E-835 Hydrogen Gas Jet

E835 studies the charmonium states formed in anti-proton annihilations. A charm quark and an anti-charm anti-quark bound together by the strong force makes a charmonium meson. Different combinations of quantum numbers (e.g. spin and angular momentum) of the two bound constituents form different charmonium particle states. The study of the different states' masses, resonance widths and decay channels increases what is know about the strong force and tests many different theories concerning the strong interaction. The Gas Jet produces a beam of hydrogen that is 420 degrees below zero, inside a near perfect vacuum (10-9 torr). This dense hydrogen is the target for the anti-protons.

Gas Jet Target installed in the anti- proton ring.

The interaction area of the E-835 Gas Jet.

Density Detector that is used to determine the size, density and profile of the hydrogen beam of the gas jet.

Gas Jet Cryostat produces a 20 Degree Kelvin hydrogen beam