Jul 4 – 11, 2018
Asia/Seoul timezone

Studies of HERA deep inelastic scattering data at low Q^2 and low x_Bj

Jul 5, 2018, 12:00 PM
101 (COEX, Seoul)


COEX, Seoul

Parallel Strong Interactions and Hadron Physics Strong Interactions and Hadron Physics


Dr Volodymyr Myronenko (Deutsches Elektronen-Synchrotron)


A phenomenological study of the final combined HERA data on inclusive deep inelastic scattering (DIS) has been performed. The data are presented and investigated for a kinematic range extending from values of the four-momentum transfer, $Q^2$, above $10^4$ GeV$^2$ down to the lowest values observable at
HERA of $Q^2 = 0.045$ GeV$^2$ and Bjorken $x$, $x_{\rm Bj} = 6 \times 10^{−7}$. The data are well described by fits based on perturbative quantum chromodynamics (QCD) using collinear factorisation and evolution of the parton densities encompassed in the DGLAP formalism from the highest $Q^2$ down to $Q^2$ of a few GeV$^2$. The standard DGLAP evolution was augmented by including an additional higher-twist term in the description of the longitudinal structure function, $F_L$. This additional term, $F_L A_L^{\rm HT}/Q^2$, improves the description of the reduced cross sections significantly. The resulting predictions for F_L suggest that further corrections are required for $Q^2$ less than about 2 GeV$^2$. The Regge formalism can describe the data up to $Q^2 \sim 0.65$ GeV$^2$. The complete data set can be described by a new fit using the ALLM parameterisation. The region between the Regge and the perturbative QCD regimes is of particular interest.

Primary authors

Matthew Wing (University College London) Katarzyna Wichmann (Deutsches Elektronen-Synchrotron (DE)) Dr Volodymyr Myronenko (Deutsches Elektronen-Synchrotron) Brian Foster (University of Oxford (GB)) Amanda Sarkar (University of Oxford (GB)) Iris Abt (MPI)

Presentation materials