Teaching Modern Physics - QuarkNet - Fermilab

5. Now draw the p vectors of p + and π - before they curved. With these vectors you can now
get the angle at which they are traveling in.
Angle of p + : 10 o
Angle of π - : -8 o or 352 o
6. Draw these to scale recalling that R~p so the radius value is the magnitude of the
momentum vectors of p + and π + . Add these two vectors to get the resultant, which will be
the initial p of Λ ο . (Recall the idea of conservation!) Show your work below.
p +
π -
Λ o
Λ o
p +
Λ o
π -
Momentum Angle x mag(cos Θ) y mag(sin Θ)
.325 10 o
.315 .056
.214 -352 o
.212 -.030
.528 GeV/c .527 .026
174
π -
p +