相关论文: Is factorization for isolated photon cross section…
Consistent factorization theorems in high-energy scattering near the threshold are presented in the framework of the soft-collinear effective theory. Traditional factorization theorem separates the soft and collinear parts successfully, but…
The cross section for black hole production in hadron colliders is calculated using a factorization hypothesis in which the parton-level process is integrated over the parton density functions of the protons. The mass, spin, charge, colour,…
We review recent progress in the description of heavy-quarkonium production in 2->2 processes at next-to-leading order in the factorization framework of nonrelativistic quantum chromodynamics. Specifically, we consider the production of…
We report measurements of production cross sections for $\rho^+$, $\rho^0$, $\omega$, $K^{*+}$, $K^{*0}$, $\phi$, $\eta$, $K_S^0$, $f_0(980)$, $D^+$, $D^0$, $D_s^+$, $D^{*+}$, $D^{*0}$, and $D^{*+}_s$ in $e^+e^-$ collisions at a…
Fracture functions are parton distributions of an initial hadron in the presence of an almost collinear particle observed in the final state. They are important ingredients in QCD factorization for processes where a particle is produced…
General properties of the differential cross section and of the polarization observables are derived for the $e^++e^-\to N+\bar N$ reaction, in presence of two--photon exchange. Polarization effects are investigated for longitudinally…
Factorization violating effects in hadron scattering are due mainly to spectator-spectator interactions. While it is known that these interactions cancel in inclusive cross sections, like for the Drell-Yan process, not much is known about…
We present a recursive quantum mechanical model for the fragmentation of a string stretched between a quark and an antiquark with entangled spin states. The quarks are assumed to be produced in the $e^+e^-$ annihilation process via the…
Recent results on production and decays of polarized top quarks are reviewed. Top quark pair production in $e^+e^-$ annihilation is considered near energy threshold. For longitudinally polarized electrons the produced top quarks and…
The process of photon splitting is investigated in the presence of strongly magnetized electron-positron plasma. The amplitude of the process is calculated in general case of plasma with nonzero chemical potential and temperature. The…
We present a sample of results for the cross sections of several processes of low energetic $e^+e^-$ annihilation into final states containing pions accompanied by one or two photons, or a light lepton pair. The results, which have been…
We consider heavy quark production in high energy pA collisions and investigate the contribution of interactions of valence quarks of proton with the nucleus. The often made assumption that valence quarks of proton can be factored out is…
We calculate the differential cross section for real photon electroproduction off spinless hadron which sevres as a main probe of the hadrons structure via the concept of generalized parton distributions. Compared to previously available…
The QCD phenomenology of prompt photon production from e-p to p-p/p-pbar and A-A collisions is reviewed. The use of prompt photons as a probe of (i) parton distribution functions (in a proton or in nuclei) as well as (ii) fragmentation…
We analyse power corrections to longitudinal and transverse fragmentation processes in e^+ e^- annihilation, based on the assumption of ultraviolet dominance of power corrections. Under this assumption, we determine the dependence of power…
The bosonized QCD2+QED2 system for quarks with two flavors contains QCD2 and QED2 bound states, with an isoscalar photon at about 25 MeV and an isovector (I=1,I_3=0) photon at about 44 MeV. Consequently, when a quark and an antiquark at the…
I survey a number of interesting tests of quantum chromodynamics at the amplitude level which can be carried out in electron-positron annihilation and in photon-photon collisions at low energy, including measurements of fundamental…
Fitting $Z^0$-pole data from ALEPH and SLD, and TPC data at a lower c.m.s.\ energy, we fix the boundary condition for NLO parton$\to$hadron (hadron$=\pi^\pm, K^\pm, \sum_h h^\pm$) fragmentation functions (FFs) at the low resolution scale of…
By using path integral formulation of QCD and QED we prove that the factorization theorem is valid for light-like Wilson line but is not valid for non-light-like Wilson line. This conclusion is shown to be consistent with Ward identity and…
Two-photon annihilate contributions in the process $e^+ + e^- \to p + \bar{p}$ including $N$ and $\Delta$ intermediate are discussed in a simple hadronic model. The corrections to the unpolarized cross section and polarized observables…