Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · nucl-th/0107011

Spectroscopic amplitudes and microscopic substructure effects in nucleon capture reactions

Jutta Escher·Byron K. Jennings·Helmy S. Sherif
View original source ↗Read source document ↗Export metadata ↓

Abstract

Spectroscopic amplitudes play an important role in nuclear capture reactions. These amplitudes are shown to include both single-particle and polarization effects: the former through their spatial dependence and the latter through their normalization (the spectroscopic factors). Coupled-channels equations are developed for the spectroscopic amplitudes. These equations serve as a convenient starting point for the derivation of several approximations: Hartree, Hartree-Fock and two different single-particle models. The single-particle models include antisymmetry in different ways, but both miss many-body effects. Therefore, cross sections calculated with either of these models need to be multiplied by the spectroscopic factor.

Explore related subjects

nucl-th

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jutta Escher, Byron K. Jennings, Helmy S. Sherif. 2001-10-10. Spectroscopic amplitudes and microscopic substructure effects in nucleon capture reactions. https://doi.org/10.1103/physrevc.64.065801

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Intertwined quantum phase transitions in the even-even $^{90-100}$Sr isotopes

The even-even $^{90-100}$Sr isotopes are identified as a region of intertwined quantum phase transitions (IQPTs). In this scenario, a quantum phase transition involving the crossing of normal and intruder configurations is accompanied by a shape evolution within the intruder configuration. Using the interacting boson model with configuration mixing (IBM-CM), its is shown that the strontium chain exhibits the IQPT scenario, where the intruder configuration evolves from a near-spherical structure in $^{90\text{--}96}$Sr to a deformed one in $^{98,100}$Sr, while the normal and intruder configurations cross between $^{96}$Sr and $^{98}$Sr. As a result, the ground state changes abruptly from a weakly collective normal configuration to a deformed intruder configuration. Evidence for this scenario is provided by a detailed comparison with experimental excitation energies, isotope shifts, and monopole $E0$ transition strengths, together with the configuration and $n_d$ decompositions of the calculated wave functions. The results place the strontium isotopes alongside the neighboring zirconium chain as a realization of IQPTs in the intricate $A\approx100$ region.

nucl-th↗
arXiv2026

Imprints of the nuclear liquid-gas phase transition on net-baryon number fluctuations

We investigate net-baryon number fluctuations in the high-density, low-temperature region of the QCD phase diagram using the parity-doublet model (PDM) under the mean-field approximation. We compute the fluctuation ratios up to sixth order around the nuclear liquid-gas (LG) phase transition, where the high-order ratios are particularly sensitive. To connect the results with heavy-ion experiments, we test several different scenarios of chemical freeze-out. We find that near the LG transition the extracted fluctuations depend strongly on the choice of freeze-out curve. We self-consistently determine four freeze-out points from preliminary results of the STAR Collaboration. Comparing the experimental data with the PDM results along these four points, we find that the model describes the low energy ($\sqrt{s_{NN}}\lesssim$ 4 GeV) data well. This suggests that nucleon interactions and the LG phase transition may contribute significantly to the fluctuations in low energy heavy-ion collisions.

nucl-th↗
arXiv2026

Strangeness Production in Heavy-Ion Collisions: Color Ropes or Hydrodynamic Evolution?

We investigate strangeness production and transverse dynamics in heavy-ion collisions at $\sqrt{s_{\mathrm{NN}}}\approx 2.5-20~\mathrm{GeV}$ using the transport approach SMASH (Simulating Many Accelerated Strongly-interacting Hadrons), its extension with rope hadronization, and the SMASH+vHLLE hybrid approach. Results from the Pythia-based heavy-ion model Angantyr, with and without rope hadronization, are included for comparison. We study midrapidity particle yields and average transverse masses as functions of the number of wounded nucleons, as well as their energy dependence. For the $K^+/π^+$ ratio, SMASH+vHLLE overpredicts strangeness production at low energies but describes the higher-energy behavior reasonably well. SMASH+Ropes reproduces the ratio up to $\sqrt{s_{\mathrm{NN}}}\sim 10~\mathrm{GeV}$ but does not capture the turnover at higher energies. In contrast, the transverse-mass observables favor the hybrid approach, while the non-thermal models considered here do not generate sufficient collective transverse expansion. These results show that strangeness enhancement alone does not uniquely distinguish microscopic string interactions from a locally equilibrated medium. Simultaneously constraining strangeness production and transverse dynamics is therefore essential for disentangling thermal and non-thermal mechanisms in heavy-ion collisions.

nucl-th↗