Real-time transient search in HAWC with improved reconstruction*

The HAWC Observatory is a water Cherenkov observatory located in central Mexico at 4100 m above sea level. HAWC is sensitive to gamma rays with energy from a few hundred GeV to 100s of TeV. HAWC's wide field of view(~ 2 sr), large effective area and near-continuous uptime make it ideal for transient searches. Recently, HAWC's reconstruction algorithm was upgraded from Pass 4 to Pass 5, with a major improvement in sensitivity at energies below 1 TeV due to a novel noise-reduction algorithm called the multi-plane fitter. Here, we introduce the three real-time transient searches currently running in HAWC, including an untriggered GRB search, a triggered GRB/Gravitational-Wave search, and a long duration (~ days) all-sky flare search. The Pass 5 improvement on the sensitivity of real-time transient searches will be shown.