Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userTests on the molecular structure of $f_2(1270)$, $f_2(1525)$ from $psi (nS)$ and $Upsilon (nS)$ decays
250
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Based on previous studies that support the vector-vector molecular structure of the $f_2(1270)$, $f_2(1525)$, $bar{K}^{*,0}_2(1430)$, $f_0(1370)$ and $f_0(1710)$ resonances, we make predictions for $psi (2S)$ decay into $omega(phi) f_2(1270)$, $omega(phi) f_2(1525)$, $K^{*0}(892) bar{K}^{*,0}_2(1430)$ and radiative decay of $Upsilon (1S),Upsilon (2S), psi (2S)$ into $gamma f_2(1270)$, $gamma f_2(1525)$, $gamma f_0(1370)$, $gamma f_0(1710)$. Agreement with experimental data is found for three available ratios, without using free parameters, and predictions are done for other cases.
rate research
Read More
Decay $Upsilon(1s)togamma f_2(1270)$ is studied by an approach in which the tensor meson, $f_2(1270)$, is strongly coupled to gluons. Besides the strong suppression of the amplitude $Upsilon(1s)togamma gg, ggto f_2$ by the mass of b-quark, d-wave dominance in $Upsilon(1s)togamma f_2(1270)$ is revealed from this approach, which provides a large enhancement. The combination of these two factors leads to larger $B(Upsilon(1s)togamma f_2(1270))$. The decay rate of $Upsilon(1s)togamma f_2(1270)$ and the ratios of the helicity amplitudes are obtained and they are in agreement with data.
We perform a QCD analysis for the radiative decay of a heavy $^3S_1$ quarkonium into the tensor meson $f_2(1270)$. We make an attempt to separate the nonperturbative effect related to the quarkonium and that related to the tensor meson, the former is represented by NRQCD matrix elements, while the later is parameterized by distribution amplitudes of gluons in the tensor meson at twist-2 level and at twist-3 level. We find that at twist-2 level the helicity $lambda$ of the tensor meson can be 0 and 2 and the amplitude with $lambda =2$ is suppressed. At twist-3 level the tensor meson can have $lambda =1$. A comparison with experiment is made, an agreement of our results with experiment can be found. We also briefly discuss the radiative decay into $eta$ and obtain a prediction for $Upsilontogamma+eta$.
DELPHI results are presented on the inclusive production of the neutral mesons rho^0, f_0(980), f_2(1270), K^*0_2(1430) and f_2(1525) in hadronic Z^0 decays. They are based on about 2 million multihadronic events collected in 1994 and 1995, using the particle identification capabilities of the DELPHI Ring Imaging Cherenkov detectors and measured ionization losses in the Time Projection Chamber. The total production rates per hadronic Z^0 decay have been determined to be: 1.19 +/- 0.10 for rho^0; 0.164 +/- 0.021 for f_0(980); 0.214 +/- 0.038 for f_2(1270); 0.073 +/- 0.023 for K^*0_2(1430); and 0.012 +/- 0.006 for f_2(1525). The total production rates for all mesons and differential cross-sections for the rho^0, f_0(980) and f_2(1270) are compared with the results of other LEP experiments and with models.
The Light-front quark model (LFQM) has been applied to calculate the transition matrix elements of heavy hadron decays. However, it is noted that using the traditional wave functions of the LFQM given in literature, the theoretically determined decay constants of the $Upsilon(nS)$ obviously contradict to the data. It implies that the wave functions must be modified. Keeping the orthogonality among the $nS$ states and fitting their decay constants we obtain a series of the wave functions for $Upsilon(nS)$. Based on these wave functions and by analogy to the hydrogen atom, we suggest a modified analytical form for the $Upsilon(nS)$ wave functions. By use of the modified wave functions, the obtained decay constants are close to the experimental data. Then we calculate the rates of radiative decays of $Upsilon(nS)to eta_b+gamma$. Our predictions are consistent with the experimental data on decays $Upsilon(3S)to eta_b+gamma$ within the theoretical and experimental errors.
We report a measurement of the branching fraction of the decay $B^0_sto J/psi,phi(1020)$, evidence and a branching fraction measurement for $B^0_sto J/psi,f_2(1525)$, and the determination of the total $B^0_sto J/psi,K^+K^-$ branching fraction, including the resonant and non-resonant contributions to the $K^+K^-$ channel. We also determine the $S$-wave contribution within the $phi(1020)$ mass region. The absolute branching fractions are $mathcal{B}[B^0_sto J/psi,phi(1020)]=(1.25 pm 0.07left(mathrm{stat}right)pm 0.08left(mathrm{syst}right)pm 0.22left(f_sright))times 10^{-3}$, $mathcal{B}[B^0_sto J/psi,f_2(1525)]=(0.26pm 0.06left(mathrm{stat}right)pm 0.02left(mathrm{syst}right) pm 0.05left(f_sright))times 10^{-3}$ and $mathcal{B}[B^0_sto J/psi,K^+K^-] = (1.01pm 0.09left(mathrm{stat}right) pm 0.10left(mathrm{syst}right)pm 0.18left(f_sright))times 10^{-3}$, where the last systematic error is due to the branching fraction of $bbar{b}to B^{(*)}_s B^{(*)}_s$. The branching fraction ratio is found to be $mathcal{B}[B^0_sto J/psi,f_2(1525)]/mathcal{B}[B^0_sto J/psi,phi(1020)]=(21.5pm 4.9left(mathrm{stat}right) pm2.6left(mathrm{syst}right))%$. All results are based on a 121.4 fb$^{-1}$ data sample collected at the $Upsilon(5S)$ resonance by the Belle experiment at the KEKB asymmetric-energy $e^+e^-$ collider.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
