m of silicon: a Poisson distribution of mean 4. Then for each
interaction, the energy losses are calculated according to [1].
In 90% of all collisions, the energy loss is less than 170eV, and the
mean energy loss for these collisions is 30eV. However in 2% of cases,
it is greater than 1000eV, and in 0.2% of cases, it is greater than 10000eV.
It is these high energy fluctuations which lead to the well known
quasi-Landau distribution for the sum of all energy losses in the silicon.
Since these large fluctuations occur rarely, they cause biases in the
position determination on an event-by-event basis. Over many events, this
leads to a broadening in the resolution.