Physics with polarized proton and electron collisions at HERA

✍ Scribed by F. Kunne

• Book ID: 104336508
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 630 KB
• Volume: 622
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(97)00336-9

✦ Synopsis

We describe here some possible measurements at the HERA collider in the scenario where both the electron and the proton beam are polarized. The proposed experiments have been studied during the recent workshop on Future Physics at HERA in the dedicated working group "polarized protons and electrons".

The measurement of the polarized gluon distribution function AG(x,Q2) from photongluon fusion processes in electron-proton deep inelastic scattering producing two jets has been investigated. The size of the expected spin asymmetry and corresponding statistical uncertainties have been estimated. The results show that the asymmetry can reach a few percent, and is not washed out by hadronization and higher order processes.

Estimates of possible data on spin dependent asymmetries in inclusive deep inelastic ~*ff scattering are presented. By accessing a new kinematic domain in x and Q~ these data would shed light on the behaviour of the polarized structure function of the proton gap at low x and high Q2. They would reduce substantially the uncertainty on the determination of the polarized gluon distribution AG(x,Q2) from QCD evolution equations.

Finally, the spin asymmetries from charged current events allow to measure the spin dependent structure function g5 which is related to the polarized distribution functions. The charged current reactions allow to distinguish quark and antiquark flavours. These measurements would provide data on Au~ and Adv at high x and high Q2 complementary to the fixed target data, with a very good statistical precision. In addition, semi inclusive D-production events could give a good signal for the determination of As and As.

* Highlights from the Workshop on the Future Physics at HERA, Working Group No 7: "Polarized protons and electrons"-DESY, September 95 -may 96.