It is shown that the virtual states and relative momentum of the constituents of the bound states are very important for the cross section of the process e+e-→J/ψ+ηc with the help of the Bethe-Salpeter wave functio...It is shown that the virtual states and relative momentum of the constituents of the bound states are very important for the cross section of the process e+e-→J/ψ+ηc with the help of the Bethe-Salpeter wave function description of the bound states. The gauge invariance of the cross section is demonstrated. The numerical results can explain the experimental data.展开更多
In this work, we investigate the spectroscopy and decay rates of charmonia within the framework of the non-relativistic SchrSdinger equation by employing an approximate inter quark-antiquark potential. The spin hyperf...In this work, we investigate the spectroscopy and decay rates of charmonia within the framework of the non-relativistic SchrSdinger equation by employing an approximate inter quark-antiquark potential. The spin hyperfine, spin-orbit and tensor components of the one gluon exchange interaction are employed to compute the spectroscopy of the excited S states and a few low-lying P and D waves. The resultant wave functions at zero inter- quark separation as well as some finite separations are employed to predict the di-gamma, di-leptonic and di-gluon decay rates of charmonia states using the conventional Van Royen-Weisskopf formula. The di-gamma and di-leptonic decay widths are also computed by incorporating the relativistic corrections of order v4 within the NRQCD formalism. We have observed that the NRQCD predictions with their matrix elements computed at finite radial separation yield results which are found to be in better agreement with experimentM values for both di-gamma and di-leptonic decays. The same scenario is seen in the case when di-gamma and di-leptonic decay widths are computed with the Van Royen- Weisskopf formula. It is also observed that the di-gluon decay width with the inclusion of binding energy effects are in better agreement with the experimental data available for 1S-2S and 1P. The di-gluon decay width of 3S and 2P waves waves are Mso predicted. Thus, the present study of decay rates clearly indicates the importance of binding energy effects.展开更多
文摘It is shown that the virtual states and relative momentum of the constituents of the bound states are very important for the cross section of the process e+e-→J/ψ+ηc with the help of the Bethe-Salpeter wave function description of the bound states. The gauge invariance of the cross section is demonstrated. The numerical results can explain the experimental data.
基金Supported by Major Research Project NO.F.40-457/2011(SR),UGC,India
文摘In this work, we investigate the spectroscopy and decay rates of charmonia within the framework of the non-relativistic SchrSdinger equation by employing an approximate inter quark-antiquark potential. The spin hyperfine, spin-orbit and tensor components of the one gluon exchange interaction are employed to compute the spectroscopy of the excited S states and a few low-lying P and D waves. The resultant wave functions at zero inter- quark separation as well as some finite separations are employed to predict the di-gamma, di-leptonic and di-gluon decay rates of charmonia states using the conventional Van Royen-Weisskopf formula. The di-gamma and di-leptonic decay widths are also computed by incorporating the relativistic corrections of order v4 within the NRQCD formalism. We have observed that the NRQCD predictions with their matrix elements computed at finite radial separation yield results which are found to be in better agreement with experimentM values for both di-gamma and di-leptonic decays. The same scenario is seen in the case when di-gamma and di-leptonic decay widths are computed with the Van Royen- Weisskopf formula. It is also observed that the di-gluon decay width with the inclusion of binding energy effects are in better agreement with the experimental data available for 1S-2S and 1P. The di-gluon decay width of 3S and 2P waves waves are Mso predicted. Thus, the present study of decay rates clearly indicates the importance of binding energy effects.
