Tagging and suppression of pile-up jets in the forward region using timing information with the ATLAS detector at √s = 14 TeV at HL-LHC

The High-Luminosity LHC (HL-LHC) will operate at an instantaneous luminosity of up to 7.5 × 1034 cm−2 s−1, corresponding to an unprecedented average number of proton-proton collisions per bunch crossing of up to 200. Efficient techniques to identify and suppress jets originating from pile-up interactions are critical to achieve the physics potential of the HL-LHC. At the HL-LHC, the jet-vertex taggers, employed successfully in Run 1 and Run 2, will be also applicable in the high 𝜂 region, due to the extended coverage of the new Inner Tracker. However, the performance in the forward region is expected to be worse compared to that in the central region, due to the higher amount of material and the harsher environment. Timing information provided at the HL-LHC by the High Granularity Timing Detector in the forward region, in combination with tracking information, can be used to efficiently improve performance and offers the possibility for new techniques for event-wise selections.