With the diquark structure of ∧c, we investigate the branching ratio of ∧c→nπ^+ and pπ^0. The results show that without considering the finM state interaction (FSI), the branching ratio of ∧c→pπ^0 is only of o...With the diquark structure of ∧c, we investigate the branching ratio of ∧c→nπ^+ and pπ^0. The results show that without considering the finM state interaction (FSI), the branching ratio of ∧c→pπ^0 is only of order 10^-6 whereas this ratio could reach 10^-4 and is at the same order as ∧c→nπ^+ if taking into account the FSI effects. Concrete values depend on phenomenologicM parameters adopted in the calculations. These branching ratios can be measured in the experiments to come.展开更多
The constituent quarks in the nucleon have always been considered as a point-like particle in the relativistic constituent quark model. However its calculation results of GnE agree poorly with the new experimental dat...The constituent quarks in the nucleon have always been considered as a point-like particle in the relativistic constituent quark model. However its calculation results of GnE agree poorly with the new experimental data. The electromagnetic structure of light front constituent quarks is considered in this paper. We find that the calculation results have good agreement with the new experimental data of GnE after considering the contribution of the quark structure term. This treatment seems to be able to improve the fit to experimental data of Gep/GMp, /Q2F2p/kpF1p,and Gen/GMn as well.展开更多
Tensor Polarization t20 of the deuteron is calculated on the basis of a hybrid quark-hadron model.A relativistic wavefunction of the deuteron is used to calculate the relativistic impulse approximation and the contri...Tensor Polarization t20 of the deuteron is calculated on the basis of a hybrid quark-hadron model.A relativistic wavefunction of the deuteron is used to calculate the relativistic impulse approximation and the contribution of the ρπγ meson exchange process.A good agreement with experimental data is achieved when and only when the ρπγ coupling is taken as positive.展开更多
The phase diagram of bulk quark matter in equilibrium with a finite hadronic gas is studied. Different from previous investigations, we treat the quark phase with the quark mass density-and-temperature-dependent model...The phase diagram of bulk quark matter in equilibrium with a finite hadronic gas is studied. Different from previous investigations, we treat the quark phase with the quark mass density-and-temperature-dependent model to take the strong quark interaction into account, while the hadron phase is treated by hard core repulsion factor. It is found that the phase diagram in this model is, in several aspects, different from those in the conventional MIT bag model, especially at high temperature. The new phase diagram also has strong effects on the mass-radius relation of compact hybrid stars.展开更多
Jefferson Lab has implemented a scalable,distributed,high performance mass storage system-JASMine.The system is entirely implemented in Java,provides access to robotic tape storage and includes disk cache and stage ma...Jefferson Lab has implemented a scalable,distributed,high performance mass storage system-JASMine.The system is entirely implemented in Java,provides access to robotic tape storage and includes disk cache and stage manager components.The disk manager subsystem may be used independently to manage stand-alone disk pools.The system includes a scheduler to provide policy-based access to the storage systems.Security is provided by pluggable authentication modules and is implemented at the network socket level.The tape and disk cache systems have well defined interfaces in order to provids integration with grid-based services.The system is in production and being used to archive 1 TB per day from the experiments.and currently moves over 2 TB per day total.This paper will describe the architecture of JASMine;discuss the rationale for building the system,and present a transparent 3^rd party file replication service to move data to collab-orating institutes using JASMine,XML,and servlet technology interfacing to grid-based file transfer mechanisms.展开更多
We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structur...We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structure function is also analyzed. Effects of the Δ(1232) and Roper P<SUB>11</SUB>(1440) resonances on the spin structure function and on the difference are mentioned. The results of different models for the Roper resonance are also addressed.展开更多
By employing the parametrization form of the nucleon spin structure functionin the resonance region, which includes the contributions of the resonance peaks and of nonresonancebackground, we study Bloom—Oilman quark-...By employing the parametrization form of the nucleon spin structure functionin the resonance region, which includes the contributions of the resonance peaks and of nonresonancebackground, we study Bloom—Oilman quark-hadron duality of g_1 both in the inelastic resonanceregion and elastic one.展开更多
