Laboratoire d'Annecy de Physique des Particules

ERC DITTO


Despite the success of the Standard Model (SM) of particle physics, experimental evidence suggests that it is an incomplete description of the universe, serving only as a low-energy approximation of a more fundamental theory. The search for new phenomena (NP) beyond the SM is a key focus of the Large Hadron Collider (LHC). While no direct evidence of NP has been found, intriguing deviations in beauty hadron decays suggest that NP may interact differently with the three generations of matter. The ERC-funded DITTO project aims to measure the high-mass Drell-Yan (HMDY) process with precision. These measurements will explore NP at energy scales beyond the LHC’s reach, providing crucial insights into the physics beyond the Standard Model.

Link to the project page

Objective

In the Drell-Yan process, a quark of one proton and an antiquark of another proton annihilate, creating a virtual boson which then decays into a pair of oppositely-charged leptons or a lepton and a neutrino. The HMDY differential cross-section measurements of these six processes (ev/μv/τv/ee/µµ and ττ) are performed using proton-proton collision data collected by the ATLAS collaboration at the LHC in 2015-2018 and 2022-2026 (Run 3). Studies of lepton performance and trigger improvements proposed in the DITTO project are important to enhance precision of these measurements with the Run 3 data and for the future HL-LHC data taking, which is expected to start in 2030.

Physicists

  • Rahul Balasubramanian (from 1.05.2024)
  • Nihal Brahimi (from 1.10.2023)
  • Daniel Lewis (from 1.08.2024)
  • Tetiana Hrynova (from 1.10.2023)

PhD Students

  • Maxime Zumbihl (from 1.10.2024)
  • Timoty Duong (from 1.10.2024)
  • Tom Cavaliere (1.10.2022-6.10.2025, CNRS funding)

Interns

  • Maxime Zumbihl (M2, 2024),
  • Timoty Duong (M2, 2024),
  • Ariane Arnaud (2024),
  • Raphael Assoun (M1, 2024),
  • Rayan Meftah Ben Hamida (2025)

Related projects and partner institutes

  • [1] The ATLAS trigger system for LHC Run 3 and trigger performance in 2022, ATLAS Collaboration (JINST 19 (2024) P06029, https://arxiv.org/abs/2401.06630).
  • [2] A measurement of the high-mass tautau production cross-section at centre-of-mass energy of 13 TeV with the ATLAS detector and constraints on new particles and couplings, ATLAS Collaboration, (JHEP 10 (2025) 54, https://arxiv.org/pdf/2503.19836).

Conferences, Schools, Workshops with talks

Seminars, Outreach