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I am sorry if my question is completely wrong or foolish I would feel glad to be corrected

On the wiki page for Bhabha Scattering,
it is mentioned that it is used as luminosity monitor in many collision experiments .Can anyone explain how they do it and what is the advantage of higher luminosity in collision experiments, i.e why does it matter?

(My knowledge is limited to very basic QFT.)

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Luminosity is necessary in order to turn number of interactions to crossections, because theories provide crossections to compare with experiments.

luminosity

Experiments measure number of interactions. A well known crossection, as is Bhabha scattering, substituted on the right will give the luminosity to be used in the other observed interactions in the experiment. Of course it works for electron colliders, but the logic of calibration is the same for other colliders too.

From the formula one sees that the higher the luminosity the more number of interactions per unit time. As the statistical error on the values extracted from the data come from the number N, the larger the number the better the accuracy of all measurements.

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  • $\begingroup$ In particular one has to keep in mind that cross sections generally (not hitting a resonance) decrease inverse proportionally with the square of the center of mass energy $s=(p_1+p_2)^2$, i.e. as higher the energy as smaller the cross section. $\endgroup$
    – Frederic Thomas
    Commented Jul 14, 2014 at 14:28
  • $\begingroup$ Let's also say that in terms of the incoming beams of $n$ particles colliding head-on every $T$ time with area $A$, the luminosity is $L=n^2/ AT$. $\endgroup$
    – innisfree
    Commented Jul 14, 2014 at 15:31

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