You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


---
abstract: 'Recent results from BES-II experiment on hadron spectroscopy using ${J/\psi}$ and ${\psi^{\prime}}$ data samples collected in ${e^+e^-}$ annihilation are presented, including study of the scalar particles in ${J/\psi}$ radiative and hadronic decays, the observation of $X(1810)$ in $J/\psi \to \gamma \phi \omega$, as well as pair productions of scalars in ${\chi_{c0}}$ hadronic decays.'
address: 'Institute of High Energy Physics, P.O.Box 918, Beijing 100049, China'
author:
- 'Haibo Li [^1]'
title: 'Study of Scalar Mesons at BES-II'
---

Introduction
============

The scalar mesons are one of the most controversial subjects in hadron physics. Below 1.0 GeV, there are two $I = 0$ saclar candidates, $\sigma$ ($\pi\pi$ S-Wave), $f_0(980)$ and one $I = 1/2$ $K\pi$ S-wave, $\kappa$, in the Particle Data Group (PDG) lists [@pdg]. Between 1.0 GeV and 2.2 GeV, PDG lists the following $I = 0$ scalar states: $f_0(1370)$, $f_0(1500)$ $f_0(1710)$ and one $I = 1/2$ scalar state: $K^*_0(1430)$. Scalar mesons have been traditionally studied in scattering experiments. However, in these experiments the mesons can be difficult to disentangle from non-resonant backgrounds. Radiative and hadronic $J/\psi$ decays provide an excellent laboratory to probe these states.

Recently, based on 58 million $J/\psi$ decay events and 14 million $\psi(2S)$ decay events collected with BES-II detector [@bes-ii], many detailed partial wave analyses (PWA) have been performed in order to understand the structure, decays and production of the scalar mesons. In this paper, we present some of the results from such study at BES-II.

Scalars in $J/\psi$ Radiative and Hadronic Decays
=================================================

Using the world largest ${J/\psi}$ data sample in $e^+e^-$ annihilation experiment, BES-II studied the scalars decay into pair of pseudoscalars (${\pi^+}{\pi^-}$, ${\pi^0}{\pi^0}$, ${K^+}{K^-}$ and ${K^0_s}{K^0_s}$) in ${J/\psi}$ radiative decays as well as recoiling against a $\phi$ or an $\omega$ [@wpipi; @wkk; @phipipi; @gkk]. The full mass spectra and the scalar part in them are shown in Fig. \[scalars\].

$\sigma$ and $\kappa$
---------------------

From the analyses, BES-II sees significant contributions of $\sigma$ particle in $\omega{\pi^+}{\pi^-}$ and $\omega{K^+}{K^-}$, and also hint in $\phi{\pi^+}{\pi^-}$. In $J/\psi \rightarrow \omega \pi^+\pi^-$, there are conspicuous $\omega
f_2(1270)$ and $b_1(1235)\pi$ signals. At low $\pi\pi$ mass, a large, broad peak due to the $\sigma$ is observed as shown in Fig. \[scalars\](a). Two independent partial wave analyses are performed on $\omega{\pi^+}{\pi^-}$ data and four different parameterizations of the $\sigma$ amplitude are tried [@wpipi], all give consistent results for the $\sigma$ pole, which is at $(541 \pm
39) - i(252 \pm 42)$ MeV/c$^2$. Recently, an analysis of $\psi(2S) \rightarrow \pi^+\pi^- J/\psi$ has been performed to study the $\sigma$ [@zhuys]. The pole position of $\sigma$ is consistent with that from $J/\psi \rightarrow \omega
\pi^+\pi^-$.

Events over all of the 4-body phase space for $J/\psi \rightarrow K^+ K^- \pi^+\pi^-$ have been fitted. We find evidence for the $\kappa$ in the process $J/\psi \rightarrow 
 \overline{K}^*(892)^0 \kappa$, $\kappa \rightarrow (K\pi)_S$. We select a $K^- \pi^+$ pair in the $\overline{K}^*(892)^0$ mass range $892 \pm 100$ MeV. Two independent PWA, by the covariant helicity amplitude method [@34] and by the variant mass and width method [@24] have been performed, providing a cross check with each other. They reproduce the data well, and the results are in good agreement. The low mass enhancement is well described by the scalar $\kappa$, which is highly required in the analyses. Parameter values of Breit-Wigner (BW) mass and width of the $\kappa$, averaged from those obtained by the two methods, are $878\pm23^{+64}_{-55}$ MeV/$c^2$ and $499\pm 52^{+55}_{-87}$ MeV/$c^2$. The pole position is determined to be $(841\pm 30^{+81}_{-73})-i(309 \pm
45^{+48}_{-72})$ MeV/$c^2$ [@kappa_paper].

