I agree there’s some unit missing… This article link about a Japanese collider comes close to defining it as the number of collisions on a surface per second. It would have direct correlation to beam density and the more collisions in a target area the more statistically likely it is that something interesting will happen !

From your link – “The new record measured a level of luminosity of 467,000 billion billion billion—467 followed by 30 zeros—per square centimetre per second”.

The units in question are collisions/cm^2/sec.

Still not enough information.

So there’s apparently a very narrow beam that if it were as wide as1 cm^2 would result in 4.67×10^32 PHOTON collisions with anything placed in it’s path? How does that compare with something I am familiar with, like sunshine?

I must apologise, my previous answer was grossly incorrect.

Luminosity, in this sense, appears to be a measure of beam intensity. “Luminosity gives a measure of how many collisions are happening in a particle accelerator: the higher the luminosity, the more particles are likely to collide.” (Source). That means, as far as I can tell, that the units given are correct. A beam of X luminosity is equivalent to a beam in which X number of particles pass through 1cm^2/sec. This serves to increase the probability of collisions, due to a greater density of particles.

@FireMadeFlesh that sounds like a correct definition but I’d still agree with @6rant6 that it could make more sense to put particles/cm2*sec or collisions/cm2*sec. Or are those ‘units’ close but not really correct either?

@dabbler This is really going beyond my knowledge now, and I’m sure they have a good reason for expressing it in that way. Maybe there is a weighting factor applied depending on the types of particles involved as well, since a proton beam wouldn’t really be comparable to a neutron beam or an electron beam etc. Also on that scale, each particle appears as a wave function, so you cannot say it is in a particular location. Therefore you cannot say X number of particles are within a certain space when the given space is so small, because no particle is definitely within that space.

I’ll do some more reading and see if I can find a better answer. This question is really bending my mind!