A non-topological soliton model with strange quarks is suggested to investigate the phase structure of strange matter.The results are qualitatively in agreement with that obtained by MIT bag model provided the ratio o...A non-topological soliton model with strange quarks is suggested to investigate the phase structure of strange matter.The results are qualitatively in agreement with that obtained by MIT bag model provided the ratio of coupling constants of different quarks to soliton scalar field x_(σ)≡g_(gσ)/g_(qσ) larger than a critical value χ_(c)~0.86,but as χ_(σ) gets smaller than xc,the phase structure may change.展开更多
In this work, we evaluate the lifetimes of the doubly charmed baryons Ξcc^＋ ,Ξcc^＋＋, and Ωcc^＋. We carefully calculate the non-spectator contributions at the quark level, where the Cabibbo-suppressed diagrams a...In this work, we evaluate the lifetimes of the doubly charmed baryons Ξcc^＋ ,Ξcc^＋＋, and Ωcc^＋. We carefully calculate the non-spectator contributions at the quark level, where the Cabibbo-suppressed diagrams are also included. The hadronic matrix elements are evaluated in the simple non-relativistic harmonic oscillator model. Our numerical results are generally consistent with that obtained by other authors who used the diquark model. However, all the theoretical predictions on the lifetimes are one order larger than the upper limit set by the recent SELEX measurement. This discrepancy would be clarified by the future experiment. If more accurate experiment still confirms the value of the SELEX collaboration, there must be some unknown mechanism to be explored.展开更多
As well known, if the Higgs boson were not observed at LHC, the technicolor model would be the most favorable candidate responsible for the symmetry breaking. To overcome some defects in the previous model, some exten...As well known, if the Higgs boson were not observed at LHC, the technicolor model would be the most favorable candidate responsible for the symmetry breaking. To overcome some defects in the previous model, some extended versions have been proposed. In the TC2 model typical signature is existence of heavy HTC and technipion ∏. A direct proof of validity of the model is to produce them at accelerator. Thus we study the production rates of e＋e^- → HTC∏^0 and e＋e^- → ∏＋∏- at ILC in the topcolor-assisted technicolor （TC2） model. In fact, there is a flood of models belonging to new physics, which can result in products with characteristics similar to HTC ＋ ∏ of the TC2 model. Therefore to distinguish this model from others one may need to investigate some details by calculating the cross section to NLO. We indeed find that the NLO corrections are significant, namely the ratio δ ≡（ σNLO - σLO）/σLO in e＋e- →HTC∏^0 exceeds 100% within a plausible parameter space.展开更多
The newly observed D^＊aj family containing D^＊aj（2317）, Daj（2460）, and Daj（2632） attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this...The newly observed D^＊aj family containing D^＊aj（2317）, Daj（2460）, and Daj（2632） attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this work we use a non-relativistic model （the harmonic oscillator model） to evaluate the production rate of D^＊aj （2317） from the decays of ψ（4415）. For a comparison, we a/so employ the widely adopted heavy quark effective theory to repeat the calculation. We lind that the rate is sizable and may be observed at BES III and CLEO, if it is a p-wave excited state of Da（1968）. Unfortunately, the other two members of the family cannot be observed through decays of charmonia, because of the constraints from the final state phase space.展开更多
In this work, we employ the Bethe-Salpeter （B-S） equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks wit...In this work, we employ the Bethe-Salpeter （B-S） equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks with two heavy quarks or one heavy and one light quarks, but for two light-quark systems, the results are not reliable. There are a few free parameters in the whole scenario which can only be fixed phenomenologically. Thus, to determine them, one has to study baryons which are composed of quarks and diquarks.展开更多
We study constraints on neutrino properties for a class of bi-large mixing See-Saw mass matrices with texture zeros and with the related Dirac neutrino mass matrix to be proportional to a diagonal matrix of the form d...We study constraints on neutrino properties for a class of bi-large mixing See-Saw mass matrices with texture zeros and with the related Dirac neutrino mass matrix to be proportional to a diagonal matrix of the form diag （e, 1, 1）. Texture zeros may occur in the light （class a）） or in the heavy （class b）） neutrino mass matrices. Each of these two classes has 5 different forms which can produce non-trivial three generation mixing with at least one texture zero. We tind that two types of texture zero mass matrices in both class a and class b can be consistent with present data on neutrino masses and mixing. None of the neutrinos can have zero masses and the lightest of the light neutrinos has a mass larger than about 0.046 eV for class a and 0.0027 eV for class b. In these models although the CK.M CP violating phase vanishes, the non-zero Majorana phases can exist and can play an important role in producing the observed baryon asymmetry in our universe through leptogenesis mechanism. The requirement of producing the observed baryon asymmetry can further distinguish different models and also restrict the See-Saw scale to be in the range of 10^12- 10^15 GeV. We also discuss RG effects on V^13.展开更多
