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The Angular Momenta Dipole Moments and Gyromagnetic Ratios of the Electron and the Proton  [PDF]
A. Georgiou
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.514125
Abstract:

We had previously obtained analytical formulae for the dipole moments and angular momenta of rotating spherical bodies. The resulting formulae were applied to the Sun, the star 78 Virginis and the Earth. The agreement of the theoretical formulae with the actual real situations is indeed remarkable. In this note we apply the same formulae to the electron and the proton, using the classical values of the radii, so no quantum mechanical treatment is considered.

Gyromagnetic Ratios of Bound Particles  [PDF]
Michael I. Eides,Howard Grotch
Physics , 1997, DOI: 10.1006/aphy.1997.5725
Abstract: A new approach to calculation of the binding corrections to the magnetic moments of the constituents in a loosely bound system, based on the Bargmann-Michel-Telegdi equation, is suggested. Binding corrections are calculated in this framework, and the results confirm earlier calculations performed by other methods. Our method clearly demonstrates independence of the binding corrections on the magnitude of the spin of the constituents.
Precision Measurement of the Electron/Muon Gyromagnetic Factors  [PDF]
A. M. Awobode
Physics , 2010,
Abstract: Clear, persuasive arguments are brought forward to motivate the need for highly precise measurements of the electron/muon orbital g, i.e. gL. First, we briefly review results obtained using an extended Dirac equation, which conclusively showed that, as a consequence of quantum relativistic corrections arising from the time-dependence of the rest-energy, the electron gyromagnetic factors are corrected. It is next demonstrated, using the data of Kusch & Foley on the measurement of deltaS minus 2 deltaL together with the modern precise measurements of the electron deltaS where deltaS identically equal to gS minus 2, that deltaL may be a small, non-zero quantity, where we have assumed Russel-Saunders LS coupling and proposed, along with Kusch and Foley, that gS = 2 plus deltaS and gS = 1 plus deltaL. Therefore, there is probable evidence from experimental data that gS is not exactly equal to 1; the expectation that quantum effects will significantly modify the classical value of the orbital g is therefore reasonable. Finally, we show that if, as suggested by the results obtained from the modified Dirac theory, deltaS and deltaL depend linearly on a dimensionless parameter DELTA such that the gyromagnetic factors are considered corrected as follows; gS = 2 plus 2 DELTA and gL = 1 minus DELTA, then the Kusch-Foley data implies that the correction DELTA approximately equals 1.0 times 10-3 . Modern, high precision measurements of the electron and muon orbital gL are therefore required, in order to properly determine by experiments the true value of gL minus 1, perhaps to about one part in a trillion as was recently done for gS minus 2.
New Experiments to Measure the Muon Anomalous Gyromagnetic Moment  [PDF]
M. Eads
Physics , 2015,
Abstract: The magnetic moment is a fundamental property of particles. The measurement of these magnetic moments and the comparison with the values predicted by the standard model of particle physics is a way to test our understanding of the fundamental building blocks of our world. In some cases, such as for the electron, this comparison has resulted in confirmation of the standard model with incredible precision. In contrast, the magnetic moment of the muon has shown a long-standing disagreement in the measured and the predicted value. There is currently a tantalizing three-standard-deviation difference between the current best measurement (with a precision of 0.54 ppm) and the state-of-the-art standard model prediction. This represents one of the very few experimental hints for physics beyond the standard model. There are currently two major experimental efforts underway to improve the precision of the muon magnetic moment measurement. The first is an evolution of the E-821 experiment, originally located at Brookhaven National Laboratory in the United States. This is experiment, E-989, is located at Fermilab and will measure the spin precession rate of positive muons in a 14-m diameter storage ring using decay positrons. The goal of the experiment is to reduce the current experimental uncertainty by a factor of three. The experiment is currently being constructed and aims to start taking data in 2017. An alternative, and very complementary, experiment is being planned at J-PARC in Japan. This experiment, E-34, will utilize low energy, ultra-cold muons in a much smaller storage ring. This experiment aims for a similar precision to the Fermilab experiment and aims to begin data taking on a similar timescale.
Simultaneous pi/2 rotation of two spin species of different gyromagnetic ratios  [PDF]
Ping-Han Chu,Jen-Chieh Peng
Physics , 2015, DOI: 10.1016/j.nima.2015.05.062
Abstract: We examine the characteristics of the pi/2 pulse for simultaneously rotating two spin species of different gyromagnetic ratios with the same sign. For a pi/2 pulse using a rotating magnetic field, we derive the equation relating the frequency and strength of the pulse to the gyromagnetic ratios of the two particles and the strength of the constant holding field. For a pi/2 pulse using a linear oscillatory magnetic field, we obtain the solutions numerically, and compare them with the solutions for the rotating pi/2 pulse. Application of this analysis to the specific case of rotating neutrons and 3He atoms simultaneously with a pi/2 pulse, proposed for a neutron electric dipole moment experiment, is also presented.
