Charged Higgs Decay to Bottom and Charm Quarks from $Z_3$-Flavored Two Higgs Doublet Models

Abstract

The phenomenology of a charged Higgs present in a model with two Higgs SU(2) doublets and a $Z_3$ flavor symmetry is analyzed. It is shown that it is possible to generate an enhancement of its flavor changing coupling to c and b quarks and also to reproduce the ATLAS excess associated to the process $H^\pm \to bc$ for a charge Higgs mass of $130$~GeV. Furthermore, by considering the possibility of a search at the future LHeC, the analysis suggests viability for its detection.

Figures (7)

• Figure 1: Left: Values of $V_{ct}$ and $V_{ut}$ for sets of parameters $\vec{s}=(a_{ij},b_{ij})$ that reproduce quark masses values and $V_{CKM}$ entries (other than $V_{ct}$ and $V_{ut}$) for three values of $\tan\beta$. The small rectangular area corresponds to the experimentally allowed values of $V_{ct}$ and $V_{ut}$ where only $125$ sets remain ($25$ for each value of $\tan \beta$). Right: A zoom of the region containing sets consistent with all quark masses and $V_{CKM}$ entries.
• Figure 2: We apply, to the survivor parameter space, one of the strongest experimental limits at low energies $b \to s \gamma$ and $B_0-\overline{B}_0$ mixing. The shaded region is the allowed by both constraints.
• Figure 3: Considering the points that survive in Figure \ref{['fig:BB']}, we now apply the strongest constraints that coming from $b \to s \gamma$ and the electric dipole moment of the neutron. The shaded region is the allowed by both constraints.
• Figure 4: $BR( H^\pm \to c b,cs,\tau \nu)$ for the benchmark points of the model. The effect of the $Z_3$ flavor symmetry on the quark sector can be seen in the enhancement of the channel decay $H^\pm \to c b$, which is dominant with $BR \sim 70 \%$ for $\tan \beta=5$, $10$, $20$. The upper panel shows the THDMZ3 Type-A case while the THDMZ3 Type-B case in shown on the bottom panel.
• Figure 5: $BR(t\to H^\pm b)BR( H^\pm \to c b) \%$ vs. $\tan \beta$, benchmark points of the model are selected. The upper panel shows the THDMZ3 Type-A case while the THDMZ3 Type-B case in shown on the bottom panel. The shaded region is the allowed region for the experimental data of LHC ATLAS:2023bzb.