Isospin triplet A=14: search for states with enhanced radii

A S Demyanova,Yu B Gurov,W H Trzaska,V I Starastsin,A N Danilov,T L Belyaeva,T I Leonova,A A Ogloblin,S A Goncharov,S V Dmitriev

doi:10.1088/1742-6596/1690/1/012034

Abstract

This article is devoted to study of isobar-analogue states 1− in triplet A=14: 14C-14N-14O. Previously signs of neutron halo in the 1−, 6.09 MeV state of 14C were obtained by two independent groups. In this article we propose to study neighbouring nuclei 14N and 14O using the Modified diffraction model (MDM) method and the method of Asymptotic normalization coefficients (ANC). Methods were applied to experimental differential cross sections of 14C(α,α)14C scattering and reactions 13C(3He,d)14N and 14N(3He,t)14O. MDM and ANC gave practically similar within errors radii for the studied 1− states: the 6.09 MeV state in 14C – 2.7±0.1 fm, the 8.06 MeV state in 14N – 2.7 ± 0.1 fm, the 5.17 MeV state in 14O – 2.6 ± 0.2 fm. Moreover, the signs of proton halo in the 1− state of 14N were obtained for the first time.

Highlights

Discovery of the neutron halo in the ground states of some light nuclei [1] was one of the most striking discoveries in nuclear physics made at the end of the last century
Modified diffraction model (MDM) application to charge-exchange reactions In order to measure nuclear radii in unbound states, we propose to use the MDM [13] for the analysis of inelastic differential cross sections
Two independent methods Asymptotic normalization coefficients (ANC) and MDM were used for analysis of the isobar analogue states (IAS) 1− states in members of isobaric triplet A=14

Summary

Introduction

Discovery of the neutron halo in the ground states of some light nuclei [1] was one of the most striking discoveries in nuclear physics made at the end of the last century. According to [2,3,4,5,6] the halo signs are (i) a large probability for finding a cluster component in the total many-body wave function and (ii) a large spatial extension implying that more than half of the probability should be in the classically forbidden region outside the outer classical turning point. Liu and collaborators [10] observed signs of neutron halo for states 6.09 MeV, 1− and 6.90 MeV, 0− in 14C This result was obtained in ANC analysis of experimental data 13C(d,p)14C at E(d) = 17.7 MeV [11].

Methods

Results

Conclusion