First evidence of a structure in the J/ψΛinvariant mass distribution is obtained from an amplitude analysis of■b^(-)J/ψΛK^(-)decays.The observed structure is consistent with being due to a charmonium pentaquark w...First evidence of a structure in the J/ψΛinvariant mass distribution is obtained from an amplitude analysis of■b^(-)J/ψΛK^(-)decays.The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1r including systematic uncertainties and lookelsewhere effect.Its mass and width are determined to be 4458:8±2:9t4:7-1:1 MeV and 17:3±6:5t8:0-5:7 MeV,respectively,where the quoted uncertainties are statistical and systematic.The structure is also consistent with being due to two resonances.In addition,the narrow excited■^(-)states,N■(1690)and■(1820),are seen for the first time in a■b^(-)decay,and their masses and widths are measured with improved precision.The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb^(-1),collected with the LHCb experiment at centre-of-mass energies of 7,8 and 13 TeV.展开更多
The quark model based on quark–antiquark mesons and three-quark baryons has been very successful in classifying the hadrons.However,quantum chromodynamics(QCD)does not forbid the existence of exotic hadronic states w...The quark model based on quark–antiquark mesons and three-quark baryons has been very successful in classifying the hadrons.However,quantum chromodynamics(QCD)does not forbid the existence of exotic hadronic states with other quark–gluon configurations,such as展开更多
The structure and decay properties of d＊ have been detailedly investigated in both the chiral SU（3） quark model and the extended chiral SU（3） quark model that describe the energies of baryon ground states and the...The structure and decay properties of d＊ have been detailedly investigated in both the chiral SU（3） quark model and the extended chiral SU（3） quark model that describe the energies of baryon ground states and the nucleon-nucleon （NN） scattering data satisfactorily. By performing a dynamical coupled-channels study of the system of △△ and hidden-color channel （CC） with quantum numbers l（JP） = 0（3^＋） in the framework of the resonating group method （RGM）, we find that the d＊ has a mass of about 2.38-2.42 GeV and a root-mean-square radius （RMS） of about 0.76-0.88 fm. The channel wave function is extracted by a projection of the RGM wave function onto the physical basis, and the fraction of CC component in the d＊ is found to be about 66%-68%, which indicates that the d＊ is a hexaquark-dominated exotic state. Based on this scenario the partial decay widths of d＊ → dπ^0π^0 and d＊ → dn^＋n^- are further explicitly evaluated and the total width is then obtained by use of the branching ratios extracted from the measured cross sections of other possible decay channels. Both the mass and the decay width of d＊ calculated in this work are compatible with the data （M ≈ 2380 MeV, F ≈ 70 MeV） reported by WASA-at-COSY Collaboration.展开更多
文摘With the diquark structure of ∧c, we investigate the branching ratio of ∧c→nπ^+ and pπ^0. The results show that without considering the finM state interaction (FSI), the branching ratio of ∧c→pπ^0 is only of order 10^-6 whereas this ratio could reach 10^-4 and is at the same order as ∧c→nπ^+ if taking into account the FSI effects. Concrete values depend on phenomenologicM parameters adopted in the calculations. These branching ratios can be measured in the experiments to come.
文摘The constituent quarks in the nucleon have always been considered as a point-like particle in the relativistic constituent quark model. However its calculation results of GnE agree poorly with the new experimental data. The electromagnetic structure of light front constituent quarks is considered in this paper. We find that the calculation results have good agreement with the new experimental data of GnE after considering the contribution of the quark structure term. This treatment seems to be able to improve the fit to experimental data of Gep/GMp, /Q2F2p/kpF1p,and Gen/GMn as well.
文摘Tensor Polarization t20 of the deuteron is calculated on the basis of a hybrid quark-hadron model.A relativistic wavefunction of the deuteron is used to calculate the relativistic impulse approximation and the contribution of the ρπγ meson exchange process.A good agreement with experimental data is achieved when and only when the ρπγ coupling is taken as positive.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10375074, 90203004, 10135030, and 10475089
文摘The phase diagram of bulk quark matter in equilibrium with a finite hadronic gas is studied. Different from previous investigations, we treat the quark phase with the quark mass density-and-temperature-dependent model to take the strong quark interaction into account, while the hadron phase is treated by hard core repulsion factor. It is found that the phase diagram in this model is, in several aspects, different from those in the conventional MIT bag model, especially at high temperature. The new phase diagram also has strong effects on the mass-radius relation of compact hybrid stars.
