Study of the reaction e^{+}e^{-}->psi(2S)pi^{-}pi^{-} via initial state radiation at BaBar
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
(2)
,
P. Roudeau
(2)
,
M.H. Schune
(2)
,
A. Stocchi
(2)
,
G. Wormser
(2)
,
D. Bernard
(3)
,
M. Verderi
(3)
,
S. Emery
(4)
,
G. Hamel de Monchenault
(4)
,
G. Vasseur
(4)
,
Ch. Yèche
(4)
,
S. Akar
(5)
,
E. Ben-Haim
(5)
,
M. Bomben
(5)
,
G.R. Bonneaud
(5)
,
H. Briand
(5)
,
G. Calderini
(5)
,
J. Chauvau
(5)
,
O. Hamon
(5)
,
Ph. Leruste
(5)
,
G. Marchiori
(5)
,
J. Ocariz
(5)
,
S. Sitt
(5)
N. Arnaud
- Fonction : Auteur
- PersonId : 16841
- IdHAL : nicolas-arnaud
- ORCID : 0000-0001-6589-8673
G. Vasseur
- Fonction : Auteur
- PersonId : 745439
- IdHAL : georges-vasseur
E. Ben-Haim
- Fonction : Auteur
- PersonId : 1444626
- IdRef : 090175859
M. Bomben
- Fonction : Auteur
- PersonId : 1380362
- ORCID : 0000-0002-9807-861X
- IdRef : 242005462
G. Calderini
- Fonction : Auteur
- PersonId : 10608
- IdHAL : giovanni-calderini
- ORCID : 0000-0002-9495-9145
- IdRef : 172243211
G. Marchiori
- Fonction : Auteur
- PersonId : 741274
- IdHAL : giovanni-marchiori
- ORCID : 0000-0003-2655-7643
- IdRef : 180997203
Résumé
We study the process $e^+e^-\to\psi(2S)\pi^{+}\pi^{-}$ with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the \BaBar detector at center-of-mass energies at and near the $\Upsilon(\mathrm{nS})$ (n = 2, 3, 4) resonances and correspond to an integrated luminosity of 520$fb^{-}$. We investigate the $\psi(2S)\pi^{+}\pi^{-}$ mass distribution from 3.95 to 5.95 $GeV/c^{2}$, and measure the center-of-mass energy dependence of the associated $e^+e^-\to \psi(2S)\pi^{+}\pi^{-}$ cross section. The mass distribution exhibits evidence of two resonant structures. A fit to the $\psi(2S)\pi^{+}\pi^{-}$ mass distribution corresponding to the decay mode $\psi(2S)\to J/\psi \pi^{+}\pi^{-}$ yields a mass value of $4340 \pm16$ (stat) $\pm 9$ (syst) ${\mathrm {MeV/c^{2}}}and a width of $94 \pm 32$ (stat) $\pm 13$ (syst) MeV for the first resonance, and for the second a mass value of $4669 \pm 21$ (stat) $\pm 3$ (syst) ${\mathrm {MeV/c^{2}}}$ and a width of $104 \pm 48$ (stat) $\pm 10$ (syst) MeV. In addition, we show the $pi^{+}\pi^{-}$ mass distributions for these resonant regions.