PARITY CONSERVATION IN STRONG INTERACTIONS: THE $sup 7$Be(n, $alpha$$)$$sup 4$He REACTION

Journal Article · Sat Feb 01 00:00:00 EST 1958 · Phil. Mag.

DOI:https://doi.org/10.1080/14786435808244406· OSTI ID:4343824

Segal, R E; Kane, J V; Wilkinson, D H

The abundance of evidence for lack of conservation of parity in weak interactions ralses the question as to whether parity is conserved in strong interactions. The spin of the Be/sup 7/ nucleus is 3/2 and the parity odd. Since the centrifugal barrier inhibits thermal neutron interactions with orbital angular momentum greater than zero, the parity of the initial system formed by the absorption of a thermal neutron must be odd. The symmetry and parity operators are identical for identical, spinless partioles and so a Be/sup 8/ state of odd parity cannot break up into two alpha particles if purity is conserved. The Q value of the Be/sup 7/(n, gamma )He/sup 4/ reaction (from the known masses) is 18.98 Mev. The disintegration of Be/sup 7/ by slow neutrons into two 9.5 Mev alpha particles was therefore sought as an indication of violation of Parity conservation. An upper limit of 25 mb was set for the (n, alpha ) cross section. An upper limit of 1 x 10/sup -7/ is also set for the square of the amplitude of the parity non-conserving component of the wave function. The results are not sensitive to whether the parity nonconserving forces conserve isotopic spin. (A.C.)

• Research Organization: Aeronautical Research Lab., WADC; Brookhaven National Lab., Upton, N.Y.; Clarendon Lab., Oxford
• Sponsoring Organization: USDOE
• NSA Number: NSA-12-008113
• OSTI ID: 4343824
• Journal Information: Phil. Mag., Vol. Vol: (8) 3; Other Information: Orig. Receipt Date: 31-DEC-58
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

PHYSICS
ABSORPTION
ALPHA PARTICLES
ANGULAR MOMENTUM
BERYLLIUM 7
BERYLLIUM 8
CAPTURE
CROSS SECTIONS
ENERGY
FISSION
FUELS
HELIUM 4
INTERACTIONS
ISOSPIN
LOSSES
MASS
MOMENTUM
NEUTRON BEAMS
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
OPERATION
PARITY
PARTICLE MODELS
POWER PLANTS
Q-VALUE
REACTOR CORE
REACTORS
SPIN
SYMMETRY
THERMAL NEUTRONS
URANIUM 235
WATER COOLANT
WAVE MECHANICS