In this article,we study the vector meson transitions among the charmonium and bottomonium states with the heavy quark effective theory in a systematic way,and make predictions for the ratios among the vector meson de...In this article,we study the vector meson transitions among the charmonium and bottomonium states with the heavy quark effective theory in a systematic way,and make predictions for the ratios among the vector meson decay widths of a special multiplet to another multiplet.The predictions can be confronted with the experimental data in the future.展开更多
Using the phenomenological relativistic harmonic model （RHM） for quarks, we have obtained the masses of S wave charmonium states. The full Hamiltonian used in the investigation has Lorentz scalar plus vector confine...Using the phenomenological relativistic harmonic model （RHM） for quarks, we have obtained the masses of S wave charmonium states. The full Hamiltonian used in the investigation has Lorentz scalar plus vector confinement potential, along with the confined one gluon exchange potential （COGEP）. A good agreement with the experimental masses for the ground state and the radially excited states is obtained for both the triplet and singlet S wave mesons. The calculated charge radii, meson decay constants, leptonic decay width, two photon decay width, and the radiative M1 decay width are in good agreement with the experimental results.展开更多
The cross sections for e^＋e^- →π^＋ π^-J/ψ, π^＋π^-ψ（2S）, K^＋K^-J/ψ, DD1D^0D1-π^＋ ＋c.c., D^＊D＋c.c., and D^＊D^＊ are measured using data sample collected on or near the T（4S） resonance with the Bell...The cross sections for e^＋e^- →π^＋ π^-J/ψ, π^＋π^-ψ（2S）, K^＋K^-J/ψ, DD1D^0D1-π^＋ ＋c.c., D^＊D＋c.c., and D^＊D^＊ are measured using data sample collected on or near the T（4S） resonance with the Belle detector at KEKB. A peak near 4.25 GeV/c^2, corresponding to the so called Y（4260）, is observed in π^＋π^-J/ψ final state. In addition, there is another cluster of events at around 4.05 GeV/c^2. Two resonant structures are observed in the π^＋π^-ψ（2S） invariant mass distribution, one at 4361±9±9 MeV/c^2 with a width of 74±15±10 MeV/c2, and another at 4664 ±11±5 MeV/c2 with a width of 48±15±3 MeV/c^2. The rich structures observed in all these final states indicate that our understanding of the vector charmonium states above the open charm threshold is still poor, let alone the other possible dynamics such as charmonium hybrids or final state re-scattering and so on.展开更多
We have investigated the internal structure of the open-and hidden-charmed(DD^(*)/DD^(*))molecules in the unified framework.We first fit the experimental lineshape of the Tt state and extract the DD^(*)interaction,fro...We have investigated the internal structure of the open-and hidden-charmed(DD^(*)/DD^(*))molecules in the unified framework.We first fit the experimental lineshape of the Tt state and extract the DD^(*)interaction,from which the T is assumed to arise solely.Then we obtain the DD^(*)interaction by charge conjugation.Our results show that the DD*interaction is attractive but insufficient to form X(3872)as a bound state.Instead,its formation requires the crucial involvement of the coupled channel effect between the DD^(*)and cc components,although the cc accounts for approximately 1%only.Besides X(3872),we have obtained a higher-energy state around 3957.9 MeV with a width of 16.7 MeV,which may be a potential candidate for the X(3940).In J^(PC)=1^(+-)sector,we have found two states related to the iso-scalar X(3872)and h_(c)(2P),respectively.Our combined study provides valuable insights into the nature of these DD^(+)/DD^(+)exotic states.展开更多
We present a search for new charmonium like states in e^＋e^- annihilation using the initial-state radiation and the process e^＋e^- →J/ψ D（^＊）D（^＊）. The analyses are based on a huge data sample recorded near ...We present a search for new charmonium like states in e^＋e^- annihilation using the initial-state radiation and the process e^＋e^- →J/ψ D（^＊）D（^＊）. The analyses are based on a huge data sample recorded near the T（4S） resonance with the Belle detector at the KEKB e^＋e^- asymmetric-energy collider.展开更多
With its unique data samples at energies of 3.8-4.6 GeV, the BESIII experiment made a significant contribution to the study of charmonium and charinonium-like states, i.e., the XYZ states. We review the results for ob...With its unique data samples at energies of 3.8-4.6 GeV, the BESIII experiment made a significant contribution to the study of charmonium and charinonium-like states, i.e., the XYZ states. We review the results for observations of the Zc（3900） and Zc（4020） states, the X（3872） in e^＋e^- annihilation, and charmonium ψ（13D2） state, as well as measurements of the cross-sections of ωχcJ and ηJ/ψ, and the search for e^＋e^-→γχcJ and γY（4140）. We also present data from BESIII that may further strengthen the study of the XYZ and conventional charmonium states, and discuss perspectives on future experiments.展开更多
