Dalitz plot analysis of $\eta_c \to K^+ K^- \eta$ and $\eta_c \to K^+ K^- \pi^0$ in two-photon interactions
J.P. Lees
(1)
,
V. Poireau
(1)
,
V. Tisserand
(1)
,
N. Arnaud
(2)
,
M. Davier
(2)
,
D. Derkach
(2)
,
G. Grosdidier
(2)
,
F. Le Diberder
(2)
,
A.M. Lutz
(2)
,
B. Malaescu
(3)
,
P. Roudeau
(2)
,
M.H. Schune
(2)
,
A. Stocchi
(2)
,
G. Wormser
(2)
,
D. Bernard
(4)
,
M. Verderi
(4)
,
S. Emery
(5)
,
G. Hamel de Monchenault
(5)
,
G. Vasseur
(5)
,
Ch. Yèche
(5)
,
S. Akar
(3)
,
E. Ben-Haim
(3)
,
M. Bomben
(3)
,
G.R. Bonneaud
(3)
,
H. Briand
(3)
,
G. Calderini
(3)
,
J. Chauvau
(3)
,
O. Hamon
(3)
,
Ph. Leruste
(3)
,
G. Marchiori
(3)
,
J. Ocariz
(3)
,
S. Sitt
(3)
N. Arnaud
- Function : Author
- PersonId : 16841
- IdHAL : nicolas-arnaud
- ORCID : 0000-0001-6589-8673
G. Vasseur
- Function : Author
- PersonId : 745439
- IdHAL : georges-vasseur
M. Bomben
- Function : Author
- PersonId : 1380362
- ORCID : 0000-0002-9807-861X
- IdRef : 242005462
G. Calderini
- Function : Author
- PersonId : 10608
- IdHAL : giovanni-calderini
- ORCID : 0000-0002-9495-9145
- IdRef : 172243211
G. Marchiori
- Function : Author
- PersonId : 741274
- IdHAL : giovanni-marchiori
- ORCID : 0000-0003-2655-7643
- IdRef : 180997203
Abstract
We study the processes $\gamma \gamma \to K^+ K^- \eta$ and $\gamma \gamma \to K^+ K^- \pi^0$ 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 $\Upsilon(nS)$ ($n = 2,3,4$) resonances. We observe $\eta_c \to K^+ K^- \eta$ and $\eta_c \to K^+ K^- \pi^0$ decays, measure their relative branching fraction, and perform a Dalitz plot analysis for each decay. We observe the $K^*_0(1430) \to K \eta$ decay and measure its branching fraction relative to the $K \pi$ decay mode to be ${\cal R}(K^*_0(1430)) = \frac{{\cal B}(K^*_0(1430) \to K \eta)}{{\cal B}(K^*_0(1430) \to K \pi)} = 0.092 \pm 0.025^{+0.010}_{-0.025}$. The $\eta_c \to K^+ K^- \eta$ and $K^*_0(1430) \to K \eta$ results correspond to the first observations of these channels. The data also show evidence for $\eta_c(2S) \to K^+ K^- \pi^0$ and first evidence for $\eta_c(2S) \to K^+ K^- \eta$.