Strange Meson and Baryon Photoproduction

Ohio University, Athens OH

Investigators

Abstract

The goal of this research is to learn how different types of quarks can combine to form short-lived particles. These data help physicists to understand more about the fundamental theory of the strong force, called quantum chromodynamics or QCD for short. This is the same force that binds together protons and neutrons inside the nucleus of an atom. The particles being studied here have a heavier quark, called the strange quark, which is not found isolated in a stable nucleus. Instead, these particles are created using the energy of a collision between a beam of gamma-rays (high-energy photons) and a stationary target of protons, called photoproduction. The reason to look for particles with the strange quark is that the properties of particles with heavy quarks are easier to calculate than are particles with only light quarks. Even though strange particles are not abundant in nature, they help us understand the theoretical calculations of QCD, which also apply to stable particles and the nuclei of all atoms. The broader impact of this research is to advance technology and to train young scientists. Advances in technology come from building new particle detectors, such as the Pre-shower Calorimeter which is part of the CLAS12 detector being constructed at Jefferson Lab. This detector measures the energy of charged particles that strike it. New materials, such as wavelength-shifting optical fibers, along with high-speed electronics are part of the technology used for this detector, which is funded in part by the NSF. Young scientists, both at the undergraduate and graduate levels, are helping to construct and test the detector. Past graduates of this program have gone on to work at other laboratories, universities and private industry, both in the USA and abroad.