We apply random matrix theory to small metallic grains in different spin-states of S=0,1/2,1,3/2,2,5/2,...,and find that there exist theoretical critical level spacings dc at which the superconductivity would break do...We apply random matrix theory to small metallic grains in different spin-states of S=0,1/2,1,3/2,2,5/2,...,and find that there exist theoretical critical level spacings dc at which the superconductivity would break down.We also find that the higher the spin-state,the smaller the critical level spacing,and for the state of S=0 there actually exists the superconducting enhancement.展开更多
By solving the eigenvalue equation for the quark-antiquark potential which emerges from an effective dilatongluon coupling inspired by superstring theory, we obtain the spin-averaged energy levels of charmonium (cc) a...By solving the eigenvalue equation for the quark-antiquark potential which emerges from an effective dilatongluon coupling inspired by superstring theory, we obtain the spin-averaged energy levels of charmonium (cc) and bottonium (bb) and show that the masses of the cc and bb states are well in agreement with the available experimental data.展开更多
The energy levels of the odd-odd nucleus ^(86)Nb at low spins are calculated by using quasi-particles plus a rotor model. The distribution of the nearest-neighbour spacing and the spectral rigidity are studied. We fin...The energy levels of the odd-odd nucleus ^(86)Nb at low spins are calculated by using quasi-particles plus a rotor model. The distribution of the nearest-neighbour spacing and the spectral rigidity are studied. We find that the chaotic degree of the energy spectra increases with the increasing spin and reaches a maximum at I = 10;then it decreases gradually for spins above I = 10. The recoil term in the model Haniltonian makes the energy spectra slightly regular. The Coriolis force, however, makes the spectra chaotic and plays a major role in the spectral statistics of the odd-odd nucleus ^(86)Nb.展开更多
Superconductivity in small metallic grains is carefully checked as their size is decreased to a few nm when the average level spacing d could be compared with the bulk gapΔ.Using random matrix theory to the mean fiel...Superconductivity in small metallic grains is carefully checked as their size is decreased to a few nm when the average level spacing d could be compared with the bulk gapΔ.Using random matrix theory to the mean field,we find that the average theoretical values of the critical level spacing for both odd and even numbers of electrons and the transition temperature Tc in three Gauss ensembles are quite different for those from the model of uniformly spaced levels.For Sz=1/2,as grain size is reduced,the transition temperature or the granular gap decreases monotonously,and the relation 2△(0)/kB T_(c)≤3.53 always exists.展开更多
In this paper,the axial symmetry rotor plus quasiparticle model is generalized from odd nuclei to odd-odd nuclei.Energy spectra of yrast bands for nuclei ^(160)Ho,^(162)Tm and ^(164)Tm are calculated by using the meth...In this paper,the axial symmetry rotor plus quasiparticle model is generalized from odd nuclei to odd-odd nuclei.Energy spectra of yrast bands for nuclei ^(160)Ho,^(162)Tm and ^(164)Tm are calculated by using the method.Signature inversions in these three nuclei are reproduced,and one possible signature inversion mechanism connected with the calculation is also discussed.展开更多
The important fact that the second kind of moment of inertia J(2)is larger than the first kind of moment of inertia J(1)can be derived naturally from the 2-parameter expression for the rotational spectra,E(I)=a(√1+bI...The important fact that the second kind of moment of inertia J(2)is larger than the first kind of moment of inertia J(1)can be derived naturally from the 2-parameter expression for the rotational spectra,E(I)=a(√1+bI(I+1)-1),in its derivation the nuclear triaxiality has been taken into account.展开更多
Energy spectrum of yrast band for ^(122)Cs is studied by using particle-rotor model(PRM)of odd-odd nuclei,in which special attention is paid to the model basis accounting for the effect of the instabilityγvibration p...Energy spectrum of yrast band for ^(122)Cs is studied by using particle-rotor model(PRM)of odd-odd nuclei,in which special attention is paid to the model basis accounting for the effect of the instabilityγvibration perturbation around axial symmetry.In order to check the assignments of this band,two calculation schemes are put into practice.The first one is for previousπh11/2 vg7/2 configuration with bandhead spin I_(0)=(6^(-))which was obtained from cranked shell model(CSM)calculation,and the other one is forπh_(11/2) vh_(11/2) configuration with I_(0)=(9^(+))supported by the systematic analyses of experimental data.A qualitative comparison between the present PRM calculation and that of CSM has also been made.The results indicate that,rather thanπh_(11/2) vg_(7/2) I_(0)=(6^(-)),πh_(11/2) vh_(11/2) with I_(0)=(9^(+))is a more reasonable assignment to the yrast band in ^(122)Cs.展开更多
The behaviour of dilaton-gluon coupling （DGC） potential is investigated by studying charmonium spectra, annihilation rates and E1 transition rates systematically. We find that in the non-relativistic quantum chromod...The behaviour of dilaton-gluon coupling （DGC） potential is investigated by studying charmonium spectra, annihilation rates and E1 transition rates systematically. We find that in the non-relativistic quantum chromodynamics approximation, the charmonium properties can be described by the DGC potential.展开更多
