What is the unit of a value returned by myjet.pt()? Is it GeV? And do we need to check if particles satisfy
‘VeryLoose’ likelihood identification criteria
(for electrons)
I also assume that transverse impact parameter can be ignored as not mentioned in your post.
Edit: OK, transverse impact criteria is only for signal particles, not baseline ones, is that correct?
A transverse momentum is always expressed in GeV... for particle physicists. The trick is that in our system of units, the Planck constant equals 1, and the speed of light equals 1. With this in mind, everything is much simpler :)
For the 'loose' stuff, please ignore it. Electrons can sometimes be confused with jets, as I said in the post. Therefore, you impose different identification criteria to determine whether an electron-like object is really a electron or is in fact a jet. There are many of these things we cannot handle with public tools. So that we make approximations. For now, just ignore it. In the next post, I will start addressing the part we can cope with.
Exactly! For anything :)
I was wondering whether everything was fine or if you had any more questions relatively to the exercise?
Yes, sure, I'm just a bit short on time lately.
No problem! I will wait for you (I was just wondering since I didn't receive any news ;) )
I'm having a little trouble interpreting the 4th column matching criterion. Specifically, the term
in the denominator.
I'm pretty confident that the first term is just the momentum of the lepton being compared, but what screws me up is the division by GeV. Is this just to remove units?
In particle physics, the system of unit is the following
Under these conditions, a momentum is expressed in energy units. GeV is one of those (and very appropriate for LHC physics). The fraction pT / GeV means that the numerical value to be used for the pT has to be given in GeV units. By default, madanalysis 5 returns the pT in GeV.
In short: you can ignore the GeV. I just leads to a dimensionless quantity (an angular distance is dimensionless). Does it clarify?
Definitely clarifies. We do similar dimension removal for a bunch of fluid dynamics stuff, but I'm not used to the convention of putting the units into the equation like that. Glad to see my intuition was good.
A goods choice of units is always healthy to make our lives easier :)
I can't help but feel that 'unis' is a bit of a Freudian slip.
Although it's not dimensionless, my favorite is how we civil engineers often refer to pressure in units of 'head'. Literally, the height of a water column per unit area. (Analogous in concept to mm Hg) A very handy unit when you're concerned with lifting fluids/making sure they flow well after friction losses.
The typo is fixed :D
What is the atmospheric pressure in terms of heads? 10 or something?