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This study explores the nuclear matrix elements for tensor interactions that violate local Lorentz invariance. The authors investigate the energy of the first 2+ state in deformed nuclei, the spatial and momentum distributions, and the properties of neutrino mass. The search for CPT-even Lorentz violations with nuclear spin is discussed, along with the bounds on the neutron coefficient. The results are relevant for understanding fundamental symmetries and the structure of heavy nuclei.
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Nuclear Matrix Elements for Tensor Interactions that Violate Local Lorentz Invariance Alex Brown (Michigan State University) Vladimir Zelevinsky (Michigan State University) Michael Romalis (Princeton) George Bertsch (University of Washington) Luis Robledo (Universidad Autonoma de Madrid) Phys. Rev. Lett. 119, 192504 (2017).
Energy of first 2+ state (MeV) Shell Model 21Ne, deformed nuclei I >1/2
Spatial distribution Momentum distribution
Typical situation Measured quantity = (basic fundamental symmetry quantity) x (well known constants and phase space) x (calculated nuclear matrix element)
n = light neutrino N = heavy neutrino neutrino mass properties nuclear matrix elements phase space - contains the weak axial vector coupling factor (gA)4
Search for CPT-even Lorentz violation with nuclear spin • Need nuclei with orbital angular momentum and total spin >1/2 • Quadrupole energy shift proportional to the kinetic energy of the valence nucleon • Previosly has been searched for in two experiments using 201Hg and 21Ne with sensitivity of about 0.5 mHz • Bounds on neutron cn~10-27– already most stringent bound on c coefficient! Suppressed by vEarth
For the region of 21Ne (the sd-shell) the 3d harmonic oscillator is a good starting point (90%) N = 4 N = 3 N = 2 (sd) N = 1 (p filled) N = 0 (s filled)
For the region of 21Ne (the sd-shell) the 3d harmonic oscillator is a good starting point (90%) N = 4 N = 3 N = 2 (sd) N = 1 (p filled) N = 0 (s filled)
Typical situation Measured quantity = (basic fundamental symmetry quantity) x (well known constants and phase space) x (calculated nuclear matrix element) M = 0?