$f_0(980)$ in $J/\psi$ Decays
-----------------------------

Strong $f_0(980)$ is seen in $J/\psi \rightarrow \phi \pi ^+\pi ^-$ and $\phi
K^+K^-$ modes [@phipipi], from which the resonance parameters are measured to be $M =
965 \pm 8(stat) \pm 6(syst) $ MeV/c$^2$, $g_1 = 165 \pm 10(stat)
\pm 15(syst)$ MeV/c$^2$ and $g_2/g_1 = 4.21 \pm 0.25(stat) \pm
0.21(syst)$, where $M$ is the mass, and $g_1$ and $g_2$ are the couplings to $\pi\pi$ and $K\bar{K}$ respectively if the $f_0(980)$ is parameterized using the the Flatté’s formula. The production of $f_0(980)$ is very weak recoiling against an $\omega$ or a photon, which indicates $s\bar{s}$ is the dominant component in it.

Scalar above $1.0$ GeV in $J/\psi$ Decays
-----------------------------------------

In $J/\psi \rightarrow \phi {\pi^+}{\pi^-}$ decay, a scalar contribution near 1.4 GeV on $\pi^+\pi^-$ invariant mass distribution is found as shown in Fig. ref[scalars]{}(c), it is due to the dominant $f_0(1370)$ interfering with a smaller $f_0(1500)$ component. The mass and width of $f_0(1370)$ are determined to be: $M = 1350 \pm
50$ MeV/c$^2$ and $\Gamma = 265 \pm 40$ MeV/c$^2$. In $\gamma {\pi^+}{\pi^-}$, a similar structure is observed in the same mass region, the fit yields a resonance at mass $1466\pm 6(stat)\pm
16(syst)$ MeV/c$^2$ with width of $108^{+14}_{-11}(stat) \pm
21(syst)$ MeV/c$^2$, possibly the $f_0(1500)$ [@phipipi], and the contribution from the $f_0(1370)$ can not be excluded. While, the production of $f_0(1370)$ and $f_0(1500)$ in $\gamma K \bar{K}$ is insignificant [@gkk].

The $K^+K^-$ invariant mass distributions from $\gamma K \bar{K}$ and $\omega K^+K^-$, the ${\pi^+}{\pi^-}$ invariant mass distributions from $\gamma {\pi^+}{\pi^-}$, and $\phi{\pi^+}{\pi^-}$ show clear scalar contribution around 1.75 GeV/c$^2$. Two states are resolved from the bump, one is $f_0(1710)$ with $M \sim 1740$ MeV/c$^2$ and $\Gamma\sim 150$ MeV/c$^2$ which decays to $K \bar{K}$ mostly, and one possible new state $f_0(1790)$ with $M \sim 1790$ MeV/c$^2$ and $\Gamma\sim 270$ MeV/c$^2$ which couples to $\pi\pi$ stronger than to $K\bar{K}$. However, the existence of the second scalar particle needs confirmation: the signal observed in $\phi
f_0(1790)$ is rather in the edge of the phase space, and the reconstruction efficiency of the $\phi$ decreases dramatically as the momentum of the $\phi$ decreases thus the momentum of the kaon from $\phi$ decays is very low and can not be detected [@zhuys]. Furthermore, there are wide higher mass scalar states above 2 GeV/c$^2$ as observed in $\gamma {\pi^+}{\pi^-}$ (Fig. \[scalars\]e) and $\gamma K \bar{K}$ [@pdg], whose tails may interfere with the $f_0(1710)$ and produce structure near the edge of the phase space.

The discussions of these measurements for understanding the nature of the scalar particles can be found in Refs. [@oset; @close; @zhao], where the ${J/\psi}$ decay dynamics and the fractions of the possible $q\bar{q}$ and glueball components in the states are examined.

Observation of Threshold Enhancements in $J/\psi$ Decays
========================================================

In the last few years, anomalous enhancements near threshold in the invariant mass spectra of $p \bar p$ and $p \bar \Lambda$ pairs were observed in $J/\psi \to \gamma p \bar p$ [@gppb] and $J/\psi \to p K \bar
\Lambda$ [@pkl] decays, respectively, by the BES-II experiment. These surprising experimental observations stimulated many theoretical speculations. Therefore it is of special interests to search for possible resonances in other baryon-antibaryon, baryon-meson, and meson-meson final states.

