Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy...Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).展开更多
We study one possible production mechanism for the hidden-charm pentaquark via a color-octet cc pair fragmentation in e^(+)e^(-)collision.The pentaquark production at B factory energy is dominated by e^(+)e^(-)→ccg→...We study one possible production mechanism for the hidden-charm pentaquark via a color-octet cc pair fragmentation in e^(+)e^(-)collision.The pentaquark production at B factory energy is dominated by e^(+)e^(-)→ccg→P_(c)+X,while at Z^(0)pole energy,there are several partonic processes playing significant role.Our results show that it is possible to search for the direct pentaquark production signal at e^(+)e^(-)colliders,which is important to understand the properties of pentaquark.展开更多
The non-relativistic wave function framework is applied to study the production and decay of exotic hadrons, which can be effectively described as bound states of other hadrons. Employing the factorized formulation,wi...The non-relativistic wave function framework is applied to study the production and decay of exotic hadrons, which can be effectively described as bound states of other hadrons. Employing the factorized formulation,with the help of event generators, we investigate the production of exotic hadrons in multiproduction processes at high energy hadron colliders. This study provides crucial information for the measurements of the relevant exotic hadrons.展开更多
We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that...We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that have only the(QQ)(3):(qq)_(3).color structure are related with those of conventional hadrons using HDAS.Thereafter,the masses of their partner states are determined with the mass splittings in the CMI model.Our numerical results reveal that(i)the lightest ccnn(n=u,d)is an I(J^(P))=0(1^(+))state around 3929 MeV(53 MeV above the DD^(*) threshold),and none of the double-charm tetraquarks are stable;(ii)the stable double-bottom tetraquarks are the lowest 0(1^(+))bbin around 10488 MeV(≈116 MeV below the BB^(*)threshold)and the lowest 1/2(1^(+))bbns around 10671 MeV(≈20 MeV below the BB_(s)^(*)/B_(s)B^(*)threshold);and(iii)the two lowest bcnn tetraquarks,namely the lowest 0(0^(+))around 7167 MeV and the lowest 0(1)around 7223 MeV,are in the nearthreshold states.Moreover,we discuss the constraints on the masses of double-heavy hadrons.Specifically,for the lowest nonstrange tetraquarks,we obtain T_(cc)<3965 MeV,T_(bb)<10627 MeV,and T_(bc)<7199 MeV.展开更多
We studied the spectrum and rearrangement decays of S-wave cs■tetraquark states in a simplified quark model.The masses and widths were estimated by assuming that X(4140)is the lower 1^(++)cs■tetraquark.Comparing our...We studied the spectrum and rearrangement decays of S-wave cs■tetraquark states in a simplified quark model.The masses and widths were estimated by assuming that X(4140)is the lower 1^(++)cs■tetraquark.Comparing our results with experimental measurements,we found that X(3960),recently observed by LHCb,can be considered the lowest 0^(++)sc■tetraquark state and X0(4140)could be the second lowest 0^(++)cs■tetraquark.Predictions of ratios between partial widths for the involved tetraquarks are provided in this paper.We aim to identify more cs■tetraquarks with J^(PC)=1^(+-),0^(++),and 2^(++).展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1602200)the National Natural Science Foundation of China(Nos.12341501 and 12405174)the Hefei Comprehensive National Science Center for the strong support on the STCF key technology research project.
文摘Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).
基金Supported by National Natural Science Foundation of China under Grant Nos.11775130,11775132,11635009,11325525the Natural Science Foundation of Shandong Province under Grant No.ZR2017MA002
文摘We study one possible production mechanism for the hidden-charm pentaquark via a color-octet cc pair fragmentation in e^(+)e^(-)collision.The pentaquark production at B factory energy is dominated by e^(+)e^(-)→ccg→P_(c)+X,while at Z^(0)pole energy,there are several partonic processes playing significant role.Our results show that it is possible to search for the direct pentaquark production signal at e^(+)e^(-)colliders,which is important to understand the properties of pentaquark.
基金Supported by Natural Science Foundation of Shandong Province(ZR2014AM016,ZR2016AM16)National Natural Science Foundation of China(11275115,11325525,11635009)
文摘The non-relativistic wave function framework is applied to study the production and decay of exotic hadrons, which can be effectively described as bound states of other hadrons. Employing the factorized formulation,with the help of event generators, we investigate the production of exotic hadrons in multiproduction processes at high energy hadron colliders. This study provides crucial information for the measurements of the relevant exotic hadrons.
基金Supported by National Natural Science Foundation of China (11775130, 11775132, 11635009, 11325525, 11875179)Natural Science Foundation of Shandong Province (ZR2016AM16, ZR2017MA002)。
文摘We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that have only the(QQ)(3):(qq)_(3).color structure are related with those of conventional hadrons using HDAS.Thereafter,the masses of their partner states are determined with the mass splittings in the CMI model.Our numerical results reveal that(i)the lightest ccnn(n=u,d)is an I(J^(P))=0(1^(+))state around 3929 MeV(53 MeV above the DD^(*) threshold),and none of the double-charm tetraquarks are stable;(ii)the stable double-bottom tetraquarks are the lowest 0(1^(+))bbin around 10488 MeV(≈116 MeV below the BB^(*)threshold)and the lowest 1/2(1^(+))bbns around 10671 MeV(≈20 MeV below the BB_(s)^(*)/B_(s)B^(*)threshold);and(iii)the two lowest bcnn tetraquarks,namely the lowest 0(0^(+))around 7167 MeV and the lowest 0(1)around 7223 MeV,are in the nearthreshold states.Moreover,we discuss the constraints on the masses of double-heavy hadrons.Specifically,for the lowest nonstrange tetraquarks,we obtain T_(cc)<3965 MeV,T_(bb)<10627 MeV,and T_(bc)<7199 MeV.
基金Supported by the National Natural Science Foundation of China(12235008,12275157,11905114)the Natural Science Foundation of Shandong Province,China(ZR2023MA041)。
文摘We studied the spectrum and rearrangement decays of S-wave cs■tetraquark states in a simplified quark model.The masses and widths were estimated by assuming that X(4140)is the lower 1^(++)cs■tetraquark.Comparing our results with experimental measurements,we found that X(3960),recently observed by LHCb,can be considered the lowest 0^(++)sc■tetraquark state and X0(4140)could be the second lowest 0^(++)cs■tetraquark.Predictions of ratios between partial widths for the involved tetraquarks are provided in this paper.We aim to identify more cs■tetraquarks with J^(PC)=1^(+-),0^(++),and 2^(++).
