Publications
267 results found
Jhe W, Anderson A, Hinds EA, et al., 1987, Erratum: Suppression of spontaneous decay at optical frequencies: Test of vacuum-field anisotropy in confined space (Physical Review Letters (1987) 58, 14, (1497)), Physical Review Letters, Vol: 58, ISSN: 0031-9007
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- Citations: 4
Hinds EA, Alhassid Y, Meschede D, 1987, Dynamical Symmetries of the Perturbed Hydrogen Atom: The van der Waals Interaction, Physical Review Letters, ISSN: 0031-9007
Schropp D, Cho D, Vold T, et al., 1987, New limits on time-reversal invariance from the hyperfine structure of thallium fluoride, Physical Review Letters, Vol: 59, Pages: 991-994, ISSN: 0031-9007
We have made a very precise test of time-reversal invariance using nuclear-spin resonance in a thallium fluoride molecular beam. We searched for a shift of the 120-kHz Tl resonance when an external electric field was reversed relative to the nuclear spin and found it to be (-2.2±2.1)×10-3 Hz, less than 0.02 ppm and a fivefold improvement over any previous measurement. Our result imposes new constraints on the proton electric dipole moment and on CP nonconservation in strong and weak interactions. © 1987 The American Physical Society.
Jhe W, Anderson A, Hinds EA, et al., 1987, Suppression of spontaneous decay at optical frequencies: Test of vacuum-field anisotropy in confined space, Physical Review Letters, Vol: 58, Pages: 666-669, ISSN: 0031-9007
The radiative decay of Cs atoms excited into the 5D5/2 level and passing between two metallic mirrors spaced by a 1.1-m gap is observed to depend upon their angular momentum. Spontaneous emission at a wavelength of 3.49 m is suppressed for the substates with maximum angular momentum normal to the mirrors, which survive without substantial decay during 13 natural lifetimes. The radiation rate is modified by application of a magnetic field which mixes sublevels having lifetimes in the gap. This experiment illustrates the anisotropy of the vacuum field in confined space. © 1987 The American Physical Society.
Schropp D, Cho D, Vold T, et al., 1987, NEW EXPERIMENTAL LIMITS ON P AND T VIOLATION., Pages: 16-17
The first results are announced from a molecular beam experiment on the polar molecule TIF, searching for a P and T violating interaction of the general form H//e//f//f equals d sigma multiplied by lambda , where sigma is a unit angular momentum, lambda is a unit polar vector, and d characterizes the strength of the interaction. In this case sigma and lambda lie along the TI nuclear spin direction and the internuclear axis, respectively. An external electric field E is applied along the sigma direction to polarize the molecule so that sigma multiplied by lambda does not equal 0. So far, the experiment has yielded a null result with substantially smaller uncertainty than any previous work. Interpretation of the limit on d leads to limits on the possible values of the proton electric dipole moment the thallium nuclear electric dipole moment, and the weak electron-nucleon tensor coupling C// tau .
Boshier MG, Baird PEG, Foot CJ, et al., 1987, Precision spectroscopy of hydrogen and deuterium, Nature, Vol: 330, Pages: 463-465, ISSN: 0028-0836
The hydrogen atom is an important testing ground for fundamental physical theory, because it is the simplest stable atomic system and its properties can be calculated to enormous precision. Measurements on hydrogen played a major role in the development of quantum electrodynamics (QED), a theory of electromagnetic interactions which includes quantization of the radiation field1,2. Tests of QED in hydrogen involve precision measurements of transition frequencies; the transition generally studied is between two excited states (2s2S1/2 and 2p2P1/2). Much higher precision is possible if a transition involving the ground state is studied, but this potential has not so far been exploited because of experimental difficulties. We have now carried out an experiment of this type which has given preliminary results and opens new possibilities for precision tests of QED in the future. © 1987 Nature Publishing Group.
Anderson A, Haroche S, Hinds EA, et al., 1987, ATOMIC PHYSICS EXPERIMENTS IN MICRON-SIZED CAVITIES: SUPPRESSING SPONTANEOUS DECAY AT OPTICAL FREQUENCY.
