CERN’s Large Hadron Collider (LHC) has achieved a new record in integrated luminosity, surpassing initial expectations for its third run. The milestone was reached on Monday, September 2, with the delivery of 88.9 fb⁻¹ to ATLAS and CMS, 7.6 fb⁻¹ to LHCb, and 45.6 fb⁻¹ to ALICE.
The integrated luminosity is a crucial indicator of the collider’s performance, measuring the number of collisions that occur in a given amount of time. The higher the luminosity, the more data experiments can gather to study rare processes.
Although challenges arose in the second year of Run 3 due to faults requiring extended repair periods, this year’s production has exceeded expectations. With six weeks of luminosity production remaining, the 2024 target of 110 fb⁻¹ for ATLAS and CMS is within reach.
The LHC teams have implemented performance enhancements during shutdowns and continuously explored margins to increase luminosity. The total integrated luminosity depends on the duration of the yearly proton run, with an average production of 0.56 fb⁻¹ per day in 2022 and 0.71 fb⁻¹ per day over 47.5 days in 2023.
As of September 2, a total of 88.9 fb⁻¹ has been achieved in 107 days of proton physics, resulting in an average integrated luminosity of 0.83 fb⁻¹ per day. This surpasses the total integrated luminosity of Run 2’s four-year duration.
With 40 more days of proton physics planned before transitioning to lead-ion physics, the LHC has the potential to accumulate an additional 33 fb⁻¹ and exceed the 2024 target by 12 fb⁻¹. However, this will depend on the availability of the LHC and its subsystems, as well as maintaining a stable beam ratio in the coming weeks.
Source: https://phys.org/news/2024-09-lhc-luminosity.html