We present physics opportunities and topics with the ss states （strangeonia） that can be studied with the BESⅢ detector operating at the BEPCⅡ collider. Though the dp and η/ηt states have long been established e...We present physics opportunities and topics with the ss states （strangeonia） that can be studied with the BESⅢ detector operating at the BEPCⅡ collider. Though the dp and η/ηt states have long been established experimentally, only a handful of strangeonia are well known, in contrast to the rich cc charmoium system. An overview of the ss states and their experimental status is presented in this paper. The BESⅢ experiment has collected the world＇s largest samples of J/ψ, ψ（2S）, ψ（3770）, and direct e＋e- annihilations at energies below the J/O and above 3.8 GeV, and will continue to accumulate high quality, large integrated luminosity in the T-charm energy region. These data, combined with the excellent performance of the BESⅢ detector, will offer unprecedented opportunities to explore the ss system. In this paper we describe the experimental techniques to explore strangeonia with the BESⅢ detector.展开更多
The unquenched quark model for the light quarkonium and charmonium states is explored in this study.The quark-pair creation operator in the^(3)P_(0) model,which combines the two-quark and four-quark components,is modi...The unquenched quark model for the light quarkonium and charmonium states is explored in this study.The quark-pair creation operator in the^(3)P_(0) model,which combines the two-quark and four-quark components,is modified by considering the effects of the created quark pair's energy.Furthermore,the separation between the created quark pair and valence quark pair is modified.All the wave functions,including those for the mesons and the relative motion between two mesons,are obtained by solving the corresponding Schrodinger equation using the Gaussian expansion method.The aim of this study is to find a new set of parameters that can accurately describe the mass spectrum of low-lying light quarkonium and charmonium states.Moreover,certain exotic states,such as X(3872),can be described well in the unquenched quark model.展开更多
All existing experimental evidence for the bound state nature of X(3872)relies on observing its decay products,which are measured with a finite experimental mass resolution that is typically△m≥2 MeV,and much larger ...All existing experimental evidence for the bound state nature of X(3872)relies on observing its decay products,which are measured with a finite experimental mass resolution that is typically△m≥2 MeV,and much larger than its alleged binding energy,BX=0.00(18)MeV.On the other hand,we have found recently that there is a clear cancellation in the 1^++channel of the invariant DD^*mass around the threshold between continuum and the bound state.This is very much like a similar cancellation in the proton-neutron continuum with the deuteron in the 1^++channel.Based on comparative fits with a common Tsallis distribution of the experimental cross-sections for prompt production of deuterons and X(3872)in pp collisions with a finite pT,we find a strong argument for questioning the bound state nature of this state,which also suggests that the large observed production rate could be consistent with a half-bound state.展开更多
Motivated by the large rates of B→(χc0,χc2,hc)K decays observed by the BABAR and Belle collaborations,we investigate the nonfactorizable contributions to these factorization-forbidden decays,which can occur through...Motivated by the large rates of B→(χc0,χc2,hc)K decays observed by the BABAR and Belle collaborations,we investigate the nonfactorizable contributions to these factorization-forbidden decays,which can occur through a gluon exchange between the cc system and the spectator quark.Our numerical results demonstrate that the spectator contributions are capable of producing a large branching ratio consistent with the experiments.As a by-product,we also study the Cabibbo-suppressed decays,such as B→(χc0,χc2,hc)πand the U-spin-related Bs decay,which have so far received less theoretical and experimental attention.The calculated branching ratios reach the order of 10−6,which is within the scope of the Belle-Ⅱ and LHCb experiments.Further,the CP-asymmetry parameters are also calculated for these decays.The obtained results are compared with the available experimental data and numbers from other predictions.We also investigate the sources of theoretical uncertainties in our calculation.展开更多
Based on the prediction of a D^∗D^¯∗molecular state Zc(4000)with isospin I=1 in the coupled channel approach,we suggest the search for this state in the reaction B−→J/ψρ0K−.By considering the final state inter...Based on the prediction of a D^∗D^¯∗molecular state Zc(4000)with isospin I=1 in the coupled channel approach,we suggest the search for this state in the reaction B−→J/ψρ0K−.By considering the final state interactions of J/ψρand D^∗0D^¯∗0 and the contribution from the K1(1270)resonance,we observed that the J/ψρmass distribution shows a peak around 4000 MeV,which might be associated with the D^∗D^¯∗molecular state Zc(4000).The search for Zc(4000)in the reaction B−→J/ψρ^0K−is critical for understanding the internal structures of exotic hadrons.Our predictions can be tested by the Belle II and LHCb in future studies.展开更多
基金Supported by National Natural Science Foundation of China under Grant No. 11075053the Fundamental Research Funds for the Central Universities
文摘In this article,we study the vector meson transitions among the charmonium and bottomonium states with the heavy quark effective theory in a systematic way,and make predictions for the ratios among the vector meson decay widths of a special multiplet to another multiplet.The predictions can be confronted with the experimental data in the future.