The vacuum properties at finite temperature for the linear sigma model are studied by using the effective potential formalism.It is found that the light hadronic masses drop fast with increasing temperature.An extensi...The vacuum properties at finite temperature for the linear sigma model are studied by using the effective potential formalism.It is found that the light hadronic masses drop fast with increasing temperature.An extensive scaling behavior of light hadronic masses is observed and is found to follow the scaling law postulated in dense matter.展开更多
It is shown that the meson exchange interaction between dynamical quarks generated by the chiral symmetry breaking is of crucial importance to explain the empirical value of the pion-nucleonσ-term.The large contribut...It is shown that the meson exchange interaction between dynamical quarks generated by the chiral symmetry breaking is of crucial importance to explain the empirical value of the pion-nucleonσ-term.The large contribution of ss and gluon to a nucleon mass is predicted by using the QCD energy-momentum trace anomaly from the pion-nucleonσ-term.展开更多
Let (?) be a formation locally defined by f(P), G ∈ (?) and A a ZG-module, where p ∈ π = { all primes and symbol ∞}. Then a p-main-factor U/V of G is said to be (?)-central in G if G/CG(U/V) ∈f(p). In this paper,...Let (?) be a formation locally defined by f(P), G ∈ (?) and A a ZG-module, where p ∈ π = { all primes and symbol ∞}. Then a p-main-factor U/V of G is said to be (?)-central in G if G/CG(U/V) ∈f(p). In this paper, we have proved that: let (?) be a locally defined formation consisting of locally soluble groups, G a hyper-(cyclic or finite) locally soluble group and A an artinian ZG-module with all irreducible ZG-factors of A being finite; if G ∈ (?), f(∞) ≡ f(p) . f(p)≠φ for each p ∈ π, A has an (?)-decomposition.展开更多
Debye screening mass at the next-to-leading order is studied by the resummation method based on perturbation theory at finite temperature.We find that the critical temperature for the J/ψdissociation is 0.211 GeV.The...Debye screening mass at the next-to-leading order is studied by the resummation method based on perturbation theory at finite temperature.We find that the critical temperature for the J/ψdissociation is 0.211 GeV.The contributions from the next-to-leading order are important,and critical temperature and chemical potential are shifted lower values.展开更多
In a paper published years ago by me and my collaborators, the properties of heavy quarkonium systems were studied based on the Dick potential, which explicitly included the color factor in the potential and the non-r...In a paper published years ago by me and my collaborators, the properties of heavy quarkonium systems were studied based on the Dick potential, which explicitly included the color factor in the potential and the non-relativistic SchrSedinger equation was numerically solved. However, another paper by Barakat and Chaba appeared online a few months earlier, which dealt with a similar problem, but used the shifted-expansion technique （SLET） to solve the semi-relativistic wave equation for the Dick potential up to a QCD color factor. Since both the papers solved the same Dick potential model, similar energy spectra due to the small relativistic effect were obtained for this heavy quark system. I and my collaborators did not point out this similarity in Ref. This should be added to give credit to Ref.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19875040Chongqing Commission of Science and Technology,Shanghai Commission of Education and Shanghai Teachers' University.
文摘We apply random matrix theory to small metallic grains in different spin-states of S=0,1/2,1,3/2,2,5/2,...,and find that there exist theoretical critical level spacings dc at which the superconductivity would break down.We also find that the higher the spin-state,the smaller the critical level spacing,and for the state of S=0 there actually exists the superconducting enhancement.
基金Supported in part by the Foundation of the Education Minis try of China under Grand No.99108.
文摘By solving the eigenvalue equation for the quark-antiquark potential which emerges from an effective dilatongluon coupling inspired by superstring theory, we obtain the spin-averaged energy levels of charmonium (cc) and bottonium (bb) and show that the masses of the cc and bb states are well in agreement with the available experimental data.
基金Supported by the National Natural Science Foundation of China under Grant No.19875040.
文摘The energy levels of the odd-odd nucleus ^(86)Nb at low spins are calculated by using quasi-particles plus a rotor model. The distribution of the nearest-neighbour spacing and the spectral rigidity are studied. We find that the chaotic degree of the energy spectra increases with the increasing spin and reaches a maximum at I = 10;then it decreases gradually for spins above I = 10. The recoil term in the model Haniltonian makes the energy spectra slightly regular. The Coriolis force, however, makes the spectra chaotic and plays a major role in the spectral statistics of the odd-odd nucleus ^(86)Nb.
基金Supported in part by the Science and Technology Commission of Chongqing City under Grant No.97-4730 and Key Laboratory Fund of Jiangsu Province.