Spontaneous emission from an excited atomic state reflects the properties of the surrounding vacuum field. By placing the atom near a metallic surface or in a cavity, one can modify the spectral density of the vacuum modes coupled to it and either enhance or inhibit spontaneous emission. The spontaneous emission from substates of the 5D//5/////2 level of cesium at 3. 49 mu m has been suppressed by passing the atom between two gold mirrors separated by a 1. 1- mu m gap. The atoms travel in the gap for about 13 natural lifetimes without radiating. Substates with maximum angular momentum normal to the mirrors have their emission turned off. Other substates have their radiation rate either decreased or increased by a factor of between 0. 4 and 1. 3. A magnetic field making an angle with the direction normal to the mirrors was used to study the dependence of the spontaneous emission rates on the polarization of the excited atoms in the gap, enabling the anisotropy of the vacuum-field fluctuations between the two closely spaced mirrors to be checked. The deflection of cesium Rydberg atoms attracted to a metallic surface by the dipole image van der Waals force was also observed.
Anderson A, Haroche S, Hinds EA, et al., 1986, Reflection of thermal Cs atoms grazing a polished glass surface, Physical Review A, Vol: 34, Pages: 3513-3516, ISSN: 1050-2947
We present an experimental study which shows that a large fraction (≤ 50%) of thermal Cs atoms are nearly specularly reflected by polished glass surfaces at grazing incidence. This effect is interesting in the context of projects aimed at storing cold alkali-metal atoms in boxes. © 1986 The American Physical Society.
Hinds EA, Prestage JD, Pichanick FMJ, 1986, Analysis of a level-crossing experiment on the 2 P3 state of He3, Physical Review A, Vol: 33, Pages: 68-71, ISSN: 1050-2947
We have used the theory presented by us in a recent paper to analyze a 1967 level-crossing experiment on the 2 P3 state of He3 performed at the University of Michigan. Until now a consistent analysis of the experiment had not been possible because of inadequate development of the theory. The present analysis gives excellent agreement with the results of an atomic beam magnetic resonance experiment performed recently by us at Yale University. In fact we have used the combined data to give slightly improved results for four of the 11 relevant parameters. These four are the spin-antisymmetric contact hyperfine interaction constant [C'=-4327(69) MHz)], the 2 P3 dipole hyperfine interaction constant [D=-28.145(21) MHz], the 2 P3 tensor hyperfine interaction constant [E=-7.1353(38) MHz], and the orbital g factor [gL=0.999 828 6(20)].. AE © 1986 The American Physical Society.
Prestage JD, Johnson CE, Hinds EA, et al., 1985, Precise study of hyperfine structure in the 23P state of He3, Physical Review A, Vol: 32, Pages: 2712-2724, ISSN: 1050-2947
The optical-microwave atomic-beam magnetic resonance technique has been used to measure four hyperfine transitions in the 23P state He3. These were used to determine the three hyperfine interaction constants (in MHz) as follows: contact, C=-4283.84-0.01+0.02; nuclear-moment-electron-orbit, D=-28.060.06; nuclear-moment-electron-momment, E=+7.100.02. THe results, which are in excellent agreement with theory, give a clear indication of the effects of core polarization on the hyperfine structure. We conclude that to the accuracy indicated the structure of the 2 3P state, including mass-dependet and quantum electrodynamic corrections to the fine structure, and relativistic and core-polarization corrections to the hyperfine structure, is well understood. © 1985 The American Physical Society.
Hinds EA, Prestage JD, Pichanick FMJ, 1985, Phenomenological theory of the 23P state of He3, Physical Review A, Vol: 32, Pages: 2615-2621, ISSN: 1050-2947
For the first time, a theory has been developed for the structure of the 23P state of He3 which is consistent with all experimental data. Using our effective Hamiltonian, containing both spin-symmetric and -antisymmetric operators, we have obtained new values for several important hyperfine parameters. The three most accurate of these are the spin-symmetric constants C, D, and E corresponding, respectively, to the contact, orbital, and tensor interactions. We find C=4283.84-0.01+0.02 MHz, D=-28.145(21) MHz, and D/E=-3.9445(21). We have also obtained improved values for other hyperfine parameters and for the orbital g factor. Our results are shown to be in agreement with ab initio calculations after making some plausible corrections for isotope and relativistic shifts. We believe that this state is now well understood at the level of 20 kHz in the interaction constants. © 1985 The American Physical Society.
