Related papers: Renormalization Group Improvement and QCD Sum Rule…
In this work, we chose three molecular and three diquark-antidiquark currents with the quark content $c\bar{c}s\bar{s}$ and $J^{PC}=0^{++},1^{++},2^{++}$, and estimated the masses and the meson coupling constants of the ground states…
In this article, we study the $J^{PC}=0^{++}$ and $2^{++}$ $QQ\bar{Q}\bar{Q}$ tetraquark states with the QCD sum rules, and obtain the predictions $M_{X(cc\bar{c}\bar{c},0^{++})} =5.99\pm0.08\,\rm{GeV}$, $M_{X(cc\bar{c}\bar{c},2^{++})}…
We study the uncertainties in the MSbar bottom quark mass determination using relativistic sum rules to O(alpha_S^2). We include charm mass effects and secondary b bbar production and treat the experimental continuum region more…
The masses and their variation with energy of the elementary particles obtained by solving the one loop renormalization group equation (RGE) in the Minimal Supersymmetric Standard Model (MSSM) is considered. A mass about 115 GeV for all the…
Using a specific scheme of the QCD sum rules for heavy quarkonium in the leading approximation over the inverse heavy quark mass, one gets the estimate of the difference between the masses of the heavy meson and heavy quark $\bar \Lambda =…
We calculate the light meson spectrum and the light quark masses by lattice QCD simulation, treating all light quarks dynamically and employing the Iwasaki gluon action and the nonperturbatively O(a)-improved Wilson quark action. The…
We present a sum-rule extraction of the decay constants of the D, Ds, B, and Bs mesons from the two-point correlator of heavy-light pseudoscalar currents [1]. Our main emphasis is laid on the control over the uncertainties in the decay…
Nonperturbative flow equations within an effective linear sigma model coupled to constituent quarks for two quark flavors are derived and solved. A heat kernel regularization is employed for a renormalization group improved effective…
We consider a relativistic quantum model of confined massive spinning quarks and antiquarks which describes leading Regge trajectories of mesons. The quarks are described by the Dirac equations and the gluon contribution is approximated by…
We determine the strong coupling constant \alpha_s from the \tau hadroni width using a renormalization group summed (RGS) expansion of the QCD Adler function. The main theoretical uncertainty in the extraction of \alpha_s is due to the…
We test the convergence of the QCD exponential moments by including PT corrections to order \alpha_s^3 and the NP contributions up to D=8 <G^4> condensates. Then, using the ratio of exponential sum rules where the QCD PT series is more…
We present a new lattice QCD analysis of heavy-quark pseudoscalar-pseudoscalar correlators, using gluon configurations from the MILC collaboration that include vacuum polarization from $u$, $d$, $s$ and $c$~quarks($n_f=4$). We extract new…
I review the current status of lattice calculations of light and heavy quark masses. Significant progresses, in these studies, have been allowed by the introduction of improved actions and non-perturbative renormalization techniques.…
Renormalization constants of vector ($Z_V$) and axial-vector ($Z_A$) currents are determined non-perturbatively in quenched QCD for an RG-improved gauge action and a tadpole-improved clover quark action using the Schr\"odinger functional…
We summarize recently improved results for the pseudoscalar [1,2] and vector [3] meson decay constants and their ratios from QCD spectral sum rules where N2LO + estimate of the N3LO PT and power corrections up to d< 6 dimensions have been…
We include the new, five-loop, O(alpha_s^4) correction into the QCD sum rule used for the s-quark mass determination. The pseudoscalar Borel sum rule is taken as a study case. The OPE for the correlation function with N^4LO, O(alpha_s^4)…
We determine the bottom quark mass $\hat{m}_b$ from QCD sum rules of moments of the vector current correlator calculated in perturbative QCD to ${\cal O} (\hat\alpha_s^3)$. Our approach is based on the mutual consistency across a set of…
We review our results in Refs.[1,2] for the masses and couplings of heavy-light DD(BB)-like molecules and (Qq)(Qq)-like four-quark states from relativistic QCD Laplace sum rules (LSR) where next-to-next-to-leading order (N2LO) PT…
The hadronic scalar molecules $\mathcal{M}_{b}$ and $\mathcal{M}_{c}$ with asymmetric quark contents $bb \overline{b}\overline{c}$ and $cc \overline{c} \overline{b}$ are explored by means of the QCD sum rule method. Their masses and current…
We report on the determination of $|V_{cb}|$ from the comparison of the semileptonic inclusive decay rates of B-- and D--mesons using the heavy quark symmetry of QCD. While the renormalization scale ambiguity does not allow for a reliable…