English
Related papers

Related papers: A study of the fine-structure constant dependence …

200 papers

We study the dependence of the primordial nuclear abundances as a function of the electromagnetic fine-structure constant $\alpha$, keeping all other fundamental constants fixed. We update the leading nuclear reaction rates, in particular…

High Energy Physics - Theory · Physics 2023-05-26 Ulf-G. Meißner , Bernard Ch. Metsch , Helen Meyer

In this work we study the radiative capture of ${\rm {}^3He}$ on ${\rm {}^4He}$ within the halo effective field theory (EFT) framework. At leading order the capture amplitude comprises the initial state $s$-wave strong and Coulomb…

Nuclear Theory · Physics 2018-05-29 Renato Higa , Gautam Rupak , Akshay Vaghani

We compute primordial light-element abundances for cases with fine structure constant alpha different from the present value, including many sources of alpha dependence neglected in previous calculations. Specifically, we consider…

Astrophysics · Physics 2008-11-26 Kenneth M. Nollett , Robert E. Lopez

We use relativistic Hartree-Fock and configuration interaction methods to calculate the dependence of transition frequencies for singly ionized cobalt on the fine structure constant. The results are to be used in the search for variation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 V. A. Dzuba , V. V. Flambaum

Nuclear halos emerge as new degrees of freedom near the neutron and proton driplines. They consist of a core and one or a few nucleons which spend most of their time in the classically-forbidden region outside the range of the interaction.…

Nuclear Theory · Physics 2017-11-07 H. -W. Hammer , C. Ji , D. R. Phillips

Murphy et al. (2003a, MNRAS, 345, 609) claim to find evidence of cosmological variations of the fine structure constant $\alpha$ in the spectra of intervening QSO absorption line systems. We find that this result is affected by systematic…

Astrophysics · Physics 2016-08-30 Rino Bandiera , Edvige Corbelli

Aside from being a one-neutron halo nucleus, $^{15}$C is interesting because it is involved in reactions of relevance for several nucleosynthesis scenarios. The aim of this work is to analyze various reactions involving $^{15}$C, using a…

Nuclear Theory · Physics 2019-10-30 Laura Moschini , Jiecheng Yang , Pierre Capel

Background: The halo effective field theory (Halo-EFT) provides a very efficient description of loosely-bound nuclei in models of reaction. It offers a very systematical ranking of the significance of nuclear-structure observables in…

Nuclear Theory · Physics 2025-04-22 L. -P. Kubushishi , P. Capel

We use the relativistic Hartree-Fock method, many-body perturbation theory and configuration-interaction method to calculate the dependence of atomic transition frequencies on the fine structure constant, alpha. The results of these…

Atomic Physics · Physics 2008-11-26 J. C. Berengut , V. A. Dzuba , V. V. Flambaum , M. V. Marchenko

We report a calculation of the fine structure splitting in light helium-like atoms, which accounts for all quantum electrodynamical effects up to order \alpha^5 Ry. For the helium atom, we resolve the previously reported disagreement…

Atomic Physics · Physics 2015-05-18 Krzysztof Pachucki , Vladimir A. Yerokhin

The cross section for radiative capture of neutron on carbon-14 is calculated using the model-independent formalism of halo effective field theory. The dominant contribution from E1 transition is considered, and the cross section is…

Nuclear Theory · Physics 2015-06-04 Gautam Rupak , Lakma Fernando , Akshay Vaghani

The connection between the neutron halo observed in light neutron rich nuclei and the neutron radiative capture process is outlined. We show how nuclear structure information such as spectroscopic factors and external components of the…

Nuclear Theory · Physics 2007-05-23 A. Mengoni , T. Otsuka , T. Nakamura , M. Ishihara

The clear separation of scales observed in halo nuclei between the extended halo and the compact core makes these exotic nuclei a perfect subject for Effective Field Theory (EFT). Such description leads to a systematic expansion of the…

Nuclear Theory · Physics 2022-01-05 Pierre Capel

We put bounds on the variation of the value of the fine structure constant $\alpha$, at the time of Big Bang nucleosynthesis. We study carefully all light elements up to $^7$Li. We correct a previous upper limit on $|\Delta \alpha /…

Astrophysics · Physics 2009-10-31 L. Bergstrom , S. Iguri , H. Rubinstein

We present a description of the break-up of halo nuclei in peripheral nuclear reactions by coupling a model of the projectile motivated by Halo Effective Field Theory with a fully dynamical treatment of the reaction using the Dynamical…

Nuclear Theory · Physics 2021-12-02 P. Capel , D. R. Phillips , H. -W. Hammer

Halo effective field theory (Halo-EFT) has proved to be very efficient for describing halo nuclei within models of nuclear reactions. Its order-by-order expansion scheme enables us to single out the structure observables that are probed in…

Nuclear Theory · Physics 2025-07-21 Live-Palm Kubushishi , Pierre Capel

We show examples of neutron capture, photo dissociation and Coulomb dissociation processes, relevant for studying nuclear structure properties of some light nuclei. In the case of the neutron capture, we show how interference effects among…

Nuclear Theory · Physics 2009-10-31 A. Mengoni , T. Otsuka

A new method for measuring a possible time dependence of the fine-structure constant ($\alpha$) is proposed. The method is based on the level-crossing in two-electron highly-charged ions facilitating resonance laser measurements of the…

Atomic Physics · Physics 2009-11-11 O. Yu. Andreev , L. N. Labzowsky , G. Plunien , G. Soff

Coulomb dissociation is an especially simple and important reaction mechanism. Since the perturbation due to the electric field of the (target) nucleus is exactly known, firm conclusions can be drawn from such measurements. Electromagnetic…

Nuclear Theory · Physics 2007-05-23 G. Baur , K. Hencken , D. Trautmann , S. Typel

The optical response and the ground state of graphene and graphene-like systems are determined self-consistently. Deriving equations of motion for the basic variables, graphene Bloch equations are introduced and combined with a variational…

Materials Science · Physics 2012-01-10 T. Stroucken , J. H. Grönqvist , S. W. Koch
‹ Prev 1 2 3 10 Next ›