Structure functions and structure function ratio Fn2/Fp2 at small xBj and Q2 in muon-nucleon scattering

1995 ◽  
Author(s):  
Panagiotis Spentzouris
Keyword(s):  
Structure Function ◽  
Structure Functions ◽  
Nucleon Scattering

scholarly journals STRUCTURE FUNCTIONS IN DEEP INELASTIC LEPTON-NUCLEON SCATTERING

2000 ◽  
Vol 15 (supp01b) ◽  
pp. 467-494 ◽  
Author(s):  
MAX KLEIN
Keyword(s):  
Inelastic Scattering ◽  
Structure Function ◽  
Deep Inelastic Scattering ◽  
Gluon Distribution ◽  
Structure Functions ◽  
Heavy Flavor ◽  
Nucleon Scattering ◽  
High Q ◽  
Low X

This report presents the latest results on structure functions, as available at the Lepton-Photon Symposium 1999. It focuses on three experimental areas: new structure function measurements, in particular from HERA at low x and high Q2; results on light and heavy flavor densities; and determinations of the gluon distribution and of αs. As the talk was delivered at a historic moment and place, a few remarks were added recalling the exciting past and looking into the promising future of deep inelastic scattering (DIS).

NON-SINGLET PART OF THE LONGITUDINAL STRUCTURE FUNCTION FL UP TO $O(\alpha_s^3)$

2011 ◽  
Vol 26 (03n04) ◽  
pp. 686-687 ◽  
Author(s):  
M. SOLEYMANINIA ◽  
ALI N. KHORRAMIAN
Keyword(s):  
Structure Function ◽  
Structure Functions ◽  
Distribution Functions ◽  
Nucleon Structure ◽  
Heavy Flavor ◽  
Longitudinal Structure ◽  
Nucleon Scattering ◽  
Longitudinal Structure Function ◽  
Nucleon Structure Function ◽  
Qcd Analysis

The unpolarized longitudinal nucleon structure function FL, measured in the deep inelastic lepton-nucleon scattering, is contained of three parts, singlet, non-singlet and gluon. The aim of this paper is to perform a QCD analysis of the longitudinal heavy and light structure functions FL(x, Q2) in the non-singlet part up to [Formula: see text]. We use the light and heavy flavor Wilson coefficients and distribution functions in Mellin space. Also we need to use the Padé approximation for αs analysis.

scholarly journals The Observational Error of Automated Wind Reports from Aircraft

1986 ◽  
Vol 67 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Lauren L. Morone
Keyword(s):  
Measurement Error ◽  
Structure Function ◽  
Error Variance ◽  
Structure Functions ◽  
Separation Distance ◽  
Observational Error ◽  
Random Measurement Error ◽  
Measurement Error Variance ◽  
Flight Level ◽  
Types Of Error

Data collected from aircraft equipped with AIDS (Aircraft Integrated Data System) instrumentation during the Global Weather Experiment year of 1979 are used to estimate the observational error of winds at flight level from this and other aircraft automated wind-reporting systems. Structure functions are computed from reports that are paired using specific criteria. The value of this function extrapolated to zero separation distance is an estimate of twice the random measurement-error variance of the AIDS-measured winds. Component-wind errors computed in this way range from 2.1 to 3.1 m · s−1 for the two months of data examined, January and August 1979. Observational error, specified in optimum-interpolation analyses to allow the analysis to distinguish among observations of differing quality, is composed of both measurement error and the error of unrepresentativeness. The latter type of error is a function of the resolvable scale of the analysis-prediction system. The structure function, which measures the variability of a field as a function of separation distance, includes both of these types of error. If the resolvable scale of an analysis procedure is known, an estimate of the observational error can be computed from the structure function at that particular distance. An observational error of 5.3 m · s−1 was computed for the u and v wind components for a sample resolvable scale of 300 km. The errors computed from the structure functions are compared to colocation statistics from radiosondes. The errors associated with automated wind reports are found to compare favorably with those estimated for radiosonde winds at that level.

scholarly journals Froissart bound and self-similarity based models of proton structure functions

2018 ◽  
Vol 33 (08) ◽  
pp. 1850046 ◽  
Author(s):  
D. K. Choudhury ◽  
Baishali Saikia
Keyword(s):  
Structure Function ◽  
Cross Section ◽  
Structure Functions ◽  
Proton Structure Function ◽  
Self Similarity ◽  
Proton Proton ◽  
Proton Structure

Froissart bound implies that the total proton–proton cross-section (or equivalently proton structure function) cannot rise faster than [Formula: see text]. Compatibility of such behavior with the notion of self-similarity in proton structure function was suggested by us sometime back. In the present work, we generalize and improve it further by considering more recent self-similarity based models of proton structure functions and compare with recent data as well as with the model of Block, Durand, Ha and McKay.

