In this report we investigate Wmeson productions on the proton via electromagnetic and hadron probes in a chiral quark model approach. The observables, such as, differential cross section and beam asymmetry for the tw...In this report we investigate Wmeson productions on the proton via electromagnetic and hadron probes in a chiral quark model approach. The observables, such as, differential cross section and beam asymmetry for the two productions are calculated and compared with the experiment. The five known resonances S11（1535）,S11（1650）, P13（1720）, D13（1520）, and F15（1680） are found to be dominant in the reaction mechanisms in both channels. Significant contribution ＂missing resonances, no evidence is found within πp→ηn are also presented. from a new S11 resonances are deduced. For the so-called the investigated reactions. The partial wave amplitudes for展开更多
A chiral quark model is applied to calculate the spectra of pseudoscalar mesons η and η . By analyzing the obtained spectra, we find that the mesons η （2 1 S 0 ）, η（4 1 S 0 ）, η （3 1 S 0 ） and η （4 1 S 0 ...A chiral quark model is applied to calculate the spectra of pseudoscalar mesons η and η . By analyzing the obtained spectra, we find that the mesons η （2 1 S 0 ）, η（4 1 S 0 ）, η （3 1 S 0 ） and η （4 1 S 0 ） are the possible candidates of η（1760）, X（1835）, X（2120） and X（2370）. The strong decay widths of these pseudoscalars to all the possible two-body decay channels are calculated within the framework of the 3 P 0 model. Although the total width of η （21S0 ） is compatible with the BES Collaboration＇s experimental value for η（1760）, the partial decay width to ωω is too small, which is not consistent with the BES result. If X（1835） is interpreted as η（4 1 S 0 ）, the total decay width is compatible with the experimental data, and the main decay modes will be πa 0 （980） and πa 0 （1450）, which needs to be checked experimentally. The assignment of X（2120） and X（2370） to η （31S0 ） and η （41S0 ） is disfavored in the present calculation because of the incompatibility of the decay widths.展开更多
After summarizing the experimental results and present status of the d^＊（2380） observed at WASA@COSY,two “extreme” models for explaining its structure, a compact hexaquark dominated model and a loose △△＇-D_（1...After summarizing the experimental results and present status of the d^＊（2380） observed at WASA@COSY,two “extreme” models for explaining its structure, a compact hexaquark dominated model and a loose △△＇-D_（12）π model, are briefly discussed, especially the former. By comparing their results with the corresponding data, the differences of the two models are addressed. As a remedy for the latter model, a mixing model and its result are also quoted for a comparison. It is shown that the compact hexaquark dominated structure might be more promising.However, the mixing model is also a possible structure, and more accurate Γ_（d^＊）→NN_π data are needed for confirmation.展开更多
The polarized distribution functions of mesons, including pion, kaon and eta, using the proton structure function, are calculated. We are looking for a relationship between the polarized distribution of mesons and the...The polarized distribution functions of mesons, including pion, kaon and eta, using the proton structure function, are calculated. We are looking for a relationship between the polarized distribution of mesons and the polarized structure of nucleons. We show that the meson polarized parton distributions leads to zero total spin for the concerned mesons, considering the orbital angular momentum of quarks and gluons inside the meson. Two separate Monte Carlo algorithms are applied to compute the polarized parton distributions of the kaon. Via the mass dependence of quark distributions, the distribution function of the eta meson is obtained. A new method by which the polarized sea quark distributions of protons are evolved separately which cannot be performed easily using the standard solution of DGLAP equations - is introduced. The mass dependence of these distributions is obtained, using the renormalization group equation which makes their evolutions more precise. Comparison between the evolved distributions and the available experimental data validates the suggested solutions for separated evolutions.展开更多
An effective potential in a meson-meson system is discussed based on the SU（3） chiral constituent quark model, and the analytic form of the potential is explicitly given. In addition, the effective potential is empl...An effective potential in a meson-meson system is discussed based on the SU（3） chiral constituent quark model, and the analytic form of the potential is explicitly given. In addition, the effective potential is employed to study the bound state problem of ωφ, which is related to the new resonance of f0（1810） observed in BES Ⅱ very recently.展开更多
The constituent counting rule, determining the scaling behavior of the transition amplitudes in an exclusive process at high energies, is applied to probe the internal structure of the newly observed d*(2380) resonanc...The constituent counting rule, determining the scaling behavior of the transition amplitudes in an exclusive process at high energies, is applied to probe the internal structure of the newly observed d*(2380) resonance. Several selected exclusive processes at high energies for the production of d* are discussed. Results of two structural scenarios for d*(2380), a hexaquark dominant compact system in the quark degrees of freedom, and a threebody bound state in the hadronic degrees of freedom, are analyzed and compared. A rather remarkable difference between the results of these two scenarios for the mentioned processes are addressed.展开更多
