磁场及磁矩的测量实验

对地磁水平分量测量实验加以改进,将其扩充为能够测量亥姆霍兹线圈磁场分布和磁针的转动惯量以及磁针磁矩的实验.使其成为一个综合性较强,适用于开展研究性实验的项目.     

Measurement of the gluon polarization in lepton pair production

The process of the lepton pair production in the collisions of unpolarized and longitudinally-polarized protons is considered in the framework of the perturbative QCD. The possibility of using such process for the measurement of the gluon polarization inside the proton is studied     

Core polarization and magnetic moment of some odd-mass nuclei around N = 50

The effect of core polarization on the magnetic moment is studied for odd-mass nuclei around $\text{N = 50:}{}^{\mathrm{85,\; 87}}\text{Kr}\text{,}{}^{\mathrm{87,\; 89}}\text{Sr}\text{,}{}^{91}\text{Zr and}{}^{89}\text{Y}$. The calculation is done in the framework of the modified Tamm-Dancoff approximation (MTDA). The ground-state wave function is calculated using the configuration space of p?f$\text{\$}\text{?}$and ?dg$\text{\$}\text{?}$shells. The core polarization correction to the magnetic moment is considerable for all the nuclei, except ⁸⁹Y, and it depends upon the particular form of the interaction. For ⁸⁹Y the last odd proton is in the $\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ level and the smallness of the correction is supported by the observed value of the magnetic moment.     

Measurement of the nuclear magnetic moment of tritium to nine-digit accuracy

A series of ten pair spectra has been obtained by simultaneously detecting the proton and tritium NMR spectra of the gaseous TH sample, which is an analogue of molecular hydrogen. The numerical processing of the data yields the ratio F(TH)/F(HT) = 1.066 639 8933(7) of the magnetic moments of tritium and proton in the TH molecule. The relative statistical error of this result is 7 × 10⁻¹⁰. To find the nuclear magnetic moment of tritium from F(TH)/F(HT), it is sufficient to use the previously calculated correction factor δ = (1 + 20.4 × 10⁻⁹), which originates from a small asymmetry of the electron cloud of the molecule.     

Measurement of the positive muon anomalous magnetic moment to 0.7 ppm

A higher precision measurement of the anomalous g value, a(mu)=(g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a(mu(+))=11 659 204(7)(5)x10(-10) (0.7 ppm) is in good agreement with previous measurements and has an error about one-half that of the combined previous data. The present world average experimental value is a(mu)(expt)=11 659 203(8)x10(-10) (0.7 ppm).     

Measurement of the negative muon anomalous magnetic moment to 0.7 ppm

The anomalous magnetic moment of the negative muon has been measured to a precision of 0.7 ppm (ppm) at the Brookhaven Alternating Gradient Synchrotron. This result is based on data collected in 2001, and is over an order of magnitude more precise than the previous measurement for the negative muon. The result a(mu(-))=11 659 214(8)(3) x 10(-10) (0.7 ppm), where the first uncertainty is statistical and the second is systematic, is consistent with previous measurements of the anomaly for the positive and the negative muon. The average of the measurements of the muon anomaly is a(mu)(exp)=11 659 208(6) x 10(-10) (0.5 ppm).     

Measurement of the magnetic moment of a negative muon in zinc and cadmium

The magnetic moment (g factor) of a negative muon on the 1s atomic levels of zinc and cadmium was measured with an accuracy higher by a factor of 7 than the accuracy achieved in other measurements. The experimental value of the g factor differs substantially from the theoretical results. Possible causes of this discrepancy are discussed.     

On magnetic moment and magnetic induction

An attempt is made to introduce the concept of magnetic moment and magnetic induction directly from observed mechanical interactions between magnets, without bringing in the idealized notion of isolated magnetic poles.     

Enhanced production of TeV right-handed neutrinos through the large magnetic moment

We examine the effects of magnetic moments of right-handed neutrinos, whose masses are set at around TeV scale, then it is plausible to have a large enhancement for the production cross section of TeV scale right-handed neutrinos though the Drell–Yan process, e⁺e⁻→γ$e^{+}{e}^{-}\to \gamma$, Z^∗→NiNj$Z^{\ast }\to N_i{N}_j$(i≠j)$(i\ne j)$, which is within the reach of the future linear collider (ILC).