Three-Nucleon Charge Radius: A Precise Laser Determination Using<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow /><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>He

Shiner, David; Dixson, Ronald G.; Vedantham, Vasanth

doi:10.1103/physrevlett.74.3553

Cited by 109 publications

(162 citation statements)

References 26 publications

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“…Combined with a previous measurement on 6 He [4] and earlier studies of the two stable isotopes, 3 He [6] and 4 He [7], there is now a complete picture of the evolution of nuclear charge radii in the helium isotopic chain.…”

Section: The Mass Shift δν Msmentioning

confidence: 99%

“…The trapping and spectroscopy setup has been previously described in detail in connection with the nuclear charge radius measurement of 6 He at Argonne's ATLAS facility [4,9].…”

Section: The Mass Shift δν Msmentioning

confidence: 99%

“…The experiment was carried out at the GANIL facility where 6 He and 8 He were simultaneously produced from a primary beam of 75 MeV/u 13 C impinging on a heated (∼ 2000 K) graphite target. Low-energy (20 keV) beams of either 6 He or 8 He with yields of around 1 × 10 8 and 5 × 10 5 ions per second, respectively [8], were delivered to an adjacent lowradiation area where the helium ion beam was stopped in a hot, 1 cm 2 sized graphite foil for neutralization.…”

Section: The Mass Shift δν Msmentioning

confidence: 99%

“…Low-energy (20 keV) beams of either 6 He or 8 He with yields of around 1 × 10 8 and 5 × 10 5 ions per second, respectively [8], were delivered to an adjacent lowradiation area where the helium ion beam was stopped in a hot, 1 cm 2 sized graphite foil for neutralization. The released neutral, thermal helium atoms were pumped within 250 ms into the atomic beam apparatus resulting in rates of approximately 5 × 10 7 s −1 and 1 × 10 5 s −1 for 6 He and 8 He, respectively.…”

Section: The Mass Shift δν Msmentioning

confidence: 99%

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Nuclear Charge Radius ofHe8

et al. 2007

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The root-mean-square (rms) nuclear charge radius of 8 He, the most neutron-rich of all particlestable nuclei, has been determined for the first time to be 1.93(3) fm. In addition, the rms charge radius of 6 He was measured to be 2.068(11) fm, in excellent agreement with a previous result.The significant reduction in charge radius from 6 He to 8 He is an indication of the change in the correlations of the excess neutrons and is consistent with the 8 He neutron halo structure. The experiment was based on laser spectroscopy of individual helium atoms cooled and confined in a magneto-optical trap. Charge radii were extracted from the measured isotope shifts with the help of precision atomic theory calculations. * Electronic address: pmueller@anl.gov 1

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Section: The Mass Shift δν Msmentioning

confidence: 99%

“…The trapping and spectroscopy setup has been previously described in detail in connection with the nuclear charge radius measurement of 6 He at Argonne's ATLAS facility [4,9].…”

Section: The Mass Shift δν Msmentioning

confidence: 99%

Section: The Mass Shift δν Msmentioning

confidence: 99%

Section: The Mass Shift δν Msmentioning

confidence: 99%

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Nuclear Charge Radius ofHe8

et al. 2007

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“…These QED limited accuracies allow extraction of the squared nuclear charge radius difference with an accuracy that will be similar to values deduced from the muonic helium experiments if the experimental accuracy of the isotope shift is of similar or higher accuracy. Presently, for the 2 3 S 1 -2 1 S 0 transition, the accuracy is 2.4 kHz [7] while for the 2 3 S 1 -2 3 P transition the isotope shift accuracy is 3.2 kHz [8,9]. Surprisingly, a four standard deviation difference exists between the nuclear charge radius difference extracted from both measurements.…”

Section: Introductionmentioning

confidence: 99%

Ultracold metastable helium: Ramsey fringes and atom interferometry

et al. 2016

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equation cannot be solved exactly. Level energies are therefore more difficult to calculate than for atomic hydrogen showing a more stringent test of atomic physics theory. Calculations of level energies and transition frequencies have pushed our understanding of atomic physics since the twenties of last century. A major breakthrough occurred in the nineties with the advent of variational calculations in a double basis set in correlated form for the electrons, adding relativistic and quantum electrodynamics (QED) terms in orders of the fine structure constant α and the reduced electron to helium mass ratio µ/M He [1, 2]. As nonrelativistic calculations can now be performed to virtually arbitrary precision, measurements of level energies nowadays are sensitive to QED and nuclear size effects. As these effects are strongest for S-states and small principle quantum number n, the n 1,3 S states are theoretically the most promising to test QED. In particular the n = 2 states are important for high-resolution spectroscopy as these also show long lifetimes, 7800 s for the 2 3 S 1 state and 20 ms for the 2 1 S 0 state (natural linewidth 8 Hz), while the 2 3 P state has, for an allowed electric dipole transition, a relatively long lifetime of 98 ns (natural linewidth 1.6 MHz). A helium level scheme is shown in Fig. 1.Transition frequencies in helium can nowadays be measured more accurately than calculated, where the theoretical limitation is in the calculation of high-order QED terms. This hampers extraction of the charge radius of the helium nucleus (the alpha-particle for 4 He and the helion for 3 He ) from transition frequencies with an accuracy that can compete with other experiments. However, in calculating transition isotope shifts between 4 He and 3 He, QED terms cancel to a large extent, allowing very accurate extraction of the difference in the (squared) nuclear charge radii of the alpha-particle and the helion. This is particularly interesting in relation to the proton size puzzle [3][4][5]. To help solving Abstract We report on interference studies in the internal and external degrees of freedom of metastable triplet helium atoms trapped near quantum degeneracy in a 1.5 µm optical dipole trap. Applying a single π/2 rf pulse we demonstrate that 50% of the atoms initially in the m = +1 state can be transferred to the magnetic field insensitive m = 0 state. Two π/2 pulses with varying time delay allow a Ramsey-type measurement of the Zeeman shift for a high precision measurement of the 2 3 S 1 -2 1 S 0 transition frequency. We show that this method also allows strong suppression of mean-field effects on the measurement of the Zeeman shift, which is necessary to reach the accuracy goal of 0.1 kHz on the absolute transition frequencies. Theoretically the feasibility of using metastable triplet helium atoms in the m = 0 state for atom interferometry is studied demonstrating favorable conditions, compared to the alkali atoms that are used traditionally, for a non-QED determination of the fine structure constant.

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