Hi everyone,
I have a question that maybe is stupid, but I’m a beginner, so have pity!
I have some data: for each event I have four particles, and for each particle I have their values of pt, eta, phi and m.
For each particles I collected that values in a TLorentzVector (for example i call it “elec1”) in such ways that:
elec1[0]=pt
elec1[1]=eta
elec1[2]=phi
elec1[3]=m
That’s the question:
What can I do if I want to calculate the invariant mass of two of these four-vectors (for example elec1 and elec2)?
If I try using something like this:
TLorentzVector sum;
float m;
sum=elec1+elec2;
m=sum.M();
I obtain something that haven’t any physic meaning.
That’s probably because I have to use four-momentum of each particle instead of four vector like elec. But I can’t found a way to trasform a vector in a system of variables like elec in the corresponding four momentum of the same particle, thus in the system EPxPyPz.
Can you help me?
Thank you!