ãWith rapid growth of the database of the BES III and the proposed super flavor factory,measurement of the rare J/ψdecays may be feasible,especially the weak decays into baryon final states.In this work,we study...ãWith rapid growth of the database of the BES III and the proposed super flavor factory,measurement of the rare J/ψdecays may be feasible,especially the weak decays into baryon final states.In this work,we study the decay rate of J/ψtoΛc+øverlineΣ+in the standard model(SM)and physics beyond the SM(here we use the unparticle model as an example).The quark−pair-creation model is employed to describe the creation of a pair of qq from a vacuum.We find that the rate of J/ψ→Λc+Σ^(+) is of the order of 10−10 in the SM,whereas the contribution of the unparticle is too small to be substantial.Therefore if a large branching ratio is observed,it must be due to new physics beyond the SM,but by no means the unparticle.展开更多
Based on the flux tube model, the effects of the confining potentials of different configurations, namely the △-type and the Y-type, on the spectra of baryons are studied on SUSF（6） basis. The baryon spectra are ob...Based on the flux tube model, the effects of the confining potentials of different configurations, namely the △-type and the Y-type, on the spectra of baryons are studied on SUSF（6） basis. The baryon spectra are obtained in a unified manner. Our result shows that by employing either the △-mode or the Y-mode confining potential, one can achieve reasonable baryon spectra. The △-mode may be mostly effective for the short- and medium-distances, while the Y-mode may offer more contributions to the spectra for long-distances. Although the binding energies in baryon spectra may deviate by a few to several tens MeV for different modes, it is hard to determine either one to be dominant by simply evaluating the baryon spectra. One may need to invoke the baryon decay process to make further judgement.展开更多
We discuss the moment analysis method for the 0^(++)and 2^(++)coupling mode of fJ(1710)for incomplete phase space in the radiative decay J/ψ→γK^(+)K^(-),and give a new formulation of analyzing the fJ(1710)structure...We discuss the moment analysis method for the 0^(++)and 2^(++)coupling mode of fJ(1710)for incomplete phase space in the radiative decay J/ψ→γK^(+)K^(-),and give a new formulation of analyzing the fJ(1710)structure for the Beijing Spectrometer detector at the Beijing Electron-Positron Collider.The incomplete detection phase space results in a significant effect on the moment analysis.展开更多
We investigate the finite-temperature phase structure in a scaled chiral model which includes the dilaton(glueball)field.It is shown that hot nuclear matter undergoes a discontinuous transition in the mean field of sc...We investigate the finite-temperature phase structure in a scaled chiral model which includes the dilaton(glueball)field.It is shown that hot nuclear matter undergoes a discontinuous transition in the mean field of scalar mesons as well as the Lee-Wick abnormal transition.The corresponding behavior of the gluon condensate during the chiral phase transition is also studied.展开更多
The effect of higher dimensional quark-gluon condensates on the effective quark-antiquark potential is investigated.In this scenario,cc and bb spectra are studied.It is shown that the vacuum condensates of the d=5 and...The effect of higher dimensional quark-gluon condensates on the effective quark-antiquark potential is investigated.In this scenario,cc and bb spectra are studied.It is shown that the vacuum condensates of the d=5 and d=6 operators,where d denotes the dimension of the operator,still cause notable effects.The perturbative loop contributions from the s-channel scattering and t-channel annihilation processes to the potential are almost the same.These contributions are opposite in sign to the non-perturbative contributions of the d=4 operator condensates.展开更多
We indicated in our previous work that for QED the role of the scalar potential which appears at the loop level is much smaller than that of the vector potential and is in fact negligible. But the situation is differe...We indicated in our previous work that for QED the role of the scalar potential which appears at the loop level is much smaller than that of the vector potential and is in fact negligible. But the situation is different for QCD, one reason is that the loop effects are more significant because as is much larger than a, and second the non-perturbative QCD effects may induce a sizable scalar potential. In this work, we study phenomenologically the contribution of the scalar potential to the spectra of charmonia, bottomonia and bC（bc） families. Taking into account both vector and scalar potentials, by fitting the well measured charmonia and bottomonia spectra, we re-fix the relevant parameters and test them by calculating other states of not only the eharmonia and bottomonia families, but also the bc family. We also consider the Lamb shift of the spectra.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grant No.19575010.
