LLP2025: Fifteenth workshop of the Long-Lived Particle Community

Session

Theory and pheno IV

4 Jun 2025, 09:30

València - ADEIT

Conveners

Theory and pheno IV

• Chandan Hati
• Jan Hajer (CFTP, IST, Universidade de Lisboa)

19. Long-lived Light Mediators in a Higgs Portal Model at the FCC-ee and FCC-hh

Rhitaja Sengupta (BCTP and Physikalisches Institut der Universität Bonn, Germany)

04/06/2025, 09:30

In the search for beyond the Standard Model (SM) physics, long-lived particles (LLPs) have emerged as potential candidates and are being explored in various ongoing experiments. Future lepton colliders, such as the FCC-ee, shall provide an excellent opportunity to probe LLPs, owing to their clean environment and improved particle identification. This study investigates the potential of the...

25. Long-Lived Particle Searches at a Future Higgs Factory with the ILD experiment

Jan Franciszek Klamka (University of Warsaw (PL))

04/06/2025, 09:50

Future e$^+$e$^-$ colliders provide a unique opportunity for long-lived particle (LLP) searches. We present a full simulation study of LLP searches using the International Large Detector (ILD), a detector concept for a future Higgs factory, with a gaseous time projection chamber as its main tracking device. Signatures of displaced vertices and kinked tracks are explored. We study challenging...

5. Heavy Neutral Leptons without prejudice

Dr Kuldeep Deka (New York University Abu Dhabi)

04/06/2025, 10:10

We analyze prominent signatures in Higgs physics at colliders (LHC and FCC-ee) that arise when the Standard Model (SM) is extended by a Yukawa interaction with heavy neutral leptons (HNLs). This setup assumes no direct mapping between the Yukawa coupling and mixing with active neutrinos. At the LHC, we investigate HNL production through Higgs bosons, followed by decays through Higgs or gauge...

42. The LOHENGRIN Experiment: Status and Theory Predictions

Martin Schürmann

04/06/2025, 10:30

We present a proposal for a future light dark matter search experiment at the Electron Stretcher Accelerator ELSA in Bonn: LOHENGRIN.
It employs the fixed-target missing momentum based technique to search for long-lived dark-sector particles.
The LOHENGRIN experiment uses a high rate single electron beam of 3.2 GeV that is extracted from the ELSA accelerator and shot onto a thin target to...

66. Improved Mass Bounds on HECOs via Dyson-Schwinger Resummation Technique

Emanuela Musumeci (IFIC - Univ. of Valencia and CSIC (ES))

04/06/2025, 10:50

High-Electric-Charge compact Objects (HECOs) arise in various extensions of the Standard Model and are actively investigated at the LHC. Existing experimental searches constrain their masses by relying on tree-level predictions from Drell-Yan and photon-fusion production mechanisms. However, these conventional approaches lose validity due to the breakdown of perturbative QED at the high...