TESS Planets in Known Radial-velocity Cold Jupiter Systems: Hot Super-Earth Occurrence is Enhanced by Cold Jupiters

Abstract The correlation between inner super-Earths (SEs) and outer cold Jupiters (CJs) provides an important constraint on the formation and dynamical evolution of planetary systems. Previous studies have suggested a positive connection between these two populations, particularly around metal-rich stars, and proposed that nearly all CJ-hosting stars may also harbor inner SEs. In this work, we use TESS transits to investigate the occurrence of hot SEs (HSEs; 1–4 R ⊕ , P < 10 days) in systems with known CJs detected by radial velocities (RVs). Out of a statistical sample of 132 CJ systems, we identify five transiting HSEs around four stars, including one new candidate (TOI-6965.01) around HD 50554. To enable statistical analysis, we first validate the two candidates around HD 50554 using TESS photometry, archival RV measurements, and Gaia astrometry. After accounting for detection sensitivity and geometric transit probability, we find that the presence of CJs enhances the occurrence rate of HSEs by a factor of 6 . 5 − 2.3 + 3.1 relative to field stars, with the case of no enhancement being ruled out at 99.9% confidence level. Taking into account the average multiplicity of HSEs, we find that about 91% of CJ systems host at least one HSE. Our results provide strong supporting evidence for a positive HSE–CJ correlation. We also briefly explore the correlation around metal-poor hosts and for specific subpopulations (e.g., warm SEs or cold super-Jupiters).