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Francisco O. Durães

Publications and source records attributed to Francisco O. Durães.

2 recordsLinked to original sources

QCD sum rules study of Ξ_c and Ξ_b baryons

We use QCD sum rules to study the masses of the baryons $Ξ_c$ and $Ξ_b$. We work with a current where the strange and the light quarks are in a relative spin zero, at leading order in $α_s$. We consider the contributions of condensates up to dimension six. For $Ξ_b$ we get $m_{Ξ_{b}}= (5.75\pm 0.25) {\rm GeV}$, and for $Ξ_c$ we get $m_{Ξ_{c}}= (2.5\pm 0.2) {\rm GeV}$, both in excelent agreement with the experimental values. We also make predictions to the state $Ω_b(ssb)$ obtaining m_{Ω_{b}}= (5.82\pm 0.23) GeV.

hep-ph↗

$J/ψ$ dissociation by pions in QCD

We compute the $J/ψπ\to {charmed mesons}$ cross section using QCD sum rules. This cross section is important to distinguish the suppression in the production of $J/ψ$ through the dissociation by comoving pions and through the formation of quark-gluon plasma. Our sum rules for the $J/ψπ\to \bar{D} D^*$, $D \bar{D}^*$, ${\bar D}^* D^*$ and ${\bar D} D$ hadronic matrix elements are constructed by using vaccum-pion correlation functions, and we work up to twist-4 in the soft-pion limit. After doing a thermal average we get $<σ^{πJ/ψ} v>\sim 0.2 - 0.4$ mb at $T=150\MeV$

nucl-th↗