"Hadron-in-fat-jet'' AI Tagging to Detect Rare Decays Such as W±→π±γ
Abstract
We investigate a novel class of boosted-object signatures at the LHC, where a high-pT fat-jet contains an identifiable hadron or quarkonium state originating from rare or semi-exclusive decays. Unlike conventional boosted jet studies, which focus on multi-prong partonic substructure, our approach probes hybrid configurations such as W±→π±γ, where a localized hadronic or quarkonium signal is embedded within a collimated jet. By fine-tuning the signature-oriented, pre-trained Sophon AI model optimized for large-radius jets, and combining it with an event-level BDT and a soft-drop-mass shape fit, we obtain an expected 95\% CL upper limit of cal B(W±→π±γ)<2.78×10−5 for 450 fb−1 in our nominal setup. This study serves as a first proof-of-principle demonstration of the ``hadron-in-fat-jet'' paradigm; substantial gains in sensitivity are expected from improved trigger strategies, additional production channels, and dedicated taggers, while the methodology itself is broadly applicable to a wide range of rare Standard Model processes and searches for light or exotic resonances at present and future collider experiments.
Versions
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BibTeX
@misc{chen2026hadroninfatjet,
title = {{"Hadron-in-fat-jet'' AI Tagging to Detect Rare Decays Such as $W^\pm\toπ^\pmγ$}},
author = {Linrui Chen and Tianyi Yang and Zixun Kou and Zijian Wang and Youpeng Wu and Leyun Gao and Qiang Li},
howpublished = {arXiv},
year = {2026},
month = jun,
doi = {10.48550/arxiv.2606.09458},
eprint = {2606.09458},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.09458},
}
RIS
TY - UNPB
TI - "Hadron-in-fat-jet'' AI Tagging to Detect Rare Decays Such as W^±→π^±γ
AU - Linrui Chen
AU - Tianyi Yang
AU - Zixun Kou
AU - Zijian Wang
AU - Youpeng Wu
AU - Leyun Gao
AU - Qiang Li
PY - 2026
DA - 2026/06/08
PB - arXiv
DO - 10.48550/arxiv.2606.09458
UR - https://arxiv.org/abs/2606.09458
AB - We investigate a novel class of boosted-object signatures at the LHC, where a high-p_T fat-jet contains an identifiable hadron or quarkonium state originating from rare or semi-exclusive decays. Unlike conventional boosted jet studies, which focus on multi-prong partonic substructure, our approach probes hybrid configurations such as W^±→π^±γ, where a localized hadronic or quarkonium signal is embedded within a collimated jet. By fine-tuning the signature-oriented, pre-trained Sophon AI model optimized for large-radius jets, and combining it with an event-level BDT and a soft-drop-mass shape fit, we obtain an expected 95\% CL upper limit of cal B(W^±→π^±γ)<2.78×10^−5 for 450 fb^−1 in our nominal setup. This study serves as a first proof-of-principle demonstration of the ``hadron-in-fat-jet'' paradigm; substantial gains in sensitivity are expected from improved trigger strategies, additional production channels, and dedicated taggers, while the methodology itself is broadly applicable to a wide range of rare Standard Model processes and searches for light or exotic resonances at present and future collider experiments.
ER -