The decay widths of Υ（nS）→d^＊（2380）＋X with n=1,2,3 are studied in a phenomenological way. With the help of crossing symmetry, the decay widths are obtained by investigating the imaginary part of the forward sc...The decay widths of Υ（nS）→d^＊（2380）＋X with n=1,2,3 are studied in a phenomenological way. With the help of crossing symmetry, the decay widths are obtained by investigating the imaginary part of the forward scattering amplitudes between d^＊ and Υ（nS）. The wave functions of d^＊ and deuteron obtained in previous studies are used for calculating the amplitude. The interaction between d^＊（d） and Υ is governed by the quark-meson interaction, where the coupling constant is determined by fitting the observed widths of Υ（nS）→d＋X. The numerical results show that the decay widths of Υ（nS）→d^＊＋X are about 2-10 times smaller than that of d＋X. The calculated momentum of d^＊ is in the range 0.3-0.8 GeV. Therefore, it is very likely that one can find d^＊（2380） in these semi-inclusive decay processes.展开更多
Belle Collaboration reported a new observed value of K＊- （892） mass by studying τ^- → Ksπ^-vτ decay, which is significantly different from the current world average value given by Particle Data Group 2006. Moti...Belle Collaboration reported a new observed value of K＊- （892） mass by studying τ^- → Ksπ^-vτ decay, which is significantly different from the current world average value given by Particle Data Group 2006. Motivated by this new data, we revisit the issue on the K^＊0（892）- K^＊±（892） mass splitting. Our theoretical estimation favors the new measurement by Belle Collaboration. Therefore further experimental efforts are urgently needed to improve our understanding of these issues.展开更多
We present recent investigations on the vector and axial-vector transitions of the baryon antidecuplet within the framework of the self-consistent SU（3） chiral quark-soliton model, taking into account the 1/No rotat...We present recent investigations on the vector and axial-vector transitions of the baryon antidecuplet within the framework of the self-consistent SU（3） chiral quark-soliton model, taking into account the 1/No rotational and linear mscorrections. The main contribution to the electric-like transition form factor comes from the wave-function corrections. This is a consequence of the generalized Ademollo-Gatto theorem. It is also found that in general the leading-order contributions are almost canceled by the rotational 1/No corrections. The results are summarized as follows： the vector and tensor K＇NO coupling constants, gK＊N= 0.74--0.87 and fk＊N =0.53--1.16, respectively, and F→KN = 0.71 MeV, based on the result of the KN coupling constant gKne =0.83. We also show the differential cross sections and beam asymmetries, based on the present results. We also discuss the connection of present results with the original work by Diakonov, Petrov, and Polyakov.展开更多
文摘In this report we investigate Wmeson productions on the proton via electromagnetic and hadron probes in a chiral quark model approach. The observables, such as, differential cross section and beam asymmetry for the two productions are calculated and compared with the experiment. The five known resonances S11（1535）,S11（1650）, P13（1720）, D13（1520）, and F15（1680） are found to be dominant in the reaction mechanisms in both channels. Significant contribution ＂missing resonances, no evidence is found within πp→ηn are also presented. from a new S11 resonances are deduced. For the so-called the investigated reactions. The partial wave amplitudes for
基金Supported by National Natural Science Foundation of China(11035006,11175088)
文摘A chiral quark model is applied to calculate the spectra of pseudoscalar mesons η and η . By analyzing the obtained spectra, we find that the mesons η （2 1 S 0 ）, η（4 1 S 0 ）, η （3 1 S 0 ） and η （4 1 S 0 ） are the possible candidates of η（1760）, X（1835）, X（2120） and X（2370）. The strong decay widths of these pseudoscalars to all the possible two-body decay channels are calculated within the framework of the 3 P 0 model. Although the total width of η （21S0 ） is compatible with the BES Collaboration＇s experimental value for η（1760）, the partial decay width to ωω is too small, which is not consistent with the BES result. If X（1835） is interpreted as η（4 1 S 0 ）, the total decay width is compatible with the experimental data, and the main decay modes will be πa 0 （980） and πa 0 （1450）, which needs to be checked experimentally. The assignment of X（2120） and X（2370） to η （31S0 ） and η （41S0 ） is disfavored in the present calculation because of the incompatibility of the decay widths.
基金Supported by National Natural Science Foundation of China(11475192,11475181,11521505,11565007,11635009)fund provided to the Sino-German CRC 110 “Symmetries and the Emergence of Structure in QCD” project by NSFC(11621131001)+1 种基金the IHEP Innovation Fund(Y4545190Y2)the support of the Youth Innovation Promotion Association of CAS(2015358)
文摘After summarizing the experimental results and present status of the d^＊（2380） observed at WASA@COSY,two “extreme” models for explaining its structure, a compact hexaquark dominated model and a loose △△＇-D_（12）π model, are briefly discussed, especially the former. By comparing their results with the corresponding data, the differences of the two models are addressed. As a remedy for the latter model, a mixing model and its result are also quoted for a comparison. It is shown that the compact hexaquark dominated structure might be more promising.However, the mixing model is also a possible structure, and more accurate Γ_（d^＊）→NN_π data are needed for confirmation.
