Photon Structure

This page contains the collection of results on the structure of the photon which have been presented in Phys Rep 332(2000) 165-317. The full paper is available as PDF or PostScript file. A preprint version of this work is available as hep-ex/9912049.

This page provides access to the Encapsulated PostScript files of all Figures. In addition listed are the numerical results presented in the Tables of the appendices C and D. Since the tables are not completely standardised it is advisable to always consult the manuscript before using the numerical results! For convenience, the gzip'ed tar files which always contain the complete most up-to-date Set of Figures and Set of Tables are also available. The results have been collected with great care, however mistakes are not exluded. Please feel free to contact Richard Nisius should you have any comment or question.

Whenever new data on photon structure functions are available or preliminary results are finalised, I intend to update the summary figures. In this case the figure is marked as (updated) and you are directed to a new page giving the record of the changes made. Tables will only be updated should there be an error discovered and corrected.

List of known misprints and acknowledgements
Unfortunately, there are still some misprints in the document.

If you spot something else that is wrong, please let me know.


List of Figures

Figure Description
Fig01 Probing the structure of quasi-real photons, g, by highly virtual photons, g*.
Fig02 The different appearances of the photon.
Fig03 A diagram of the reaction ee –> ee ff, proceeding via the exchange of two photons.
Fig04 The different contributions to the reaction ee –> ee g(*)g(*) –> ee ff.
Fig05 Illustrations of the scattering angles barphi, theta* and chi in the photon-photon centre-of-mass system.
Fig06 A schematic view of the OPAL detector.
Fig07 The kinematical coverage of the OPAL detector.
Fig08 The predicted differential cross-section dsigma/dx for the reaction ee –> ee µ+µ- for the acceptance of the PLUTO experiment, and for two different lower limits on W.
Fig09 The predicted differential cross-section dsigma/dx for the reaction ee –> eeµ+µ- for some typical acceptances of a LEP experiment.
Fig10 Comparison of the equivalent photon and the Weizsäcker-Williams approximations.
Fig11 A diagram of the reaction eg –> eg*g –> e ff .
Fig12 The structure functions F2,QED, FA,QED and FB,QED for µµ final states at Q2=1 GeV2.
Fig13 The structure functions F2,QED, FA,QED and FB,QED for µµ final states at Q2=100 GeV2.
Fig14 The P2 dependence of the structure function F2,QED.
Fig15 The QPM prediction for the structure function F2 for light quarks.
Fig16 Comparison of the parametrisations of the x dependence of the leading order asymptotic solution of F2.
Fig17 Comparison of the asymptotic solution and the leading order GRV parametrisation of F2.
Fig18 The structure function F2 in the limit Q2 >> P2 >> Lambda2.
Fig19 The leading order contributions to F2,h.
Fig20 The point-like heavy quark contribution to F2 for various values of Q2.
Fig21 Comparison of parametrisations of the hadron-like contribution to the photon structure function F2.
Fig22 The Q2 dependence of the photon structure function F2 in comparison to the hadron-like contribution.
Fig23 The structure function F2 from the LAC parton distribution functions.
Fig24 The structure function F2 from the WHIT parton distribution functions.
Fig25 Comparison of the GRV leading order and next-to-leading order parametrisations of the photon structure function F2.
Fig26 Comparison of the higher order structure function F2 from AFG and GRV.
Fig27 Comparison of the leading order GRV and GRSc parametrisations of F2.
Fig28 The structure function F2 from the SaS parton distribution functions for several values of Q2.
Fig29 Predictions for the Q2 evolution of the photon structure function F2 for various x ranges.
Fig30 Comparison of leading order parametrisations of the photon structure function F2 for virtual photons.
Fig31 The variation of the P2 suppression of F2 in the SaS1D parametrisations.
Fig32 The predicted P2 suppression of the photon structure function F2(uds).
Fig33 Comparison of the photon structure function F2 for virtual photons with the purely perturbative point-like part.
Fig34 The point-like and hadron-like contributions to F2,c (updated).
Fig35 The measured average structure function <F2,QED> from the CELLO, DELPHI, L3 and the TPC/2g experiments, compared to QED predictions.
Fig36 The world summary of F2,QED measurements (updated).
Fig37 The measured Q2 evolution of F2,QED (updated).
Fig38 The dependence of F2,QED on P2 and on the mass of the muon.
Fig39 The measurements of FA,QED / F2,QED and ½ FB,QED / F2,QED (updated).
Fig40 The measurements of FA,QED and FB,QED.
Fig41 The measurement of the differential QED cross section dsigma/dx for highly virtual photons.
Fig42 The general behaviour of the hadronic energy flow.
Fig43 The correlation between the measured and generated hadronic invariant mass.
Fig44 The measured Et,out distribution for <Q2> = 13 GeV2 in bins of x.
Fig45 The corrected hadronic energy flow for <Q2> = 13 GeV2.
Fig46 The corrected hadronic energy flow for <Q2> = 135 GeV2.
Fig47 Comparison of different methods for the reconstruction of the invariant mass of the hadronic final state.
Fig48 The measured hadronic energy flow from L3.
Fig49 Measurements of the hadronic structure function F2 except from LEP.
Fig50 Comparison of measurements of F2 at low values of Q2.
Fig51 Preliminary update of F2 at low values of Q2 from OPAL.
Fig52 The measurements of F2 at low values of Q2 from L3.
Fig53 The first measurement of F2 for sqrt(see) > mZ .
Fig54 Measurements of the hadronic structure function F2 from LEP (updated).
Fig55 Summary of measurement of the hadronic structure function F2 (updated).
Fig56 The measured Q2 evolution of F2 for three active flavours.
Fig57 The measured Q2 evolution of F2 from OPAL (updated).
Fig58 The measured Q2 evolution of F2 from L3.
Fig59 The measured Q2 evolution of F2 at medium x (updated).
Fig60 Summary of the measurements of the Q2 evolution of F2 (updated).
Fig61 Measurements of the Q2 evolution of F2 compared to a linear fit (updated).
Fig62 The Q2 evolution of F2 for three active flavours compared to the asymptotic solution and the QPM prediction (updated).
Fig63 The effective photon structure function F2,eff from PLUTO.
Fig64 The effective photon structure function F2,eff from L3.
Fig65a , Fig65b The virtuality dependence of F2,eff.
Fig66 The hadronic cross-section for the exchange of two virtual photons from L3.
Fig67 The hadronic cross-section for the exchange of two virtual photons from OPAL.
Fig68 The forward region of a future linear collider detector.
Fig69 The production mechanism for high energetic photons.
Fig70 Prospects for structure function measurements at a future linear collider.
Fig71 Prospects for the measurement of the Q2 evolution of F2 at a future linear collider (updated).
Fig72 Published results on sigmagg as a function of W.
Fig73 Preliminary results on sigmagg as a function of W .
Fig74 Fits to sigmagg using various data and fit assumptions.
Fig75 Transverse momentum distribution dsigma / dpT for hadron production in photon-photon scattering compared to other experiments.
Fig76 Transverse momentum distribution dsigma / dpT for hadron production in photon-photon scattering compared to next-to-leading order calculations.
Fig77a , Fig77b Angular dependence of di-jet production in photon-photon scattering.
Fig78 Transverse energy distribution dsigma / dEjet,T for jet production in photon-photon scattering compared to next-to-leading order calculations.
Fig79 Transverse energy distribution dsigma / dEjet,T for jet production in photon-photon scattering compared to predictions for different parton distribution functions.
Fig80 Differential cross-sections for charm quark production with semileptonic decays into electrons.
Fig81 Differential cross-sections for charm quark production with tagged D* mesons.
Fig82 The separation of the D* production into direct and single-resolved contributions.
Fig83 Total cross-section for charm quark production.
Fig84 Di-jet cross-section in photon-proton scattering compared to next-to-leading order QCD predictions.
Fig85 Inclusive di-jet cross-section for photon-proton scattering from H1.
Fig86a , Fig86b Leading order effective parton distribution function of the photon from H1.
Fig87a , Fig87b Measurements of the gluon distribution function of the photon from H1.
Fig88 Triple differential jet cross-section dsigma/dP2dET2dxg for virtual photons from H1.
Fig89 Leading order effective parton distribution function of virtual photons from H1.
Fig90 The P2 suppression of the leading order effective parton distribution function of virtual photon from H1.