文摘Jefferson Lab has implemented a scalable,distributed,high performance mass storage system-JASMine.The system is entirely implemented in Java,provides access to robotic tape storage and includes disk cache and stage manager components.The disk manager subsystem may be used independently to manage stand-alone disk pools.The system includes a scheduler to provide policy-based access to the storage systems.Security is provided by pluggable authentication modules and is implemented at the network socket level.The tape and disk cache systems have well defined interfaces in order to provids integration with grid-based services.The system is in production and being used to archive 1 TB per day from the experiments.and currently moves over 2 TB per day total.This paper will describe the architecture of JASMine;discuss the rationale for building the system,and present a transparent 3^rd party file replication service to move data to collab-orating institutes using JASMine,XML,and servlet technology interfacing to grid-based file transfer mechanisms.
文摘We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structure function is also analyzed. Effects of the Δ(1232) and Roper P<SUB>11</SUB>(1440) resonances on the spin structure function and on the difference are mentioned. The results of different models for the Roper resonance are also addressed.
文摘By employing the parametrization form of the nucleon spin structure functionin the resonance region, which includes the contributions of the resonance peaks and of nonresonancebackground, we study Bloom—Oilman quark-hadron duality of g_1 both in the inelastic resonanceregion and elastic one.
文摘First evidence of a structure in the J/ψΛinvariant mass distribution is obtained from an amplitude analysis of■b^(-)J/ψΛK^(-)decays.The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1r including systematic uncertainties and lookelsewhere effect.Its mass and width are determined to be 4458:8±2:9t4:7-1:1 MeV and 17:3±6:5t8:0-5:7 MeV,respectively,where the quoted uncertainties are statistical and systematic.The structure is also consistent with being due to two resonances.In addition,the narrow excited■^(-)states,N■(1690)and■(1820),are seen for the first time in a■b^(-)decay,and their masses and widths are measured with improved precision.The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb^(-1),collected with the LHCb experiment at centre-of-mass energies of 7,8 and 13 TeV.
文摘The quark model based on quark–antiquark mesons and three-quark baryons has been very successful in classifying the hadrons.However,quantum chromodynamics(QCD)does not forbid the existence of exotic hadronic states with other quark–gluon configurations,such as
基金the National Natural Science Foundation of China(Grant Nos.1147518111475192+2 种基金11035006 and 11165005)the fund provided to the Sino-German CRC 110"Symmetries and the Emergence of Structure in QCD"project by the DFGthe IHEP InnovationFund(Grant No.Y4545190Y2)
文摘The structure and decay properties of d＊ have been detailedly investigated in both the chiral SU（3） quark model and the extended chiral SU（3） quark model that describe the energies of baryon ground states and the nucleon-nucleon （NN） scattering data satisfactorily. By performing a dynamical coupled-channels study of the system of △△ and hidden-color channel （CC） with quantum numbers l（JP） = 0（3^＋） in the framework of the resonating group method （RGM）, we find that the d＊ has a mass of about 2.38-2.42 GeV and a root-mean-square radius （RMS） of about 0.76-0.88 fm. The channel wave function is extracted by a projection of the RGM wave function onto the physical basis, and the fraction of CC component in the d＊ is found to be about 66%-68%, which indicates that the d＊ is a hexaquark-dominated exotic state. Based on this scenario the partial decay widths of d＊ → dπ^0π^0 and d＊ → dn^＋n^- are further explicitly evaluated and the total width is then obtained by use of the branching ratios extracted from the measured cross sections of other possible decay channels. Both the mass and the decay width of d＊ calculated in this work are compatible with the data （M ≈ 2380 MeV, F ≈ 70 MeV） reported by WASA-at-COSY Collaboration.
