The contribution of valence quarks in the nucleon GE and GM

2019 ◽  
Vol 34 (27) ◽  
pp. 1950148
Author(s):  
Negin Sattary Nikkhoo ◽  
Mohammad Reza Shojaei
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Form Factor ◽  
Total Angular Momentum ◽  
Form Factors ◽  
Distribution Functions ◽  
The Other ◽  
Parton Distribution Functions ◽  
Nucleon Electromagnetic Form Factor ◽  
Elastic Form

The goal of this paper is to extract the flavor decomposition of nucleon electromagnetic form factor using the modified Gaussian and extended Regge ansatzes in the GPDs. We consider the CJ15 and JR09 parton distribution functions for both of these ansatzes in calculating the nucleon elastic form factors. Our results are compared with experimental data in the range [Formula: see text] 4-momentum transfers. Also, we calculate the total angular momentum carried by quarks, the gravitational form factors, and the transverse gravitational density for quarks of the nucleon. In the end, our results are compared with the other studies.

Calculation of inelastic electron–nucleus scattering form factors of 29Si

2014 ◽  
Vol 23 (09) ◽  
pp. 1450046 ◽  
Author(s):  
A. D. Salman ◽  
N. Al-Dahan ◽  
F. I. Sharrad ◽  
I. Hossain
Keyword(s):  
Experimental Data ◽  
Electron Scattering ◽  
Total Angular Momentum ◽  
Form Factors ◽  
Second Order ◽  
Inelastic Electron ◽  
First Order ◽  
Inelastic Electron Scattering ◽  
Nucleus Scattering ◽  
Energy Configurations

Inelastic electron scattering form factors for 29 Si nucleus with total angular momentum and positive parity (Jπ) and excited energy (3/2+, 1.273 MeV; 5/2+, 2.028 MeV; 3/2+, 2.425 MeV and 7/2+, 4.079 MeV) have been calculated using higher energy configurations outside the sd-shell. The calculations of inelastic form factors up to the first- and second-order with and without core-polarization (CP) effects were compared with the available experimental data. The calculations of inelastic electron scattering form factors up to the first-order with CP effects are in agreement with the experimental data, excepted for states 3/2+(1.273 MeV) and 5/2+(2.028 MeV) and without this effect are failed for all states. Furthermore, the calculations of inelastic electron scattering form factors up to the second-order with CP effects are in agreement with the experimental data for 3/2+(1.273 MeV) and 5/2+(2.028 MeV).

Takeoff Mechanics of the Double Backward Somersault

1990 ◽  
Vol 6 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Inseong Hwang ◽  
Gukung Seo ◽  
Zhi Cheng Liu
Keyword(s):  
Angular Momentum ◽  
Total Angular Momentum ◽  
Dominant Role ◽  
Center Of Mass ◽  
Velocity Curve ◽  
The Other ◽  
Transverse Axis ◽  
Angular Momenta ◽  
Total Body ◽  
Direction Opposite

This study examined the biomechanical profiles of the takeoff phase of double backward somersaults in three flight positions: seven layout double backward somersaults (L), seven twisting double backward somersaults (TW), and seven tucked double backward somersaults (TDB). Selected kinematic variables and angular momenta were calculated in order to compare the differences resulting from different aerial maneuvers. The amount of total body angular momentum about the transverse axis through the gymnasts' center of mass progressively increased from TDB to TW to L. The gymnasts performing the skill in the layout position tried to minimize the angle of block in a direction opposite the intended motion by maximizing the angle of touchdown and takeoff. In so doing, the horizontal velocity center-of-mass curve of the L showed a slowly decreasing curve compared with those of the other two somersaults while the vertical velocity curve of the L increased more slowly than the other curves during the takeoff phase. In all cases the legs played the dominant role in contributing to total angular momentum during takeoff.

Progress in the calculation of nucleon form factors and parton distribution functions

2003 ◽  
Vol 721 ◽  
pp. C915-C921 ◽  
Author(s):  
A.W. Thomas ◽  
J.D. Ashley ◽  
W. Detmold ◽  
D.B. Leinweber ◽  
W. Melnitchouk ◽  
...  
Keyword(s):  
Parton Distribution ◽  
Form Factors ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Nucleon Form Factors

UNCERTAINTY OF POLARIZED PARTON DISTRIBUTIONS

2003 ◽  
Vol 18 (08) ◽  
pp. 1203-1210 ◽  
Author(s):  
◽  
M. HIRAI ◽  
Y. GOTO ◽  
T. HORAGUCHI ◽  
H. KOBAYASHI ◽  
...  
Keyword(s):  
Experimental Data ◽  
Parton Distribution ◽  
Gluon Distribution ◽  
Distribution Functions ◽  
Prompt Photon ◽  
Parton Distribution Functions ◽  
Parton Distributions ◽  
Photon Process ◽  
Hessian Method ◽  
Polarized Gluon

