Heavy Higgsino Dark Matter With Low Reheating in View of the LZ High-Recoil Event

We show that a heavy higgsino $\tilde{h}$ with mass $m_{\tilde{h}}\sim 0.1\mathrm{P}\mathrm{e}\mathrm{V}$, which can be made consistent with the recent LUX-ZEPLIN event avoiding constraints from direct and indirect detection, can account for the present cold dark matter abundance of the universe, if the reheating temperature is bounded as $T_{\mathrm{r}\mathrm{h}}\lesssim 595\mathrm{G}\mathrm{e}\mathrm{V}$. These values can be achieved by a possible out-of-equilibrium decay of a modulus $\phi$ with mass $m_{\phi }\gg m_{\tilde{h}}$ and a non-vanishing branching ratio into $\tilde{h}$’s which plays a decisive role in reducing $T_{\mathrm{r}\mathrm{h}}$ below its upper limit via the non-thermal $\tilde{h}$ production. The modulus $\phi$ can be identified with the scalar component of the goldstino superfield which is involved in the generation of the $\mu$ parameter of MSSM (with $\mu \simeq m_{\tilde{h}}$) via the Giudice-Masiero mechanism.