Photoproduction cross-section of the n' meson with CLAS

Abstract

Quantum Chromodynamics (QCD) is the theory of strong interaction, which is a fundamental force to hold nucleons inside the nucleus. The coupling strength is very large at low momentum transfer regime of QCD compare to high momentum and hadrons are the degrees of freedom in this regime. So, the study of hadronic decay of di erent light mesons( 0, , eta0) is very useful tool to explore the low energy regime of QCD. Photoproduc- tion of the 0 meson has been studied in the present work using Continuous Electron Beam Accelerator Facility(CEBAF) and the CLAS detector setup at Je erson Lab, USA. Tagged photon beam of energy from 1.2 GeV to 5.5 GeV and hydrogen target of length 40cm and radius 2cm have been used for the photoproduction of light mesons ( ; !; ; 0 ; ) in this experi- ment. Main physics motivation of this project is to determine di erential cross-section of the 0 meson using the channel 0 􀀀! + 􀀀 from beam energy 1.2 GeV to 5.5 GeV. All the nal state charged particles(p, +; 􀀀) and neutral particles are detected by the CLAS spectrometer. Finally two charge particles and any number of neutral particles along with proton (p) have been used as a selection criteria for data skimming from huge data set. A missing mass technique from the kinematical information of proton, and two pions +; 􀀀 has been used to reconstruct the meson of nal state. Missing mass of the meson from mean ( = 548 GeV=c2) to 3 ( = 10MeV=c2) and invariant mass of + 􀀀 0.3 GeV to 0.6 GeV have been selected to reduce background from other channels. Total number of the 0 meson has been estimated after the e ciency correction. Then di erential cross-section has been calculated and compared with previous published measurement.