D* MESON PRODUCTION AND $F_2^{c\bar c}$ IN DIS AT HERA

2011 ◽  
Vol 26 (03n04) ◽  
pp. 675-676 ◽  
Author(s):  
AGNIESZKA ŁUSZCZAK

I calculate [Formula: see text] within two dipole models: GBW and CGC. I compare predictions with the last data from HERA. In the GBW and CGC saturation model the heavy quark contribution to F2 was considered in the form of the [Formula: see text] pair production. I calculate inclusive charm production in terms of [Formula: see text] and diffractive charm production in terms of [Formula: see text]. I find good agreement with data both in diffractive and inclusive case. [Formula: see text], measured by HERA, is an important issue in the determination of parton distribution functions (PDFs). Last measurement from H 16 shows that [Formula: see text] is consistent with D* data.

2015 ◽  
Vol 37 ◽  
pp. 1560053
Author(s):  
Pedro Jimenez-Delgado

Reports on our latest extractions of parton distribution functions of the nucleon are given. First an overview of the recent JR14 upgrade of our unpolarized PDFs, including NNLO determinations of the strong coupling constant and a discussion of the role of the input scale in parton distribution analysis. In the second part of the talk recent results on the determination of spin-dependent PDFs from the JAM collaboration are reported, including a careful treatment of hadronic and nuclear corrections, as well as reports on the impact of present and future data in our understanding of the spin of the nucleon.


2019 ◽  
Vol 222 ◽  
pp. 03021
Author(s):  
A. Aleshko ◽  
E. Boos ◽  
V. Bunichev

The new method for studying polarized parton distribution functions via the Drell-Yan process with tau production is proposed. The hadronic decay of tau to single charged pi-meson and neutrino is utilised for determination of the polarization state of the tau-lepton. The key feature of our approach is that we do not sum over the polarizations states of tau, but preserve this information through energies ofpions produced in corresponding decays. The new method in addition to existing ones should improve the accuracy of measurements of polarized structure functions of hadrons. In the current work, the feasibility of such an approach is assessed through numerical simulations.


2016 ◽  
Vol 31 (25) ◽  
pp. 1630023 ◽  
Author(s):  
S. Alekhin ◽  
J. Blümlein ◽  
S.-O. Moch

The status of the determination of the strong coupling constant [Formula: see text] from deep-inelastic scattering and related hard scattering data is reviewed.


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.


2005 ◽  
Vol 20 (08n09) ◽  
pp. 1927-1930 ◽  
Author(s):  
S. ATASHBAR TEHRANI ◽  
ALI N. KHORRAMIAN ◽  
A. MIRJALILI

We calculate nuclear parton distribution functions (PDFs), using the constituent quark model. We find the bounded valon distributions in a nuclear to be related to free valon distributions in a nucleon. By using improved bounded valon distributions for a nuclear with atomic number A and the partonic structure functions inside the valon, we can calculate the nuclear structure function in x space. The results for nuclear structure-function ratio [Formula: see text] at some values of A, are in good agreement with the experimental data.


2016 ◽  
Vol 40 ◽  
pp. 1660016 ◽  
Author(s):  
Emanuele R. Nocera

I review the current status of the determination of helicity-dependent, or polarized, parton distribution functions from a comprehensive analysis of experimental data in perturbative quantum chromodynamics. I illustrate the latest achievements driven by new measurements in polarized proton-proton collisions at the Relativistic Heavy Ion Collider, namely the first evidence of a sizable polarized light sea quark asymmetry and of a positive polarized gluon distribution in the proton. I discuss which are the open issues in the determination of polarized distributions, and how these may be addressed in the future by ongoing, planned and proposed experimental programs.


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