Measurements of the Separated Longitudinal Structure Function F_L from Hydrogen and Deuterium Targets at Low Q^2

Abstract

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the quark dynamics within the nucleon. However, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available for the longitudinal structure function in particular. Here we present separated structure functions for hydrogen and deuterium at low four--momentum transfer squared, Q^2< 1 GeV^2, and compare these with parton distribution parameterizations and a k_T factorization approach. While differences are found, the parameterizations generally agree with the data even at the very low Q^2 scale of the data. The deuterium data show a smaller longitudinal structure function, and smaller ratio of longitudinal to transverse cross section R, than the proton. This suggests either an unexpected difference in R for the proton and neutron or a suppression of the gluonic distribution in nuclei.

arXiv comment11 pages, 7 figures, 2 data tables

References in corpus (36)

• Measurement of the proton and deuteron structure functions, F2p and F2d, and of the ratio sigma(L)/sigma(T)
• Parton distribution functions and benchmark cross sections at NNLO
• Global analysis of proton elastic form factor data with two-photon exchange corrections
• The 3-, 4-, and 5-flavor NNLO Parton from Deep-Inelastic-Scattering Data and at Hadron Colliders
• Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2
• Measurements of electron-proton elastic cross sections for $0.4<Q^2<5.5(GeV/c{)}^2$
• Dynamical NNLO parton distributions
• Review of two-photon exchange in electron scattering
• Final Analysis of Proton Form Factor Ratio Data at ${\mathbf{Q}}^2=4.0$, 4.8 and 5.6 GeV${}^2$
• Empirical Fit to Precision Inclusive Electron-Proton Cross Sections in the Resonance Region
• Two-Photon Physics in Hadronic Processes
• Measurement of the Inclusive e{\pm}p Scattering Cross Section at High Inelasticity y and of the Structure Function FL
• Accurate Measurement of F2d/F2p and Rd-Rp
• Measurement of the two-photon exchange contribution to the elastic $e^{\pm }p$ scattering cross sections at the VEPP-3 storage ring
• Empirical Fit to Inelastic Electron-Deuteron and Electron-Neutron Resonance Region Transverse Cross Sections
• Towards a resolution of the proton form factor problem: new electron and positron scattering data
• A Study of the Quasi-elastic (e,e'p) Reaction on ${}^{12}$C, ${}^{56}$Fe and ${}^{97}$Au
• Description of F2 and FL at small x using a collinearly-improved BFKL resummation
• Uncertainties in determining parton distributions at large x
• Erratum to: "Nuclear Effects on R=σ_L/σ_T in Deep-Inelastic Scattering" Phys.Lett. B475(2000)386
• Nuclear Effects on R = sigma_L / sigma_T in Deep-Inelastic Scattering
• Experimental constraints on non-linearities induced by two-photon effects in elastic and inelastic Rosenbluth separations
• Applications of quark-hadron duality in F2 structure function
• Deep inelastic cross-section measurements at large y with the ZEUS detector at HERA
• How well do we know the neutron structure function?
• Neutron Structure Functions
• Longitudinal-Transverse Separations of Structure Functions at Low $Q^2$ for Hydrogen and Deuterium
• Low $Q^2$, Low $x$ Region in Electroproduction $-$ an Overview
• F_L proton structure function from the unified DGLAP/BFKL approach
• Constraints on the large-x d/u ratio from electron-nucleus scattering at x>1
• The lead-glass electromagnetic calorimeters for the magnetic spectrometers in Hall C at Jefferson Lab
• Impact of nuclear dependence of R=σ_L/σ_T on antishadowing in nuclear structure functions
• Two-photon-exchange effects in the electro-excitation of the $\Delta$ resonance
• The New F_L Measurement from HERA and the Dipole Model
• Calculation of two-photon exchange effects for $\Delta$ production in electron-proton collisions
• Hard- Pomeron behavior of the Longitudinal Structure Function $F_L$ in the Next- to- Leading- Order at low $x$

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• Longitudinal structure function from the parton parameterization
• Resonant contributions to polarized proton structure functions
• Ratio of the structure functions and the color dipole model bound
• Higher order approximations to the longitudinal structure function $F_L$ from the parametrization of $F_2$ based on the Laplace transformation
• Effect of the parameterization of the distribution functions on the longitudinal structure function at small $x$
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• Longitudinal structure function $F_L$ at low $Q^2$ and low $x$ with model for higher twist: an update
• Examining the EMC Effect using the $F_2^n$ neutron structure function
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• inclusiveAI: A machine learning representation of the $F_2$ structure function over all charted $Q^2$ and $x$ range
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• Polarized proton structure in the resonance region
• Longitudinal Structure Function at the Limit $x=Q^2/s$