Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userAnalysis of the strong coupling form factors of $Sigma_bNB$ and $Sigma_c ND$ in QCD sum rules
50
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In this article, we study the strong interaction of the vertexes $Sigma_bNB$ and $Sigma_c ND$ using the three-point QCD sum rules under two different dirac structures. Considering the contributions of the vacuum condensates up to dimension $5$ in the operation product expansion, the form factors of these vertexes are calculated. Then, we fit the form factors into analytical functions and extrapolate them into time-like regions, which giving the coupling constant. Our analysis indicates that the coupling constant for these two vertexes are $G_{Sigma_bNB}=0.43pm0.01GeV^{-1}$ and $G_{Sigma_cND}=3.76pm0.05GeV^{-1}$.
rate research
Read More
In this article, we analyze the strong vertexes $Sigma_{c}^{*}ND$ and $Sigma_{b}^{*}NB$ using the three-point QCD sum rules under the Dirac structure of $q!!!/p!!!/gamma_{mu}$. We perform our analysis by considering the contributions of the perturbative part and the condensate terms of $<overline{q}q>$ and $<frac{alpha_{s}}{pi}GG>$. After the form factors are calculated, they are then fitted into analytical functions which are used to get the strong coupling constants for these two vertexes. The final results are $g_{Sigma_{c}^{*}ND}=7.19^{+8.49}_{-3.11}pm1.76$ and $g_{Sigma_{b}^{*}NB}=10.54^{+15.59}_{-5.23}pm1.82$.
The strong coupling constant is an important parameter which can help us to understand the strong decay behaviors of baryons. In our previous work, we have analyzed strong vertices $Sigma_{c}^{*}ND$, $Sigma_{b}^{*}NB$, $Sigma_{c}ND$, $Sigma_{b}NB$ in QCD sum rules. Following these work, we further analyze the strong vertices $Sigma_{c}ND^{*}$ and $Sigma_{b}NB^{*}$ using the three-point QCD sum rules under Dirac structures $q!!!/p!!!/gamma_{alpha}$ and $q!!!/p!!!/p_{alpha}$. In this work, we first calculate strong form factors considering contributions of the perturbative part and the condensate terms $langleoverline{q}qrangle$, $langlefrac{alpha_{s}}{pi}GGrangle$ and $langleoverline{q}g_{s}sigma Gqrangle$. Then, these form factors are used to fit into analytical functions. According to these functions, we finally determine the values of the strong coupling constants for these two vertices $Sigma_{c}ND^{*}$ and $Sigma_{b}NB^{*}$.
We review the calculations of form factors and coupling constants in vertices with charm mesons in the framework of QCD sum rules. We first discuss the motivation for this work, describing possible applications of these form factors to heavy ion collisions and to B decays. We then present an introduction to the method of QCD sum rules and describe how to work with the three-point function. We give special attention to the procedure employed to extrapolate results obtained in the deep euclidean region to the poles of the particles, located in the time-like region. We present a table of ready-to-use parametrizations of all the form factors, which are relevant for the processes mentioned in the introduction. We discuss the uncertainties in our results. We also give the coupling constants and compare them with estimates obtained with other methods. Finally we apply our results to the calculation of the cross section of the reaction $J/psi + pi rightarrow D + bar{D^*}$.
We derive QCD light-cone sum rules for the hadronic matrix elements of the heavy baryon transitions to nucleon. In the correlation functions the $Lambda_c,Sigma_c$ and $Lambda_b$ -baryons are interpolated by three-quark currents and the nucleon distribution amplitudes are used. To eliminate the contributions of negative parity heavy baryons, we combine the sum rules obtained from different kinematical structures. The results are then less sensitive to the choice of the interpolating current. We predict the $Lambda_{b}to p$ form factor and calculate the widths of the $Lambda_{b}to pell u_l$ and $Lambda_{b}to p pi$ decays. Furthermore, we consider double dispersion relations for the same correlation functions and derive the light-cone sum rules for the $Lambda_cND^{(*)}$ and $Sigma_cND^{(*)}$ strong couplings. Their predicted values can be used in the models of charm production in $pbar{p}$ collisions.
The $H^*Hpi$ form factor for H = B and D mesons is evaluated in a QCD sum rule calculation. We study the Borel sum rule for the three point function of two pseudoscalar and one vector meson currents up to order four in the operator product expansion. The double Borel transform is performed with respect to the heavy meson momenta. We discuss the momentum dependence of the form factors and two different approaches to extract the $H^*Hpi$ coupling constant.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
