339 research outputs found

    Nuclear spin-dependent interactions: Searches for WIMP, Axion and Topological Defect Dark Matter, and Tests of Fundamental Symmetries

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    We calculate the proton and neutron spin contributions for nuclei using semi-empirical methods, as well as a novel hybrid \emph{ab initio}/semi-empirical method, for interpretation of experimental data. We demonstrate that core-polarisation corrections to \emph{ab initio} nuclear shell model calculations generally reduce discrepancies in proton and neutron spin expectation values from different calculations. We derive constraints on the spin-dependent P,T-violating interaction of a bound proton with nucleons, which for certain ranges of exchanged pseudoscalar boson masses improve on the most stringent laboratory limits by several orders of magnitude. We derive a limit on the CPT and Lorentz-invariance-violating parameter ∣b~βŠ₯p∣<7.6Γ—10βˆ’33|\tilde{b}_{\perp}^p| < 7.6 \times 10^{-33} GeV, which improves on the most stringent existing limit by a factor of 8, and demonstrate sensitivities to the parameters d~βŠ₯p\tilde{d}_{\perp}^p and g~DβŠ₯p\tilde{g}_{ D\perp}^p at the level ∼10βˆ’29βˆ’10βˆ’28\sim 10^{-29} - 10^{-28} GeV, which is a one order of magnitude improvement compared to the corresponding existing sensitivities. We extend previous analysis of nuclear anapole moment data for Cs to obtain new limits on several other CPT and Lorentz-invariance-violating parameters: ∣b0p∣<7Γ—10βˆ’8\left|b_0^p \right| < 7 \times 10^{-8} GeV, ∣d00p∣<8Γ—10βˆ’8\left|d_{00}^p \right| < 8 \times 10^{-8}, ∣b0n∣<3Γ—10βˆ’7\left|b_0^n \right| < 3 \times 10^{-7} GeV and ∣d00n∣<3Γ—10βˆ’7\left|d_{00}^n \right| < 3 \times 10^{-7}.Comment: 8 pages. The present work is a significantly extended and improved version of our previous work, and contains many new result
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