ACT-Consistent B-L Higgs Inflation in Supergravity

Abstract

We consider a renormalizable extension of the minimal supersymmetric standard model (MSSM) endowed by an R and a gauged B - L symmetry. The model incorporates chaotic inflation driven by a quartic potential, associated with the Higgs superfields which lead to a spontaneous breaking of U(1)B-L. Consistency with the ACT data is achieved by considering a fractional shift-symmetric Kaehler potential which includes two free parameters (p,N) constrained in the ranges 1.355<p<6.7 and 6x10^-5<N<0.7. An explanation of the mu term of the MSSM is also provided, under the condition that a related parameter in the superpotential is somewhat small. Baryogenesis occurs via non-thermal leptogenesis which is also realized by the inflaton's decay to the lightest and/or next-to-lightest right-handed neutrinos for normal ordered light neutrino masses.

Figures (3)

• Figure 1: (a) Canonically normalized inflaton $\widehat{\phi}$ as a function of $\phi$ for $N=1$ and $p=5$ (solid line) or $p=2$ (dashed line); (b) inflationary potential $V_{\rm pHI}$ for $(p,N)=(1,2)$ as a function of $\phi$ (black line) and $\widehat{\phi}$ (gray line). Values corresponding to $\phi_\star$, $\phi_{\rm f}$, $\widehat{\phi}_\star$ and $\widehat{\phi}_{\rm f}$ are also depicted in both panels.
• Figure 2: (a) Allowed curves in the $n_{\rm s}-r$ plane with the $N$ values indicated along them -- the marginalized joint $68\%$ [$95\%$] region from P-ACT-LB-BK18 data is depicted by the dark [light] shaded contour; (b) Allowed (shaded) region as determined by Eq. (3.17) -- (3.20) in the $p-N$ plane. The conventions adopted for the various lines are also shown in both panels.
• Figure 3: Contours in the $N-m_{\rm 3D}$ plane yielding the central $Y_B$ in Eq. (4.14) consistently with the remaining inflationary and post-inflationary requirements for $m_{3/2}=10\mu=50~{\hbox{\rm TeV}}$, $N_{\rm st}=1$ and the values of $m_{i\nu}$, $m_{\rm 1D}$, $m_{\rm 2D}$, $\varphi_1$ and $\varphi_2$ which correspond to benchmarks A (solid line), B (dashed line) and C (dot-dashed line) shown in the Table.