A New Search for Elementary Particles with Fractional Electric Charge Using an Improved Millikan Technique

Technical Report · Mon Aug 18 04:00:00 EDT 2003

DOI:https://doi.org/10.2172/815296· OSTI ID:815296

Mar, Nancy ^[1]

---

1. SLAC

The authors have devised and demonstrated the successful operation of a low cost, high mass throughput technique capable of performing bulk matter searches for fractionally charged particles based on an improved Millikan liquid drop method. The method uses a stroboscopic lamp and a CCD video camera to image the trajectories of silicone oil drops falling through air in the presence of a vertical, alternating electric field. The images of the trajectories are computer processed in real time, the electric charge on a drop being measured with an rms error of 0.025 of an electron charge. This error is dominated by Brownian motion. In the first use of this method, they have looked at 5,974,941 drops and found no evidence for fractional charges in 1.07 mg of oil. With 95% confidence, the concentration of isolated quarks with {+-} 1/3e or {+-} 2/3e in silicone oil is less than one per 2.14 x 10{sup 20} nucleons.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (US)
• Sponsoring Organization: USDOE Office of Science (US)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 815296
• Report Number(s): SLAC-R-640
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AIR
CAMERAS
CHARGED PARTICLES
COMPUTERS
ELECTRIC CHARGES
ELECTRIC FIELDS
ELECTRONS
ELEMENTARY PARTICLES
LIGHT BULBS
NUCLEONS
QUARKS
SILICONES
TRAJECTORIES