Structure Functions at Small x from HERA
Abstract
Since the beginning of data-taking in 1992, both the ZEUS and H1 experiments have extended the measurement of proton structure functions (F_2, F_L, xG, and F_2^charm) to very small x. These measurements were initially made at values of the four momentum transfer, Q^2, large enough such that the data could be described by perturbative QCD using the equations initially developed by Altarelli and Parisi (now called DGLAP). Despite the increasing luminosities delivered by the HERA ep collider, detector upgrades and improvements in measurement techniques have enabled the kinematic range to be pushed to even lower x and Q^2, testing the limits of the perturbative QCD approach. Recently, F2 measurements at very low Q^2 have been compared to both hard (perturbative) and soft (non-perturbative) QCD predictions, indicating the range in the scale defining the transition between the two approaches.
- Publication:
-
APS April Meeting Abstracts
- Pub Date:
- April 1998
- Bibcode:
- 1998APS..APR.6WK05M