Measurement of proton-distribution radii of neutron-rich nitrogen isotopes

¹ Astronomy and Physics Department, Saint Mary’s University Halifax, NS B3H 3C3, Canada
² GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291, Darmstadt, Germany
³ Justus-Liebig University, 35392, Giessen, Germany
⁴ TRIUMF, Vancouver BC V6T 4A3, Canada
⁵ Department of Physics, Hokkaido University, Sapporo 060-0810, Japan
⁶ Physics Division, Oak Ridge National Laboratory, Oak Ridge TN 37831, USA
⁷ Department of Physics and Astronomy, University of Tennessee, Knoxville TN 37996, USA
⁸ Department of Physics, Nihon University, Setagaya-ku, Tokyo 156-8550, Japan
⁹ Universidad de Santiago de Compostela, E-15706, Santiago de Compostela, Spain
¹⁰ Faculty of Mathematics and Physics, Comenius University, 84215, Bratislava, Slovakia
¹¹ Department of Physics and Atmospheric Science, Dalhousie University, Halifax NS B3H 4R2, Canada
¹² RCNP, Osaka University, Mihogaoka, Ibaraki Osaka 567 0047, Japan
¹³ School of Physics and Nuclear Energy Engineering and IRCNPC, Beihang University, Beijing 100191, China

^* e-mail: s.bagchi@gsi.de

Published online: 4 December 2019

Abstract

Measurement of root-mean-square radii of proton distributions of ^17–22N from charge-changing cross section shows the emergence of thick neutron skin towards the neutron-drip line. Signature of N = 14 shell gap has been found in nitrogen isotopes along with the emergence of neutron halo in ²²N. The measured radii are in good agreement with the shell model calculations.