scholarly journals A new approach to semi-inclusive deep-inelastic scattering with QED and QCD factorization

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Tianbo Liu ◽  
W. Melnitchouk ◽  
Jian-Wei Qiu ◽  
N. Sato
Keyword(s):  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Radiation Effects ◽  
Collinear Factorization ◽  
Parton Distributions ◽  
New Approach ◽  
Transverse Momentum Dependent ◽  
Step Process ◽  
Qcd Factorization ◽  
Inclusive Processes

Abstract We present the details of a new factorized approach to semi-inclusive deep-inelastic scattering which treats QED and QCD radiation on equal footing, and provides a systematically improvable approximation to the extraction of transverse momentum dependent parton distributions. We demonstrate how the QED contributions can be well approximated by collinear factorization, and illustrate the application of the factorized approach to QED radiation in inclusive scattering. For semi-inclusive processes, we show how radiation effects prevent a well-defined “photon-nucleon” frame, forcing one to use a two-step process to account for the radiation. We illustrate the utility of the new method by explicit application to the spin-dependent Sivers and Collins asymmetries.

scholarly journals Transverse Momentum Dependent Hadron Multiplicities at COMPASS

2016 ◽  
Vol 40 ◽  
pp. 1660031
Author(s):  
Nour Makke
Keyword(s):  
Transverse Momentum ◽  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Spin Structure ◽  
Parton Distributions ◽  
Transverse Momentum Dependent ◽  
Compass Experiment ◽  
Fragmentation Functions

Unpolarised semi-inclusive deep inelastic scattering is receiving a growing interest as a powerful tool to access poorly known transverse momentum dependent parton distributions and fragmentation functions that play a key role in many processes, in particular in the study of the spin structure of the nucleon. These functions can be investigated through experimental observables. New results on these observables by the COMPASS experiment at CERN will be shown and discussed.

Exploring the Flavor Dependence of Partonic Transverse Momentum

2015 ◽  
Vol 37 ◽  
pp. 1560024 ◽  
Author(s):  
Marco Radici ◽  
Alessandro Bacchetta ◽  
Andrea Signori ◽  
Gunar Schnell
Keyword(s):  
Transverse Momentum ◽  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Momentum Dependence ◽  
Parton Distributions ◽  
Average Transverse Momentum ◽  
Transverse Momentum Dependent ◽  
Transverse Momentum Dependence ◽  
Hermes Data ◽  
Fragmentation Functions

Using recently published HERMES data on multiplicities in semi-inclusive deep-inelastic scattering, we discuss the flavor dependence of unpolarized transverse-momentum dependent distribution and fragmentation functions. We find convincing indications that favored fragmentation into pions have smaller average transverse momentum than unfavored ones and fragmentation into kaons. We find weaker indications of flavor dependence in the transverse-momentum dependence of parton distributions.

EXPERIMENTAL DATA ON TRANSVERSE-MOMENTUM DISTRIBUTIONS FROM SEMI-INCLUSIVE DEEP-INELASTIC SCATTERING

2014 ◽  
Vol 25 ◽  
pp. 1460013
Author(s):  
GUNAR SCHNELL
Keyword(s):  
Transverse Momentum ◽  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
The Novel ◽  
Parton Distributions ◽  
Transverse Momentum Dependent ◽  
Quark Spin ◽  
Momentum Distributions ◽  
Sivers Function ◽  
Fragmentation Functions

The exploration of the structure of the nucleon reaches a new level of sophistication when explicit dependences on transverse momenta of partons in both parton distributions and fragmentation functions are included. These dependences lead to a manifold of new correlations between the nucleon and quark spin as well as their momenta and thus a wealth of experimental observables. A particular example is the novel Sivers function that—according to firm QCD predictions—has to change sign when going from the Drell-Yan process to semi-inclusive deep-inelastic scattering. Here a review is given on which knowledge has been gathered about transverse-momentum-dependent (TMD) distribution and fragmentation functions from semi-inclusive deep-inelastic scattering experiments.

Sign in / Sign up

Export Citation Format

Share Document