Five Dimensional Rotating Black Hole in a Uniform Magnetic Field. The Gyromagnetic Ratio  [PDF]
A. N. Aliev,Valeri P. Frolov
Physics , 2004, DOI: 10.1103/PhysRevD.69.084022
Abstract: In four dimensional general relativity, the fact that a Killing vector in a vacuum spacetime serves as a vector potential for a test Maxwell field provides one with an elegant way of describing the behaviour of electromagnetic fields near a rotating Kerr black hole immersed in a uniform magnetic field. We use a similar approach to examine the case of a five dimensional rotating black hole placed in a uniform magnetic field of configuration with bi-azimuthal symmetry, that is aligned with the angular momenta of the Myers-Perry spacetime. Assuming that the black hole may also possess a small electric charge we construct the 5-vector potential of the electromagnetic field in the Myers-Perry metric using its three commuting Killing vector fields. We show that, like its four dimensional counterparts, the five dimensional Myers-Perry black hole rotating in a uniform magnetic field produces an inductive potential difference between the event horizon and an infinitely distant surface. This potential difference is determined by a superposition of two independent Coulomb fields consistent with the two angular momenta of the black hole and two nonvanishing components of the magnetic field. We also show that a weakly charged rotating black hole in five dimensions possesses two independent magnetic dipole moments specified in terms of its electric charge, mass, and angular momentum parameters. We prove that a five dimensional weakly charged Myers-Perry black hole must have the value of the gyromagnetic ratio g=3.
Muon ID- Taking Care of Lower Momenta Muons  [PDF]
C. Milstene,G. Fisk,A. Para
Physics , 2006,
Abstract: In the Muon package under study, the tracks are extrapolated using an algorithm which accounts for the magnetic field and the ionization (dE/dx). We improved the calculation of the field dependent term to increase the muon detection efficiency at lower momenta using a Runge-Kutta method. The muon identification and hadron separation in b-bbar jets is reported with the improved software. In the same framework, the utilization of the Kalman filter is introduced. The principle of the Kalman filter is described in some detail with the propagation matrix, with the Runge-Kutta term included, and the effect on low momenta single muons particles is described.
Universality of Leading Relativistic Corrections to Bound State Gyromagnetic Ratios  [PDF]
Michael I. Eides,Timothy J. S. Martin
Physics , 2010, DOI: 10.1139/P10-074
Abstract: We discuss the leading relativistic (nonrecoil and recoil) corrections to bound state $g$-factors of particles with arbitrary spin. These corrections are universal for any spin and depend only on the free particle gyromagnetic ratios. We explain the physical reasons behind this universality.
Lepton Dipole Moments  [PDF]
B. Lee Roberts
Physics , 2003, DOI: 10.1063/1.1664193
Abstract: From the famous experiments of Stern and Gerlach to the present, measurements of magnetic dipole moments, and searches for electric dipole moments of ``elementary'' particles have played a major role in our understanding of sub-atomic physics. In this talk I discuss the progress on measurements and theory of the magnetic dipole moments of the electron and muon. I also discuss a new proposal to search for a permanent electric dipole moment (EDM) of the muon and put it into the more general context of other EDM searches.
Black rings with a small electric charge: gyromagnetic ratios and algebraic alignment  [PDF]
Marcello Ortaggio,Vojtech Pravda
Physics , 2006, DOI: 10.1088/1126-6708/2006/12/054
Abstract: We study electromagnetic test fields in the background of vacuum black rings using Killing vectors as vector potentials. We consider both spacetimes with a rotating S^1 and with a rotating S^2 and we demonstrate, in particular, that the gyromagnetic ratio of slightly charged black rings takes the value g=3 (this will in fact apply to a wider class of spacetimes). We also observe that a S^2-rotating black ring immersed in an external "aligned" magnetic field completely expels the magnetic flux in the extremal limit. Finally, we discuss the mutual alignment of principal null directions of the Maxwell 2-form and of the Weyl tensor, and the algebraic type of exact charged black rings. In contrast to spherical black holes, charged rings display new distinctive features and provide us with an explicit example of algebraically general (type G) spacetimes in higher dimensions. Appendix A contains some global results on black rings with a rotating 2-sphere. Appendix C shows that g=D-2 in any D>=4 dimensions for test electromagnetic fields generated by a time translation.
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