Periodic Reporting for period 2 - BoostDiscovery (Boosting the discovery using τs in the ATLAS detector at the Large Hadron Collider)
Berichtszeitraum: 2022-07-01 bis 2023-12-31
Almost ten years into the highly successful program both in ATLAS and CMS, our understanding of the Standard Model (SM) of particle physics has deepened. Nonetheless, what lies beyond the SM remains one of the most urgent questions of physics in the 21st century. To move forward, one must think outside of the box and leap into uncharted waters. Searches today are aiming at the high-energy frontier, while low-mass resonances are mostly overlooked by the Large Hadron Collider (LHC). Consequently, far-reaching hints of new physics may silently hide in the data. Motivated by numerous New Physics (NP) scenarios that often predict light states, such as extended Higgs sectors, axion physics, or dark sector models, among others, the PI will develop new techniques to search for low-mass resonances decaying into two collimated low-pT hadronic τ leptons. τs, being the heaviest, third-generation leptons, provide a unique experimental op- portunity to search for low-lying states that would otherwise go undetected. In particular, novel methods to identify boosted hadronic τ+τ− pairs will be established. These techniques will then be used to pave a new path towards discovery of low-mass resonances produced through various production modes. As part of this proposal, the PI will also develop new trigger-level capabilities to further extend the reach of this program at Run-3. As a former leader of the ATLAS Beyond the Standard Model physics group, and current leader of low-mass resonance searches, the PI is ideally positioned to establish a strong research team and take this project to completion, laying the groundwork for the discovery of new physics beyond the SM.
The program, BoostDiscovery, is expected not only to shed light on one of the biggest open questions in physics, but also to introduce novel techniques for boosted τ+τ− as well as for triggers in collider physics. This new methodology will then be used to have better precision measurements involved τs and to renovate other objects’ triggers.
The program, BoostDiscovery, is expected not only to shed light on one of the biggest open questions in physics, but also to introduce novel techniques for boosted τ+τ− as well as for triggers in collider physics. This new methodology will then be used to have better precision measurements involved τs and to renovate other objects’ triggers.
Offline boosted ditaus:
1. Run2: tagger algorithm is final, validation using ATLAS run2 data is under Editorial Board approval (paper has been written and will be circulated soon).
2. Run3: ATLAS study has been started and dedicated Monte-Carlo samples are being prepared.
Trigger:
1. Boosted ditaus - the new boosted DiTau L1 and HLT triggers have been fully validated in terms of rate and cost and have been officially approved by the ATLAS Trigger Expert.
2. single tau phase 1 - BDT algorithm has been approved and under HW final validations (will be working for the next data year).
3. single tau phase 2 - different NNs have been tried both at the SW and the HW levels. More studies are still needed.
4. Single tau POC paper have been uploaded to the arxiv: Comparing machine learning models for tau triggers (2306.06743).
Analyses:
1. ttX analysis - aiming for unblinding soon - under Editorial Board review).
2. H->xx->yytautau - analysis strategy is final and Editorial Board will form in the next month.
3. The group has joined the Run2 search for resonance decaying to ditau with mass around 95GeV (due to the CMS peak).
1. Run2: tagger algorithm is final, validation using ATLAS run2 data is under Editorial Board approval (paper has been written and will be circulated soon).
2. Run3: ATLAS study has been started and dedicated Monte-Carlo samples are being prepared.
Trigger:
1. Boosted ditaus - the new boosted DiTau L1 and HLT triggers have been fully validated in terms of rate and cost and have been officially approved by the ATLAS Trigger Expert.
2. single tau phase 1 - BDT algorithm has been approved and under HW final validations (will be working for the next data year).
3. single tau phase 2 - different NNs have been tried both at the SW and the HW levels. More studies are still needed.
4. Single tau POC paper have been uploaded to the arxiv: Comparing machine learning models for tau triggers (2306.06743).
Analyses:
1. ttX analysis - aiming for unblinding soon - under Editorial Board review).
2. H->xx->yytautau - analysis strategy is final and Editorial Board will form in the next month.
3. The group has joined the Run2 search for resonance decaying to ditau with mass around 95GeV (due to the CMS peak).
New techniques have been studied both for complicated trigger signatures as well as for the challenging low pt hadronic boosted ditaus.
Discovering new physics will rely heavily on those advanced algorithms.
Discovering new physics will rely heavily on those advanced algorithms.