What's jet multiplicity?

That's a basic thing, but, surprisingly, it is very difficult to find concise explanation of:

• What is the definition of jet multiplicity?
• Why is it interesting?
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well, it's the number of jets in whatever you're counting (probably in an event). it's interesting because in hadron collisions we have lots of jets and knowing the number of them is important. Maybe you're interested in how to deduce the number of jets in an event, starting from the hard process (CKKW and MLM matching might be keywords) – luksen Sep 29 '11 at 11:01
To understand why jet multiplicity is interesting you have to understand what jets are in this context and how they form...are you good to go on that? From the experimenters point of view the jet multiplicity often chosen as part of event selection (as in we consider only events with two leptons, two jets and missing transverse momentum...). – dmckee Sep 29 '11 at 14:15