scholarly journals EFFECT DUE TO COMPOSITENESS OF NUCLEONS IN DEEP INELASTIC LEPTON NUCLEUS SCATTERING

1992 ◽  
Vol 01 (04) ◽  
pp. 809-821 ◽  
Author(s):  
BO-QIANG MA
Keyword(s):  
Structure Function ◽  
Nuclear Structure ◽  
Light Cone ◽  
Degrees Of Freedom ◽  
Structure Functions ◽  
Nucleon Structure ◽  
Nucleon Structure Function ◽  
Nucleus Scattering ◽  
Quark Structure ◽  
Nuclear Structure Functions

The off-shell behaviors of bound nucleons in deep inelastic lepton nucleus scattering are discussed in two scenarios with the basic constituents chosen to be baryon-mesons and quark-gluons respectively in light-cone formalism. It is found that when taking into account the effect due to internal quark structure of nucleons, the derived scaling variable for bound nucleons and the calculated nuclear structure functions are different from those in considering the baryon-mesons as the effective elementary constituents. This implies that the pure baryon-meson descriptions of nuclei give the inaccurate off-shell behavior of the bound nucleon structure function, thereby the quark-gluons seem to be the most appropriate degrees of freedom for nuclear descriptions.

Structure functions and charge ratios in muon-nucleon scattering

1978 ◽  
Vol 17 (11) ◽  
pp. 2843-2846 ◽  
Author(s):  
C. del Papa ◽  
D. Dorfan ◽  
S. M. Flatté ◽  
C. A. Heusch ◽  
B. Lieberman ◽  
...  
Keyword(s):  
Structure Functions ◽  
Nucleon Scattering

scholarly journals Towards mapping turbulence in the intra-cluster medium

2019 ◽  
Vol 629 ◽  
pp. A144 ◽  
Author(s):  
E. Cucchetti ◽  
N. Clerc ◽  
E. Pointecouteau ◽  
P. Peille ◽  
F. Pajot
Keyword(s):  
Structure Function ◽  
Spatial Scales ◽  
Companion Paper ◽  
Structure Functions ◽  
Order Structure ◽  
Sampling Variance ◽  
Function Estimation ◽  
X Ray ◽  
Spatially Resolved Spectroscopy ◽  
Field Unit

X-ray observations of the hot gas filling the intra-cluster medium (ICM) provide a wealth of information on the dynamics of clusters of galaxies. The global equilibrium of the ICM is believed to be ensured by non-thermal and thermal pressure support sources, among which gas movements and the dissipation of energy through turbulent motions. Accurate mapping of turbulence using X-ray emission lines is challenging due to the lack of spatially resolved spectroscopy. Only future instruments such as the X-ray Integral Field Unit (X-IFU) on Athena will have the spatial and spectral resolution to quantitatively investigate the ICM turbulence over a broad range of spatial scales. Powerful diagnostics for these studies are line shift and the line broadening maps, and the second-order structure function. When estimating these quantities, instruments will be limited by uncertainties of their measurements, and by the sampling variance (also known as cosmic variance) of the observation. Here, we extend the formalism started in our companion Paper I to include the effect of statistical uncertainties of measurements in the estimation of these line diagnostics, in particular for structure functions. We demonstrate that statistics contribute to the total variance through different terms, which depend on the geometry of the detector, the spatial binning and the nature of the turbulent field. These terms are particularly important when probing the small scales of the turbulence. An application of these equations is performed for the X-IFU, using synthetic turbulent velocity maps of a Coma-like cluster. Results are in excellent agreement with the formulas both for the structure function estimation (≤3%) and its variance (≤10%). The expressions derived here and in Paper I are generic, and ensure an estimation of the total errors in any X-ray measurement of turbulent structure functions. They also open the way for optimisations in the upcoming instrumentation and in observational strategies.

Bounding the stochastic performance of continuum structure functions. II

1987 ◽  
Vol 24 (03) ◽  
pp. 609-618 ◽  
Author(s):  
Laurence A. Baxter ◽  
Chul Kim
Keyword(s):  
Structure Function ◽  
Random Variables ◽  
Structure Functions ◽  
Unit Interval ◽  
Modular Decomposition ◽  
Associated Random Variables ◽  
Unit Hypercube ◽  
Continuum Structure

A continuum structure function γ is a non-decreasing mapping from the unit hypercube to the unit interval. Block and Savits (1984) use the sets and to determine bounds on the distribution of γ (X) when X is a vector of associated random variables. It is shown that, if γ admits of a modular decomposition, improved bounds may be obtained.

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