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G. E. Mitchell North Carolina State University. Parity Violation in the Compound Nucleus. SYMMETRY BREAKING, RMT AND NUCLEI. USE NUCLEUS AS TEST LABORATORY FOR RMT PREDICTIONS ASSUME RMT TO INTERPRET NUCLEAR PHENOMENA ISOSPIN SYMMETRY BREAKING EFFECT ON LEVEL STATISTICS - PowerPoint PPT Presentation
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Parity Violation in the Compound Nucleus
G. E. Mitchell
North Carolina State University
SYMMETRY BREAKING, RMT AND NUCLEI
• USE NUCLEUS AS TEST LABORATORY FOR RMT PREDICTIONS
• ASSUME RMT TO INTERPRET NUCLEAR PHENOMENA
• ISOSPIN SYMMETRY BREAKING
EFFECT ON LEVEL STATISTICS
EFFECT ON TRANSITIONS • PARITY VIOLATION
ENHANCEMENT IN COMPOUND NUCLEUS
FOLLOWINGWU-AMBLER, GARWIN-LEDERMAN
MANY STUDIES OF PARITY VIOLATION IN STRONG INTERACTION PROCESSES
CONFLICTING RESULTS (MAINLY RUSSIAN) IN NEUTRON-INDUCED REACTIONS LOOKING AT GAMMA RAYS
FINNALY AT ILL VERY LARGE NEUTRON SPIN ROTATION
CONFUSIONEXTREME EXAMPLE
RESORT TO FIFTH FORCEEXPLANATION
SUSHKOV-FLAMBAUM
OBSERVATION OF LARGE PARITY VIOLATION IN NEUTRON RESONANCES IN 139LA FRANK LABORATORY, DUBNA
THEN WE STARTED TRIPLE COLLABORATION
p-wave level s-wave levels many levels contribute PNC asymmetry)
x neutron decay amplitude
Ex resonance energies
V matrix element of PNC interaction between levels and
n
n
n
n EEA
(
(
)/() 2/1
VAp
One measured variable p
many matrix elements V
A known
Assume V independent Gaussian
Random variables with mean zero and variance Mj2
Mj2 is the weak interaction mean squared matrix element
p is sum of variables V with constant coefficients
Therefore p is Gaussian random variable with variance Mj
2A2
Determine Mj2 from experimental data
22 AA
SIGN CORRELATIONEXPLANATIONS
AUERBACHDESPLANQUES
FLAMBAUMHAYES
KERMANKOONIN
WEIDENMUELLERET AL.
NO SUCH EFFECT IN ALL OTHER MEASUREMENTS FOR 15 NUCLEI
EXTENDED MEASUREMENTS TO HIGHER ENERGIES
OBSERVED OPPOSITE SIGN FOR PV
BEST GUESS
LOCAL DOORWAY
CONSISTENT WITH KERMAN’S VIEW
GENERAL OVERVIEW
G.E.MITCHELL AND H.A. WEIDENMUELLER
REV.MOD.PHYS. 71,445 (1999)
ALL THE DETAILSG.E.MITCHELL, J.D.BOWMAN,
S.I.PENTTILA, E.I.SHARAPOVPHYS. REPORTS 354, 157 (2001)