اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدStudy on the properties of the coupling constants of $J/psi rightarrow VP$ decays
46
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Basing on the branching fractions of J/psi to VP from different experiments, we investigate on the properties of the coupling constants of J/psi to VP decays with a model-dependent approach. We find that the octet coupling constant, g_8, of strong interaction is about twice larger than that of the singlet coupling constant g_1; the electromagnetic breaking parameters g^i_E are larger than the mass breaking parameters g^i_M, moreover, the three parameters of electromagnetic effect are about equal, but the three parameters of mass effect are obviously different and their uncertainties are also large; and the phase angle between strong and electromagnetic interaction is in the range of 70^{circ} sim 80^{circ}. It deepens our understanding of the coupling constant of J/psi to VP decays.
قيم البحث
اقرأ أيضاً
Using $4.48 times 10^{8}$ $psi(3686)$ events collected with the BESIII detector, we search for the decays $chi_{cJ} rightarrow mu^{+}mu^{-}J/psi$ through the radiative decays $psi(3686) rightarrow gammachi_{cJ}$, where $J=0,1,2$. The decays $chi_{c1,
2} rightarrow mu^{+}mu^{-}J/psi$ are observed, and the corresponding branching fractions are measured to be $mathcal{B}(chi_{c1} rightarrow mu^{+}mu^{-}J/psi) = (2.51 pm 0.18 pm 0.20)times10^{-4}$ and $mathcal{B}(chi_{c2} rightarrow mu^{+}mu^{-}J/psi) = (2.33 pm 0.18 pm 0.29)times10^{-4}$, where the first uncertainty is statistical and the second one systematic. No significant $chi_{c0} rightarrow mu^{+}mu^{-}J/psi$ decay is observed, and the upper limit on the branching fraction is determined to be $2.0times10^{-5}$ at 90% confidence level. Also, we present a study of di-muon invariant mass dependent transition form factor for the decays $chi_{c1,2} rightarrow mu^{+}mu^{-}J/psi$.
The decays $B^+rightarrow J/psi 3pi^+ 2pi^-$ and $B^+rightarrow psi(2S) pi^+pi^+pi^-$ are observed for the first time using a data sample corresponding to an integrated luminosity of $3.0fb^{-1}$, collected by the LHCb experiment in proton-proton col
lisions at the centre-of-mass energies of 7 and 8 TeV. The branching fractions relative to that of $B^+ rightarrow psi(2S)K^+$ are measured to be begin{eqnarray*} frac {mathcal{B}left(B^+rightarrow J/psi 3pi^+ 2pi^- right)} {mathcal{B}left(B^+ rightarrow psi(2S)K^+ right)} & = & left(1.88pm0.17pm0.09right)times10^{-2}, frac {mathcal{B}left(B^+rightarrow psi(2S) pi^+pi^+pi^- right)} {mathcal{B}left(B^+ rightarrow psi(2S)K^+ right)} & = & left(3.04pm0.50pm0.26right)times10^{-2}, end{eqnarray*} where the first uncertainties are statistical and the second are systematic.
We aim to explore the production rate of the pseudoscalar glueball in $J/psi$ radiative decay by lattice QCD in quenched approximation. The calculation is performed on three anisotropic lattices with the spatial lattice spacing ranging from 0.222(2)
fm to 0.110(1) fm. As a calibration of some systematical uncertainties, we first extract the $M1$ form factor $hat{V}(0)$ of the process $J/psitogammaeta_{c}$ and get the result $hat{V}(0)=1.933(41)$ in the continuum limit, which gives the partial width $Gamma(J/psitogammaeta_{c})=2.47(11)$ keV. These results are in agreement with that of previous lattice studies. As for the pseudoscalar glueball $G_{0^{-+}}$, its mass is derived to be $2.395(14)$ GeV, and the form factor $hat{V}(0)$ of the process $J/psitogamma G_{0^{-+}}$ is determined to be $hat{V}(0)=0.0246(43)$ after continuum extrapolation. Finally, the production rate of the pseudoscalar glueball is predicted to be $2.31(90)times10^{-4}$, which is much smaller than that of conventional light $qbar{q}$ $eta$ states. After the subtraction of the phase space factor, the couplings of $J/psi Xgamma$ are similar where $X$ stands for $eta$ states and the pseudoscalar glueball. Possibly, the $U_{A}(1)$ anomaly plays an important role for the large couplings of gluons to the flavor singlet $eta$ states in $J/psi$ radiative decays.
A measurement of the number of $J/psi$ events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the $J/psi$ . The number of $J/psi$ events taken in 2009 is recalculated to be $(223.7pm1.4)times 10^6$, which is
in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESIII software. The number of $J/psi$ events taken in 2012 is determined to be $(1086.9pm 6.0)times 10^6$. In total, the number of $J/psi$ events collected with the BESIII detector is measured to be $(1310.6pm 7.0)times 10^6$, where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.
In our previous study, we calculated the transition from factors of $J/psito D^{(*)}_{(s)}$ using the QCD sum rules. Based on the factorization approximation, the obtained form factors can be applied to evaluate the weak non-leptonic decay rates of $
J/psito D^{(*)}_{(s)}+M$, where $M$ stands for a light pseudoscalar or vector meson. We predict that the branching ratio for inclusive non-leptonic two-body weak decays of $J/psi$ which are realized via the spectator mechanism, can be as large as $1.3 times 10^{-8}$, in particular, the branching ratio of $J/psito D^{*pm}_s+rho^mp$ can reach $5.3 times 10^{-9}$. Such values will be marginally accessed by the ability of BESIII which will begin running very soon.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
