Barrel Scintillator

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Definitions and Abbreviations

General acronyms or terms used for the ALPHA-g experiment

rTPC	Radial Time projection Chamber
z	Coordinate along the main axis of the trap and rTPC
φ	Azimuthal coordinate, φ = 0 is in direction of cartesian x
θ	Angle towards the z-axis
r	Radial coordinate in the cylindrical rTPC system
pφ	φ component of the pion's original momentum
pθ	θ component of the pion's original momentum
GEANT4	GEometry ANd Tracking, particle physics simulation package
Garfield++	Gas detector simulation package

Table 1 – ALPHA-g Abbreviations

Studies

Cosmic Rejection

... from the simulation document ...

Antihydrogen annihilation identification in ALPHA crucially depends on the software capability to reject background events, i.e., cosmic rays. Given that the ALPHA-g detectors offer more information than what was available in ALPHA, new and more sophisticated algorithms will be developed to remove backgrounds events. Two types of tools will be deployed: “online” software aimed to monitor antihydrogen production and “machine learning algorithms” to eliminate background from the physics measurements.