Dark Matter Search Results from 1.54 Tonne·Year Exposure of PandaX-4T.

In this Letter, we report the dark matter search results from the commissioning run (Run0) and the first science run (Run1) of the PandaX-4T experiment. The two datasets were processed with a unified procedure, with the Run1 data treated blindly. The data processing is improved compared to previous work, unifying the low-level signal reconstruction in a wide energy range up to 120 keV. With a total exposure of 1.54 tonne·year, no significant excess of nuclear recoil events is found. The lowest 90% confidence level exclusion on the spin-independent cross section is 1.6×10^{-47} cm^{2} at a dark matter mass of 40 GeV/c^{2}. Our results represent the most stringent constraint for a dark matter mass above 100 GeV/c^{2}.