The nuclear magnetic field, Cabibbo angle, and CP violation in the nucleus

1977 ◽  
Vol 55 (6) ◽  
pp. 578-581 ◽  
Author(s):  
H. C. Lee ◽  
F. C. Khanna
Keyword(s):  
Magnetic Field ◽  
Cp Violation ◽  
Coupling Constants ◽  
Cabibbo Angle ◽  
The Magnetic Field ◽  
Nuclear Magnetic

The magnetic field in the nucleus is calculated microscopically. It is deduced that Salam and Strathdee's theory will unlikely provide an explanation for anomalies in the Fermi coupling constants in 35Arand 93Nb. CP violation in the β-decays of n and 19Neis not ruled out.

NUCLEAR MAGNETIC RESONANCE SPECTRUM OF B11 IN KERNITE

1955 ◽  
Vol 33 (5) ◽  
pp. 156-175 ◽  
Author(s):  
H. H. Waterman ◽  
G. M. Volkoff
Keyword(s):  
Magnetic Field ◽  
Coupling Constants ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Radio Frequency Spectrum ◽  
Asymmetry Parameters ◽  
Crystallographic Axes ◽  
The Magnetic Field

The radio-frequency spectrum of B11 in a single crystal of Na2B4O7∙4H2O (kernite) is examined experimentally as the monoclinic crystal is rotated in an external magnetic field of 7060 gauss in turn about each of three axes (b, c crystallographic axes, and a third perpendicular direction) held normal to the magnetic field. A maximum of 21 lines (some of which show small additional splitting) is observed, which reduces to 11 when the b symmetry axis is perpendicular or parallel to the magnetic field. The results are interpreted in terms of four essentially non-equivalent B11 sites in kernite characterized respectively by quadrupole coupling constants [Formula: see text], 0.588 ± 0.003, 2.563 ± 0.007, 2.567 ± 0.010 Mc./sec, and asymmetry parameters 77 [Formula: see text], 0.60 ± 0.02, 0.163 ± 0.010, 0.116 ± 0.010. The orientations of the principal axes of the four [Formula: see text] tensors are also determined. These observations on boron are consistent with previous X-ray results, but preliminary observations on Na23 in kernite contradict previous X-ray position assignments.

Comparative study of helical-cut notch–coil magnets for fast-field-cycling nuclear magnetic resonance

2014 ◽  
Vol 92 (11) ◽  
pp. 1430-1440 ◽  
Author(s):  
S. Kruber ◽  
G.D. Farrher ◽  
E. Anoardo
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnet System ◽  
Fast Switching ◽  
Magnetic Field Homogeneity ◽  
Field Cycling ◽  
Fast Field ◽  
The Magnetic Field ◽  
Nuclear Magnetic

In this manuscript we describe an α-helical-cut notch–coil magnet system designed for fast switching of the magnetic field. An attempt was made to determine the extent to which such a magnet configuration can be efficiently used for fast-field-cycling (FFC) nuclear magnetic resonance (NMR) instruments. In addition to the typical technical requirements (high field-to-power ratio, adequate electric performance for fast-switching of the magnetic field and NMR-compatible magnetic field homogeneity), a tunable homogeneity within the sample volume and more uniform heat dissipation along the magnet body are included. A helical-cut notch–coil machined in metallic cylinders with external movable pieces was found to fit these requirements very well. A key factor for the optimization of the magnet parameters is the use of a novel calculation procedure based on a more realistic model that consider a magnet geometry with broken azimuthal symmetry. The aim of this paper is to theoretically compare the proposed geometry with other existing designs. No particular prototype is presented here. A clear understanding of the notch–coil performance was found to be an essential step for its further consideration as a potential autoadaptive (electronically controlled) magnet system for FFC applications.

TORSION BOUNDS FROM CP VIOLATION α2-DYNAMO IN AXION–PHOTON COSMIC PLASMA

2011 ◽  
Vol 26 (38) ◽  
pp. 2863-2868 ◽  
Author(s):  
L. C. GARCIA DE ANDRADE
Keyword(s):  
Magnetic Field ◽  
Cp Violation ◽  
Maxwell Equations ◽  
Lorentz Violation ◽  
Classical Level ◽  
K Meson ◽  
Field Amplification ◽  
Frequency Peak ◽  
Galactic Dynamos ◽  
The Magnetic Field

