Antiprotons are another matter
Theories of gravity abound, whereas experiments in gravity are few in number. An important experiment in gravity that has not been performed is the measurement of the gravitational acceleration of antimatter. Although there have been attempts to infer these properties from those of normal matter, none of these theoretical arguments are compelling. Modern theories of gravity that attempt to unify gravity with the other forces of nature predict that in principle antimatter can fall differently than normal matter in the Earth's field. Some of these supergravity theories predict that antimatter will fall faster, and that normal matter will fall with a small Baryon-number dependance in the earth's field. All of these predictions violate the Weak Equivalence Principle, a cornerstone of General Relativity, but are consistent with CPT conservation. In our approved experiment at LEAR (PS-200) we will test the Weak Equivalence Principle for antimatter by measuring the gravitational acceleration of the antiproton. Through a series of deceleration stages, antiprotons from LEAR will be lowered in energy to approx.4 Kelvin at which energy the gravitational effect will be measureable. The measurement will employ the time-of-flight technique wherein the antiprotons are released vertically in a drift tube. The spectrum of time-of-flight measurements can be used to extract the gravitational acceleration experienced by the particles. The system will be calibrated using H/sup -/ ions which simulates the electromagnetic behavior of the antiproton, yet is a baryon to approx.0.1%. To extract the gravitational acceleration of the antiproton relative to the H/sup -/ ion with a statistical precision of 1% will require the release of approx.10/sup 6/ to 10/sup 7/ particles.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6232315
- Report Number(s):
- LA-UR-87-2386; CONF-8706176-2; ON: DE87013159
- Resource Relation:
- Journal Volume: T22; Conference: Workshop and symposium on the physics of low energy, stored, and trapped particles, Stockholm, Sweden, 14 Jun 1987; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
ANTIPROTONS
GRAVITATIONAL INTERACTIONS
ANALYTICAL SOLUTION
BOLTZMANN STATISTICS
CALIBRATION
EQUIVALENCE PRINCIPLE
GENERAL RELATIVITY THEORY
HYDROGEN IONS 1 MINUS
SUPERGRAVITY
TESTING
TIME-OF-FLIGHT METHOD
ANIONS
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
BARYONS
BASIC INTERACTIONS
CHARGED PARTICLES
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
HADRONS
HYDROGEN IONS
INTERACTIONS
IONS
NUCLEI
NUCLEONS
UNIFIED-FIELD THEORIES
657003* - Theoretical & Mathematical Physics- Relativity & Gravitation