Frieze W, Hinds EA, Kponou A, et al., 1984, HELIUM FINE STRUCTURE AND THE FINE STRUCTURE CONSTANT., Pages: 149-151, ISSN: 0083-1883
A series of precision measurements have been made of a specified fine structure interval in the 2**3P state of helium. The results are nu //0//1 equals 29 616. 864(36) MHz (1. 2 ppm), nu //1//2 equals 2 291. 196(5) MHz (2. 2 ppm), and nu //0//2 equals 31 908. 040(20) MHz (0. 6 ppm). These results are self-consistent and in good agreement with theory. Experiment and theory can be combined to produce an independent value for the fine structure constant alpha ** minus **1 equals 137. 036 13(11) (0. 8 ppm), in good agreement with the more accurate value currently accepted alpha ** minus **1 equals 137. 035 963(15) (0. 11 ppm).
Hershcovitch AI, Hinds EA, 1984, GENERATION OF INTENSE POLARIZED BEAMS BY SELECTIVE NEUTRALIZATION OF NEGATIVE IONS., Pages: 763-768, ISSN: 0094-243X
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- Citations: 1
Prestage JD, Hinds EA, Pichanick FMJ, 1983, Precise measurements of hyperfine structure in the 2 P3 state of He3, Physical Review Letters, Vol: 50, Pages: 828-832, ISSN: 0031-9007
Transitions within the 2 P3 state of He3 were measured to determine the parameters C, D, and E which represent respectively the contact, dipole, and tensor terms in the hyperfine Hamiltonian. For the first time, the effect of core polarization on the hyperfine structure has been detected. The present results are C=-4283.84(1) MHz, D=-28.02(6) MHz, and E=+7.08(2) MHz and are consistent with the theoretical values after the combined fine and hyperfine interactions with the 2 P1 state are taken into account in the analysis of the data. © 1983 The American Physical Society.
Cornelius WD, Taylor DJ, York RL, et al., 1982, OPTICAL PUMPING FOR INTENSE POLARIZED ION SOURCES., Pages: 355-364, ISSN: 0250-4375
Cornelius WD, Taylor DJ, York RL, et al., 1982, Optical pumping of dense charge-exchange targets for polarized Ion sources, Physical Review Letters, Vol: 49, Pages: 870-873, ISSN: 0031-9007
Optical pumping by a single-frequency cw ring dye laser of thick sodium vapor targets (NL>1013 atoms/cm2) without buffer gas has been investigated for application in a polarized ion source. The atomic polarization of the sodium was determined from the optical rotation of a second dye laser tuned midway between the D lines. Rate-equation calculations reproduce the experimental data and predict very high polarizations (P>~0.8) with the use of one or more single-frequency dye lasers in thick alkali-metal vapor targets. © 1982 The American Physical Society.
Hinds EA, Edwards JW, Greene GL, 1981, STATE SELECTION OF 2^2S_l/2 HYPERFINE LEVELS OF HYDROGEN IN ZERO MAGNETIC FIELD, Nuclear Instruments and Methods, ISSN: 0029-554X
Hinds EA, Cornelius WD, York RL, 1981, Depolarization effects in optically pumped polarized proton sources, Nuclear Instruments and Methods, Vol: 189, Pages: 599-602, ISSN: 0029-554X
We discuss the electron spin depolarization of a hydrogen beam formed by charge capture in a polarized alkali vapor. An expression is derived for the final ground-state polarization of the hydrogen beam as a function of external-magnetic-field strength. This expression reveals the interesting possibility of producing a polarized beam with an unpolarized target. Some additional implications of our result for a practical polarized proton source are considered. © 1981.
Hinds EA, Frieze WE, Hughes VW, et al., 1981, Experiments on the 2^3P_0 - 2^3P_2 Fine-Structure Interval, Physical Review A, ISSN: 1050-2947
Hinds EA, Sandars PGH, 1980, Electric dipole hyperfine structure of TIF, Physical Review A, Vol: 21, Pages: 471-479, ISSN: 1050-2947
The authors have calculated the electric dipole interaction energy of the TI205 nucleus in TIF assuming a nonzero electric dipole moment dp on the proton. The result is used in the accompanying experimental paper to obtain a new value of (-1.46)×10-21 e cm for dp. © 1980 The American Physical Society.