Years ago Mohanty and Sarkar [Phys. Lett. B433, 424 (1998)] have placed bounds on torsion mass from K meson physics. In this paper, associating torsion to axions a la Campanelli et al. [Phys. Rev. D72, 123001 (2005)], it is shown that it is possible to place limits on spacetime torsion by considering an efficient α2-dynamo CP violation term. Therefore instead of Kostelecky et al. [Phys. Rev. Lett.100, 111102 (2008)] torsion bounds from Lorentz violation, here torsion bounds are obtained from CP violation through dynamo magnetic field amplification. It is also shown that oscillating photon–axion frequency peak is reduced to 10-7 Hz due to torsion mass (or Planck mass when torsion does not propagate) contribution to the photon–axion–torsion action. Though torsion does not couple to electromagnetic fields at classical level, it does at the quantum level. Recently, Garcia de Andrade [Phys. Lett. B468, 28 (2011)] has shown that the photon sector of Lorentz violation (LV) Lagrangian leads to linear nonstandard Maxwell equations where the magnetic field decays slower giving rise to a seed for galactic dynamos. Torsion constraints of the order of K0≈10-42 GeV can be obtained which are more stringent than the value obtained by Kostelecky et al. A lower bound for the existence of galactic dynamos is obtained for torsion as K0≈10-37 GeV .

scholarly journals Polarization Transfer via Field Sweeping in Parahydrogen-Enhanced Nuclear Magnetic Resonance

2019 ◽  
Author(s):  
James Eills ◽  
John W. Blanchard ◽  
Teng Wu ◽  
Christian Bengs ◽  
Julia Hollenbach ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Maleic Acid ◽  
Hydrogen Gas ◽  
Zero Field ◽  
Field Sweep ◽  
The Magnetic Field ◽  
Proton Singlet ◽  
Nuclear Magnetic

<div><br></div><div><table><tr><td>We show that in a spin system of two magnetically inequivalent protons coupled to a heteronucleus such as 13C, an adiabatic magnetic field sweep, passing through zero field, transfers proton singlet order into magnetization of the coupled heteronucleus. This effect is potentially useful in parahydrogen-enhanced nuclear magnetic resonance, and is demonstrated on singlet-hyperpolarized [1-13C]maleic acid, which is prepared via the reaction between [1-13C]acetylene dicarboxylic acid and para-enriched hydrogen gas. The magnetic field sweeps are of microtesla amplitudes, and have durations on the order of seconds. We show a polarization enhancement by a factor of 10<sup>4</sup> in the 13C spectra of [1-13C]maleic acid in a 1.4 T magnetic field.</td></tr></table></div>

Nuclear magnetic resonance in paramagnetic Mn2P2O7

1969 ◽  
Vol 47 (15) ◽  
pp. 1557-1562 ◽  
Author(s):  
R. J. Atkinson ◽  
C. V. Stager
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Single Crystals ◽  
Room Temperature ◽  
Paramagnetic Shift ◽  
Isotropic Component ◽  
The Magnetic Field ◽  
Nuclear Magnetic

The nuclear magnetic resonance of 31P has been observed in single crystals of Mn2P2O7 at room temperature. The paramagnetic shift of the 31P resonance from γH0 has been determined for rotations of the magnetic field in three principal planes. The isotropic component of the shift indicates the presence of 0.647 ± 0.01% of a single unpaired s electron on the phosphorus ion.

High Resolution Nuclear Magnetic Resonance Spectroscopy on Biological Tissue and Metabolomics

2019 ◽  
Vol 26 (12) ◽  
pp. 2190-2207 ◽  
Author(s):  
Yanqin Lin ◽  
Qing Zeng ◽  
Liangjie Lin ◽  
Zhong Chen
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Biological Tissues ◽  
Coupling Constants ◽  
Field Inhomogeneity ◽  
Nuclear Magnetic

High-resolution nuclear magnetic resonance (NMR) spectroscopy is a universal analytical tool. It can provide detailed information on chemical shifts, J coupling constants, multiplet patterns, and relative peak areas. It plays an important role in the fields of chemistry, biology, medicine, and pharmacy. A highly homogeneous magnetic field is a prerequisite for excellent spectral resolution. However, in some cases, such as in vivo and ex vivo biological tissues, the magnetic field inhomogeneity due to magnetic susceptibility variation in samples is unavoidable and hard to eliminate by conventional methods. The techniques based on intermolecular multiple quantum coherences and conventional single quantum coherence can remove the influence of the field inhomogeneity effects and be applied to obtain highresolution NMR spectra of biological tissues, including in vivo animal and human tissues. Broadband 1H homo-decoupled NMR spectroscopy displays J coupled resonances as collapsed singlets, resulting in highly resolved spectra. It can be used to acquire high-resolution spectra of some pharmaceuticals. The J-difference edited spectra can be used to detect J coupled metabolites, such as γ-aminobutyric acid, the detection of which is interfered by intense neighboring peaks. High-resolution 1H NMR spectroscopy has been widely utilized for the identification and characterization of biological fluids, constituting an important tool in drug discovery, drug development, and disease diagnosis.

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