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Efros, V.D.; Leidemann, Winfried; Orlandini, Giuseppina

doi:10.1103/physrevlett.78.4015

Cited by 126 publications

(366 citation statements)

References 20 publications

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“…Of particular controversy is the height of the cross section at the peak, alternatively found to be either pronounced or suppressed with differences up to a factor of 2 between different experimental data. With the exception of [17], early evaluations of the 4 He photo-disintegration [18,19,14] showed better agreement with the high-peaked experiments, and, ultimately, with those of Ref. [16].…”

supporting

confidence: 49%

The 4He total photo-absorption cross section with two- plus three-nucleon interactions from chiral effective field theory

Quaglioni

Navrátil

2007

Physics Letters B

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The total photo-absorption cross section of 4 He is evaluated microscopically using two-(NN) and three-nucleon (NNN) interactions based upon chiral effective field theory (χEFT). The calculation is performed using the Lorentz integral transform method along with the ab initio no-core shell model approach. An important feature of the present study is the consistency of the NN and NNN interactions and also, through the Siegert theorem, of the two-and three-body current operators. This is due to the application of the χEFT framework. The inclusion of the NNN interaction produces a suppression of the low-energy peak and enhancement of the high-energy tail of the cross section. We compare to calculations obtained using other interactions and to representative experiments. The rather confused experimental situation in the giant resonance region prevents discrimination among different interaction models.Key words: PACS: 25.20.Dc, 21.60.Cs, 27.10.+h Interactions among nucleons are governed by quantum chromodynamics (QCD). In the low-energy regime relevant to nuclear structure and reactions, this theory is nonperturbative, and, therefore, hard to solve. Thus, theory has been forced to resort to models for the interaction, which have limited physical basis. New theoretical developments, however, allow us to connect QCD with low-energy nuclear physics. Chiral effective field theory (χEFT) [1,2] provides a promising bridge to the underlying theory, QCD. Beginning with the pionic or the nucleon-pion system [3] one works consistently with systems of increasing number of nucleons [4]. One makes use of spontaneous breaking of chiral symmetry to systematically expand the strong interaction in terms of a generic small momentum and takes the explicit breaking of chiral symmetry into account by expanding in the pion mass. Nuclear interactions are nonperturbative, because diagrams with purely nucleonic intermediate states are enhanced [1,2]. Therefore, the chiral perturbation expansion is performed for the potential. The χEFT predicts, along with the nucleon-nucleon (NN) interaction at the leading order, a three-nucleon (NNN) interaction at the next-to-next-to-leading order or N 2 LO [2,5,6], and even a four-nucleon (NNNN) interaction at the fourth Email addresses: quaglioni1@llnl.gov (Sofia Quaglioni), navratil1@llnl.gov (Petr Navrátil). order (N 3 LO) [7]. The details of QCD dynamics are contained in parameters, low-energy constants (LECs), not fixed by the symmetry, but can be constrained by experiment. At present, high-quality NN potentials have been determined at N 3 LO [8]. A crucial feature of χEFT is the consistency between the NN, NNN and NNNN parts. As a consequence, at N 2 LO and N 3 LO, except for two parameters assigned to two NNN diagrams, the potential is fully constrained by the parameters defining the NN interaction. The full interaction up to N 2 LO was first applied to the analysis of nd scattering [6] and later the N 3 LO NN potential was combined with the available NNN at N 2 LO to study the 7 Li stru...

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supporting

confidence: 49%

The 4He total photo-absorption cross section with two- plus three-nucleon interactions from chiral effective field theory

Quaglioni

Navrátil

2007

Physics Letters B

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“…This is an exact method and includes the full dynamics of the chosen Hamiltonian. Related to that are approaches with Stieltjes transforms [46] or transformations by a Lorentz kernel [47].…”

Section: Introductionmentioning

confidence: 99%

“…The group in Trento uses the Lorentz integral transform (LIT) method [47] and employs also hyperspherical harmonic expansions. In this method one avoids the direct treatment of the continuum which requires the handling of the complex boundary conditions.…”

Section: Introductionmentioning

confidence: 99%

Electron and photon scattering on three-nucleon bound states

et al. 2005

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A big spectrum of processes induced by real and virtual photons on the 3 He and 3 H nuclei is theoretically investigated through many examples based on nonrelativistic Faddeev calculations for bound and continuum states. The modern nucleon-nucleon potential AV18 together with the threenucleon force UrbanaIX is used. The single nucleon current is augmented by explicit π-and ρ-like two-body currents which fulfill the current continuity equation together with the corresponding parts of the AV18 potential. We also employ the Siegert theorem, which induces many-body contributions to the current operator. The interplay of these different dynamical ingredients in the various electromagnetic processes is studied and the theory is compared to the experimental data.Overall we find fair to good agreement but also cases of strong disagreement between theory and experiment, which calls for improved dynamics. In several cases we refer the reader to the work of other groups and compare their results with ours. In addition we list a number of predictions for observables in different processes which would challenge this dynamical scenario even more stringently and systematically.

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“…As NN interaction model we employ the semirealistic MTI-III potential [17]. We note in passing that calculations of the total photoabsorption cross section of 3 H and 4 He via the LIT already exist [4,5,7].…”

Section: Resultsmentioning

confidence: 99%

“…Various applications of this method for reactions of nuclei up to four nucleons can be found in the literature (see e.g. [1][2][3][4][5][6][7]). …”

Section: Introductionmentioning

confidence: 99%

Efficient Method for Lorentz Integral Transforms of Reaction Cross Sections

et al. 2003

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The Lorentz Integral Transform (LIT) method is reformulated via the Lanczos algorithm both for inclusive and exclusive reactions. The new technique is tested for the total photoabsorption cross section of 3 H and 4 He. Due to the rapid convergence of the algorithm one has a decrease in cpu time by two orders of magnitude, but at the same time an excellent agreement with the results of a conventional LIT calculation. The present work opens up the possibility of ab initio calculations for inclusive and exclusive processes for A≥6 with inclusion of complete final state interactions.

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Is There a Pronounced Giant Dipole Resonance inH4e?

Cited by 126 publications

References 20 publications

The 4He total photo-absorption cross section with two- plus three-nucleon interactions from chiral effective field theory

The 4He total photo-absorption cross section with two- plus three-nucleon interactions from chiral effective field theory

Electron and photon scattering on three-nucleon bound states

Efficient Method for Lorentz Integral Transforms of Reaction Cross Sections

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