ImpactObjec,ves§  Determinethesizeoftheatomicnucleuscalcium-48.Forthenucleus

calcium-48,whichconsistsof20protonsand28neutrons,theneutrondistribu>onextendsbeyondtheprotondistribu>onandtherebysetstheactualsizeofthenucleus

§  Ab-ini>ocomputa>onoftheneutronandweak-chargedistribu>onsof48Cabasedonstate-of-the-artop>mizedchiraleffec>veinterac>ons

§  Provideaconstraintontheradiusofaneutronstar

§  Provideacri>calbridgebetweenstate-of-the-artabini,ocalcula>onsandcalcula>onsbasedonnucleardensityfunc>onaltheory(DFT)

§  NeutronradiuswillbemeasuredbytheCREX(Calcium-RadiusEXperiment)atJeffersonLaboratory,andthedipolepolarizabilityispresentlybeinganalyzedbytheDarmstadt-Osakacollabora>on

§  Thesizeoftheatomicnucleus48Caimpactsthesizeofaneutronstar

§  KnowledgeoftheneutronskinofatomicnucleisofarmostlybasedonnuclearDFT

§  Theatomicnucleuscalcium-48providesamee>ngpointforab-ini>ocomputa>onsandcalcula>onsbasedonnuclearDFT

§  Computedthesizeofatomicnucleus48Cafromfirstprinciples

§  Extendedthereachofreliableabini>ocomputa>onstomedium-massnuclei

§  Revealedthattheneutronskinofcalcium-48issignificantlythinnerthanpreviouslythought,whiletherelateddipolepolarizabilityisconsistentwithcalcula>onsbasedonnuclearDFT

§  Foundneutronskintobeindependentoftheemployedchiraleffec>veinterac>onsbetweenthecons>tuentnucleons—protonsandneutrons

Accomplishments

Compu&ngthesizeoftheatomicnucleuscalcium-48

Cap,on:Imageconnectsthefirst-principlescomputa,onofthecalcium-48nucleuswiththeneutronstaratthecenteroftheCrabNebula.Understandingtheneutrondistribu,onofanatomicnucleusallowsresearcherstoconstrainthesizeofaneutronstar.Theseobjectsdifferinsizeby18ordersofmagnitude.Imagecredit:OakRidgeNa,onalLaboratory,U.S.Dept.ofEnergy;conceptualartbyLeJeanHardinandAndySproles

Reference:G.Hagenetal.,NaturePhysics(2015),doi:10.1038/nphys3529Contact:G.Hagen,hageng@ornl.gov