arXiv subjects

B. Osório Rodrigues

Publications and source records attributed to B. Osório Rodrigues.

7 recordsLinked to original sources

arXiv2021

The $D_sDK^*$ vertex in QCD Sum Rules: form factors and coupling constant

In this work we study the meson vertex $D_sDK^*$ using the QCD sum rules. We compute the three point correlation functions for the three cases of different off-shell mesons. The form factors for each case are fitted to the numerical calculation of the correlation functions and the coupling constant of the vertex is obtained by comparing the form factors at their respective off-shell meson pole. The result obtained for the coupling constant is $g_{D_sDK^*} = 2.29^{+0.65}_{-0.41}$.

hep-ph↗

arXiv2017

A QCD sum rules calculation of the $η_c D^* D$ and $η_c D_s^* D_s$ form factors and strong coupling constants

We use the QCD sum rules for the three point correlation functions to compute the strong coupling constants of the meson vertices $η_c D^* D$ and $η_c D_s^* D_s$. We consider perturbative and non-perturbative contributions, working up to dimension five on the OPE. The vertices were studied considering that each one of its three mesons are off-shell alternately. The vertex coupling constant is evaluated through the extrapolation of the three different form factors. The results obtained for the coupling constants are $g_{η_c D^* D} = 5.23^{+1.80}_{-1.38}$ and $g_{η_c D_s^* D_s}=5.55^{+1.29}_{-1.55}$.

hep-ph↗

arXiv2015

A QCD sum rules calculation of the $J/ψD_s^* D_s$ strong coupling constant

In this work, we calculate the form factors and the coupling constant of the strange-charmed vertex $J/ψD_s^* D_s$ in the framework of the QCD sum rules by studying their three-point correlation functions. All the possible off-shell cases are considered, $D_s$, $D_s^*$ and $J/ψ$, resulting in three different form factors. These form factors are extrapolated to the pole of their respective off-shell mesons, giving the same coupling constant for the process. Our final result for the $J/ψD_s^* D_s$ coupling constant is $g_{J/ψD^*_s D_s} = 4.30^{+0.42}_{-0.37}\text{GeV}^{-1}$.

hep-ph↗

arXiv2015

$B_s B^* K $ and $B_s B K^*$ vertices using QCD sum rules

The form factors and the coupling constant of the $B_s B^* K $ and $B_s B K^*$ vertices are calculated using the QCD sum rules method. Three point correlation functions are computed considering both the heavy and light mesons off-shell in each vertex, from which, after an extrapolation of the QCDSR results at the pole of the off-shell mesons, we obtain the coupling constant of the vertex. The form factors obtained have different behaviors but their simultaneous extrapolation reach the same value of the coupling constant $g_{B_s B^* K}=8.41 \pm 1.23 $ and $g_{B_s BK^*}=3.3 \pm 0.5$. We compare our result with other theoretical estimates and compute the uncertainties of the method.

hep-ph↗

arXiv2012

Obtaining the strong coupling constants g_{J/ψD_s D_s} and g_{ϕD_s D_s} from QCD Sum Rules

The form factors and coupling constants of the meson vertices J/ψD_s D_s and ϕD_s D_s were calculated using three point correlation functions within the QCD Sum Rules formalism. We have considered the cases where ϕ, D_s and J/ψmesons are off-shell obtaining, for each vertex, two different form factors and its corresponding coupling constants, namely g_{J/ψD_s D_s} = 6.20^{+0.97}_{-1.15} and g_{ϕD_s D_s} = 1.85^{+0.22}_{-0.23}.

hep-ph↗

arXiv2011

$B_s^* B K$ vertex from QCD sum rules

The form factors and the coupling constant of the $B_s^* B K$ vertex are calculated using the QCD sum rules method. Three point correlation functions are computed considering both $K$ and $B$ mesons off-shell and, after an extrapolation of the QCDSR results, we obtain the coupling constant of the vertex. We study the uncertainties in our result by calculating a third form factor obtained when the $B^*_s$ is the off-shell meson, considering other acceptable structures and computing the variations of the sum rules' parameters. The form factors obtained have different behaviors but their simultaneous extrapolations reach to the same value of the coupling constant $g_{B_s^* B K}=10.6 \pm 1.7$. We compare our result with other theoretical estimates.

hep-ph↗

arXiv2011

An inspection on the Borel masses relation used in QCD sum rules

In this work, we studied the Borel masses relation used in QCDSR calculations. These masses are the parameters of the Borel transform used when the three point function is calculated. We analised an usual and a more general linear relations. We concluded that a general linear relation between these masses provides the best results regarding the standard deviation.

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