We report results of a new technique to measure the electric dipole moment of Xe129 with He3 comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred to a ...measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result from a one week measurement campaign in 2017 and a 2.5 week campaign in 2018, combined with detailed study of systematic effects, is dA(Xe129)=(1.4±6.6stat±2.0syst)×10-28 e cm. This corresponds to an upper limit of |dA(Xe129)|<1.4×10-27 e cm (95% C.L.), a factor of 5 more sensitive than the limit set in 2001.
The investigation focused on the separation, through selective dissolution, of polyamide 66 (PA 66) from mixtures with cellulose fibers with calcium chloride‐ethanol‐water (CEW). The dissolved PA 66 ...was reprecipitated by addition of water. Analysis of the cellulose after separation revealed no change in mechanical strength, suggesting the polymer was undamaged by the treatment. There were residues of the polyamide retained on the cellulose, but a substantial proportion could be removed by carding. About 80–90% of the PA 66 originally present in the mixtures was recovered. Effective removal of calcium residues from the recovered PA 66 is found to be critical, as calcium contents of greater than ca. 0.8 wt% in the polymer is observed to change the melt behavior. These investigations are being conducted in the broad context of fiber‐to‐fiber recycling from textiles, and will be followed up by investigations on the impact and fate of colorants present in the fibers.
Permanent electric dipole moments (EDMs) arise due to the breaking of time-reversal or, equivalently, CP-symmetry. Although EDM searches have so far only set upper limits, which are many orders of ...magnitude larger than Standard Model (SM) predictions, the motivation for more sensitive searches is stronger than ever. A new effort at FRM-II incorporating
129
Xe and
3
He as a co-magnetometer can potentially improve the current limit. The noble gas mixture of
129
Xe and
3
He is simultanously polarized by spin-exchange optical pumping and then transferred into a high-performance magnetically shielded room. Inside, both species can freely precess in the presence of applied magnetic and electric fields. The precession signals are detected by LTc SQUID sensors. In EDM cells with silicon electrodes we observed spin lifetimes in excess of 2500 s without and with high-voltage applied. This meets one requirement to achieve our goal of improving the EDM limit on
129
Xe by several orders of magnitude.
We present a new measurement of the positive muon magnetic anomaly, $a$$μ$≡($g$$μ$-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 ...times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution $\tilde {ω}$'p, and of the anomalous precession frequency corrected for beam dynamics effects, $ω$$a$. From the ratio $ω$$a$/$\tilde {ω}$'$p$, together with precisely determined external parameters, we determine $a$$μ$ = 116592057(25)×10-11 (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain aμ(FNAL)=116592055(24)×10-11 (0.20 ppm). The new experimental world average is $a$$μ$(Exp)=116592059(22)×10-11 (0.19 ppm), which represents a factor of 2 improvement in precision.
We report results of a new technique to measure the electric dipole moment of 129Xe with 3He comagnetometry. In this work, both species are polarized using spin-exchange optical pumping, transferred ...to a measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result from a one week measurement campaign in 2017 and a 2.5 week campaign in 2018, combined with detailed study of systematic effects, is dA(129Xe) = 1.4 ± 6.6stat ± 2.0syst) × 10–28 e cm. This corresponds to an upper limit of |dA(129Xe)| < 1.4 × 10–27 e cm (95% C.L.), a factor of 5 more sensitive than the limit set in 2001.
We report results of a new technique to measure the electric dipole moment of Xe129 with He3 comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred to a ...measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result from a one week measurement campaign in 2017 and a 2.5 week campaign in 2018, combined with detailed study of systematic effects, is dA(Xe129)=(1.4±6.6stat±2.0syst)×10−28 e cm. This corresponds to an upper limit of |dA(Xe129)|<1.4×10−27 e cm (95% C.L.), a factor of 5 more sensitive than the limit set in 2001.
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