Derivation of transition density from the observed 4He(e,e')4He(0^+_2) form factor raising the alpha-particle monopole puzzle

Abstract

Recently, the monopole transition form factor of the electron-scattering excitation of the 0^+_2 state (E_x=20.21 MeV) of the 4He nucleus was observed over a broad momentum transfer range (0.5 < q^2 < 5.0 fm^-2) with dramatically improved preision compared with older sets of data; modern nuclear forces, including those derived from the chiral effective field theory, failed to reproduce the form factor, which is called the alpha-particle monopole puzzle. To resolve this puzzle by improving the study of spatial structure of the 0^+_2 state, we derive in this letter a possible 0^+_1 --> 0^+_2 transition density ρ_tr(r) for r > 1 fm from the observed form factor. The shape of the transition density is significantly different from that obtained theoretically in the literature

13 pages, 6 figures, minor changes in descriptions, published virsion

References in corpus (5)

• Local three-nucleon interaction from chiral effective field theory
• Three-Nucleon Low-Energy Constants from the Consistency of Interactions and Currents in Chiral Effective Field Theory
• The Lorentz Integral Transform (LIT) method and its applications to perturbation induced reactions
• Inversion doublets of 3N+N cluster structure in excited states of ${}^4$He
• Is the first excited state of the $\alpha$-particle a breathing mode?