基金the BRNS for funding the project(Sanction No.2010/37P/18/BRNS)
文摘Using the phenomenological relativistic harmonic model （RHM） for quarks, we have obtained the masses of S wave charmonium states. The full Hamiltonian used in the investigation has Lorentz scalar plus vector confinement potential, along with the confined one gluon exchange potential （COGEP）. A good agreement with the experimental masses for the ground state and the radially excited states is obtained for both the triplet and singlet S wave mesons. The calculated charge radii, meson decay constants, leptonic decay width, two photon decay width, and the radiative M1 decay width are in good agreement with the experimental results.
基金National Natural Science Foundation of China(10775142)and 100 Talents Program of CAS(U-25)
文摘The cross sections for e^＋e^- →π^＋ π^-J/ψ, π^＋π^-ψ（2S）, K^＋K^-J/ψ, DD1D^0D1-π^＋ ＋c.c., D^＊D＋c.c., and D^＊D^＊ are measured using data sample collected on or near the T（4S） resonance with the Belle detector at KEKB. A peak near 4.25 GeV/c^2, corresponding to the so called Y（4260）, is observed in π^＋π^-J/ψ final state. In addition, there is another cluster of events at around 4.05 GeV/c^2. Two resonant structures are observed in the π^＋π^-ψ（2S） invariant mass distribution, one at 4361±9±9 MeV/c^2 with a width of 74±15±10 MeV/c2, and another at 4664 ±11±5 MeV/c2 with a width of 48±15±3 MeV/c^2. The rich structures observed in all these final states indicate that our understanding of the vector charmonium states above the open charm threshold is still poor, let alone the other possible dynamics such as charmonium hybrids or final state re-scattering and so on.
基金supported by the KAKENHI(19H05159,20K03959,and 21H00132(M.O.),and 23K03427(M.O.and G.J.W),24K17055(G.J.W))the National Natural Science Foundation of China(12275046(Z.Y.),12175239 and 12221005(J.J.W),11975033 and 12070131001(S.L.Z.))+2 种基金the Natural Science Foundation of Sichuan Province(2022NSFSC1795(Z.Y.))the National Key R&D Program of China(2020YFA0406400(J.J.W))the Chinese Academy of Sciences(YSBR-101(J.J.W)).
文摘We have investigated the internal structure of the open-and hidden-charmed(DD^(*)/DD^(*))molecules in the unified framework.We first fit the experimental lineshape of the Tt state and extract the DD^(*)interaction,from which the T is assumed to arise solely.Then we obtain the DD^(*)interaction by charge conjugation.Our results show that the DD*interaction is attractive but insufficient to form X(3872)as a bound state.Instead,its formation requires the crucial involvement of the coupled channel effect between the DD^(*)and cc components,although the cc accounts for approximately 1%only.Besides X(3872),we have obtained a higher-energy state around 3957.9 MeV with a width of 16.7 MeV,which may be a potential candidate for the X(3940).In J^(PC)=1^(+-)sector,we have found two states related to the iso-scalar X(3872)and h_(c)(2P),respectively.Our combined study provides valuable insights into the nature of these DD^(+)/DD^(+)exotic states.
文摘We present a search for new charmonium like states in e^＋e^- annihilation using the initial-state radiation and the process e^＋e^- →J/ψ D（^＊）D（^＊）. The analyses are based on a huge data sample recorded near the T（4S） resonance with the Belle detector at the KEKB e^＋e^- asymmetric-energy collider.
基金Acknowledgements This work was supported in part by the National Natural Science Foundation of China （NSFC） under Grant Nos. 11235011 and 11475187 the Ministry of Science and Technology of China under Grant No. 2015CB856701, and the CAS Center for Excellence in Particle Physics （CCEPP）.
文摘With its unique data samples at energies of 3.8-4.6 GeV, the BESIII experiment made a significant contribution to the study of charmonium and charinonium-like states, i.e., the XYZ states. We review the results for observations of the Zc（3900） and Zc（4020） states, the X（3872） in e^＋e^- annihilation, and charmonium ψ（13D2） state, as well as measurements of the cross-sections of ωχcJ and ηJ/ψ, and the search for e^＋e^-→γχcJ and γY（4140）. We also present data from BESIII that may further strengthen the study of the XYZ and conventional charmonium states, and discuss perspectives on future experiments.