文摘A non-topological soliton model with strange quarks is suggested to investigate the phase structure of strange matter.The results are qualitatively in agreement with that obtained by MIT bag model provided the ratio of coupling constants of different quarks to soliton scalar field x_(σ)≡g_(gσ)/g_(qσ) larger than a critical value χ_(c)~0.86,but as χ_(σ) gets smaller than xc,the phase structure may change.
基金The project supported by National Natural Science Foundation of China
文摘In this work, we evaluate the lifetimes of the doubly charmed baryons Ξcc^＋ ,Ξcc^＋＋, and Ωcc^＋. We carefully calculate the non-spectator contributions at the quark level, where the Cabibbo-suppressed diagrams are also included. The hadronic matrix elements are evaluated in the simple non-relativistic harmonic oscillator model. Our numerical results are generally consistent with that obtained by other authors who used the diquark model. However, all the theoretical predictions on the lifetimes are one order larger than the upper limit set by the recent SELEX measurement. This discrepancy would be clarified by the future experiment. If more accurate experiment still confirms the value of the SELEX collaboration, there must be some unknown mechanism to be explored.
基金Supported by National Natural Science Foundation of China and the Special Grant for the PHD program of the Education Ministry of China under Grant No.10775073
文摘As well known, if the Higgs boson were not observed at LHC, the technicolor model would be the most favorable candidate responsible for the symmetry breaking. To overcome some defects in the previous model, some extended versions have been proposed. In the TC2 model typical signature is existence of heavy HTC and technipion ∏. A direct proof of validity of the model is to produce them at accelerator. Thus we study the production rates of e＋e^- → HTC∏^0 and e＋e^- → ∏＋∏- at ILC in the topcolor-assisted technicolor （TC2） model. In fact, there is a flood of models belonging to new physics, which can result in products with characteristics similar to HTC ＋ ∏ of the TC2 model. Therefore to distinguish this model from others one may need to investigate some details by calculating the cross section to NLO. We indeed find that the NLO corrections are significant, namely the ratio δ ≡（ σNLO - σLO）/σLO in e＋e- →HTC∏^0 exceeds 100% within a plausible parameter space.
基金The project supported by National Natural Science Foundation of China and the Special Research Fund for Doctor Programs of the Chinese Universities
文摘The newly observed D^＊aj family containing D^＊aj（2317）, Daj（2460）, and Daj（2632） attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this work we use a non-relativistic model （the harmonic oscillator model） to evaluate the production rate of D^＊aj （2317） from the decays of ψ（4415）. For a comparison, we a/so employ the widely adopted heavy quark effective theory to repeat the calculation. We lind that the rate is sizable and may be observed at BES III and CLEO, if it is a p-wave excited state of Da（1968）. Unfortunately, the other two members of the family cannot be observed through decays of charmonia, because of the constraints from the final state phase space.
基金The project partly supported by National Natural Science Foundation of China and the Special Fund for the Doctorate Programs of Universities. We highly benefit from discussions with Prof. C.H. Chang, who kindly introduces their new methods for numerically solving the B-S equation to us and indicates some important physics problems which we did not notice.
文摘In this work, we employ the Bethe-Salpeter （B-S） equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks with two heavy quarks or one heavy and one light quarks, but for two light-quark systems, the results are not reliable. There are a few free parameters in the whole scenario which can only be fixed phenomenologically. Thus, to determine them, one has to study baryons which are composed of quarks and diquarks.
基金＊The project partly supported by the Special Scientific Research Foundation for Ph. D. Program of Universities of China, National Natural Science Foundation of China
文摘We study constraints on neutrino properties for a class of bi-large mixing See-Saw mass matrices with texture zeros and with the related Dirac neutrino mass matrix to be proportional to a diagonal matrix of the form diag （e, 1, 1）. Texture zeros may occur in the light （class a）） or in the heavy （class b）） neutrino mass matrices. Each of these two classes has 5 different forms which can produce non-trivial three generation mixing with at least one texture zero. We tind that two types of texture zero mass matrices in both class a and class b can be consistent with present data on neutrino masses and mixing. None of the neutrinos can have zero masses and the lightest of the light neutrinos has a mass larger than about 0.046 eV for class a and 0.0027 eV for class b. In these models although the CK.M CP violating phase vanishes, the non-zero Majorana phases can exist and can play an important role in producing the observed baryon asymmetry in our universe through leptogenesis mechanism. The requirement of producing the observed baryon asymmetry can further distinguish different models and also restrict the See-Saw scale to be in the range of 10^12- 10^15 GeV. We also discuss RG effects on V^13.
