Interference effects in tt production at the LHC as a window on new physics

TY - JOUR

T1 - Interference effects in tt production at the LHC as a window on new physics

AU - Djouadi, Abdelhak

AU - Ellis, John

AU - Popov, Andrey

AU - Quevillon, Jérémie

PY - 2019/3/21

Y1 - 2019/3/21

N2 - Many extensions of the Standard Model (SM) contain (pseudo)scalar bosons with masses in the TeV range. At hadron colliders, such particles would predominantly be produced in gluon fusion and would decay into top quark pair final sates, a signal that interferes with the large QCD background gg→tt. This phenomenon is of interest for searches for by the LHC experiments. Here, we consider the signal and background interference in this process and study it in various benchmark scenarios, including models with extra singlet (pseudo)scalar resonances, two-Higgs doublet models (2HDM), and the minimal supersymmetric extension of the SM with parameters chosen to obtain the measured light Higgs mass (the hMSSM). We allow for the possible exchanges of beyond the SM vector-like particles as well as scalar quarks. We calculate the possible interference effects including realistic estimates of the attainable detection efficiency and mass resolution. Studies of our benchmark scenarios indicate that searches with an LHC detector could permit the observation of the tt final states or constrain significantly large regions of the parameter spaces of the benchmark scenarios.

AB - Many extensions of the Standard Model (SM) contain (pseudo)scalar bosons with masses in the TeV range. At hadron colliders, such particles would predominantly be produced in gluon fusion and would decay into top quark pair final sates, a signal that interferes with the large QCD background gg→tt. This phenomenon is of interest for searches for by the LHC experiments. Here, we consider the signal and background interference in this process and study it in various benchmark scenarios, including models with extra singlet (pseudo)scalar resonances, two-Higgs doublet models (2HDM), and the minimal supersymmetric extension of the SM with parameters chosen to obtain the measured light Higgs mass (the hMSSM). We allow for the possible exchanges of beyond the SM vector-like particles as well as scalar quarks. We calculate the possible interference effects including realistic estimates of the attainable detection efficiency and mass resolution. Studies of our benchmark scenarios indicate that searches with an LHC detector could permit the observation of the tt final states or constrain significantly large regions of the parameter spaces of the benchmark scenarios.

U2 - 10.1007/JHEP03

DO - 10.1007/JHEP03

M3 - Article

SN - 1029-8479

VL - 2019

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

IS - 3

M1 - 119

ER -