Article
Optics
Vojtech Patkos, Vladimir A. Yerokhin, Krzysztof Pachucki
Summary: This paper investigates the nuclear polarizability effects in the hyperfine splitting of light atomic systems. Previous calculations have only been done for the hydrogen atom, showing that these effects contribute about 5% to the total nuclear correction. It is generally expected that the polarizability effects would be more pronounced for composite nuclei. In this study, the nuclear polarizability correction to the hyperfine splitting in He+ is determined by comparing the experimental hyperfine splitting with electron scattering. Surprisingly, the nuclear polarizability of the helion contributes just 3% of the total nuclear correction, which is smaller than for the proton.
Article
Optics
David M. Jacobs
Summary: An effective theory of excited states of positronium is derived, with practical applications in accurately fitting the positronium spectrum and revealing nontrivial relationships within bound-state QED. The theory may also provide predictions for corrections beyond order m alpha(6) in the positronium spectrum and can be extended to other hydrogenic systems.
Article
Physics, Nuclear
Marcus Scheck, Robert Chapman, Jacek Dobaczewski, Claude Ederer, Peter Ivanov, Guiseppe Lorusso, David O'Donnell, Christian Schroder
Summary: This work proposes a new approach to search for CP-violating odd-electric and even-magnetic nuclear moments. The quadrupole-deformed and octupole-correlated nucleus 227-actinium is a potential candidate to find such moments. By analyzing the recoil-free self-absorption technique, specifically Mossbauer spectroscopy, on the 27.4keV E1 transition between the 3/2(+) parity-doublet partner and the 3/2(-) ground state, the lower limit of triangle E = 2 center dot gamma is estimated to be 23.7(1) x10(-9) eV for the achievable energy resolution. This work presents the first ideas on the patterns caused by CP-violating moments on the quadrupole splitting and nuclear Zeeman effect.
EUROPEAN PHYSICAL JOURNAL A
(2023)
Article
Optics
M. Z. Milosevic, A. Bunjac, D. B. Popovic, N. S. Simonovic
Summary: The presence of an external electric field destabilizes positronium due to field-induced ionization, with the ionization rate becoming dominant in the over-the-barrier ionization regime. The hyperfine splitting of the positronium lowest level decreases with increasing field strength, while additional splitting of triplet levels occurs. The lowest energy levels and ionization rates for positronium and hydrogen atom are found to be related to scaling transformations within the gross structure.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2021)
Article
Optics
A. Del angel, P. Solano, P. Barberis-Blostein
Summary: We study the interaction between one or two two-level atoms and the electromagnetic field in the vicinity of an optical nanofiber, without making the Born or Markov approximations. By modeling the nanofiber's dielectric response, we observe deviations from standard super- and subradiant decays. We also discuss the validity of approximating atom-atom communication speed with the guided field's group velocity in the presence of nontrivial environment correlations. This work enhances our understanding of commonly used approximations in recent waveguide QED platforms.
Article
Optics
Ziqiang Tian, Zhiming Tang, Yi Li, Yang Yang, Zhongwen Wu, Yaming Zou
Summary: This study investigates the linear polarization of magnetic-quadrupole emission lines of Be-like ions with nuclear spin through the use of density-matrix theory and relativistic distorted-wave theory. The effects of hyperfine interaction and different nuclear magnetic dipole moments on the polarization of these lines are explored. The findings suggest that precise polarization measurements of magnetic-quadrupole lines could be used to study the hyperfine interaction and nuclear magnetic dipole moment of isotopes with nonzero spins.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2023)
Article
Optics
L. Gurung, T. J. Babij, J. Perez-Rios, S. D. Hogan, D. B. Cassidy
Summary: New measurements of the positronium (Ps) 2(3)S(1)-> 2(3)P(J) fine-structure intervals were reported, with findings of asymmetric line shapes for nu(1) and nu(2) but not for nu(0). The observed interval was found to deviate from QED theory by 4.2 standard deviations.
Article
Optics
Michael Eides, Valery A. Shelyuto
Summary: We calculate the three-loop radiative corrections to energy levels in muonium and positronium, which arise from radiative corrections with polarization insertions in two-photon exchange diagrams. These corrections could be important for precise measurements of 1S-2S and 2S-2P transitions in muonium and positronium.
Article
Astronomy & Astrophysics
Matthias Heller, Niklas Keil, Marc Vanderhaeghen
Summary: We studied the leading-order QED radiative corrections to the timelike Compton scattering process and found that they range from 5%-10% in the low-energy regime and around 20% in the high-energy regime. These corrections nearly cancel out in both dilepton forward-backward asymmetry and photon beam helicity asymmetry, making them ideal observables for extracting the real and imaginary parts of the TCS amplitude. Our results demonstrate the sensitivity of these asymmetries to GPD parametrizations in recent TCS experiments at CLAS12@JLab.
