Measurement of the I=1 /2 Kπ S -wave amplitude from Dalitz plot analyses of ηc →k K ¯ π in two-photon interactions

We study the processes γγ→K^0_SK^±π^∓ and γγ→K^+K^−π^0 using a data sample of 519  fb^(−1) recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e+e− collider at center-of-mass energies at and near the Υ(nS) (n=2, 3, 4) resonances. We observe ηc decays to both final states and perform Dalitz plot analyses using a model-independent partial wave analysis technique. This allows a model-independent measurement of the mass-dependence of the I=1/2 Kπ S-wave amplitude and phase. A comparison between the present measurement and those from previous experiments indicates similar behavior for the phase up to a mass of 1.5  GeV/c^2. In contrast, the amplitudes show very marked differences. The data require the presence of a new a_0(1950) resonance with parameters m=1931±14±22  MeV/c^2 and Γ=271±22±29  MeV.

[1]  A. Dell'Acqua,et al.  Geant4 - A simulation toolkit , 2003 .

[2]  E. al.,et al.  Model Independent Measurement of \swave $K^{-}\pi^{+}$ systems using $\Dp\to K\pi\pi$ Decays from Fermilab E791 , 2005, hep-ex/0507099.

[3]  Tecnología.  SLAC National Accelerator Laboratory , 2010 .

[4]  L. J. Levinson,et al.  A study of K - π + scattering in the reaction K - p→K - π + n at 11 GeV/ c , 1988 .

[5]  Dug Young Kim,et al.  The FOCUS Collaboration , 2004 .

[6]  P. E. Condon,et al.  Channel Likelihood: An Extension of Maximum Likelihood for Multibody Final States , 1974 .

[7]  G. Hooft,et al.  A theory of scalar mesons , 2008, 0801.2288.

[8]  E. al.,et al.  Evidence for direct CP violation in the decay B±→ D(*)K±, D→KS0π+π - and measurement of the CKM phase φ3 , 2010, 1003.3360.

[9]  C. Yang.  Selection Rules for the Dematerialization of a Particle into Two Photons , 1950 .

[10]  Jae Hyun Kim,et al.  Experimental constraints on the spin and parity of the Z(4430) , 2007, 1306.4894.

[11]  I. Perlman,et al.  Theoretical nuclear physics , 1953 .

[12]  → D−π,et al.  The LHCb Collaboration , 2011 .

[13]  F. Goozen,et al.  The BaBar detector , 2001 .

[14]  Maria Grazia Pia,et al.  The BABAR Detector: Upgrades, Operation and Performance , 2013, 1305.3560.

[15]  L. Gibbons,et al.  Beam simulation : beam transport in the bunch compressor main-linacs and beam delivery systems , beam halo modeling and transport , and implementation as a diagnostic tool for commissioning and operation Personnel and Institution ( s ) requesting funding , 1994 .

[16]  et al.,et al.  Dalitz plot analysis of the D+ → K- π+ π+ decay in the FOCUS experiment , 2007, 0705.2248.

[17]  A. Napier,et al.  Dalitz Plot Analysis of the Decay D + -->K - π + π + and Indication of a Low-Mass Scalar Kπ Resonance , 2002 .

[18]  J. Lees,et al.  Time-Integrated Luminosity Recorded by the BABAR Detector at the PEP-II e + e − Collider , 2013, 1301.2703.

[19]  for the BaBar Collaboration , 2001 .

[20]  D. Lange,et al.  The EvtGen particle decay simulation package , 2001 .

[21]  T. Aushev,et al.  Search for lepton-flavor-violating tau-lepton decays to ‘γ at Belle The BELLE collaboration , 2001 .

[22]  M. Kunze,et al.  The Crystal Barrel Collaboration , 2001 .

[23]  Time-integrated and time-dependent angular analyses of B → J/ψKπ: A measurement of cos2β with no sign ambiguity from strong phases , 2005 .

[24]  L. A. Granado Cardoso,et al.  Observation of the resonant character of the Z(4430)(-) state. , 2014, Physical review letters.

[25]  A. Napier,et al.  Publisher’s Note: Model-independent measurement ofS-waveK−π+systems usingD+→Kππdecays from Fermilab E791 [Phys. Rev. D 73, 032004 (2006)] , 2006 .

[26]  et al,et al.  Dalitz plot analysis of the D + ! K + + decay , 2007, 0707.3060.

[27]  W. Ochs.  The Status of Glueballs , 2013, 1301.5183.