Search for Fractionally Charged Particles in Proton-Proton Collisions at sqrt[s]=13  TeV

Area of Science:

• High Energy Physics
• Particle Physics
• Collider Physics

Background:

• Searches for new physics phenomena at the Large Hadron Collider (LHC) are crucial for understanding fundamental particles.
• Previous searches have explored various charge states, but fractionally charged particles below the electron charge (e) remain largely unconstrained.
• The Drell-Yan production mechanism is a key process for producing new particles in proton-proton collisions.

Purpose of the Study:

• To conduct the first search at the LHC for new particles with fractional electric charges between e/3 and 0.9e.
• To extend previous limits for particles with a charge of 2e/3.
• To establish the most stringent exclusion limits for such particles in a specific production channel.

Main Methods:

• Utilized a dataset of 138 inverse femtobarns of proton-proton collision data collected at a center-of-mass energy of 13 TeV between 2016 and 2018.
• Employed the small energy loss in the tracking detector as a primary observable to identify potential signals of fractionally charged particles.
• Analyzed data from the CERN LHC, focusing on Drell-Yan-like production processes.

Main Results:

• Excluded fractionally charged particles with masses up to 640 GeV at a 95% confidence level.
• Set new exclusion limits for particles with charges as low as e/3.
• Established the most stringent limits to date for Drell-Yan-like production of particles with charges between e/3 and 0.9e.

Conclusions:

• The search successfully constrained the parameter space for fractionally charged particles at the LHC.
• The results demonstrate the sensitivity of LHC experiments to low-charge particle searches.
• This study significantly advances the search for physics beyond the Standard Model.