Study of $e^{+}{e}^{-}\to \eta \varphi$ via Initial State Radiation at Belle

Abstract

Using $980f{b}^{-1}$ of data collected on and around the ${\rm Y}(nS)(n=1,2,3,4,5)$ resonances with the Belle detector at the KEKB collider, we measure the cross section of $e^{+}{e}^{-}\to \eta \varphi$ from threshold to $3.95\mathrm{GeV}/c^2$ via initial-state radiation. From a multi-parameter fit assuming $\varphi (2170)$ exists in the $\eta \varphi$ final state according to previous measurement by BESIII, the resonant parameters of $\varphi (1680)$ are determined to be $m_{\varphi (1680)}=(1683\pm 7\pm 9)\mathrm{MeV}/c^2$ (statistical and systematic errors, respectively), ${\Gamma }_{\varphi (1680)}=(149\pm 12\pm 13)\mathrm{MeV}$ and, depending on the possible presence of interfering resonances, ${\Gamma }_{\varphi (1680)}^{e^{+}{e}^{-}}\cdot \mathcal{B}[\varphi (1680)\to \eta \varphi ]=(122\pm 6\pm 13)\mathrm{eV}$, $(219\pm 15\pm 18)\mathrm{eV}$, $(163\pm 11\pm 13)\mathrm{eV}$ or $(203\pm 12\pm 18)\mathrm{eV}$. The branching fraction of $\varphi (1680)\to \eta \varphi$ decay is determined to be approximately 20%. Additionally, the branching fraction for $J/\psi \to \eta \varphi$ is measured to be $(7.1\pm 1.0\pm 0.5)\times 10^{-4}$. However, there is no significant observed $\varphi (2170)$ signal in the $\eta \varphi$ final states in this analysis, and correspondingly the upper limit for ${\Gamma }_{\varphi (2170)}^{e^{+}{e}^{-}}\cdot \mathcal{B}(\varphi (2170)\to \eta \varphi )$ is determined to be either $0.17\mathrm{eV}$ (for two fits), or $18.6\mathrm{eV}$ (remaining two fits), at 90% confidence level.

References in corpus (34)

• Observation of a narrow charmonium-like state in exclusive B+ -> K+ pi+pi- J/psi decays
• Observation of a New Narrow Charmonium State in Exclusive B+-->K+ pi+pi- J/psi Decays
• Observation of a charged charmoniumlike structure in e+e- to pi+pi-J/psi at \sqrt{s}=4.26 GeV
• Non-Standard Heavy Mesons and Baryons, an Experimental Review
• Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts
• Observation of a Broad Structure in the ${\pi }^{+}{\pi }^{-}J/\psi$ Mass Spectrum around 4.26 GeV/$c^2$
• Study of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}J/\psi$ and Observation of a Charged Charmonium-like State at Belle
• The muon $g-2$ and $\alpha (M_Z^2)$: a new data-based analysis
• Observation of a charged charmoniumlike structure Z_c(4020) and search for the Z_c(3900) in e+e- to pi+pi-h_c
• Quest for precision in hadronic cross sections at low energy: Monte Carlo tools vs. experimental data
• Measurements of e+e- -> K+K-eta, K+K-pi0 and KsK+pi- Cross Sections Using Initial State Radiation Events
• Strong Decays of Strange Quarkonia
• The $e^{+}{e}^{-}\to 2({\pi }^{+}{\pi }^{-}){\pi }^0$, 2(π^+π^-)η$,$K^+ K^-π^+π^-π^0$and$K^+ K^-π^+π^-η$ Cross Sections Measured with Initial-State Radiation
• Radiative return at NLO and the measurement of the hadronic cross-section in electron-positron annihilation
• Hybrid Meson Decay Phenomenology
• A Structure at 2175 MeV in $e^{+}{e}^{-}\to \varphi f_0(980)$ Observed via Initial-State Radiation
• X(2175) as a resonant state of the $\varphi K\bar{K}$ system
• Measurement of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\psi (2S)$ via Initial State Radiation at Belle
• New Hadron States
• Analysis of Y(2175) as a tetraquark state with QCD sum rules
• Observation of the $\varphi (1680)$ and the Y(2175) in $e^{+}{e}^{-}\to \varphi {\pi }^{+}{\pi }^{-}$
• Measurement of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\psi (3686)$ from 4.008 to 4.600$\sim$GeV and observation of a charged structure in the ${\pi }^{\pm }\psi (3686)$ mass spectrum
• One Explanation for the Exotic State Y(4260)
• A Candidate for $1^{--}$ Strangeonium Hybrid
• Y(2175): Distinguish Hybrid State from Higher Quarkonium
• The Y(2175) State in the QCD Sum Rule
• Observation of ψ(4040) and ψ(4160) decay into ηJ/ψ
• Selected strong decays of $\eta (2225)$ and $\varphi (2170)$ as $\Lambda \bar{\Lambda }$ bound states
• The electromagnetic form factors of $\Lambda$ hyperon in the vector meson dominance model
• Observation of a structure in $e^{+}{e}^{-}\to \varphi {\eta }^{\prime }$ at $\sqrt{s}$ from 2.05 to 3.08 GeV
• Mass spectrum and strong decays of strangeonium in a constituent quark model
• Study of the process $e^{+}{e}^{-}\to \varphi \eta$ at center-of-mass energies between 2.00 and 3.08 GeV
• Study of the process $e^{+}{e}^{-}\to K^{+}{K}^{-}\eta$ with the CMD-3 detector at the VEPP-2000 collider
• Strangeonium-like hybrids on the lattice