Discovery prospects for NMSSM Higgs bosons at the high-energy Large Hadron Collider

We investigate the discovery prospects for Higgs bosons in the next-to-mininmal supersymmetric extension of the Standard Model (NMSSM) during the 13 TeV run of the LHC. While one of the neutral Higgs bosons is demanded to have a mass around 125 GeV and Standard Model-like properties, there can be substantially lighter, nearby or heavier Higgs bosons that have not been excluded yet by LEP, Tevatron or the 8 TeV run of the LHC. The challenge consists in discovering the whole NMSSM Higgs mass spectrum. We present the rates for production and subsequent decay of the neutral NMSSM Higgs bosons in the most promising final states and discuss their possible discovery. The prospects for pinning down the Higgs sector of the natural NMSSM will be analyzed taking into account alternative search channels. We give a series of benchmark scenarios compatible with the experimental constraints, that feature Higgs-to-Higgs decays and entail (exotic) signatures with multifermion and/or multiphoton final states. These decay chains furthermore give access to the trilinear Higgs self-couplings. We briefly discuss the possibility of exploiting coupling sum rules in case not all the NMSSM Higgs bosons are discovered.

Figure 1

Parameter distributions in the $\kappa -\lambda$ plane (left) and in the $\tan \beta -\lambda$ plane (right). The SM-like Higgs boson $h$ corresponds to either $H_1$ (red points) or $H_2$ (blue points). Green points correspond to $h\equiv H_1$ and $H_2$ mass values above 1 TeV.

Figure 2

Distribution of $\tan \beta$ (left) and ${\mu }_{\mathrm{eff}}$ (right). Normalized to the total number of parameter points of $\sim 8000$.

Figure 3

Upper: Distribution of $\lambda$ (left) and $\kappa$ values (right). Lower: Distribution of $A_{\lambda }$ (left) and $A_{\kappa }$ values (right). Normalized to the total number of parameter points of $\sim 8000$.

Figure 4

Distribution of $A_t$ (left) and $m_{{\tilde{t}}_1}$ (right), normalized to the total number of parameter points of $\sim 8000$.

Figure 5

Mass values of the non-SM-like $CP$-even Higgs boson $H_i$ ($i=1$ or 2) and the lightest pseudoscalar $A_1$ for all points passing our constraints. Blue (pink) points are for scenarios with $\tan \beta <(>)5$.

Figure 6

The singlet component $|S_{H_i,h_s}{|}^2$ of the non-SM-like $CP$-even Higgs boson $H_i$ (upper left), $|P_{A_1,a_s}{|}^2$ of the lightest pseudoscalar $A_1$ (upper right), $|S_{H_3,h_s}{|}^2$ of the heavy $CP$-even Higgs boson $H_3$ (lower left) and $|P_{A_2,a_s}{|}^2$ of the heavy pseudoscalar $A_2$ (lower right). Blue (pink) points refer to scenarios with $\tan \beta <(>)5$.

Figure 7

Production rates in pb for the non-SM-like $CP$-even Higgs boson $H_i$ ($i=1,2$) into the $\gamma \gamma$ (upper left), the $b\overline{b}$ (upper right), the $ZZ$ (lower left) and $t\overline{t}$ (lower right) final states for $\tan \beta <5$ (blue) and $\tan \beta >5$ (pink), as a function of $M_{H_i}$ at a c.m. energy $\sqrt{s}=13\mathrm{TeV}$. The full black line shows the production rate for a SM Higgs boson with same mass.

Figure 8

Production rates in pb for the lightest $CP$-odd Higgs boson $A_1$ in associated production with $b\overline{b}$ in the $b\overline{b}$ final state (left) and in inclusive production with subsequent decay into $t\overline{t}$ final states (right) $\tan \beta <5$ (blue) and $\tan \beta >5$ (pink), as a function of $M_{A_1}$, at $\sqrt{s}=13\mathrm{TeV}$. The full black line is the production rate for a SM Higgs boson with same mass.

Figure 9

Production rates in pb for the heaviest $CP$-even Higgs boson $H_3$ into the $b\overline{b}$ (upper left), the $t\overline{t}$ (upper right), the $WW$ (lower left) and $ZZ$ (lower right) final states for $\tan \beta <5$ (blue) and $\tan \beta >5$ (pink), as a function of $M_{H_3}$, at $\sqrt{s}=13\mathrm{TeV}$. The full black line is the production rate for a SM Higgs boson with same mass.

Figure 10

The gluon fusion production cross section at $\sqrt{s}=13\mathrm{TeV}$ for $H$ (left) and $A$ (right) as a function of their mass.

Figure 11

The gluon fusion production cross section at $\sqrt{s}=13\mathrm{TeV}$ for $H_s$ (left) and $A_s$ (right) as a function of their mass.

Figure 12

Production rates for $H_s$ (upper) and $A_s$ (lower) production in gluon fusion with subsequent decay into the $\tau \tau$ (left) and $\gamma \gamma$ (right) final states as a function of the involved singlet mass, at $\sqrt{s}=13\mathrm{TeV}$. Red (green) points mark cross sections above (below) 1 fb.

Figure 13

Cross sections for $H_s{H}_s$ production (upper two rows) and $h{H}_s$ production (lower two rows) from $H$ decay, in the $(2\tau )(2b)$ (upper/lower left), $4\tau$ (upper/lower right) and $(2\gamma )(2b)$ (middle) final states at $\sqrt{s}=13\mathrm{TeV}$ as a function of the singlet mass $M_{H_s}$. Red (green) points mark cross sections above (below) 1 fb.

Figure 14

Cross sections for $A_s{H}_s$ production (upper two rows) and $h{A}_s$ production (lower two rows) from $A$ decay, in the $(2\tau )(2b)$ (upper/lower left), $4\tau$ (upper/lower right) and $(2\gamma )(2b)$ (middle) final states at $\sqrt{s}=13\mathrm{TeV}$ as a function of the singlet mass $M_{A_s}$. Red (green) points mark cross sections above (below) 1 fb.

Figure 15

Cross sections for $Z{A}_s$ production from $H$ decay (upper) and for $Z{H}_s$ production from $A$ decay (lower) in the $Z+2b$ (left) and $Z+2\tau$ (right) final state, respectively, as a function of the involved singlet mass, at $\sqrt{s}=13\mathrm{TeV}$. Red (green) points mark cross sections above (below) 1 fb.