文摘Superconductivity in small metallic grains is carefully checked as their size is decreased to a few nm when the average level spacing d could be compared with the bulk gapΔ.Using random matrix theory to the mean field,we find that the average theoretical values of the critical level spacing for both odd and even numbers of electrons and the transition temperature Tc in three Gauss ensembles are quite different for those from the model of uniformly spaced levels.For Sz=1/2,as grain size is reduced,the transition temperature or the granular gap decreases monotonously,and the relation 2△(0)/kB T_(c)≤3.53 always exists.
基金Supported by the National Natural Science Foundation of China,。
文摘In this paper,the axial symmetry rotor plus quasiparticle model is generalized from odd nuclei to odd-odd nuclei.Energy spectra of yrast bands for nuclei ^(160)Ho,^(162)Tm and ^(164)Tm are calculated by using the method.Signature inversions in these three nuclei are reproduced,and one possible signature inversion mechanism connected with the calculation is also discussed.
文摘The important fact that the second kind of moment of inertia J(2)is larger than the first kind of moment of inertia J(1)can be derived naturally from the 2-parameter expression for the rotational spectra,E(I)=a(√1+bI(I+1)-1),in its derivation the nuclear triaxiality has been taken into account.
基金Supported by the National Natural Science Foundation of China under Grant No.19475030。
文摘Energy spectrum of yrast band for ^(122)Cs is studied by using particle-rotor model(PRM)of odd-odd nuclei,in which special attention is paid to the model basis accounting for the effect of the instabilityγvibration perturbation around axial symmetry.In order to check the assignments of this band,two calculation schemes are put into practice.The first one is for previousπh11/2 vg7/2 configuration with bandhead spin I_(0)=(6^(-))which was obtained from cranked shell model(CSM)calculation,and the other one is forπh_(11/2) vh_(11/2) configuration with I_(0)=(9^(+))supported by the systematic analyses of experimental data.A qualitative comparison between the present PRM calculation and that of CSM has also been made.The results indicate that,rather thanπh_(11/2) vg_(7/2) I_(0)=(6^(-)),πh_(11/2) vh_(11/2) with I_(0)=(9^(+))is a more reasonable assignment to the yrast band in ^(122)Cs.
基金Supported partially by the National Natural Science Foundation of China under Grants Nos 10447130 and 10375074.
文摘The behaviour of dilaton-gluon coupling （DGC） potential is investigated by studying charmonium spectra, annihilation rates and E1 transition rates systematically. We find that in the non-relativistic quantum chromodynamics approximation, the charmonium properties can be described by the DGC potential.
基金Supported in part by the National Natural Science Foundation of China under Grant No.19375048。
文摘The vacuum properties at finite temperature for the linear sigma model are studied by using the effective potential formalism.It is found that the light hadronic masses drop fast with increasing temperature.An extensive scaling behavior of light hadronic masses is observed and is found to follow the scaling law postulated in dense matter.
文摘It is shown that the meson exchange interaction between dynamical quarks generated by the chiral symmetry breaking is of crucial importance to explain the empirical value of the pion-nucleonσ-term.The large contribution of ss and gluon to a nucleon mass is predicted by using the QCD energy-momentum trace anomaly from the pion-nucleonσ-term.
文摘Let (?) be a formation locally defined by f(P), G ∈ (?) and A a ZG-module, where p ∈ π = { all primes and symbol ∞}. Then a p-main-factor U/V of G is said to be (?)-central in G if G/CG(U/V) ∈f(p). In this paper, we have proved that: let (?) be a locally defined formation consisting of locally soluble groups, G a hyper-(cyclic or finite) locally soluble group and A an artinian ZG-module with all irreducible ZG-factors of A being finite; if G ∈ (?), f(∞) ≡ f(p) . f(p)≠φ for each p ∈ π, A has an (?)-decomposition.
基金Supported by the National Natural Science Foundation of China under Grant No.19675044.
文摘Debye screening mass at the next-to-leading order is studied by the resummation method based on perturbation theory at finite temperature.We find that the critical temperature for the J/ψdissociation is 0.211 GeV.The contributions from the next-to-leading order are important,and critical temperature and chemical potential are shifted lower values.
文摘In a paper published years ago by me and my collaborators, the properties of heavy quarkonium systems were studied based on the Dick potential, which explicitly included the color factor in the potential and the non-relativistic SchrSedinger equation was numerically solved. However, another paper by Barakat and Chaba appeared online a few months earlier, which dealt with a similar problem, but used the shifted-expansion technique （SLET） to solve the semi-relativistic wave equation for the Dick potential up to a QCD color factor. Since both the papers solved the same Dick potential model, similar energy spectra due to the small relativistic effect were obtained for this heavy quark system. I and my collaborators did not point out this similarity in Ref. This should be added to give credit to Ref.
