Measurement of the Electric Polarizability of the Neutron

Schmiedmayer, Jörg; Rauch, H.; Riehs, P.

doi:10.1103/physrevlett.61.2509

Cited by 8 publications

(10 citation statements)

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“…Since we have the estimates of w q from the prior run saved to disk, we use them in combination with the new diluted estimates of w q to produce an estimate of w 2 q on each configuration. For the first order term we find that the standard deviation is σ w q = 23 (1). This includes both the stochastic noise and the gauge fluctuations.…”

Section: A Reweighting Factorsmentioning

confidence: 85%

Sea quark contributions to the electric polarizability of hadrons

et al. 2014

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We present a lattice QCD calculation of the polarizability of the neutron and other neutral hadrons that includes the effects of the background field on the sea quarks. This is done by perturbatively reweighting the charges of the sea quarks to couple them to the background field. The main challenge in such a calculation is stochastic estimation of the weight factors, and we discuss the difficulties in this estimation. Here we use an extremely aggressive dilution scheme to reduce the stochastic noise to a manageable level. The pion mass in our calculation is 300 MeV and the lattice size is 3 fm. For the neutron, we find that αE = 2.70(55) × 10 −4 fm 3 , which is the most precise lattice QCD determination of the polarizability to date that includes sea effects.

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Section: A Reweighting Factorsmentioning

confidence: 85%

Sea quark contributions to the electric polarizability of hadrons

et al. 2014

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“…The neutron electric polarizibility was measured by the energy dependent neutron transmission though lead (Schmiedmayer et al, 1991), with an error of same size as for the result obtained from deuteron break-up d np…”

Section: Electromagnetic Polarizabilitymentioning

confidence: 99%

The neutron and its role in cosmology and particle physics

2011

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arXiv 18 May 2011, extended version of: Reviews of Modern Physics, in print.Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis, the mechanism behind the evident dominance of matter over antimatter in the universe. The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model. These experiments start closing the remaining "axion window" on new spindependent forces in the submillimeter range. Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.DOI: xx,xxxx/RevModPhys.xx.xxx PACS number(s): 14.20.Dh,

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“…The most interesting such quantity is the electric polarizability of the neutron, since it is difficult to access experimentally due to the lack of free neutrons; the best measurements have been obtained by neutron-lead [1] and neutron-deuteron [2] scattering. A basic computation of this quantity is not too hard to do using the background-field method [3]; the difficulties come in the approach to the physical point that can be compared with experiment.…”

Section: Introductionmentioning

confidence: 99%

Sea Contributions to Hadron Electric Polarizabilities through Reweighting

Freeman¹,

Alexandru²,

Lee³

et al. 2012

Proceedings of the 30th International Symposium on Lattice Field Theory — PoS(Lattice 2012)

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As part of our ongoing lattice study of the electric polarizabilities of hadrons using the background field approach, we use reweighting to examine the effect of the field on the sea quarks. As with other reweighting studies, the chief difficulty lies in the construction of a stochastic estimate of the ratio of the fermion determinants. In contrast to the case of reweighting in the quark mass, these estimators converge extremely slowly, and are resistant to common variance-reduction techniques such as low-mode subtraction. However, it is possible to construct an alternate estimator, taking advantage of the fact that we are interested in only perturbatively small fields; this estimator is susceptible to a variance-reduction technique based on a hopping parameter expansion.

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Measurement of the Electric Polarizability of the Neutron

Cited by 8 publications

References 0 publications

Sea quark contributions to the electric polarizability of hadrons

Sea quark contributions to the electric polarizability of hadrons

The neutron and its role in cosmology and particle physics

Sea Contributions to Hadron Electric Polarizabilities through Reweighting

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