München 2019 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 41: Heavy-Ion Collisions and QCD Phases VIII

HK 41.6: Vortrag

Mittwoch, 20. März 2019, 18:00–18:15, HS 15

Azimuthal particle correlations as a probe of collectivity in deep inelastic electron-proton collisions at HERA — •Dhevan Gangadharan for the ZEUS collaboration — Univeristat Heidelberg

Recent observations at RHIC and the LHC of two- and multi-particle correlations in high multiplicity relativistic proton-proton and proton-ion collisions and similarity of the results to those observed in central heavy-ion collisions are often interpreted as an evidence for collective particle production in small collision systems. These results motivate a study in even smaller systems, such as produced in relativistic electron-proton collisions.

A measurement is presented of two-particle correlations in collisions of electron beams at 27.5 GeV with beams of protons at 920 GeV, which corresponds to 318 GeV centre-of-mass energy. A sample of events equivalent to the integrated luminosity of 430 inverse pb was recorded with the ZEUS experiment in 2003-2007. The correlations are measured for charged hadrons as a function of event multiplicity for the lab pseudorapidity range -1.5<ηlab<2. To probe the possible contribution due to collective effects, the correlations are studied as a function of the particle's pair separation in pseudorapidity and the pair mean transverse momentum. The observed correlations are compared to available Monte Carlo models of deep inelastic electron-proton scattering. Observations based on the analysis of the ZEUS data put a limit on the possible collective effects in high multiplicity electron-proton collisions.