1. What is the CNI experiment
The CNI experiment studies pion elastic scattering off fixed hydrogen target in the Coulomb Nuclear Interference region
We bombard an hydrogen target (that means, for us, a proton target) with pion projectiles in the kinetic energy range from 15 to 70 MeV. We detect scattered particles in the whole reaction plane, except an hole of around 5 degrees around the beam direction. In particular, we are concerned with particles scattered at small angles ,say, below 30 degrees. This kinematic region is called the Coulomb Interference Region because both the e.m. and the hadronic component of the pion-proton interaction are strong enough to give a substantial interference contribution.
15 < T < 70 MeV
5º <   < 30º

2. Who performs CNI CHAOS collaboration: (,2 ), p, DCX Canadian High
Acceptance
Orbital
Spectrometer
Detects charge particles within 360º in-plane
7º out-of-plane

3. Where is CNI performed
M13 low energy pion channel
TRIUMF, Vancouver

4. Why CNI

5. Vertex reconstruction
Empty target
Hydrogen target

6. Experimental layout Drift wire chambers Beam counter MWPCs
Hydrogen target
E telescope
/ telescope
Magnet yoke

7. Momentum reconstruction