Search For Isolated Fractionally Charged Particles

Isolated Fractionally Charged Matter


"I have discarded one uncertain and unduplicated observation apparently on a singly charged drop, which gave a value of the charge on the drop some 30 percent lower than the final value of e."

Robert A. Millikan
Philos. Mag. 110, 209(1910)


Why search for fractionally charged free particles?

The scientific and engineering payoff if fractionally charged particles are found is very high.

  • Discovery or lack of discovery constrains theory
  • Stable fractionally charged particles may be technologically useful


The main evidence against the existence of isolated fractionally charged matter is that it has never been observed in a repeatable experiment.

  • Quark confinement is not based upon fundamental theory but was invented to explain the lack of observation of free fractional charge
  • Observations of fractional charge have been made
  • None of the experiments were repeatable


Possible origin of isolated fractionally charge particles in bulk matter
  1. Creation of free fractionally charged particles in the Big Bang

  2. Attachment of these particles to normal atoms

  3. Condensing of these atoms with bound fractionally charged particles with the material of protostellar nebula to form planets and stars

This is analogous to the process of how rare heavy elements formed in supernova are mixed with the more common light elements.

Searching for isolated fractionally charged particles


Search in bulk matter

  • Big Bang was the ultimate high energy event, much higher energy than accelerators
  • Fractionally charged particles are stable


Search taking account altered electronegativities caused by fractional charge

  • Fractionally charged atoms are chemically unique
  • Exact chemistry is uncertain
  • Best materials are substances that have not undergone complex chemistry that can unpredictably segregate out atoms with attached fractional charges
  • Carbonaceous chondritic meteoric material and moon dust may be good candidates


Search using a high mass throughput technique

  • Past failures to consistently detect fractional charge could have been due to inadequate throughput


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April 30, 2007
Stanford Linear Accelerator Center
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