Signal versus background interference in $$ {H}^{+}\to t\overline{b} $$ signals for MSSM benchmark scenarios

In this paper, we investigate sizeable interference effects between a heavy charged Higgs boson signal produced dominantly via $$ gg\to t\overline{b}{H}^{-} $$ gg → t b ¯ H − (+ c.c.) followed by the decay $$ {H}^{-}\to b\overline{t} $$ H − → b t ¯ (+ c.c.) and the irreducible background given by $$ pp\to t\overline{t}b\overline{b} $$ pp → t t ¯ b b ¯ topologies at the Large Hadron Collider (LHC). We show that it may be possible that such effects could spoil current H± searches where signal and background are normally treated separately. The reason for this is that a heavy charged Higgs boson can have a large total width, in turn enabling such interferences, altogether leading to potentially very significant alterations, both at the inclusive and exclusive level, of the yield induced by the signal alone. This therefore implies that currently established LHC searches for such wide charged Higgs bosons might require modifications. We show such effects quantitatively using two different benchmark configurations of the minimal realisation of Supersymmetry, wherein such H± states naturally exist. However, on the basis of the limited computing resources available, we are unable to always bring the statistical error down to a level where all such interference effects are unequivocal, so that we advocate dedicated experimental analyses to confirm this with higher statistics data samples.