The next generation of collider experiments prioritized by the European particle physics roadmap will study the Higgs and Electro-Weak physics with an unprecedented precision. One of the options to reach a superior precision on the di-jet issued from the Boson's decays is the use of Particle Flow methods and optimized detectors, especially highly-granular calorimeters.

Recently, the potential of having a precision timing in those calorimeters was realized : event cleaning, particle identification by time-of-flight, but also an easier tracking of particle contributions in the calorimeters, one of the key input to Particle Flow methods.
The T-Calo ANR contract aims precisely at this goal over the next 4 years.

It proposed to evaluate the full potential and limits of a timing measurement of particle showers and jets, on detailed simulations.

The full span of evaluation will be covered: shower reconstruction, separation and matching, jet reconstruction and physical performances. This will define the implication on the hardware development, and the design of the experiments.

- Basics understanding of timing in showers, using realistic MC GEANT4 & GARFIELD simulations
- Development of innovative technique to use the timing in algorithms to make them simpler, more robust, and more performant. This will extend in in-shower particle ID.
- Establishing the performance gain for multiple physics cases at low and high energy, and more specifically on Higgs physics.
- Leading the effort toward a report on the expected performances near Higgs factory.

The work will be done in the ee-collider group at LLR, École polytechnique, starting in March 2024, and in close relation with senior physicist at the origin of the Particle Flow concepts, electronics engineers, colleagues and PhD from the T-Calo team of IP2I (Lyon).

The work is also very likely to benefit to the CMS upgrade, especially the HGCAL, with a strong team at LLR, and other future facilities (EIC).