Bound on Lorentz- and CPT-Violating Boost Effects for the Neutron

New limit on Lorentz and CPT-violating neutron spin interactions

We performed a search for neutron spin coupling to a Lorentz and CPT-violating background field using a magnetometer with overlapping ensembles of K and $^3$He atoms. The co-magnetometer is mounted on a rotary platform for frequent reversal of its orientation. We measure sidereal oscillations in the signal to search for anomalous spin coupling of extra-solar origin. We determine the equatorial components of the background field interacting with the neutron spin to be $\widetilde{b}^n_X = (0.1 \pm 1.6) \times 10^{-33}$ GeV and $\widetilde{b}^n_Y = (2.5 \pm 1.6) \times 10^{-33}$ GeV, improving o…

Limit on Lorentz-Invariance- and CPT-Violating Neutron Spin Interactions Using a $^3$He-$^{129}$Xe Comagnetometer

We performed a search for a Lorentz-invariance- and CPT-violating coupling of the $^3$He and $^{129}$Xe nuclear spins to posited background fields. Our experimental approach is to measure the free precession of nuclear spin polarized $^3$He and $^{129}$Xe atoms using SQUID detectors. As the laboratory reference frame rotates with respect to distant stars, we look for a sidereal modulation of the Larmor frequencies of the co-located spin samples. As a result we obtain an upper limit on the equatorial component of the background field $\tilde{b}^n_{\bot}< 8.4 \cdot 10^{-34}$ GeV (68\% C.L.). Fur…

Constraint from Lamb Shift and Anomalous Magnetic Moment on Radiatively Induced Lorentz and CPT Violation in Quantum Electrodynamics

We investigate the precisely measured anomalous magnetic moment and Lamb shift as tests for the possible existence of the radiatively induced Lorentz and CPT violation effects in quantum electrodynamics. To this end we calculate the one-loop vacuum polarization tensor and vertex radiative correction in dimensional reduction and on-shell renormalization scheme. We explicitly show how the Lorentz and CPT violation sector affects the anomalous magnetic moment and Lamb shift. Remarkably, we find infrared divergences coming from Lorentz and CPT violating term that do not cancel in physical cross se…

洛伦兹和CPT破坏与氢和反氢分子离子II——超精细塞曼谱

Lorentz and CPT violation and the hydrogen and antihydrogen molecular ions II -- hyperfine-Zeeman spectrum

通过研究氢分子离子和反氢分子离子的超精细塞曼谱，探讨洛伦兹和CPT破坏在质子部分的高灵敏度检测，结合旋轨耦合效应分析。

New limit on Lorentz and CPT violating neutron spin interactions using a free precession 3He-129Xe co-magnetometer

We report on the search for a CPT and Lorentz invariance violating coupling of the 3He and 129Xe nuclear spins (each largely determined by a valence neutron) to background tensor fields which permeate the universe. Our experimental approach is to measure the free precession of nuclear spin polarized 3He and 129Xe atoms in a homogeneous magnetic guiding field of about 400 nT using LTC SQUIDs as low-noise magnetic flux detectors. As the laboratory reference frame rotates with respect to distant stars, we look for a sidereal modulation of the Larmor frequencies of the co-located spin samples. As …