However, a $$\varUpsilon (5S)$$ Υ ( 5 S ) –H(1P) mixing may give account of them supporting previous analyses of dipion decays of $$\varUpsilon (10860)$$ Υ ( 10860 ) and suggesting a possible experimental evidence of H(1P).