The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be...The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be helpful for experimental searches for these particles. The long-distance contributions are first studied in the doubly heavy baryon decays, and found to be significantly enhanced. Comparing all the processes, Ξ;→Λ;K;π;π;andΞ;π;are the most favorable decay modes for experiments to search for doubly heavy baryons.展开更多
In physics, the symmetries and their violation always provide deep insights into the Nature. The parity (P) symmetry represents the system is unchanged under the space reflection. The violation of parity, firstly prop...In physics, the symmetries and their violation always provide deep insights into the Nature. The parity (P) symmetry represents the system is unchanged under the space reflection. The violation of parity, firstly proposed by Lee and Yang and subsequently discovered in 1956, plays the key role in the understanding of the weak interaction which is one of the four basic forces of nature.展开更多
In this study,we investigate the discovery potential of double-charm tetraquarks■.We find that their production cross sections at the LHCb with■TeV reach O(10^(4))pb,which indicates that the LHCb has collected O(10^...In this study,we investigate the discovery potential of double-charm tetraquarks■.We find that their production cross sections at the LHCb with■TeV reach O(10^(4))pb,which indicates that the LHCb has collected O(10^(8))such particles.Through the decay channels of■or■or■(if unstable),it is highly expected that they get discovered at the LHCb in the near future.We also discuss the productions and decays of the double-charm tetraquarks at future Tera-Z factories.展开更多
The doubly charmed baryon■cc++was recently observed by LHCb via the decay processes of■cc++→∧+cK^(-)π^(+)π^(+)and■c+π^(+).These discovery channels were successfully predicted in a framework in which the short-...The doubly charmed baryon■cc++was recently observed by LHCb via the decay processes of■cc++→∧+cK^(-)π^(+)π^(+)and■c+π^(+).These discovery channels were successfully predicted in a framework in which the short-distance contributions are calculated under the factorization hypothesis and the long-distance contributions are estimated using the rescattering mechanism for the final-state-interaction effcts.In this paper,we illustrate the above framework in detail by systematic studies on the tw o-body baryonic decays Bcc→BcP involving the doubly charmed baryons Bcc=(■cc++,■cc++,Ωcc+),the singly charmed baryons Bc=(B3,B6)and the light pseudoscalar mesons P=(π,K,η1,8).展开更多
We calculate theD^0-D^-0 mixing parameter y in the factorization-assisted topological-amplitude（FAT）approach, considering contributions from D^0→PP, PV, and VV modes, where P（V） stands for a pseudoscalar（vector...We calculate theD^0-D^-0 mixing parameter y in the factorization-assisted topological-amplitude（FAT）approach, considering contributions from D^0→PP, PV, and VV modes, where P（V） stands for a pseudoscalar（vector） meson. The D^0→PP and PV decay amplitudes are extracted in the FAT approach, and the D^0→VV decay amplitudes with final states in the longitudinal polarization are estimated via the parameter set for D^0→PV. It is found that the VV contribution to y, being of order of 10-4, is negligible, and that the PP and PV contributions amount only up to y_（PP＋PV） =（0.21±0.07）%, a prediction more precise than those previously obtained in the literature,and much lower than the experimental data yexp =（0.61 ±0.08）%. We conclude that D^0 meson decays into other two-body and multi-particle final states are relevant to the evaluation of y, so it is difficult to understand it fully in an exclusive approach.展开更多
目前,奇异轴矢介子的性质并没有被很好地理解,而这类介子是可以在D介子衰变中得到更多的研究。将窄宽近似下的等式关系和强衰变中CP守恒应用到四体衰变D0→K+K-π+π-中的D0→K±K1■(1270)(→ρK or K*π)的实验数据中,可以发现实...目前,奇异轴矢介子的性质并没有被很好地理解,而这类介子是可以在D介子衰变中得到更多的研究。将窄宽近似下的等式关系和强衰变中CP守恒应用到四体衰变D0→K+K-π+π-中的D0→K±K1■(1270)(→ρK or K*π)的实验数据中,可以发现实验数据与理论存在矛盾,然而,当考虑更多K1(1270)的衰变过程后,可以发现,B(D0→K-K1+(1270)(→K*0π+))的实验数据很可能被高估了一个量级。考虑共振态K1(1400)的贡献,利用因子化方法计算相应的衰变过程的分支比,可以发现,B(D0→K-K1+(1400)(→K*0π+))的分支比与使用等式关系得到的B(D0→K-K1+(1270)(→K*0π+))的分支比在量级上是相同的。另外,对于含有奇异轴矢介子的D介子衰变实验数据的合理性,实验可以通过测量K1(1270)→ρK和K*π分支比的比值来检验,或者通过验证D介子衰变中的等式关系来检验。展开更多
基金Supported by National Natural Science Foundation of China(11505083,11505098,11647310,11575110,11375208,11521505,11621131001,11235005,11447032,U1732101)Natural Science Foundation of Shanghai(15DZ2272100)
文摘The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be helpful for experimental searches for these particles. The long-distance contributions are first studied in the doubly heavy baryon decays, and found to be significantly enhanced. Comparing all the processes, Ξ;→Λ;K;π;π;andΞ;π;are the most favorable decay modes for experiments to search for doubly heavy baryons.