基金Supported by CAS/SAFEA International Partnership Program for Creative Research Teams,CAS and IHEP grants for the Thousand/Hundred Talent programs and National Natural Science Foundation of China(11175189)
文摘We present physics opportunities and topics with the ss states （strangeonia） that can be studied with the BESⅢ detector operating at the BEPCⅡ collider. Though the dp and η/ηt states have long been established experimentally, only a handful of strangeonia are well known, in contrast to the rich cc charmoium system. An overview of the ss states and their experimental status is presented in this paper. The BESⅢ experiment has collected the world＇s largest samples of J/ψ, ψ（2S）, ψ（3770）, and direct e＋e- annihilations at energies below the J/O and above 3.8 GeV, and will continue to accumulate high quality, large integrated luminosity in the T-charm energy region. These data, combined with the excellent performance of the BESⅢ detector, will offer unprecedented opportunities to explore the ss system. In this paper we describe the experimental techniques to explore strangeonia with the BESⅢ detector.
基金Supported by the National Natural Science Foundation of China(12205125,11847145,12205249,11865019)the Natural Science Foundation of Jiangsu Province,China(BK20221166)。
文摘The unquenched quark model for the light quarkonium and charmonium states is explored in this study.The quark-pair creation operator in the^(3)P_(0) model,which combines the two-quark and four-quark components,is modified by considering the effects of the created quark pair's energy.Furthermore,the separation between the created quark pair and valence quark pair is modified.All the wave functions,including those for the mesons and the relative motion between two mesons,are obtained by solving the corresponding Schrodinger equation using the Gaussian expansion method.The aim of this study is to find a new set of parameters that can accurately describe the mass spectrum of low-lying light quarkonium and charmonium states.Moreover,certain exotic states,such as X(3872),can be described well in the unquenched quark model.
基金partly supported by the Spanish Ministerio de Economía y Competitividad and European FEDER funds(FPA2016-77177-C2-2-P,FIS2017-85053-C2-1-P)and Junta de Andalucía(FQM-225)
文摘All existing experimental evidence for the bound state nature of X(3872)relies on observing its decay products,which are measured with a finite experimental mass resolution that is typically△m≥2 MeV,and much larger than its alleged binding energy,BX=0.00(18)MeV.On the other hand,we have found recently that there is a clear cancellation in the 1^++channel of the invariant DD^*mass around the threshold between continuum and the bound state.This is very much like a similar cancellation in the proton-neutron continuum with the deuteron in the 1^++channel.Based on comparative fits with a common Tsallis distribution of the experimental cross-sections for prompt production of deuterons and X(3872)in pp collisions with a finite pT,we find a strong argument for questioning the bound state nature of this state,which also suggests that the large observed production rate could be consistent with a half-bound state.
基金Supported in part by the National Natural Science Foundation of China(11605060,11547020)the Natural Science Foundation of Hebei Province(A2019209449)Department of Education of Hebei Province(BJ2016041)。
文摘Motivated by the large rates of B→(χc0,χc2,hc)K decays observed by the BABAR and Belle collaborations,we investigate the nonfactorizable contributions to these factorization-forbidden decays,which can occur through a gluon exchange between the cc system and the spectator quark.Our numerical results demonstrate that the spectator contributions are capable of producing a large branching ratio consistent with the experiments.As a by-product,we also study the Cabibbo-suppressed decays,such as B→(χc0,χc2,hc)πand the U-spin-related Bs decay,which have so far received less theoretical and experimental attention.The calculated branching ratios reach the order of 10−6,which is within the scope of the Belle-Ⅱ and LHCb experiments.Further,the CP-asymmetry parameters are also calculated for these decays.The obtained results are compared with the available experimental data and numbers from other predictions.We also investigate the sources of theoretical uncertainties in our calculation.
基金This work is partly Supported by the National Natural Science Foundation of China(11505158)the Key Research Projects of Henan Higher Education Institutions(20A140027)the Academic Improvement Project of Zhengzhou University。
文摘Based on the prediction of a D^∗D^¯∗molecular state Zc(4000)with isospin I=1 in the coupled channel approach,we suggest the search for this state in the reaction B−→J/ψρ0K−.By considering the final state interactions of J/ψρand D^∗0D^¯∗0 and the contribution from the K1(1270)resonance,we observed that the J/ψρmass distribution shows a peak around 4000 MeV,which might be associated with the D^∗D^¯∗molecular state Zc(4000).The search for Zc(4000)in the reaction B−→J/ψρ^0K−is critical for understanding the internal structures of exotic hadrons.Our predictions can be tested by the Belle II and LHCb in future studies.
