Collisions in Particle Physics 2
Lorenzo Galante
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If the app does not fit the display open it from Here.
How to use the Geogebra APP
- Fitting tracks with circles: click on the "Show He circle" check box and move the point on the circle to fit the Helium track. Repeat the same for the remaining two tracks (incoming pion and scattered pion). WARNING: the radius is really sensitive to small changes in the position of the point. So be careful and do your best to pass through the dark grey spots similar to those shown in the picture below!
- Evaluating the track curvature: the APP returns the values of the radii of the three circles (top - left) in Geogebra units (gGU)
- Conversion gGU to meters: the length of the CD segment in gGU corresponds to 0.60m so you can convert the radii in meters
- Evaluating momenta: open a Spreadsheet and evaluate the momentum of the three particles (remember that p = RqB). If you prefer you can make a copy of a ready to use spreadsheet here.
- Conversion to eV/c: after you have determined the momentum in SI Units, determine the conversion factor in order to express momenta in eV/c (if any problem, read this Help).
- Inserting the values of the momenta: insert the evaluated momenta in the input boxes on the top - right. Express them in 108 eV/c Units. In this way the numbers you will insert will be in the interval ]0, 10[ 108 eV/c.
- Visualizing momenta vectors: clicking on the remaining check boxes you can ask to show the momenta vectors before and after the collision.
