Right handed neutrinos, TeV scale BSM neutral Higgs boson, and FIMP dark matter in an EFT framework

We consider an effective field theory framework with three Standard Model (SM) gauge singlet right-handed neutrinos, and an additional SM gauge singlet scalar field. The framework successfully generates eV masses of light neutrinos via the seesaw mechanism, and accommodates a feebly interacting massive particle (FIMP) as a dark matter candidate. Two of the gauge singlet neutrinos participate in neutrino mass generation, while the third gauge singlet neutrino is a FIMP dark matter. We explore the correlation between the vev (vacuum expectation value) of the gauge singlet scalar field which translates as mass of the BSM Higgs, and the mass of dark matter, which arises due to the relic density constraint. We furthermore explore the constraints from the light neutrino masses in this setup. We chose the gauge singlet BSM Higgs in this framework in the TeV scale. We perform a detailed collider analysis to explore the discovery prospect of the TeV scale BSM Higgs through its difatjet signature, at a future $pp$ collider which can operate with $\sqrt{s}=100\mathrm{TeV}$ c.m. energy.

Figure 1

This plot represents constraints on $M_{N_3}$ and $v_{\chi }$ for Scenario-I. The blue band corresponds to the variation of the relic density from decay in between 0.01 and 0.12, where the latter satisfies the experimental constraint [36]. The green region corresponds to light neutrino mass in between 0.0086 eV to 0.05 eV. The red line corresponds to lifetime of $N_{1,2}$ as 1 second. The orange line correspond to $\mathrm{\Lambda }>10.0v_{\chi }$. Here we assume the mass of the BSM Higgs as $M_{H_2}=250\mathrm{GeV}$.

Figure 2

Left and Right panel: the figures correspond to scenario-IIa for two different Higgs masses $M_{H_2}=250\mathrm{GeV}$ and 1.1 TeV, respectively. The color bar indicates the variation of Dirac Yukawa coupling $y$ with respect to the variation of mass of FIMP DM $M_{N_3}$ and the Yukawa coupling $c_{11}$. The green band indicates variation of $v_{\chi }$ in between 1 TeV to 10 TeV (from left to right). See the text for additional details.

Figure 3

The figure corresponds to Scenario-IIb, and represents the variation of the Yukawa coupling $y$ w.r.t the variation of the DM mass $M_{N_3}$ and the Yukawa coupling $c_{11}$. Contours of $\tau (N_{1,2})=0.001$ (blue) and 0.05 (red) are displayed. The vertical black lines correspond to $v_{\chi }=3\mathrm{TeV}$ (left) and 10 TeV (right).

Figure 4

Similar as the Fig. 1, but for Scenario-II. See text for more details.

Figure 5

Scenario-III: Constraints from the DM relic density (blue band) and eV scale light neutrino mass (green band) in the $M_{N_3}\text{−}{v}_{\chi }$ plane. The values of other free parameters are listed in Table 2. Here we include the decay of $H_{1,2}$ for DM production.

Figure 6

Left (right) panel: $\mathrm{\Omega }{h}^2$ vs the mass of DM for Scenario-III (Scenario-II) with $\sin \theta =0.1$, $\mathrm{\Lambda }={10}^{11}\mathrm{GeV}$, $M_{H_2}=1100\mathrm{GeV}$, $M_{N_{1,2}}=5M_{N_3}$, $M_{N_3}-M_{B_3}={10}^{-8}\mathrm{GeV}$, $v_{\chi }=3\mathrm{TeV}$ (left panel), $M_{B_3}=0$, $v_{\chi }=15\mathrm{TeV}$ (right panel). The green-dashed horizontal line represents $\mathrm{\Omega }{h}^2=0.12$ [36].

Figure 7

Left panel: Relic density vs reheating temperature for Scenario-III. Right panel: variation of relic density vs vev of the singlet scalar for the same scenario. Other parameters kept fixed at $\sin \theta =0.1$, $\mathrm{\Lambda }={10}^{11}\mathrm{GeV}$, $M_{H_2}=1100\mathrm{GeV}$, $M_{N_{1,2}}=5M_{N_3}$, $M_{N_3}-M_{B_3}={10}^{-8}\mathrm{GeV}$ and $v_{\chi }=3000\mathrm{GeV}$. The green dashed horizontal line represents the experimental constraint on DM relic density [36].

Figure 8

Left panel: variation of relic density of $N_3$ in the $c_{33}\text{−}\mathrm{\Lambda }$ plane. Right panel: variation of $T_R$ in the $c_{33}\text{−}{v}_{\chi }$ plane. We consider the same constraint as in the left panel.

Figure 9

Left panel: Variation of relic density of $N_3$ vs $T_R$. Right panel: scatter plot in the $v_{\chi }\text{−}{M}_{H_2}$ plane.

Figure 10

Variation of relic density with respect to variation of $v_{\chi }$ and $T_R$. The points satisfy the mentioned DM relic density range.

Figure 11

Production cross section of $pp\to H_2\to H_1{H}_1$ vs mass of $H_2$ for different values of the Higgs mixing angle.

Figure 12

$H_T$ distribution for signal and background samples.

Figure 13

$p_T$ distribution of leading fatjet $j_1$ (Left panel) and subleading fatjet $j_2$ (right panel). We also show the $p_T$ distributions of the fatjets arising from background samples.

Figure 14

Left panel: invariant mass distribution of the leading fatjet $j_1$. Right panel: the same for the subleading fatjet $j_2$.

Figure 15

Invariant mass distribution of the fatjet pair.