相关论文: m_u+m_d From Isovector Pseudoscalar Sum Rules

The fully charmed hadronic scalar molecules $\mathcal{M}_1=\eta_c \eta_c$ and $\mathcal{M}_2=\chi_{c0}\chi_{c0}$ are studied in the context of the QCD sum rule method. The masses $m$, $\widetilde{m}$ and current couplings $f$, $…

We investigate the isovector axial vector and pseudoscalar form factors of $\Delta$ baryon by employing light-cone QCD sum rules. Numerical calculations show that the form factors can be well fitted by the exponential form. We make a…

The proton matrix element of the isovector-scalar density, $<p|\overline{u}u-\overline{d}d|p>/2M_p$, is calculated by evaluating the nucleon current correlation function in an external isovector-scalar field using the QCD sum-rule method.…

Using only independent high-scale OPE input, we investigate QCD sum rule constraints on two currently incompatible versions of the I=1 vector spectral function, one obtained from electroproduction data, the other from hadronic tau decay…

We present the results of an extensive non-perturbative calculation of the renormalization constants of bilinear quark operators for the non-perturbatively O(a)-improved Wilson action. The results are obtained at four values of the lattice…

We use improved truncated Operator Product Expansion (OPE) for the Adler function, involving two types of terms with dimension $D=6$, in the double-pinched Borel-Laplace Sum Rules and Finite Energy Sum Rules for the V+A channel strangeless…

Mass and full decay width of the hadronic tensor molecule $\mathcal{M}_{ \mathrm{T}}=B_c^{\ast +}B_c^{\ast -}$ are examined in the framework of QCD sum rule method. To find the mass $m$ and current coupling $\Lambda$ of this state, we use…

The QCD up- and down-quark masses are determined from an optimized QCD Finite Energy Sum Rule (FESR) involving the correlator of axial-vector current divergences. In the QCD sector this correlator is known to five loop order in perturbative…

Recent theoretical and experimental studies of the muon magnetic moment indicate the absence of the previously reported discrepancy, providing a vital opportunity to constrain potential BSM physics. In this work, we explore the MeV-GeV mass…

Efficiency corrected single ratios of neutron and proton spectra in central $^{112}$Sn+$^{112}$Sn and $^{124}$Sn+$^{124}$Sn collisions at 120 MeV/u are combined with double ratios to provide constraints on the density and momentum…

Considering nonforward scattering amplitude off the heavy quark in the Small Velocity limit two exact superconvergent sum rules are derived. The first sum rule leads to the lower bound \rho^2 > 3/4 for the slope of the Isgur-Wise function.…

The decay constants of B, D and K mesons are computed in quenched lattice QCD at two different values of the coupling. The action and operators are O(a) improved with non-perturbative coefficients. The results are f_B=195(6)(+24/-23) MeV,…

Analyzing 600/pb of e+e- collisions at 4170 MeV center-of-mass energy with the CLEO-c detector, we measure the branching fraction B(Ds+ -> tau+ nu)=(5.52\pm 0.57\pm 0.21)% using the tau+ -> rho^+ anti-nu decay mode. Combining with other…

Finite energy QCD sum rules with Legendre polynomial integration kernels are used to determine the heavy meson decay constant $f_{B_c}$, and revisit $f_B$ and $f_{B_s}$. Results exhibit excellent stability in a wide range of values of the…

By considering that the weak currents and the electromagnetic current are members of the same SU(3) octet, two sum rules involving leading vector form factors in hyperon semileptonic decays are derived in the limit of exact flavor SU(3)…

The B-decay constant $f_B$ is an important component for studying $B$-meson decays, which can be studied through QCD sum rules. We make a detailed discussion on $f_B$ from two sum rules, i.e. sum rules I and II, which are derived from the…

We present an improved calculation of the $D_{(s)}^*D_{(s)}V$ and $B_{(s)}^*B_{(s)}V$ coupling constants, where $V$ denotes $\rho$, $K^\ast$, $\omega$, and $\phi$ meson. These couplings govern the QCD long-distance dynamics in interactions…

The spectroscopic parameters and partial widths of the strong decay channels of the vector meson $Y(4660)$ are calculated by treating it as a bound state of a diquark and antidiquark. The mass and coupling of the $J^{PC}=1^{--}$ tetraquark…

Form factors of $D$ decays into $J^{PC}=2^{++}$ tensor mesons are calculated in the light-cone sum rules approach up to twist-4 distribution amplitudes of the tensor meson. The masses of the tensor mesons are comparable to that of the charm…

Three different ways of determining the strange quark mass using QCD sum rules are reviewed. First, from a QCD sum rule determination of the up and down quark masses, together with the current algebra ratio $ m_{s}/(m_{u}+m_{d})$. Second…