List of Tables

Table Description
TabC01 Results on the average photon structure function <F2,QED> from the CELLO experiment.
TabC02 Results on the average photon structure function <F2,QED> from the DELPHI experiment.
TabC03 Results on the average photon structure function <F2,QED> from the L3 experiment.
TabC04 Results on the photon structure function F2,QED from the OPAL experiment.
TabC05 Results on the photon structure function F2,QED from the OPAL experiment, continued.
TabC06 Results on the photon structure function F2,QED from the PLUTO experiment.
TabC07 Results on the average photon structure function <F2,QED> from the TPC/2g experiment.
TabC08 Preliminary results on the photon structure function F2,QED from the DELPHI experiment.
TabC09 Results on the photon structure functions FA,QED and FB,QED from the L3 experiment.
TabC10 Results on the photon structure functions FA,QED and FB,QED from the OPAL experiment.
TabC11 Preliminary results on the photon structure function ratios FA,QED / F2,QED and ½ FB,QED / F2,QED from the DELPHI experiment.
TabC12 Differential cross-section dsigma/dx for two exchanged virtual photons.
TabD01 Results on the photon structure function F2 from the ALEPH experiment.
TabD02 Results on the photon structure function F2 from the AMY experiment.
TabD03 Results on the photon structure function F2 from the DELPHI experiment.
TabD04 Results on the photon structure function F2 from the JADE experiment.
TabD05 Rsults on the photon structure function F2 from the L3 experiment.
TabD06 Results on the photon structure function F2 from the OPAL experiment (updated).
TabD07 Results on the photon structure function F2 from the PLUTO experiment.
TabD08 Results on the photon structure function F2 from the TASSO experiment.
TabD09 Results on the photon structure function F2 from the TPC/2g experiment.
TabD10 Results on the photon structure function F2 from the TOPAZ experiment.
TabD11 Additional preliminary results on the photon structure function F2 from the ALEPH experiment.
TabD12 Additional preliminary results on the photon structure function F2 from the DELPHI experiment.
TabD13 Additional preliminary results on the photon structure function F2 from the L3 experiment.
TabD14 Results on the Q2 evolution of F2 for three active flavours.
TabD15 Results on the Q2 evolution of F2 for four active flavours.
TabD16 Preliminary results on the Q2 evolution of F2.

Last Change: 16-Jul-2009 by Richard Nisius.