In this paper,a formalism is presented for the helicity amplitude analysis of the decays Ψ(2S)→γ_(1)χ_(c)J,χ_(c)J→γ_(2)V(V=p^(0),φ,ω)(subscripts 1 and 2 are used to distinguish the two radiative photons),and ...In this paper,a formalism is presented for the helicity amplitude analysis of the decays Ψ(2S)→γ_(1)χ_(c)J,χ_(c)J→γ_(2)V(V=p^(0),φ,ω)(subscripts 1 and 2 are used to distinguish the two radiative photons),and the polarization expressions of the P-wave charmonia χ_(c)J and the vector mesons p^(0),φ,ω for experimental measurements at an electron-positron collider.In addition,we derive formulae for the angular distributions of χ_(c1,2)→γV to extract the degree of transverse polarization P_(T) of e^(+)e^(-)pairs with symmetric beam energy as well as the ratios of two helicity amplitudes x(in χ_(c1) decays)and x,y(in χ_(c2) decays),which represent the relative magnitudes of transverse to longitudinal polarization amplitude.The results are validated by Monte Carlo simulation.Finally,the statistical sensitivity of P_(T),x,and y are estimated based on the large Ψ(2S)data samples collected at current and proposed future e^(+)e^(-)colliderexperiments.展开更多
The measurement of decay parameters is one of the important goals of particle physics experiments,and the measurement serves as a probe to search for evidence of CP violation in baryonic decays.The experimental result...The measurement of decay parameters is one of the important goals of particle physics experiments,and the measurement serves as a probe to search for evidence of CP violation in baryonic decays.The experimental results will aid in advancing existing theoretical research and establishing new experimental objectives.In this study,we formulate the asymmetric parameters that characterize parity violation,and then derive formulas for the measurement of CP violation.The formulae for the joint angular distribution of the full decay chain as well as the polarization observable of Ξ^(0),Ξ¯^(0),Λ,and Λ¯are also provided for experiments.Lastly,we evaluated the sensitivity of two asymmetric parameters:αΞ0→Λπ0(abbreviated asαΞ0)andαΞ¯0→Λ¯γ(abbreviated asαΞ¯0)for future experimental measurements.展开更多
CP violation in baryonic decays has not been significantly observed.With large data events accumulated at e+e-colliders or the Large Hadron Collider,charmed baryon decays would provide a promising laboratory to test C...CP violation in baryonic decays has not been significantly observed.With large data events accumulated at e+e-colliders or the Large Hadron Collider,charmed baryon decays would provide a promising laboratory to test CP symmetry.In this study,we formulateΛ^(+)_(c)→ΦρandΛ^(+)_(c)→ωρdecays for the measurement of their asymmetry parameters in weak decays at the BESII or LHCb experiments.The polarization transfer is analyzed in the two processes of e+e-→Λ^(+)_(c)Λ^(-)_(c)andΛ^(o)_(b)→Λ^(+)_(c)π^(-),and the formulas for the joint angular distribution of these processes are provided.The sensitivity of the measurement of the asymmetry parameters of the above two decay processes is estimated for future experiments.展开更多
基金Supported by the National Natural Science Foundation of China(11805064,11975118)State Key Laboratory of Nuclear Physics and Technology,Peking university(NPT2025KFY03)。
文摘In this paper,a formalism is presented for the helicity amplitude analysis of the decays Ψ(2S)→γ_(1)χ_(c)J,χ_(c)J→γ_(2)V(V=p^(0),φ,ω)(subscripts 1 and 2 are used to distinguish the two radiative photons),and the polarization expressions of the P-wave charmonia χ_(c)J and the vector mesons p^(0),φ,ω for experimental measurements at an electron-positron collider.In addition,we derive formulae for the angular distributions of χ_(c1,2)→γV to extract the degree of transverse polarization P_(T) of e^(+)e^(-)pairs with symmetric beam energy as well as the ratios of two helicity amplitudes x(in χ_(c1) decays)and x,y(in χ_(c2) decays),which represent the relative magnitudes of transverse to longitudinal polarization amplitude.The results are validated by Monte Carlo simulation.Finally,the statistical sensitivity of P_(T),x,and y are estimated based on the large Ψ(2S)data samples collected at current and proposed future e^(+)e^(-)colliderexperiments.
基金Supported by the National Natural Science Foundation of China(12175244,11875262,11805037,U1832121)National Key Research and Development Program of China(2020YFA0406301)。
文摘The measurement of decay parameters is one of the important goals of particle physics experiments,and the measurement serves as a probe to search for evidence of CP violation in baryonic decays.The experimental results will aid in advancing existing theoretical research and establishing new experimental objectives.In this study,we formulate the asymmetric parameters that characterize parity violation,and then derive formulas for the measurement of CP violation.The formulae for the joint angular distribution of the full decay chain as well as the polarization observable of Ξ^(0),Ξ¯^(0),Λ,and Λ¯are also provided for experiments.Lastly,we evaluated the sensitivity of two asymmetric parameters:αΞ0→Λπ0(abbreviated asαΞ0)andαΞ¯0→Λ¯γ(abbreviated asαΞ¯0)for future experimental measurements.
基金Supported by the National Natural Science Foundation of China(12175244,11875262,11805037,U1832121)the National Key Research and Development ProgramofChina(2020YFA0406301)。
文摘CP violation in baryonic decays has not been significantly observed.With large data events accumulated at e+e-colliders or the Large Hadron Collider,charmed baryon decays would provide a promising laboratory to test CP symmetry.In this study,we formulateΛ^(+)_(c)→ΦρandΛ^(+)_(c)→ωρdecays for the measurement of their asymmetry parameters in weak decays at the BESII or LHCb experiments.The polarization transfer is analyzed in the two processes of e+e-→Λ^(+)_(c)Λ^(-)_(c)andΛ^(o)_(b)→Λ^(+)_(c)π^(-),and the formulas for the joint angular distribution of these processes are provided.The sensitivity of the measurement of the asymmetry parameters of the above two decay processes is estimated for future experiments.
