ξ(2230)\xi(2230) is likely to be a glueball

On the basis of the recent results of $\xi(2230)\rightarrow \pi^+\pi^-, p\bar p$ and $\xi(2230)\rightarrow K^+K^-,~K_SK_S$, measured by the BES Collaboration in $J/\psi$ radiative decays, combined with the PS185 experiment of $p\bar p\rightarrow \xi(2230)\rightarrow K\bar K$, we argue that because of its very narrow partial decay widths to $\pi\pi$ and $K\bar K$ ( less than $1~MeV$ ), its large production rate in $J/\psi$ radiative decays, and its flavor- symmetric couplings to $\pi\pi$ and $K\bar K$, the $\xi(2230)$ is very likely to be a $J^{PC}=(even)^{++}$ glueball.Comment: 6 pages in Latex, talk presented at the CCAST Workshop on Tau-Charm Factory, Beijing, November 199

Search for C=+C=+ charmonium and bottomonium states in e+e−→γ+Xe^+e^-\to \gamma+ X at B factories

We study the production of $C=+$ charmonium states $X$ in $e^+e^-\to \gamma + X$ at B factories with $X=\eta_c(nS)$ (n=1,2,3), $\chi_{cJ}(mP)$ (m=1,2), and $^1D_2(1D)$. In the S and P wave case, contributions of tree-QED with one-loop QCD corrections are calculated within the framework of nonrelativistic QCD(NRQCD) and in the D-wave case only the tree-QED contribution are considered. We find that in most cases the QCD corrections are negative and moderate, in contrast to the case of double charmonium production $e^+e^-\to J/\psi + X$, where QCD corrections are positive and large in most cases. We also find that the production cross sections of some of these states in $e^+e^-\to \gamma + X$ are larger than that in $e^+e^-\to J/\psi + X$ by an order of magnitude even after the negative QCD corrections are included. So we argue that search for the X(3872), X(3940), Y(3940), and X(4160) in $e^+e^-\to \gamma + X$ at B factories may be helpful to clarify the nature of these states. For completeness, the production of bottomonium states in $e^+e^-$ annihilation is also discussed.Comment: 13pages, 4 figure

Reply to Comment on "Chiral suppression of scalar glueball decay"

Reply to the comment of Chao, He, and Ma

Multiquark Hadrons

A number of candidate multiquark hadrons, i.e., particle resonances with substructures that are more complex than the quark-antiquark mesons and three-quark baryons that are prescribed in the textbooks, have recently been observed. In this talk I present: some recent preliminary BESIII results on the near-threshold behavior of sigma(e+e- --> Lambda Lambda-bar) that may or may not be related to multiquark mesons in the light- and strange-quark sectors; results from Belle and LHCb on the electrically charged, charmoniumlike Z(4430)^+ --> pi^+ psi ' resonance that necessarily has a four-quark substructure; and the recent LHCb discovery of the P_c(4380) and P_c(4450) hidden-charm resonances seen as a complex structure in the J/psi p invariant mass distribution for Lambda_b --> K^-J/psi p decays and necessarily have a five-quark substructure and are, therefore, prominent candidates for pentaquark baryons.Comment: 12 pages, 9 figures, summary of a talk presented at the 12th Conference on Hypernuclear and Strange Particle Physics (HYP2015), September 7-12, 2015 Sendai, JAPAN. To appear in the JPS Conference proceeding

New high fill-factor triangular micro-lens array fabrication method using UV proximity printing

A simple and effective method to fabricate a high fill-factor triangular microlens array using the proximity printing in lithography process is reported. The technology utilizes the UV proximity printing by controlling a printing gap between the mask and substrate. The designed approximate triangle microlens array pattern can be fabricated the high fill-factor triangular microlens array in photoresist. It is due to the UV light diffraction to deflect away from the aperture edges and produce a certain exposure in photoresist material outside the aperture edges. This method can precisely control the geometric profile of high fill factor triangular microlens array. The experimental results showed that the triangular micro-lens array in photoresist could be formed automatically when the printing gap ranged from 240 micrometers to 840 micrometers. The gapless triangular microlens array will be used to increases of luminance for backlight module of liquid crystal displays.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

The Color-Octet intrinsic charm in η′\eta^\prime and B→η′XB\to \eta^\prime X decays

Color-octet mechanism for the decay B\to \eta^\prime X is proposed to explain the large branching ratio of Br(B\to \eta^\prime X)\sim 1\times 10^{-3} recently announced by CLEO. We argue that the inclusive \eta^\prime production in B decays may dominantly come from the Cabbibo favored b\to (\bar c c)_8s process where \bar c c pair is in a color-octet configuration, and followed by the nonperturbative transition (\bar c c)_8\to \eta^\prime X. The color-octet intrinsic charm component in the higher Fock states of \eta^\prime is crucial and is induced by the strong coupling of \eta^\prime to gluons via QCD axial anomaly.Comment: 9 pages, RevTex, 1 PS figur

Higher Charmonia and X,Y,Z states with Screened Potential

We incorporate the color-screening effect due to light quark pair creation into the heavy quark-antiquark potential, and investigate the effects of screened potential on the spectrum of higher charmonium. We calculate the masses, electromagnetic decays, and E1 transitions of charmonium states in the screened potential model, and propose possible assignments for the newly discovered charmonium or charmonium-like $"X,Y,Z"$ states. We find the masses of higher charmonia with screened potential are considerably lower than those with unscreened potential. The $\chi_{c2}(2P)$ mass agrees well with that of the Z(3930), and the mass of $\psi(4415)$ is compatible with $\psi(5S)$ rather than $\psi(4S)$. In particular, the discovered four $Y$ states in the ISR process, i.e., $Y(4008), Y(4260), Y(4320/4360), Y(4660)$ may be assigned as the $\psi(3S), \psi(4S), \psi(3D), \psi(6S)$ states respectively. The X(3940) and X(4160) found in the double charmonium production in $e^+e^-$ annihilation may be assigned as the $\eta_c(3S)$ and $\chi_{c0}(3P)$ states. Based on the calculated E1 transition widths for $\chi_{c1}(2P)\to \gamma J/\psi$ and $\chi_{c1}(2P)\to \gamma \psi(2S)$ and other results, we argue that the X(3872) may be a $\chi_{c1}(2P)$ dominated charmonium state with some admixture of the $D^0\bar{D}^{*0}$ component. Possible problems encountered in these assignments and comparisons with other interpretations for these $X,Y,Z$ states are discussed in detail. We emphasize that more theoretical and experimental investigations are urgently needed to clarify these assignments and other interpretations.Comment: Total width of X(3872) reestimated, references added; 12 pages, 1 figure; published version in PR

Bethe-Salpeter study of radially excited vector quarkonia

We solve the Bethe-Salpeter equation (BSE) for a system of a heavy quark-antiquark pair interacting with a Poincare invariant generalization of screened linear confining potential. In order to get reliable description the Lorentz scalar confining interaction is complemented by the effective one gluon exchange. Within presented model we reasonably reproduce all known radial excitations of the vector charmonia. We have found that $J/\Psi$ is the only charmonium left bellow naive quark-antiquark threshold $2m_c$, while the all excited states are situated above this threshold. We develop a method which is enable to provide solution of full four dimensional BSE for the all excited states. We discuss the consequences of the use of the free propagators for calculation of excited states above the threshold. The Bethe-Salpeter string breaking scale $\mu\simeq 350MeV$ appears to be relatively larger then the one defined in various potential models $\mu\simeq 150MeV$.Comment: typos and grammar correcte