Search for massive long-lived particles decaying semileptonically in the LHCb detector

TL;DR

This paper reports a search for long-lived particles decaying into a muon and two quarks using LHCb data, setting upper limits on production cross-sections across various models and parameter spaces.

Contribution

It introduces a novel search strategy for long-lived particles decaying semileptonically at LHCb, covering a broad mass and lifetime range, and interprets results within supersymmetric models.

Findings

No significant excess observed above background.

Upper limits set on production cross-sections.

Results constrain parameter space of supersymmetric models.

Abstract

A search is presented for massive long-lived particles decaying into a muon and two quarks. The dataset consists of proton-proton interactions at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 1 and 2 1/fb, respectively. The analysis is performed assuming a set of production mechanisms with simple topologies, including the production of a Higgs-like particle decaying into two long-lived particles. The mass range from 20 to 80 GeV and lifetimes from 5 to 100 ps are explored. Results are also interpreted in terms of neutralino production in different supersymmetric models, with masses in the 23-198 GeV range. No excess above the background expectation is observed and upper limits are set on the production cross-section for various points in the parameter space of theoretical models.