LLP2025: Fifteenth workshop of the Long-Lived Particle Community

Session

Theory and pheno V

5 Jun 2025, 11:40

València - ADEIT

Conveners

Theory and pheno V

• Lisa Benato (Austrian Academy of Sciences (AT))
• José Francisco Zurita (IFIC - Univ. of Valencia and CSIC (ES))

14. Placing Bounds on New Physics with Displaced Photons

Dr Joel Jones-Perez

05/06/2025, 11:40

If a neutral long-lived particle decays predominantly into photons and another stable particle, its presence can be reconstructed at the LHC in the form of displaced photons. These are recognized as such in terms of their delayed arrival time $t_\gamma$ and a non-pointing parameter $\Delta z_\gamma$.

In this work we present a detailed recast of a search for displaced photons in ATLAS, and...

16. Long-lived particles in a scotogenic-like model

Giovanna Cottin (Pontificia Universidad Católica de Chile (CL))

05/06/2025, 12:00

Neutrino masses and dark matter (DM) might have a common origin. The scotogenic model can be considered the proto-type model realizing this idea, but many other variants exist. In this talk, I will comment on long-lived particles predicted in a scotogenic-like scenario, containing a triplet scalar. We calculate the relic density and check for constraints from direct detection experiments. The...

12. Using BDTs as Surrogate Models for BSM searches in ATLAS

Abdelhamid Haddad (Laboratoire de Physique de Clermont-Auvergne (LPCA))

05/06/2025, 12:20

In this talk, I will present a novel approach for the reinterpretation of LHC searches for long-lived particles (LLPs) using Boosted Decision Trees (BDTs). This method allows us to estimate the likelihood that events from a new physics model would have been selected in a prior analysis, based solely on truth-level information. I will discuss the development and validation of method, including...

24. Probing exotic long-lived particles from the prompt side using the CONTUR method

Bruna Pascual (Université Clermont Auvergne (FR))

05/06/2025, 12:40

A method to derive constraints on new physics models featuring exotic long-lived particles using detector-corrected measurements of prompt states is presented. The CONTUR workflow is modified to either account for the fraction of long-lived particles which decay early enough to be reconstructed as prompt, or to be sensitive to the recoil of such particles against a prompt system. This makes it...