Related papers: Sum rules for asymptotic form factors in $e^+ e^- …
We assume that the Higgs doublet has a composite structure, respecting the main standard model properties, and therefore called Composite Standard Model (CSM), but leading (through Goldstone equivalence) to $Z_L$ and $W_L$ form factors. We…
In this paper, the reaction of electron-positron annihilation into $\Lambda_c^+\bar{\Lambda}_c^-$ is investigated. The $\Lambda_c^+\bar{\Lambda}_c^-$ scattering amplitudes are obtained by solving the Lippmann-Schwinger equation. The…
As a model independent approach to search for the signals of new physics~(NP) beyond the Standard Model~(SM), the SM effective field theory~(SMEFT) draws a lot of attention recently. The energy scale of a process is an important parameter…
We present the heavy-to-light form factors with two different non-vanishing masses at next-to-next-to-leading order and study its expansion in the small mass. The leading term of this small-mass expansion leads to a factorized expression…
We calculate the $B_{u,d,s}\to T$ form factors within the framework of the perturbative QCD approach, where $T$ denotes a light tensor meson with $J^P=2^+$. Due to the similarities between the wave functions of a vector and a tensor meson,…
In this paper, several calculations of the matrix elements for processes that may contribute to e+ e- --> pi+ pi- pi0 pi0 using the isobar model and the Lorentz invariant amplitude method are presented. The formulas may be used to determine…
We compute all the gravitational form factors in the scalar diquark model at the one-loop level using two different regularization methods. We check explicitly that all the Poincar\'e sum rules are satisfied and we discuss in detail the…
The gravitational form factors for a hadron, the form factors for the hadron matrix element of the QCD energy-momentum tensor, not only describe the coupling of the hadron with a graviton, but also serve as unique quantities for describing…
One of the necessary steps in constructing high precision option of KKMC was to install the double bremsstrahlung matrix element for the process e+ e- to nu_e bar nu_e into the scheme of Coherent Exclusive Exponentiation. The process is…
We study the constraints on the vertices $W^+W^- Z\gamma$, $W^+W^-\gamma\gamma$, and $ZZ\gamma\gamma$ that can be obtained from triple-gauge-boson production at the next generation of linear $e^+e^-$ colliders operating in the…
We define the form factors of the quark and gluon symmetric energy-momentum tensor (EMT). The static EMT is related to the spatial distributions of energy, spin, pressure and shear forces. They are obtained in the form of a multipole…
The data on the proton form factors in the time-like region from the BaBar, BESIII and CMD-3 Collaborations are examined to have coherent pieces of information on the proton structure. Oscillations in the annihilation cross section,…
We outline the developed approach within the light-cone sum rules at the leading order for calculation of the gravitational form factors related to the nucleon valence quark combinations. The predictions for the gravitational form factor…
In this work, the electromagnetic and gravitational form factors of a spin-$3/2$ particle, $\Delta$ resonance, are simultaneously calculated with the help of a relativistic covariant quark-diquark approach. The two kinds of form factors are…
If the Standard Model is embedded in a left-right symmetric gauge theory at the TeV scale, the pair production of light W-bosons in e^+e^- collisions, e^+e^- -> W^+W^-, will be affected by mixings in the gauge and neutrino sectors, and by…
4D CFTs have a scale anomaly characterized by the coefficient $c$, which appears as the coefficient of logarithmic terms in momentum space correlation functions of the energy-momentum tensor. By studying the CFT contribution to 4-point…
A spontaneously broken SU(2) theory is the simplest generalization of the Abelian Higgs model, containing three equally massive vector bosons and a single Higgs scalar. A strictly diagrammatic proof is presented of the tree-level unitarity…
Corrections due to gluon condensate to electromagnetic form factors of the transition $\pi+\gamma^* \to A_1$ are calculated by standard QCD sum rules technique. The obtained results are compared to the corresponding light-cone QCD sum…
We show that the Bethe-Salpeter equation for the scattering amplitude in the limit of zero incident energy can be transformed into a purely Euclidean form, as it is the case for the bound states. The decoupling between Euclidean and…
I demonstrate that the amplitude of the high-energy scattering can be factorized in a product of two independent functional integrals over "fast" and "slow" fields which interact by means of Wilson-line operators -- gauge factors ordered…