Hinds EA, Sandars PGH, 1980, Experiment to search for P- and T-violating interactions in the hyperfine structure of thallium fluoride, Physical Review A, Vol: 21, Pages: 480-487, ISSN: 1050-2947
The authors describe a molecular-beam-resonance experiment to search for P- and T-violating interactions in the thallium fluoride molecule. Specifically the interactions looked for are of the form HPT=d TlTlF, where d is a coupling constant, Tl is a unit vector parallel to the spin angular momentum of the thallium nucleus, and TlF is a unit vector along the internuclear axis. The null result of the experiment is dh=1142 mHz. This result implies new upper limits on the electric dipole moment of the proton and on a possible weak, P- and T-violating, neutral-current tensor interaction. © 1980 The American Physical Society.
Hinds EA, 1980, Sensitivity and the role of level crossings in measurements of parity nonconservation using metastable atoms, Physical Review Letters, Vol: 44, Pages: 374-376, ISSN: 0031-9007
The author points out that experiments to measure parity nonconservation in metastable atoms, such as hydrogen in the 2S state, are not, in general, made more sensitive by operating near level crossings in a magnetic field. New possibilities related to this observation are mentioned. © 1980 The American Physical Society.
Frieze WE, Hinds EA, Hughes VW, et al., 1980, Precise measurement of the 2<sup>3</sup>P<inf>0</inf>−2<sup>3</sup>P<inf>2</inf> fine structure interval in helium, "Physics Letters, Section A: General, Atomic and Solid State Physics", Vol: 78, Pages: 322-324, ISSN: 0375-9601
A measurement of the 23P0−23P2 fine structure interval in the helium has beeen made using the optical microwave atomic beam magnetic resonance technique. The result is 31.908 040 (20) GHz (0.6ppm), which establishes an internal consistency in measurements of the helium fine structure and verifies the theory to order α4Ry. When the theory is used together wit our experimental result we obtain a value for the fine structure constant α by α-1=137.03613(11) (0.8 ppm). © 1980, All rights reserved.
Hinds EA, Novick R, 1978, Precise resonant charge-transfer cross sections for He-He<sup>+</sup> between 2 and 100 eV, Journal of Physics B: Atomic and Molecular Physics, Vol: 11, Pages: 2201-2207, ISSN: 0022-3700
Ground-state total charge-transfer cross sections sigma 10 for He-He+ collisions at relative impact energies between 2 and 100 eV have been measured by observing the attenuation of a He+ ion beam in helium gas. Fitting these results to the usual functional form yields the relation sigma 1012/=6.61-0.621 ln nu , where sigma 10 is in AA2 and nu is the impact velocity in km s -1. The absolute accuracy of sigma 10 is about +or-2%.
Hinds EA, Clendenin JE, Novick R, 1978, Decay rate of the 2S122 state of singly ionized helium, Physical Review A, Vol: 17, Pages: 670-676, ISSN: 1050-2947
A precise measurement has been made of the lifetime of He+ in the metastable 2S122 state. The result, Γ2S=525±5 sec-1, is consistent with the theory of spontaneous two-photon decay and places an upper limit |δ|<2.4×10-5 on the amplitude of any parity-nonconserving 2P admixture. © 1978 The American Physical Society.
Hinds EA, Hughes VW, 1977, Parity nonconservation in hydrogen involving magnetic/electric resonance, Physics Letters B, Vol: 67, Pages: 487-488, ISSN: 0370-2693
Parity nonconservation effects in the n=2 state of hydrogen involving a simultaneous magnetic and electric microwave resonance transition are discussed as a possible test of the Weinberg-Salam theory. © 1977.
Hinds EA, Loving CE, Sandars PGH, 1976, Limits on P and T violating neutral current weak interactions, Physics Letters B, Vol: 62, Pages: 97-99, ISSN: 0370-2693
It is pointed out that presently available limits on the electric dipole moments of atoms and molecules require that the coupling constants for any scalar-pseudoscalar or tensor pseudo tensor interaction between electrons and nucleons be at least three orders of magnitude less than the Fermi constant. © 1976.
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