Study of the Pion Trajectory in the Photoproduction of Leading Neutrons at HERA

ZEUS Collaboration

Research output: Contribution to journalArticlepeer-review

Abstract

Energetic neutrons produced in ep collisions at HERA have been studied with the ZEUS detector in the photoproduction regime at a mean photon-proton center-of-mass energy of 220 GeV. The neutrons carry a large fraction 0.64<xL<0.925 of the incoming proton energy, and the four-momentum transfer squared at the proton-neutron vertex is small, |t|<0.425 GeV2. The xL distribution of the neutrons is measured in bins of t. The (1-xL) distributions in the t bins studied satisfy a power law dN/dxL∝(1-xL)a(t), with the powers a(t) following a linear function of t: a(t)=0.88±0. 09(stat.)-0.39+0.34(syst.)-(2.81±0.42(stat.)-0.62+1.13(syst.) GeV-2)t. This result is consistent with the expectations of pion-exchange models, in which the incoming proton fluctuates to a neutron-pion state, and the electron interacts with the pion.
Original languageAmerican English
Pages (from-to)199-211
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume610
Issue number3-4
DOIs
StatePublished - Mar 24 2005

Disciplines

  • Physics

Cite this