Related papers: gamma* -> rhoT impact factor with twist three accu…
We investigate all the four-body graviton interaction processes: $gX\rightarrow \gamma X$, $gX\rightarrow gX$, and $gg\rightarrow gg$ with $X$ as an elementary particle of spin less than two in the context of linearized gravity except the…
We calculate the transition form factor for the 'B_c -> B_u^* gamma' decay taking into account only the short distance contribution, in framework of QCD sum rules method. We observe that the transition form factor predicted by the QCD sum…
We apply twisted boundary conditions to lattice QCD simulations of three-point correlation functions in order to access spatial components of hadronic momenta different from the integer multiples of 2 pi / L. We calculate the vector and…
Parton Reggeization approach is the scheme of kT-factorization for multiscale hard processes, which is based on the Lipatov's gauge invariant effective field theory (EFT) for high energy processes in QCD. The new type of rapidity…
We derive an expression for the $B\to\pi$ transition form factor only depending the twist-3 distribution amplitudes by choosing an adequate chiral current correlator in the light-cone QCD sum rules. Our result show that the contribution…
In this paper we present the result of a direct QCD sum rule calculation of the transition form factor \gamma\gamma* -> pi^o in the region of moderately large invariant momentum Q^2 > 1GeV^2 of the virtual photon. In contrast to pQCD, we…
We study the pion electromagnetic and $\gamma^* + \pi^0 \to \gamma$ transition form factors at intermediate momentum transfer. We calculate soft, nonperturbative corrections to the leading perturbative amplitudes which arise from the $q\bar…
We calculate the time-like $\rho$ electromagnetic (EM) form factor in the $k_T$ factorization formalism by including the next-to-leading-order (NLO) corrections of the leading-twist and sub-leading twist contributions. It's observed that…
We have performed analytically the transverse momentum integrations in the real corrections to the longitudinal \gamma^*_L impact factor and carried out numerically the remaining integrations. I outline the analytical integration and…
Using an exact integrodifferential equation we study the properties of the gauge invariant quark Green's function, defined with a path-ordered gluon field phase factor along a straight line, in two-dimensional QCD in the large-N_c limit.…
We present an efficient method for finding the independent invariant tensors of a gauge theory. Our method uses a theorem relating invariant tensors and D-flat directions in field space. We apply our method to several examples-- SO(3) with…
Working in a perturbative QCD model approach, we obtain the essential form factor of the radiative transition $B \rightarrow V^{*} \gamma$ and estimate the branching ratio $BR(B \rightarrow K^{*} \gamma)$. The results are determined by a…
In this paper, by employing the $k_{T}$ factorization theorem, we calculate firstly the next-to-leading-order (NLO) twist-3 contributions to the pion electromagnetic form factors in the $\pi\gamma^* \to \pi$ process. From the analytical and…
In this work we probe the QCD Anderson transition by studying spectral distributions of the massless overlap operator on gauge configurations created by the twisted mass at finite temperature collaboration (tmfT) with 2+1+1 flavors of…
The low $Q^2$ slopes of the the transition form factors provide a unique method to measure the sizes of the neutral pseudo-scalar mesons, since they do not have electromagnetic form factors. From the slope one obtains the "axial transition…
The structure of the nonperturbative vector meson vertex function complicates the proof of the factorisation theorem for the reaction $\gamma^*p\to Vp$. It leads to additional contributions but, in a simple model for the vertex function,…
We study linear actions of algebraic groups on smooth projective varieties X. A guiding goal for us is to understand the cohomology of "quotients" under such actions, by generalizing (from reductive to non-reductive group actions) existing…
In this paper, the twist-3 two parton corrections in charmless $B\to PP$ decays are shown to be factorizable under the QCD factorization approach. The factorizability of the twist-3 two parton corrections is constructed on the following…
We present a method which, starting directly from QCD, permits a systematic gauge-invariant expansion to be made for all hard processes involving quarkonia in powers of the quark relative velocity, a small natural parameter for heavy quark…
We calculate the perturbative corrections in the strong coupling to the unpolarized quark transverse-momentum dependent parton distribution function (TMDPDF) operator within a background-field framework, extending the approach of Ref. [1].…