scholarly journals Virtual photon fragmentation functions

2001 ◽  
Vol 64 (7) ◽  
Author(s):  
Jianwei Qiu ◽  
Xiaofei Zhang
2016 ◽  
Vol 93 (11) ◽  
Author(s):  
Tom Kaufmann ◽  
Asmita Mukherjee ◽  
Werner Vogelsang

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
K.B. Chen ◽  
J.P. Ma ◽  
X.B. Tong

Abstract In the target fragmentation region of Semi-Inclusive Deep Inelastic Scattering, the diffractively produced hadron has small transverse momentum. If it is at order of ΛQCD, it prevents to make predictions with the standard collinear factorization. However, in this case, differential cross-sections can be predicted by the factorization with fracture functions, diffractive parton distributions. If the transverse momentum is much larger than ΛQCD but much smaller than Q which is the virtuality of the virtual photon, both factorizations apply. In this case, fracture functions can be factorized with collinear parton distributions and fragmentation functions. We study the factorization up to twist-3 level and obtain gauge invariant results. They will be helpful for modeling fracture functions and useful for resummation of large logarithm of the transverse momentum appearing in collinear factorization.


2009 ◽  
Author(s):  
Tsuneo Uematsu ◽  
Yoshio Kitadono ◽  
Ken Sasaki ◽  
Takahiro Ueda

1995 ◽  
Vol 445 (2-3) ◽  
pp. 380-396 ◽  
Author(s):  
Kun Chen ◽  
Gary R. Goldstein ◽  
R.L. Jaffe ◽  
Xiangdong Ji

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
E. Iancu ◽  
A. H. Mueller ◽  
D. N. Triantafyllopoulos ◽  
S. Y. Wei

Abstract Using the dipole picture for electron-nucleus deep inelastic scattering at small Bjorken x, we study the effects of gluon saturation in the nuclear target on the cross-section for SIDIS (single inclusive hadron, or jet, production). We argue that the sensitivity of this process to gluon saturation can be enhanced by tagging on a hadron (or jet) which carries a large fraction z ≃ 1 of the longitudinal momentum of the virtual photon. This opens the possibility to study gluon saturation in relatively hard processes, where the virtuality Q2 is (much) larger than the target saturation momentum $$ {Q}_s^2 $$ Q s 2 , but such that z(1 − z)Q2 ≲ $$ {Q}_s^2 $$ Q s 2 . Working in the limit z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we predict new phenomena which would signal saturation in the SIDIS cross-section. For sufficiently low transverse momenta k⊥ ≪ Qs of the produced particle, the dominant contribution comes from elastic scattering in the black disk limit, which exposes the unintegrated quark distribution in the virtual photon. For larger momenta k⊥ ≳ Qs, inelastic collisions take the leading role. They explore gluon saturation via multiple scattering, leading to a Gaussian distribution in k⊥ centred around Qs. When z(1 − z)Q2 ≪ Q2, this results in a Cronin peak in the nuclear modification factor (the RpA ratio) at moderate values of x. With decreasing x, this peak is washed out by the high-energy evolution and replaced by nuclear suppression (RpA< 1) up to large momenta k⊥ ≫ Qs. Still for z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we also compute SIDIS cross-sections integrated over k⊥. We find that both elastic and inelastic scattering are controlled by the black disk limit, so they yield similar contributions, of zeroth order in the QCD coupling.


2008 ◽  
Vol 23 (36) ◽  
pp. 3113-3121 ◽  
Author(s):  
MAO-ZHI YANG

In the e+e- annihilation processes [Formula: see text], D+D- near or above the threshold of [Formula: see text], there are not only the resonance contribution [Formula: see text], D+D-, but also the continuum contribution through virtual photon directly [Formula: see text], D+D-. The amplitudes through virtual photon directly and through resonance can interfere seriously. We consider the continuum and interference effect in the [Formula: see text] production process in e+e- annihilation. We find that the effect is significant near and above the threshold of the [Formula: see text] mesons.


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