Updated search for long-lived particles decaying to jet pairs

Area of Science:

• High Energy Physics
• Particle Physics
• Searches for New Physics

Background:

• The Standard Model (SM) of particle physics describes fundamental particles and forces.
• The Higgs boson is a key particle in the SM, responsible for giving mass to other particles.
• Searches for physics beyond the Standard Model often involve looking for exotic particles or phenomena.

Purpose of the Study:

• To search for long-lived particles (LLPs) with specific mass and lifetime ranges.
• To investigate the pair production of LLPs from the decay of a 125 GeV Standard-Model-like Higgs boson.
• To set limits on the production cross-section of these hypothetical LLPs.

Main Methods:

• Analysis of proton-proton collision data collected by the LHCb detector.
• Data collected at center-of-mass energies of 7 and 8 TeV, with an integrated luminosity of 2.0 fb⁻¹.
• Identification of LLPs via displaced vertices with two associated jets, originating from Higgs boson decays.

Main Results:

• No significant excess of events attributable to the signal was observed above the expected background.
• Exclusion limits were placed on the production cross-section of the long-lived particles.
• The limits are presented as a function of the mass and lifetime of the hypothetical LLPs.

Conclusions:

• The search for long-lived particles in this specific mass and lifetime range, produced from Higgs boson decays, yielded no positive signal.
• The results constrain theoretical models that predict such particles.
• Further searches with increased luminosity or different decay signatures may be necessary to probe other regions of the parameter space.