Search for the Z(4430)^- at BABAR

Abstract

We report the results of a search for Z(4430)^- decay to J/Ψ π^- or Ψ(2S)π^- in B(^-.0)→ J/Ψ π^-K^(0.+) and B^(-.0) → Ψ(2S)π^-K^(0.+) decays. The data were collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e^+e^- collider operating at center-of-mass energy 10.58 GeV, and the sample corresponds to an integrated luminosity of 413 fb^(-1). Each K π^- mass distribution exhibits clear K^*(892) and K_2^*(1430) signals, and the efficiency-corrected spectrum is well described by a superposition of the associated Breit-Wigner intensity distributions, together with an S-wave contribution obtained from the LASS I=1/2 K π^- scattering amplitude measurements. Each K π^- angular distribution varies significantly in structure with K π^- mass, and is represented in terms of low-order Legendre polynomial moments. We find that each J/Ψ π^- or Ψ (2S)π^- mass distribution is well described by the reflection of the measured K π^- mass and angular distribution structures. We see no significant evidence for a Z(4430)^- signal for any of the processes investigated, neither in the total J/Ψ π^- or Ψ(2S) π^- mass distribution, nor in the corresponding distributions for the regions of K π- mass for which observation of the Z(4430)^- signal was reported. We obtain branching-fraction upper limits [script B](B^- → Z^-[overline K]^0,Z^- → J/Ψ π^-)<1.5×10^(-5), [script B](B^0 → Z^-K^+,Z^- → J/Ψ π^-)<0.4×10^(-5), [script B](B → Z-[overline K]0,Z → Ψ(2S)π-)<4.7×10-5, and [script B](B^0 → Z^-K^+,Z^- → Ψ(2S)π^-)<3.1×10^(-5) at 95% confidence level, where the Z(4430)- mass and width have been fixed to the reported central values

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