Construction of a kinematic variable sensitive to the mass of the Standard Model Higgs boson in H -> WW* -> l(+)nu l(-)(nu)over-bar using symbolic regression

Abstract

We construct a kinematic variable that is sensitive to the mass of the Standard Model Higgs boson (M-H) in the H -> WW* -> l(+)nu l(-)(nu) over bar channel using symbolic regression method. Explicit mass reconstruction is not possible in this channel due to the presence of two neutrinos that escape detection. Mass determination problem is that of finding a mass-sensitive function that depends on the measured observables. We use symbolic regression, which is a symbolic approach to the problem of non-linear regression, to derive an analytic formula sensitive to M-H from the two lepton momenta and the missing transverse momentum. Using the newly-derived mass-sensitive variable, we expect Higgs mass resolutions between 1 to 4 GeV for M-H between 130 and 190 GeV at the LHC with 10 fb(-1) of data. This is the first time symbolic regression method has been applied to a particle physics problem.