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Register a new userPreferred-Frame and CP-Violation Tests with Polarized Electrons
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We used a torsion pendulum containing $approx 10^{23}$ polarized electrons to search new interactions that couple to electron spin. We limit CP-violating interactions between the pendulums electrons and unpolarized matter in the earth or the sun, test for rotation and boost-dependent preferred-frame effects using the earths rotation and velocity with respect to the entire cosmos, and search for exotic velocity-dependent potentials between polarized electrons and unpolarized matter in the sun and moon. Finally, we find that the gravitational mass of an electron spinning toward the galactic center differs by less than about 1 part in $10^{21}$ from an electron spinning in the opposite direction. As a byproduct of this work, the density of polarized electrons in Sm$ $Co$_5$ was measured to be $(4.19pm 0.19)times 10^{22} {rm cm}^{-3}$ at a field of 9.6 kG.
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We used a torsion pendulum containing $sim 9 times 10^{22}$ polarized electrons to search for CP-violating interactions between the pendulums electrons and unpolarized matter in the laboratorys surroundings or the sun, and to test for preferred-frame effects that would precess the electrons about a direction fixed in inertial space. We find $|g_{rm P}^e g_{rm S}^N|/(hbar c)< 1.7 times 10^{-36}$ and $|g_{rm A}^e g_{rm V}^N|/(hbar c) < 4.8 times 10^{-56}$ for $lambda > 1$AU. Our preferred-frame constraints, interpreted in the Kostelecky framework, set an upper limit on the parameter $|bm{tilde {b}}^e| leq 5.0 times 10^{-21}$ eV that should be compared to the benchmark value $m_e^2/M_{rm Planck}= 2 times 10^{-17}$ eV.
The status of Lorentz- and CPT-violation searches using measurements of the anomalous magnetic moment of the muon is reviewed. Results from muon g-2 experiments have set the majority of the most stringent limits on Standard- Model Extension Lorentz and CPT violation in the muon sector. These limits are consistent with calculations of the level of Standard-Model Extension effects required to account for the current 3.7{sigma} experiment-theory discrepancy in the muons g-2. The prospects for the new Muon g-2 Experiment at Fermilab to improve upon these searches is presented.
A key question in understanding the structure of nucleons involves the role of sea quarks in their ground state electromagnetic properties such as charge and magnetism. Parity-violating electron scattering, when combined with determination of nucleon electromagnetic form factors from parity-conserving e-N scattering, provides another degree of freedom to separately determine the up, down and strange quark contributions to nucleon electromagnetic structure. Strange quarks are unique in that they are exclusively in the nucleons sea. A program of experiments using parity violating electron scattering has been underway for approximately a decade, and results are beginning to emerge. This paper is a brief overview of the various experiments and their results to date along with a short-term outlook of what can be anticipated from experiments in the next few years.
This lecture contains a brief introduction to CP violation in the B system before discussing future experimental programmes and their CP reach in the B system.
I report some recent results on direct CP violation measurements in hadronic decays collected by the upgraded Collider Detector (CDF II) at the Fermilab Tevatron: CP-violating asymmetries in the two-body non-leptonic charmless decays of $b$-hadrons, the first reconstruction in hadron collisions of the suppressed decays $B^- to D(to K^+pi^-)K^-$ and $B^- to D(to K^+pi^-)pi^-$, and the measurement of TP asymmetries in the $B^{0}_{s} to phi phi$ decays.
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