![The $K^+K^-\pi^+\pi^-\pi^0$ invariant mass distribution for the $J/\psi\to \gamma \omega\phi$ candidate events. The dashed curve indicates the acceptance varying with the $\omega\phi$ invariant mass.[]{data-label="g-phi-omega"}](fig1d.eps){width="6.0cm" height="6.0cm"}

![$M^2(\gamma \phi)$ .vs. $M^2(\gamma \omega)$, Dalitz plot in $J/\psi \rightarrow \gamma \phi \omega$ decay.[]{data-label="g-phi-omega-2"}](fig1e.eps){width="6.0cm" height="6.0cm"}

$X(1810)$ in $J/\psi \rightarrow \gamma \phi \omega$ Decays
-----------------------------------------------------------

An enhancement near threshold is observed in the $\omega \phi$ invariant mass spectrum from the doubly OZI suppressed decays of $J/\psi \to \gamma \omega \phi$, where $\omega$ and $\phi$ are reconstructed from $\pi^+\pi^-\pi^0$ and $K^+K^-$ final states [@gphiomega], respectively. Figure \[g-phi-omega\] shows the $K^+K^-\pi^+\pi^-\pi^0$ invariant mass distribution for events with $K^+K^-$ invariant mass within the nominal $\phi$ mass range ($|m_{K^+K^-}-m_{\phi}|<15$ MeV/$c^2$) and the $\pi^+\pi^-\pi^0$ mass within the $\omega$ mass range ($|m_{\pi^+\pi^-\pi^0}
-m_{\omega}|<30$ MeV/$c^2$), and a structure peaked near $\omega\phi$ threshold is observed. The dashed curve in the figure indicates how the acceptance varies with invariant mass. The peak is also evident as a diagonal band along the upper right-hand edge of the Dalitz plot in Fig. \[g-phi-omega-2\]. There is also a horizontal band near $m^2_{\gamma K^+ K^-} = 2$ (GeV/$c^2$)$^2$ in the Dalitz plot, which mainly comes from background due to $J/\psi \to \omega K^*K$.

![The $2(\pi^+ \pi^- \pi^0)$ invariant mass distribution for candidate events. The dashed curve is the phase space invariant mass distribution, and the dotted curve shows the acceptance versus the $\omega\omega$ invariant mass.[]{data-label="fig2"}](fig2a.eps){width="6.0cm" height="6.0cm"}

![The Dalitz plot in $J/\psi \rightarrow \gamma \omega \omega$ decays. []{data-label="fig2-2"}](fig2b.eps){width="6.0cm" height="5.0cm"}

From a PWA with covariant helicity coupling amplitudes, the spin-parity of the $X = 0^{++}$ with an $\mathcal{S}$-wave $\omega\phi$ system is favored. The enhancement near is observed with a statistical significance of more than 10$\sigma$. The mass and width of the enhancement are determined to be $M = 1812^{+19}_{-26}$ (stat) $\pm$ 18 (syst) MeV/$c^2$ and $\Gamma = 105 \pm 20$ (stat) $\pm$ 28 (syst) MeV/$c^2$, and the product branching fraction is $\mathcal{B}(J/\psi\to\gamma X)\cdot
\mathcal{B}(X\to\omega\phi)$ = (2.61 $\pm$ 0.27 (stat) $\pm$ 0.65 (syst)) $\times$ $10^{-4}$. The mass and width of this state are not compatible with any known scalars listed in the PDG [@pdg]. It could be an unconventional state [@liba; @lixq; @pedro; @chaokt; @bugg]. However, more statistics and further studies are needed to clarify this.

Enhancement in $J/\psi \rightarrow \gamma \omega \omega$ Decays
---------------------------------------------------------------

The decay mode $J/\psi \rightarrow  \gamma \omega \omega$, $\omega
\rightarrow \pi^+\pi^-\pi^0$ is analyzed using a sample of 5.8 million $J/\psi$ decay events. The $\omega \omega$ invariant mass distribution peaks at 1.76 GeV/$c^2$, just above the $\omega \omega$ threshold. The histogram of Fig. \[fig2\] shows the $2(\pi^+ \pi^-
\pi^0)$ invariant mass distribution of events with both $
\pi^+ \pi^- \pi^0$ masses within the $\omega$ range ($|m_{
\pi^+\pi^-\pi^0 }-m_{\omega}| <$40 MeV/$c^2$). There are 3046 events with a clear peak at 1.76 GeV/$c^2$. The phase space invariant mass distribution and the acceptance versus $\omega \omega$ invariant mass are also shown in the figure. The corresponding Dalitz plot is shown in Fig. \[fig2-2\].