Polarized parton distribution functions are determined by a χ2 analysis of polarized deep inelastic experimental data. In this paper, uncertainty of obtained distribution functions is investigated by a Hessian method. We find that the uncertainty of the polarized gluon distribution is fairly large. Then, we estimate the gluon uncertainty by including the fake data which are generated from prompt photon process at RHIC. We observed that the uncertainty could be reduced with these data.

scholarly journals Generalized Parton Distributions and the Structure of the Hadrons

2018 ◽  
Vol 47 ◽  
pp. 1860099
Author(s):  
O. V. Selyugin
Keyword(s):  
Form Factors ◽  
Distribution Functions ◽  
Electromagnetic Form Factors ◽  
Parton Distribution Functions ◽  
Parton Distributions ◽  
Hadron Interaction ◽  
High Energies ◽  
Generalized Parton Distributions ◽  
Momentum Transfer Dependence ◽  
The Impact

The dependence of the hadron interaction on its structure is examined in the framework of the generalized parton distributions (GPDs). The [Formula: see text] dependence of the GPDs is determined by the parton distribution functions (PDFs), which were obtained from the deep inelastic scattering. The analysis of the whole sets of experimental data on the electromagnetic form factors of the proton and neutron with taking into account many forms of PDFs, obtained by the different Collaborations, make it possible to obtain the special momentum transfer dependence of the GPDs. This permits us to obtain the electromagnetic and gravitomagnetic form factors of the nucleons. The impact parameter dependence of the proton and neutron charge and matter densities is examined. The elastic hadron scattering at high energies was analyzed in the framework of the model that takes into account both these form factors (electromagnetic and gravitomagnetic).

scholarly journals NUCLEAR PARTON DENSITIES AND STRUCTURE FUNCTIONS

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1927-1930 ◽  
Author(s):  
S. ATASHBAR TEHRANI ◽  
ALI N. KHORRAMIAN ◽  
A. MIRJALILI
Keyword(s):  
Experimental Data ◽  
Structure Function ◽  
Nuclear Structure ◽  
Parton Distribution ◽  
Constituent Quark ◽  
Structure Functions ◽  
Constituent Quark Model ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Good Agreement

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.

Constraints on the ωπ form factor from analyticity and unitarity

2016 ◽  
Vol 31 (14n15) ◽  
pp. 1630020 ◽  
Author(s):  
B. Ananthanarayan ◽  
Irinel Caprini ◽  
Bastian Kubis
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Information Needs ◽  
Theoretical Calculations ◽  
Form Factors ◽  
Experimental Information ◽  
Upper And Lower Bounds ◽  
Strong Interactions ◽  
Operator Product ◽  
Using Data

Form factors are important low-energy quantities and an accurate knowledge of these sheds light on the strong interactions. A variety of methods based on general principles have been developed to use information known in different energy regimes to constrain them in regions where experimental information needs to be tested precisely. Here we review our recent work on the electromagnetic [Formula: see text] form factor in a model-independent framework known as the method of unitarity bounds, partly motivated by the discrepancies noted recently between the theoretical calculations of the form factor based on dispersion relations and certain experimental data measured from the decay [Formula: see text]. We have applied a modified dispersive formalism, which uses as input the discontinuity of the [Formula: see text] form factor calculated by unitarity below the [Formula: see text] threshold and an integral constraint on the square of its modulus above this threshold. The latter constraint was obtained by exploiting unitarity and the positivity of the spectral function of a QCD correlator, computed on the spacelike axis by operator product expansion and perturbative QCD. An alternative constraint is obtained by using data available at higher energies for evaluating an integral of the modulus squared with a suitable weight function. From these conditions we derived upper and lower bounds on the modulus of the [Formula: see text] form factor in the region below the [Formula: see text] threshold. The results confirm the existence of a disagreement between dispersion theory and experimental data on the [Formula: see text] form factor around 0.6 GeV, including those from NA60 published in 2016.

A combination of hadronic form factors for modeling the kaon photoproduction process γp → K+Λ

2015 ◽  
Vol 24 (02) ◽  
pp. 1550008 ◽  
Author(s):  
L. Syukurilla ◽  
T. Mart
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Differential Cross Section ◽  
Cross Section ◽  
Form Factors ◽  
Coupling Constants ◽  
Dipole Form Factor ◽  
Photoproduction Process ◽  
Different Types ◽  
Dipole Form

We have phenomenologically investigated the kaon photoproduction process γp → K+Λ by combining different types of hadronic form factors (HFFs) inside a covariant isobar model. We obtained the best model with the smallest χ2/N by using the dipole form factor in the Born terms and a combination of the dipole, Gaussian, as well as generalized dipole form factors in the hadronic vertices of the nucleon, kaon and hyperon resonances. By utilizing this model we found that the experimental data used in the analysis are internally consistent, whereas the behavior of differential cross-section at forward angles is not significantly affected by the variation of hadronic coupling constants (CCs) and form factor cutoffs in the model.

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