Exclusive doubly charged Higgs boson pair production in $pp$ collisions at the LHC

The type II seesaw model predicts the existence of a doubly charged Higgs boson ($H^{\pm \pm }$), which can be produced through the Drell-Yan process and photon-induced interactions at hadronic colliders. In recent years, such reactions have been largely investigated in inclusive processes, where both incident protons breakup and a large number of particles is produced in addition to the doubly charged Higgs pair. In this paper, we investigate, for the first time, the possibility of searching for $H^{\pm \pm }$ in exclusive processes, which are characterized by two rapidity gaps and two intact very forward protons in final state. We estimate the associated cross section making use of the exclusive nature of the final state, together with the use of timing information provided by forward proton detectors. Moreover, the background is estimated considering distinct amounts of pileup. Our results indicate that the exclusive doubly charged Higgs pair production is a promising way to search for signatures of the type II seesaw mechanism and to obtain lower mass bounds on $H^{\pm \pm }$.

Figure 1

Diagram for the exclusive doubly charged Higgs pair production in $pp$ collisions at the LHC.

Figure 2

Predictions for the invariant mass distribution of the four lepton system (upper left panel), transverse momentum (upper right panel) and rapidity (lower panel) distributions of the $e^{+}{e}^{+}$ pair at the generation level considering $m(H^{\pm \pm })=350\mathrm{GeV}$ and $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$. DY* indicates that the double tagging (DT) and TOF suppression factors have been applied to the inclusive DY predictions.

Figure 3

Mass dependence of the statistical significance for the exclusive doubly charge Higgs production in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$ considering two scenarios for the pileup configuration and integrated luminosity $(⟨\mu ⟩,L)$ and to distinct scenarios for the background: (a) the standard approach considering the inclusive DY production as a background (left panel), and (b) that the remaining contribution of the inclusive process enhance the number of doubly charged Higgs events (right panel). Results for the Higgs triplet model ($Y=1$). The vertical black line indicates the current upper value for $m(H^{\pm \pm })=1080\mathrm{GeV}$ obtained in Ref. [27].

Figure 4

Mass dependence of the statistical significance for the exclusive doubly charge Higgs production in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$ considering distinct $SU(2{)}_L$ representations and different scenarios for the pileup configuration and integrated luminosity $(⟨\mu ⟩,L)$.