文摘The polarized distribution functions of mesons, including pion, kaon and eta, using the proton structure function, are calculated. We are looking for a relationship between the polarized distribution of mesons and the polarized structure of nucleons. We show that the meson polarized parton distributions leads to zero total spin for the concerned mesons, considering the orbital angular momentum of quarks and gluons inside the meson. Two separate Monte Carlo algorithms are applied to compute the polarized parton distributions of the kaon. Via the mass dependence of quark distributions, the distribution function of the eta meson is obtained. A new method by which the polarized sea quark distributions of protons are evolved separately which cannot be performed easily using the standard solution of DGLAP equations - is introduced. The mass dependence of these distributions is obtained, using the renormalization group equation which makes their evolutions more precise. Comparison between the evolved distributions and the available experimental data validates the suggested solutions for separated evolutions.
基金Supported by National Natrual Science Foundation (10775146, 10775148, 10975146, 11035006)Ministry of Science and Technology of China (2009CB825200)
文摘An effective potential in a meson-meson system is discussed based on the SU（3） chiral constituent quark model, and the analytic form of the potential is explicitly given. In addition, the effective potential is employed to study the bound state problem of ωφ, which is related to the new resonance of f0（1810） observed in BES Ⅱ very recently.
基金Supported by the National Natural Sciences Foundations of China(11475192,11475181,11521505,11565007,11635009)the Sino-German CRC 110 "Symmetries and the Emergence of Structure in QCD" project by NSFC(11621131001)+1 种基金the Key Research Program of Frontier Sciences,CAS,(Y7292610K1)the IHEP Innovation Fund(Y4545190Y2)
文摘The constituent counting rule, determining the scaling behavior of the transition amplitudes in an exclusive process at high energies, is applied to probe the internal structure of the newly observed d*(2380) resonance. Several selected exclusive processes at high energies for the production of d* are discussed. Results of two structural scenarios for d*(2380), a hexaquark dominant compact system in the quark degrees of freedom, and a threebody bound state in the hadronic degrees of freedom, are analyzed and compared. A rather remarkable difference between the results of these two scenarios for the mentioned processes are addressed.
基金Supported by National Natural Sciences Foundations of China(11475186,11475192,11521505,11565007)the Sino-German CRC110 "Symmetries and the Emergence of Structure in QCD" project by NSFC(11621131001)+1 种基金the Key Research Program of Frontier Sciences,CAS,(Y7292610K1)the IHEP Innovation Fund(Y4545190Y2)
文摘The decay widths of Υ（nS）→d^＊（2380）＋X with n=1,2,3 are studied in a phenomenological way. With the help of crossing symmetry, the decay widths are obtained by investigating the imaginary part of the forward scattering amplitudes between d^＊ and Υ（nS）. The wave functions of d^＊ and deuteron obtained in previous studies are used for calculating the amplitude. The interaction between d^＊（d） and Υ is governed by the quark-meson interaction, where the coupling constant is determined by fitting the observed widths of Υ（nS）→d＋X. The numerical results show that the decay widths of Υ（nS）→d^＊＋X are about 2-10 times smaller than that of d＋X. The calculated momentum of d^＊ is in the range 0.3-0.8 GeV. Therefore, it is very likely that one can find d^＊（2380） in these semi-inclusive decay processes.
基金Supported by NSFC (10275059, 10775124, 90403021)CAS (KJCX2-SW-N10)
文摘Belle Collaboration reported a new observed value of K＊- （892） mass by studying τ^- → Ksπ^-vτ decay, which is significantly different from the current world average value given by Particle Data Group 2006. Motivated by this new data, we revisit the issue on the K^＊0（892）- K^＊±（892） mass splitting. Our theoretical estimation favors the new measurement by Belle Collaboration. Therefore further experimental efforts are urgently needed to improve our understanding of these issues.
基金Supported by Inha University Research Grant (INHA-37453)The work of S.i.N. is supported by NSC96-2112-M033-003-MY3 from the National Science Council (NSC) of Taiwan
文摘We present recent investigations on the vector and axial-vector transitions of the baryon antidecuplet within the framework of the self-consistent SU（3） chiral quark-soliton model, taking into account the 1/No rotational and linear mscorrections. The main contribution to the electric-like transition form factor comes from the wave-function corrections. This is a consequence of the generalized Ademollo-Gatto theorem. It is also found that in general the leading-order contributions are almost canceled by the rotational 1/No corrections. The results are summarized as follows： the vector and tensor K＇NO coupling constants, gK＊N= 0.74--0.87 and fk＊N =0.53--1.16, respectively, and F→KN = 0.71 MeV, based on the result of the KN coupling constant gKne =0.83. We also show the differential cross sections and beam asymmetries, based on the present results. We also discuss the connection of present results with the original work by Diakonov, Petrov, and Polyakov.
