Related papers: Axial Vector Current Matrix Elements and QCD Sum R…

The axial vector and tensor charge, defined as the first moments of the forward nucleon matrix elements of corresponding quark currents, are essential for characterizing the spin structure of the nucleon. However, the transversity…

The charged axial-vector $J^{P}=1^{+}$ tetraquarks $Z_{q}=[cq][\bar {b} \bar q ]$ and $Z_{s}=[cs][\bar {b} \bar s]$ with the open charm-bottom contents are studied in the diquark-antidiquark model. The masses and meson-current couplings of…

The QCD sum rule calculation of the in-medium pion decay constants using pseudoscalar-axial vector correlation function, $i \int d^4x e^{ip\cdot x} < \rho| T[{\bar d}(x) i \gamma_5 u (x) {\bar u}(0) \gamma_\mu \gamma_5 d (0)] | \rho>$ is…

Finite energy QCD sum rules involving nucleon current correlators are used to determine several QCD and hadronic parameters in the presence of an external, uniform, large magnetic field. The continuum hadronic threshold $s_0$, nucleon mass…

Present precision measurements of the neutron life time lead to a CKM matrix element $|V_{ud}|$ which is three standard deviations off the value inferred from heavy quark decays etc. We investigate the possibility whether isospin-breaking…

In this paper, we apply the QCD sum rules to study the vector fully-light tetraquark states with an explicit P-wave between the diquark and antidiquark pair. We observed that the…

The form-factors for the transition $ N^*(1535)\to N $ induced by isovector and isoscalar axial currents within the framework of light-cone QCD sum rules by using the most general form of the interpolating current are calculated. In…

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…

In this thesis we calculate the baryon axial current within the combined framework of the $1/N_c$ expansion and chiral perturbation theory, where $N_c$ is the number of colors. This calculation shall consider Feynman diagrams to order of…

This talk provides an update on the calculation of matrix elements of flavor diagonal axial, scalar and tensor quark bilinear operators between the nucleon ground state. The simulations are done using Wilson-clover fermions on a sea of…

Following the first clear evidence of the presence of intrinsic charm contribution in the proton, the axial-vector charges of the light and charmed baryons are investigated in the framework of $SU(4)$ chiral constituent quark model after…

The axial-vector form factors of the light, singly and doubly charmed baryons are investigated in the framework of $SU(4)$ chiral constituent quark model. The axial-vector form factors having physical significance correspond to the…

The saturation of QCD chiral sum rules of the Weinberg-type is analyzed using ALEPH and OPAL experimental data on the difference between vector and axial-vector correlators (V-A). The sum rules exhibit poor saturation up to current energies…

At the TeV scale, low-energy precision observations of neutron characteristics provide unique probes of novel physics. Precision studies of neutron decay observables are susceptible to beyond the Standard Model (BSM) tensor and scalar…

Systematics in nucleon isovector vector, $g_V$, and axialvector, $g_A$, charges calculated on a 2+1-flavor dynamical domain-wall-fermions (DWF) ensemble at physical mass jointly generated by RIKEN-BNL-Columbia (RBC) and UKQCD Collaborations…

We give a gauge-invariant treatment of the angular momentum sum-rule for the proton in terms of matrix elements of three gauge-invariant, local composite operators. These matrix elements are decomposed into three independent form factors,…

We consider a $[ud]^2\bar{s}$ current, in the finite-density QCD sum rule approach, to investigate the scalar and vector self-energies of the recently observed pentaquark state $\Theta^+(1540)$, propagating in nuclear mater. We find that,…

We compute the axial vector current, form factor, and coupling for quarks in the instanton liquid model with two light flavors. Non-local current corrections are derived, as required by the effective 't Hooft interaction. We obtain a…

The recent TRIUMF experiment for $\mu^- p \to n \nu_{\mu} \gamma$ gave a surprising result that the induced pseudoscalar coupling constant $g_P$ was larger than the value obtained from $\mu^- p \to n \nu_{\mu}$ experiment as much as 44 %.…

Two new QCD sum rules for nucleon tensor charge are derived from a mixed correlator of spin-1/2 and spin-3/2 nucleon interpolating fields. These sum rules are analyzed along with a sum rule obtained from the usual correlator of a general…