  ---------------------------------- --------------- -------------------------------------------------------------------- ------------- --
  Decay Mode                         $N^{obs}$       ${\cal BR}$($10^{-4}$)                                               s.s           

  (X)                                                ${\cal BR}(\chi_{c0} \rightarrow X \rightarrow \pi^+\pi^- K^+K^-)$                 

  ${f_0(980)f_0(980)}$               $27.9\pm8.7$    $3.46\pm                                                             $5.3\sigma$   
                                                     1.08^{+1.93}_{-1.57}$                                                              

  ${f_0(980)f_0(2200)}$              $77.1\pm13.0$   $8.42\pm1.42^{+1.65}_{-2.29}$                                        $7.1\sigma$   

  ${f_0(1370)f_0(1710)}$             $60.6\pm15.7$   $7.12\pm1.85^{+3.28}_{-1.68}$                                        $6.5\sigma$   

  ${K^*(892)^0\bar                   $64.5\pm13.5$   $8.09\pm1.69^{+2.29}_{-1.99}$                                        $7.1\sigma$   
  K^*(892)^0}$                                                                                                                          

  ${K^*_0(1430)\bar                  $82.9\pm18.8$   $10.44\pm2.37^{+3.05}_{-1.90}$                                       $7.2\sigma$   
  K^*_0(1430)}$                                                                                                                         

  ${K^*_0(1430)\bar K^*_2(1430)} +   $62.0\pm12.1$   $8.49\pm1.66^{+1.32}_{-1.99}$                                        $8.7\sigma$   
  c.c.$                                                                                                                                 

  ${K_1(1270)^{+}K^{-} + c.c.,}$                                                                                                        

     $K_1(1270)\to                   $68.3\pm13.4$   $9.32\pm1.83^{+1.81}_{-1.64}$                                        $8.6\sigma$   
  K\rho(770)$                                                                                                                           

  ${K_1(1400)^{+}K^{-} + c.c.,}$                                                                                                        

     $K_1(1400)\to                   $19.7\pm8.9$    $< 11.9$ (90% C.L.)                                                  $2.7\sigma$   
  K^*(892)\pi$                                                                                                                          
  ---------------------------------- --------------- -------------------------------------------------------------------- ------------- --

The partial wave analysis shows a strong contribution from $0^-$ for the $\omega\omega$ invariant mass below 2.0 GeV/$c^2$, and with with small contributions from $f_0(1710)$, $f_2(1640)$, and $f_2(1910)$.. Therefore the study of the $\eta(1760)$ is the main goal of this analysis. The mass of the pseudoscalar is $M$ = 1744 $\pm$ 10 (stat) $\pm$ 15 (syst) MeV/$c^2$, the width $\Gamma$ = $244^{+24}_{-21}$ (stat) $\pm$ 25 (syst) MeV/$c^2$, and the product branching fraction is Br($J/\psi\to\gamma\eta(1760)$) $\cdot$ Br($\eta(1760)\to \omega\omega$) = (1.98 $\pm$ 0.08 (stat) $\pm$ 0.32 (syst)) $\times$ 10$^{-3}$.

Pair Productions of Scalars in $\chi_{c0} \rightarrow
\pi^+\pi^- K^+ K^-$
=====================================================

PWA of $\chi_{c0} \rightarrow \pi^+ \pi^- K^+
K^-$ is performed [@ppkk] using ${\chi_{c0}}$ produced in ${\psi^{\prime}}$ decays at BES-II. In 14 M produced ${\psi^{\prime}}$ events, 1371 $\psi^{\prime} \rightarrow \gamma \chi_{c0}$, $\chi_{c0}
\rightarrow \pi^+\pi^-K^+K^-$ candidates are selected with around 3% background contamination.

Figure \[fig\_xchi0\](a) shows the scatter plot of $K^+K^-$ versus $\pi^+\pi^-$ invariant mass which provides further information on the intermediate resonant decay modes for $(\pi^+\pi^-)(K^+K^-)$ decay, while Fig. \[fig\_xchi0\](b) shows the scatter plot of $K^+\pi^-$ versus $K^-\pi^+$ invariant masses for the resonances with strange quark.

Besides $(\pi\pi)(KK)$ and $(K\pi)(K\pi)$ modes, $(K\pi\pi)K$ mode which leads to a measurement of $K_1(1270)K$ and $K_1(1400)K$ decay processes is also included in the fit. The PWA results are summarized in Table \[pwachi\]. From these results, we notice that scalar resonances have larger decay fractions compared to those of tensors, and such decays provide a relatively clean laboratory to study the properties of scalars, such as $f_0(980)$, $f_0(1370)$, $f_0(1710)$, and so on.

The above results supply important information on the understanding of the natures of the scalar states [@zhaoq].

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Bing An Li, hep-ph/0602072 Xiao-Gang He, Xue-Qian Li [*et at.*]{}, Phys. Rev. D [**73**]{} (2006) 051502. Pedro Bicudo [*et al.*]{}, hep-ph/0602172 . Kuang-Ta Chao, hep-ph/0602190. D.V. Bugg, hep-ph/0603018.

BES Collaboration, M. Ablikim, [*et al.*]{}, Phys. Rev. [**D72**]{} (2005) 092002. Q. Zhao, Phys. Rev. [**D72**]{} (2005) 074001

[^1]: Email: <PRESIDIO_ANONYMIZED_EMAIL_ADDRESS>