Doesn't work in ROOT v6.14 environment
After running RunGetter.C with pid_getter.root generated with example input, the following error is showing up
Error in <TFormula::DoEval>: Formula has error and it is not properly initialized
Error in <TFormula::DoEval>: Formula has error and it is not properly initialized
Error in <TFormula::DoEval>: Formula has error and it is not properly initialized
Error in <TFormula::DoEval>: Formula has error and it is not properly initialized
Error in <TFormula::DoEval>: Formula has error and it is not properly initialized
Error in <TFormula::DoEval>: Formula has error and it is not properly initialized
m2 = 0.755427 p = 1.17797 proton probability = nan
m2 = 0.755427 p = 1.17797 kaon probability = nan
m2 = 0.755427 p = 1.17797 pion probability = nan
m2 = 0.755427 p = 1.17797 bg probability = nan
In ROOT 6.12 the problem is not observed.