Related papers: Renormalization Group Improvement and QCD Sum Rule…
We present a new QCD sum rule with high sensitivity to the continuum regions of charm and bottom quark pair production. Combining this sum rule with existing ones yields very stable results for the MS-bar quark masses, m_c(m_c) and…
A short-distance heavy quark mass depends on two parameters, the renormalization scale mu controlling the absorption of ultraviolet fluctuations into the mass, and a scale R controlling the absorption of infrared fluctuations. 1/R can be…
We underline a problem existing in the heavy quark limit of QCD concerning the rates of semileptonic B decays into P-wave $D_J(j)$ mesons, where $j = {1 \over 2}$ (wide states) or $j = {3 \over 2}$ (narrow states). The leading order sum…
We present the results of a lattice QCD calculation of the average up-down and strange quark masses and of the light meson pseudoscalar decay constants with Nf=2 dynamical fermions. The simulation is carried out at a single value of the…
We study the behaviour of the vector and axial current renormalisation constants $Z_V$ and $Z_A$ as a function of the quark mass, $m_q$. We show that sizeable $O(am_q)$ and $O(g_0^2 a m_q)$ systematic effects are present in the Wilson and…
Stimulated by recent development of the calculation methods of the running quark masses $m_q(\mu)$ and renewal of the input data, for the purpose of making a standard table of $m_q(\mu)$ for convenience of particle physicists, the values of…
We present the results of a computation of the sum of the strange and average up-down quark masses with overlap fermions in the quenched approximation. Since the overlap regularization preserves chiral symmetry at finite cutoff and volume,…
Using the recent {\it world average} $\alpha_s(M^2_Z)= 0.118 \pm 0.006$, we give the {\it first direct extraction} from the $\Psi$ and $\Upsilon$ data of the values of the {\it running heavy quark masses} within QCD spectral sum rules to…
We present our preliminary result for the charmed quark mass, which follows from taking the D_s and K meson masses from experiment and r0=0.5 fm (or, equivalently F_K=160 MeV) to set the scale. For the renormalization group invariant quark…
We revisit the isovector pseudoscalar sum rule determination of m_u+m_d, using families of finite energy sum rules known to be very accurately satisfied in the isovector vector channel. The sum rule constraints are sufficiently strong to…
In this talk we discuss results of a new extraction of the MS-bar charm quark mass using relativistic QCD sum rules at O(as**3) based on moments of the vector and the pseudoscalar current correlators and using the available experimental…
In this article, we recalculate the contributions of all vacuum condensates up to dimension-6, in particular the one-loop corrections to the quark condensates $\alpha_s<\bar{q}q>$ and partial one-loop corrections to the four-quark…
We propose a new and simple method for determining the renormalized quark masses from lattice simulations. Renormalized quark masses are an important input to many phenomenological applications, including searching and modeling physics…
We present a QCD sum rule calculation of the strange-quark mass including four-loop QCD corrections to the correlator of scalar currents. We obtain $\bar m_s(1$ GeV$)=205.5\pm 19.1$ MeV.
We extract (for the first time) the correlated values of the running masses m_c and m_b from M_Bc using QCD Laplace sum rules (LSR) within stability criteria where pertubative (PT) expressions at N2LO and non-perturbative (NP) gluon…
We revisit QCD sum rules for the decay constants of heavy-light mesons. In the sum rules for the vector mesons B^*_(s) and D^*_(s) we improve the accuracy of OPE, taking into account the O(alpha_s^2) terms in the perturbative part and…
We summarize recent results obtained in [1] on the running m_{c,b}(m_{c,b}) in the MS scheme and f_{D_(s), B_(s)} using QCD spectral sum rules (QSSR) known to N2LO PT series, including all dimension-six NP condensate contributions in the…
Using recent values of the QCD (non-) perturbative parameters given in Table 1 and an estimate of the N3LO QCD perturbative contributions based on the geometric growth of the PT series, we re-use QCD spectral sum rules (QSSR) known to N2LO…
Our renormalization group consistent variant of optimized perturbation, RGOPT, is used to calculate the nonperturbative QCD spectral density of the Dirac operator and the related chiral quark condensate $\langle \bar q q \rangle$, for…
Motivated by the LHCb-group discovery of exotic hadrons in the range (6.2 $\sim$ 6.9) GeV, we present new results for the masses and couplings of $0^{++}$ fully heavy $(\bar{Q}Q)(Q\bar{Q})$ molecules and $(QQ)(\overline{QQ})$ tetraquaks…