Article
Optics
Konstantin N. Lyashchenko, Oleg Yu Andreev, Deyang Yu
Summary: In this theoretical study, the process of two-electron one-photon (TEOP) transitions in a He-like sequence of atomic ions from boron to uranium is considered. Transition probabilities and energies are calculated within the Quantum Electrodynamics (QED) theory, with calculations performed in various gauges. The intensity ratios between TEOP transitions and other major transitions are presented.
Article
Optics
R. S. Wilde, H. B. Ambalampitiya, I. I. Fabrikant
Summary: In this study, elastic and positronium breakup cross sections for collisions of Ps with O-2 and CO2 molecules were calculated in the fixed-nuclei approximation, incorporating electron exchange and correlations using a free-electron-gas model. The results show similarity between electron and Ps scattering when plotted as a function of projectile velocity, and resonance structures similar to those obtained earlier for Ps-N-2 scattering were observed below the Ps breakup threshold.
Article
Physics, Nuclear
S. Nothhelfer, Th E. Albrecht-Schoenzart, M. Block, P. Chhetri, Ch E. Duellmann, J. G. Ezold, V Gadelshin, A. Gaiser, F. Giacoppo, R. Heinke, T. Kieck, N. Kneip, M. Laatiaoui, Ch Mokry, S. Raeder, J. Runke, F. Schneider, J. M. Sperling, D. Studer, P. Thoerle-Pospiech, N. Trautmann, F. Weber, K. Wendt
Summary: Laser resonance ionization spectroscopy was used to measure the spectroscopic properties of rare einsteinium isotopes Es253-255. The technique successfully determined the spin values and derived the nuclear magnetic dipole moments and spectroscopic electric quadrupole moments for Es-254 and Es-255.
Article
Chemistry, Physical
C. T. Bop, F. Lique
Summary: In this work, the authors studied the excitation of HCNH+ induced by collisions with H-2 and He by calculating the collisional rate coefficients. The potential energy surfaces (PESs) obtained showed deep global minima and large anisotropies for both HCNH+-H-2 and HCNH+-He. State-to-state inelastic cross sections for the low-lying rotational energy levels of HCNH+ were derived from these PESs using the quantum mechanical close-coupling approach. The newly obtained collision data is expected to improve the disagreement between abundances retrieved from observational spectra and astrochemical models.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Jian-Jie Wan, Jiao Li, Jie Gu
Summary: The study calculated forbidden M1 and E2 transition rates, as well as fine-structure splitting, for the boron isoelectronic sequence using MCDHF and RCI methods. The relative differences and their dependence on atomic number Z were analyzed using the least square method. An empirical formula was developed to describe the relationship between the calculations and other theoretical and experimental results, allowing for estimation of fine-structure splitting, transition probabilities, and excited state lifetime.
RESULTS IN PHYSICS
(2021)
Review
Physics, Multidisciplinary
G. S. Adkins, D. B. Cassidy, J. Perez-Rios
Summary: Positronium, composed of an electron and a positron, offers a powerful tool to test bound-state quantum electrodynamics theory and explore physics beyond the Standard Model.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2022)
Article
Physics, Nuclear
Mira Varma, Oliver K. Baker
Summary: In this letter, the authors expand upon the previous work to demonstrate the entanglement observed in top quark interactions. They propose that the thermal component caused by proton collisions with top quarks emerges from entanglement within the proton wave function, and they use published results to show the expected behavior.
Article
Physics, Nuclear
E. Ya. Paryev
Summary: In this study, we investigate the near-threshold meson photoproduction from protons and nuclei and explore the possibility of observing non-strange hidden-bottom pentaquark states through differential observables. We calculate the excitation functions and energy/momentum distributions for different production processes and propose that future experiments at high-luminosity electron-ion colliders could provide evidence for the existence of these hidden-bottom pentaquark resonances.
Article
Physics, Nuclear
M. Shariq Asnain, Manoj Kumar Sharma, Mohd. Shuaib, Aquib Siddique, Ishfaq Majeed Bhat, B. P. Singh, R. Prasad
Summary: This study validates the compound nucleus theory using heavy ion beams and different targets. By analyzing cross section data and comparing reaction cross section data, the study confirms the validity of the theory, but also observes discrepancies at lower excitation energies.
Article
Physics, Nuclear
Y. G. Yao, X. Y. Wu, H. Mei
Summary: This study presents a microscopic investigation of the electromagnetic properties of the low-lying states of single-A hypernucleus 9ABe using the HyperGCM method based on covariant density functional theory. The results are compared to those of a particle-rotor model (PRM) and show close agreement. It is found that the electric quadrupole transition strengths are more sensitive to the coupling strengths of the AN interaction than the magnetic moments and M 1 transition strengths.
