Speaker
Description
The study of hadron spectroscopy and nucleon resonance structure has entered a new precision era with the 12 GeV upgrade at Jefferson Lab. The CLAS12 detector, a large-acceptance spectrometer in Hall B, provides efficient charged and neutral particle detection over a wide solid angle.
We present a preliminary analysis of the exclusive quasi-real 2 pion photoproduction, from the reaction ep → epπ⁺π⁻ where the virtuality of the exchanged photon Q² → 0. This is needed to understand the mechanisms responsible for production of meson resonances decaying into two pions. The goal of the analysis is the extraction of the differential cross sections and moments of the γp → π⁺π⁻p reaction. Selecting the properly kinematic range of the two‑pion invariant mass and momentum transfer reveals some resonances like the ρ(770) and the f2(1270).