Physics with ZEUS @ HERA

The very high energies offered by HERA in ep interactions permit one to probe deep inside the proton in order to study the structure of its constituents, the quarks and gluons. According to Uncertainty principle a measure for the smallest size D of resolved objects is the transverse momentum kick Q which the electron impacts to the proton, D ~ h/Q with Q2 values as high as 40000 GeV2 can be reached at HERA corresponding to D = 10-16 cm which is a factor 1000 smaller than the proton radius. With this resolving power exciting physics topics can be studied, such as substructure of quarks and electrons, neutral and charged current processes, tests of Quantum Chromo-dynamics, searches for new currents and for new particles. The success of such studies depends critically on the accuracy with which the energies and angles of the particles and particle bundles called jets resulting from the interactions can be measured.

ZEUS Detector at HERAZeus Detector

 Electron-Positron Interaction

                           Electron - proton scattering


Group Members

Currently following EHEP group members are participating in this ZEUS experiment at HERA since January 2007;



Physics Analysis


The group is involved in the ;


(i) Measurement of longitudinal Structure function FL

(ii) Measurement of neutral current cross-sections using beams of proton at different energies, 460, 575 & 920 GeV protons interacting with 27.5 GeV electrons/positrons.

The work is being pursued in collaboration with ZEUS team from Max Planck Institute of Physics and Astrophysics at Munich, Germany.


The participation is made possible by generous grants from Max Planck Institute, Munich, Germany and Department of Science & Technology, Govt. of India, New Delhi