基金This work was partially supported by the National Natural Science Foundation of China(U1732101 and 11975112)Gansu Natural Science Fund(18JR3RA265)+1 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2019-55)the University of Chinese Academy of Sciences Scholarship for International students.
文摘In physics, the symmetries and their violation always provide deep insights into the Nature. The parity (P) symmetry represents the system is unchanged under the space reflection. The violation of parity, firstly proposed by Lee and Yang and subsequently discovered in 1956, plays the key role in the understanding of the weak interaction which is one of the four basic forces of nature.
基金Supported by Natural Science Foundation of China(12005068,11975112)。
文摘In this study,we investigate the discovery potential of double-charm tetraquarks■.We find that their production cross sections at the LHCb with■TeV reach O(10^(4))pb,which indicates that the LHCb has collected O(10^(8))such particles.Through the decay channels of■or■or■(if unstable),it is highly expected that they get discovered at the LHCb in the near future.We also discuss the productions and decays of the double-charm tetraquarks at future Tera-Z factories.
基金the National Natural Science Foundation of China(11775117,U1732101,11975112)National Key Research and Development Program of China(2020YFA0406400)。
文摘The doubly charmed baryon■cc++was recently observed by LHCb via the decay processes of■cc++→∧+cK^(-)π^(+)π^(+)and■c+π^(+).These discovery channels were successfully predicted in a framework in which the short-distance contributions are calculated under the factorization hypothesis and the long-distance contributions are estimated using the rescattering mechanism for the final-state-interaction effcts.In this paper,we illustrate the above framework in detail by systematic studies on the tw o-body baryonic decays Bcc→BcP involving the doubly charmed baryons Bcc=(■cc++,■cc++,Ωcc+),the singly charmed baryons Bc=(B3,B6)and the light pseudoscalar mesons P=(π,K,η1,8).
基金Supported by National Natural Science Foundation of China(11347027,11505083,11375208,11521505,1162113100,11235005,U1732101)Ministry of Science and Technology of R.O.C.(MOST-104-2112-M-001-037-MY3)DFG Forschergruppe FOR 1873"Quark Flavour Physics and Effective Field Theories"
文摘We calculate theD^0-D^-0 mixing parameter y in the factorization-assisted topological-amplitude（FAT）approach, considering contributions from D^0→PP, PV, and VV modes, where P（V） stands for a pseudoscalar（vector） meson. The D^0→PP and PV decay amplitudes are extracted in the FAT approach, and the D^0→VV decay amplitudes with final states in the longitudinal polarization are estimated via the parameter set for D^0→PV. It is found that the VV contribution to y, being of order of 10-4, is negligible, and that the PP and PV contributions amount only up to y_（PP＋PV） =（0.21±0.07）%, a prediction more precise than those previously obtained in the literature,and much lower than the experimental data yexp =（0.61 ±0.08）%. We conclude that D^0 meson decays into other two-body and multi-particle final states are relevant to the evaluation of y, so it is difficult to understand it fully in an exclusive approach.
文摘目前,奇异轴矢介子的性质并没有被很好地理解,而这类介子是可以在D介子衰变中得到更多的研究。将窄宽近似下的等式关系和强衰变中CP守恒应用到四体衰变D0→K+K-π+π-中的D0→K±K1■(1270)(→ρK or K*π)的实验数据中,可以发现实验数据与理论存在矛盾,然而,当考虑更多K1(1270)的衰变过程后,可以发现,B(D0→K-K1+(1270)(→K*0π+))的实验数据很可能被高估了一个量级。考虑共振态K1(1400)的贡献,利用因子化方法计算相应的衰变过程的分支比,可以发现,B(D0→K-K1+(1400)(→K*0π+))的分支比与使用等式关系得到的B(D0→K-K1+(1270)(→K*0π+))的分支比在量级上是相同的。另外,对于含有奇异轴矢介子的D介子衰变实验数据的合理性,实验可以通过测量K1(1270)→ρK和K*π分支比的比值来检验,或者通过验证D介子衰变中的等式关系来检验。
