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Related papers: Photodetachment study of He^- quartet resonances b…

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A Feshbach resonance associated with the 1s3s4s ^{4}S state of He^{-} has been observed in the He(1s2s ^{3}S) + e^- (\epsilon s) partial photodetachment cross section. The residual He(1s2s ^{3}S) atoms were resonantly ionized and the…

Atomic negative ions are fragile quantum systems in which correlation among the valence electrons plays a very important role. For doubly excited states correlation becomes dominant. Photodetachment is the process where a negative ion…

Atomic Physics · Physics 2009-09-25 Andreas E. Klinkmueller

Two new low-lying $^6$He levels at excitation energies of about 2.4 and 2.9 MeV were observed in the experimental investigation of the p-$\alpha$ coincidence spectra obtained by the $^3$H($^4$He,p$\alpha$)2n four-body reaction at $E_{\rm…

We present the results of experimental studies of photon-negative ion interactions involving the dynamics of two electrons. Resonances associated with doubly excited states of Li^- and He^- have been observed using laser photodetachment…

Atomic Physics · Physics 2015-06-26 D. Hanstorp , G. Haeffler , A. E. Klinkmueller , U. Ljungblad , U. Berzinsh , I. Yu. Kiyan , D. J. Pegg

We investigate the properties of the excited state of $^4\mathrm{He}$, $^4\mathrm{He}^*$, within the framework of Efimov physics and its connection to the unitary point of the nuclear interaction. We explore two different approaches to…

Nuclear Theory · Physics 2023-05-29 Mario Gattobigio , Alejandro Kievsky

We have performed for the first time the simultaneous measurement of the two-body and three-body photodisintegration cross-sections of 4He in the energy range from 21.8 to 29.8 MeV using monoenergetic pulsed photons and a 4-pi time…

Nuclear Experiment · Physics 2009-11-11 T. Shima , S. Naito , Y. Nagai , T. Baba , K. Tamura , T. Takahashi , T. Kii , H. Ohgaki , H. Toyokawa

Absolute photoionization cross-section measurements are reported for Se+ in the photon energy range 18.0-31.0 eV, which spans the ionization thresholds of the 4S_{3/2} ground state and the low-lying 2P_{3/2,1/2} and 2D_{5/2,3/2} metastable…

Differential cross sections two-body ($\gamma,p$) and ($\gamma,n$) reactions of the $^4$He nucleus disintegration were measured using the bremsstrahlung beam of photons at the KIPT linac LEA-300 at the maximum energy ${\rm…

In a joint experimental and theoretical endeavour, photoionization of metastable C4+(1s 2s 3S1) ions via intermediate levels with hollow, double-K-vacancy configurations 2s2p, 2s3p, 2p3s, 2p3d, 2s4p, 2p4s and 2p4d has been investigated.…

We simultaneously measured the $^4$He($\gamma, n$)$^3$He and $^4$He($\gamma, p$)$^3$H reactions in the energy range around the giant dipole resonance. A quasi-monoenergetic photon beam produced via the laser Compton scattering technique was…

We report on the first observation of resonance structure in the total cross section for the photodetachment of Li^-. The structure arises from the autodetaching decay of doubly excited ^1P states of Li^- that are bound with respect to the…

Long-range bound states of the excited heteronuclear 3He*--4He* system that dissociate to either 3He(1s2s 3S_1) + 4He(1s2p 3P_j) or 3He(1s2p 3P_j) + 4He(1s2s 3S_1), where j=0, 1, 2, are investigated using both single-channel and…

Atomic and Molecular Clusters · Physics 2015-05-04 Daniel G. Cocks , Gillian Peach , Ian B. Whittingham

The cross section of the reaction $^3$He$(\gamma,pn)p_{spec}$ in the energy range 150 - 450 MeV has been calculated in a quasifree two-body model and compared with a recent kinematically complete experiment. In comparison with free deuteron…

Nuclear Theory · Physics 2009-10-28 P. Wilhelm , J. A. Niskanen , H. Arenhövel

Measurements of the t-t and p-t coincidence events in the $^3$H ($\alpha$, ttp) reaction have been obtained at $E_\alpha$ incident energy of 67.2 MeV. Various appropriate angular configurations of detectors were chosen in order to observe…

The two-body photodisintegration of $^4$He into a proton and a triton has been studied using the CEBAF Large-Acceptance Spectrometer (CLAS) at Jefferson Laboratory. Real photons produced with the Hall-B bremsstrahlung-tagging system in the…

Nuclear Experiment · Physics 2010-05-12 R. Nasseripour , B. L. Berman , N. Benmouna , Y. Ilieva , J. -M. Laget

The elastic resonance scattering protons decayed from $^{11}$B to the ground state of $^{10}$Be were measured using the thick-target technique in inverse kinematics at the Heavy Ion Research Facility in Lanzhou (HIRFL). The obtained…

The cross sections of the processes $^4$He($\gamma,p$)$^3$H and $^4$He($\gamma,n$)$^3$He are calculated taking into account the full final state interaction via the Lorentz integral transform (LIT) method. This is the first consistent…

The photon-ion merged-beams technique was used at a synchrotron light source for measuring absolute cross sections of double and triple photodetachment of O$^{-}$ ions. The experimental photon energy range of 524-543 eV comprised the…

Atomic Physics · Physics 2016-10-07 S. Schippers , R. Beerwerth , L. Abrok , S. Bari , T. Buhr , M. Martins , S. Ricz , J. Viefhaus , S. Fritzsche , A. Müller

We discuss the stability of homonuclear and heteronuclear mixtures of 3He and 4He atoms in the metastable 2^3S_1 state (He*) and predict positions and widths of Feshbach resonances by using the Asymptotic Bound-state Model (ABM). All…

Quantum Gases · Physics 2010-10-29 M. R. Goosen , T. G. Tiecke , W. Vassen , S. J. J. M. F. Kokkelmans

A benchmark study is performed for the excited state of $^4$He. When the Coulomb interaction is switched off, the $^4$He nucleus exhibits a bound excited state in the vicinity of $p-{}^3$H threshold. As the Coulomb interaction is gradually…

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