Usage of Beta and Gamma factor in TLorentzVector

ROOT Version: 6.14
Platform: Ubuntu16.04
Compiler: gcc630

Hi, I am running a code which needs to obtain gamma factor from its TLorentzVector.

At the moment, I fill the TLorentzVector with

TLorentzVector scalar(ip->pt(),ip->eta(),ip->phi(),ip->mass());
where ip is the generated particle in MonteCarlo simulation.

When I try to obtain the beta and gamma factor with
Double_t gamma = scalar.Gamma(); and Double_t beta = scalar.Beta();

gamma is equal to nan and beta seems to give me gamma value since it is always larger than 1, and never less than 1.

Could someone explain what is going on?

Thank you!


TLorentzVector scalar;
scalar.SetPtEtaPhiM(ip->pt(), ip->eta(), ip->phi(), ip->mass());

See also:

1 Like

It works.

Thank you!

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