Periodic Reporting for period 2 - Beauty2Charm (Precision tests of the Standard Model using Beauty to Charm decays)
Reporting period: 2022-03-01 to 2023-08-31
In order to shed light on the matter-antimatter asymmetries of the universe, the Beauty2Charm project studies particles called B mesons as they decay into Charm mesons. The project develops a new kind of data processing at the LHCb experiment at the LHC, called Real-Time Analysis in order to make extremely precise measurements with these decays. With Real-Time Analysis the data collected by the LHCb experiment is processed, categorised and studied to find the Beauty to Charm signals of interest for this proposal before being saved to permanent storage, reducing the amount of data that must be kept and saving the need for costly additional data reprocessing. The objectives of the project are to deliver Real-Time solutions for the LHCb experiment Upgrade, and exploit the data that these solutions produce to make precise measurements of Beauty to Charm decays which will inform our understanding of the ways in which matter and antimatter behave differently to each other.
Since the beginning of the project, the real-time analysis framework has been successfully delivered for the LHCb Upgrade. The main results achieved by Beauty2Charm so far are:
- The Beauty2Charm team have contributed to the implementation of 'flavour tagging', the way in which LHCb determines whether a particle is a B or anti-B meson, in the real-time framework. The results of flavor tagging can be seen in the included figure, in which particles tagged as Bs0 mesons are shown in blue, particles tagged as anti-Bs0 mesons are shown in red, and particles that did not receive a flavour tag are shown in grey.
- The project has developed a simulation of the real-time framework in order to determine the optimal allocation of processing hardware used by the real-time analysis software, the exploitation of which resulted in the LHCb collaboration deploying Graphics Processing Units in the earliest stages of the real-time data processing pipeline. This has been published in a peer-reviewed journal, disseminated in a press release in the CERN courier and on social media, as well as at several international conferences.
- The PI and team have contributed to several analyses of Beauty to Charm decays at LHCb, including the most precise measurement of the frequency at which beauty-strange mesons oscillate between their matter and antimatter counterparts. This has been published in a peer-reviewed journal, disseminated in a press release by the LHCb experiment, and presented at several international conferences. The included figure from this publication shows these incredibly precise oscillations and how the matter peaks in blue correspond to an antimatter trough in red.
- A member of the team has coauthored a peer-reviewed phenomenology paper on future sensitivity to anomalies in Beauty2Charm decays, the outcome of which has been disseminated on social media.
- The Beauty2Charm team have contributed to the implementation of 'flavour tagging', the way in which LHCb determines whether a particle is a B or anti-B meson, in the real-time framework. The results of flavor tagging can be seen in the included figure, in which particles tagged as Bs0 mesons are shown in blue, particles tagged as anti-Bs0 mesons are shown in red, and particles that did not receive a flavour tag are shown in grey.
- The project has developed a simulation of the real-time framework in order to determine the optimal allocation of processing hardware used by the real-time analysis software, the exploitation of which resulted in the LHCb collaboration deploying Graphics Processing Units in the earliest stages of the real-time data processing pipeline. This has been published in a peer-reviewed journal, disseminated in a press release in the CERN courier and on social media, as well as at several international conferences.
- The PI and team have contributed to several analyses of Beauty to Charm decays at LHCb, including the most precise measurement of the frequency at which beauty-strange mesons oscillate between their matter and antimatter counterparts. This has been published in a peer-reviewed journal, disseminated in a press release by the LHCb experiment, and presented at several international conferences. The included figure from this publication shows these incredibly precise oscillations and how the matter peaks in blue correspond to an antimatter trough in red.
- A member of the team has coauthored a peer-reviewed phenomenology paper on future sensitivity to anomalies in Beauty2Charm decays, the outcome of which has been disseminated on social media.
Progress beyond the state of the art delivered by the Beauty2Charm project includes the discovery that GPUs are a cost- and energy- competitive solution to the high throughput computing needs of high energy physics trigger and reconstruction algorithms. Further results until the end of the project include a second phenomenology paper describing the new state-of-the-art in Beauty2Charm decays, additional measurements of Beauty2Charm decays with data from the upgraded and original LHCb experiments, and further publications on the performance of the Real-Time Analysis framework adopted by the LHCb experiment.