Next-to-leading order QCD analysis of parton distribution functions with LHC data

2017 ◽  
Vol 282-284 ◽  
pp. 32-36 ◽  
Author(s):  
A. Vafaee ◽  
A. Khorramian
1992 ◽  
Vol 07 (29) ◽  
pp. 2695-2702 ◽  
Author(s):  
PRAKASH MATHEWS ◽  
V. RAVINDRAN

We analyze polarized Drell-Yan process using the factorization method and derive operator definitions for polarized parton distribution functions. We demonstrate that a factorization analogous to that in the unpolarized Drell-Yan case holds in this process. We study the leading order gluonic contribution to the first moment of polarized Drell-Yan function and show that it is consistent with the results obtained from polarized deep inelastic scattering.


2005 ◽  
Vol 20 (21) ◽  
pp. 1557-1571
Author(s):  
BURKARD REISERT

An extraction of the parton distributions of the proton by a next-to-leading order QCD fit in the framework of the Standard Model is presented. The fit implements a novel decomposition of the quark species into up- and down-type quark distributions, which is the key to enable a determination of flavor separated parton distributions from a single experiment. The fit is performed on the inclusive unpolarized neutral and charged current cross-section measurements by the H1 collaboration at HERA. The discussion of uncertainties of parton distribution functions is based upon but extends the QCD analysis published together with the H1 data.


2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Chengdong Han ◽  
Gang Xie ◽  
Rong Wang ◽  
Xurong Chen

AbstractWe present pion and kaon parton distribution functions from a global QCD analysis of the experimental data within the framework of dynamical parton model. We use the DGLAP equations with parton–parton recombination corrections and the valence input of uniform distribution which maximizes the information entropy. At our input scale $$Q_0^2$$ Q 0 2 , there are no sea quark and gluon distributions. All the sea quarks and gluons of the pion and the kaon are completely generated from the parton splitting processes. The mass-dependent parton splitting kernel is applied for the strange quark distribution in the kaon. The obtained valence quark and sea quark distributions at high $$Q^{2}$$ Q 2 ($$Q^2>5$$ Q 2 > 5 GeV$$^2$$ 2 ) are compatible with the existed experimental measurements. Furthermore, the asymptotic behaviours of parton distribution functions at small and large x have been studied for both the pion and the kaon. Lastly, the first three moments of parton distributions at high $$Q^{2}$$ Q 2 scale are calculated, which are consistent with other theoretical predictions.


2017 ◽  
Vol 32 (19n20) ◽  
pp. 1750121 ◽  
Author(s):  
H. Hosseinkhani ◽  
M. Modarres ◽  
N. Olanj

Transverse momentum dependent (TMD) parton distributions, also referred to as unintegrated parton distribution functions (UPDFs), are produced via the Kimber–Martin–Ryskin (KMR) prescription. The GJR08 set of parton distribution functions (PDFs) which are based on the valence-like distributions is used, at the leading order (LO) and the next-to-leading order (NLO) approximations, as inputs of the KMR formalism. The general and the relative behaviors of the generated TMD PDFs at LO and NLO and their ratios in a wide range of the transverse momentum values, i.e. [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] are investigated. It is shown that the properties of the parent valence-like PDFs are imprinted on the daughter TMD PDFs. Imposing the angular ordering constraint (AOC) leads to the dynamical variable limits on the integrals which in turn increase the contributions from the lower scales at lower [Formula: see text]. The results are compared with our previous studies based on the MSTW2008 input PDFs and it is shown that the present calculation gives flatter TMD PDFs. Finally, a comparison of longitudinal structure function [Formula: see text] is made by using the produced TMD PDFs and those that were generated through the MSTW2008-LO PDF from our previous work and the corresponding data from H1 and ZEUS collaborations and a reasonable agreement is found.


2009 ◽  
Author(s):  
Yoshiyuki Miyachi ◽  
Yoshimitsu Imazu ◽  
YuKi Kobayashi ◽  
Toshi-Aki Shibata ◽  
Donald G. Crabb ◽  
...  

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