基金by the National Natural Science Foundation of China under Grant Nos 11075079 and 11005079the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 20100032120065.
文摘ãWith rapid growth of the database of the BES III and the proposed super flavor factory,measurement of the rare J/ψdecays may be feasible,especially the weak decays into baryon final states.In this work,we study the decay rate of J/ψtoΛc+øverlineΣ+in the standard model(SM)and physics beyond the SM(here we use the unparticle model as an example).The quark−pair-creation model is employed to describe the creation of a pair of qq from a vacuum.We find that the rate of J/ψ→Λc+Σ^(+) is of the order of 10−10 in the SM,whereas the contribution of the unparticle is too small to be substantial.Therefore if a large branching ratio is observed,it must be due to new physics beyond the SM,but by no means the unparticle.
基金The project supported by the Special Scientific Research Foundation for Doctoral Programs of Universities of China.
文摘Based on the flux tube model, the effects of the confining potentials of different configurations, namely the △-type and the Y-type, on the spectra of baryons are studied on SUSF（6） basis. The baryon spectra are obtained in a unified manner. Our result shows that by employing either the △-mode or the Y-mode confining potential, one can achieve reasonable baryon spectra. The △-mode may be mostly effective for the short- and medium-distances, while the Y-mode may offer more contributions to the spectra for long-distances. Although the binding energies in baryon spectra may deviate by a few to several tens MeV for different modes, it is hard to determine either one to be dominant by simply evaluating the baryon spectra. One may need to invoke the baryon decay process to make further judgement.
基金Supported in part by the National Natural Science Foundation of China under Grant No.19905011the Beijing Sepectrometer Collaboration Project.
文摘We discuss the moment analysis method for the 0^(++)and 2^(++)coupling mode of fJ(1710)for incomplete phase space in the radiative decay J/ψ→γK^(+)K^(-),and give a new formulation of analyzing the fJ(1710)structure for the Beijing Spectrometer detector at the Beijing Electron-Positron Collider.The incomplete detection phase space results in a significant effect on the moment analysis.
基金Supported by the National Natural Science Foundation of China under Grant No.19875026。
文摘We investigate the finite-temperature phase structure in a scaled chiral model which includes the dilaton(glueball)field.It is shown that hot nuclear matter undergoes a discontinuous transition in the mean field of scalar mesons as well as the Lee-Wick abnormal transition.The corresponding behavior of the gluon condensate during the chiral phase transition is also studied.
基金the National Natural Science Foundation of China under Grant No.1977551Bthe Chinese Academy of Sciences under Grant No.B78.
文摘The effect of higher dimensional quark-gluon condensates on the effective quark-antiquark potential is investigated.In this scenario,cc and bb spectra are studied.It is shown that the vacuum condensates of the d=5 and d=6 operators,where d denotes the dimension of the operator,still cause notable effects.The perturbative loop contributions from the s-channel scattering and t-channel annihilation processes to the potential are almost the same.These contributions are opposite in sign to the non-perturbative contributions of the d=4 operator condensates.
基金Supported by National Natural Science Foundation of China (NSFC) (10775073, 11005079)Special Grant for Ph.D. Program of Ministry of Eduction of P.R. China (20070055037, 20100032120065)
文摘We indicated in our previous work that for QED the role of the scalar potential which appears at the loop level is much smaller than that of the vector potential and is in fact negligible. But the situation is different for QCD, one reason is that the loop effects are more significant because as is much larger than a, and second the non-perturbative QCD effects may induce a sizable scalar potential. In this work, we study phenomenologically the contribution of the scalar potential to the spectra of charmonia, bottomonia and bC（bc） families. Taking into account both vector and scalar potentials, by fitting the well measured charmonia and bottomonia spectra, we re-fix the relevant parameters and test them by calculating other states of not only the eharmonia and bottomonia families, but also the bc family. We also consider the Lamb shift of the spectra.
