同位旋物理与原子核的相变

NucleonEffectiveMassintheDBHF同位旋物理与原子核的相变

CCASTWorkshop2005年8月19日－8月21日马中玉中国原子能科学研究院

Introduction

Importanceofisospinphysicsinmanyaspects:exoticnuclei;astrophysics;heavyioncollisionetc.

Isospindependenceofmanyquantities:asymmetricenergyasfunctionofdensityeffectiveinteraction;effectivemassetc.Effectivemasscharacterizesthepropagationofanucleoninthestronglyinteractingmedium

reactiondynamicsofnuclearcollisionsbyunstablenucleineutron-protondifferentialcollectiveflow,isospin

equil.neutronstarpropertiesIntroduction

LessknowledgeofisospindependencefromexperimentsStudyfromafundamentaltheoryNNinteraction+SRcorrelationManyworksinnon-relativisticandrelativisticapproachesRMF:perties

isospindep.basedonstablenucleiUs,U0areenergyindep.

OurworkRelativisticapproachDBHF

DefinitionofeffectivemassInnon-relativisticapproacheffectivemassm*describeanindependentquasi-particlemovinginthenucl.medium

characterizesthenon-localityofthemicroscopicpotentialinspace(k-mass)andintime(E-mass)

Jeukenne,Lejeune,Mahuax‘76Effectivemasinnon-relativisticappr.Effectivemassderivedbythetwoequivalentexpression

Jaminon&Mahaux’89Itcanbedeterminedfromanalysesofexperimentaldatainnonrel.ShellmodeloropticalmodelTypicalvalueism*/m~0.70±0.05atE=30MeV

byphenomenologicalanalysesofexperimentalscatteringdataDiracmass

RelativisticapproachEffectivemassisusuallydefinedas

M*=M–Us

Diracmass(scalarmass)

describeanucleoninthemediumasaquasinucleonwitheffectivemassandeffectiveenergy,whichsatisfies

Diracequation.

M*andm*aredifferentphysicalquantitiesCannotbecomparedwitheachother

DiracandLorentzmass

RMFUs

Uo

areconstantinenergy

Us=375±40MeVRing’96~0.60±0.04

Diracmass(scalarmass)

Schroedingerequivalentequation

Schroedingerequvalentpotential,

LorentzmassIsospindep.ofeffectivemass

IsospindependenceofeffectivemssinRMF

,Energydep.ofnucleonself-energyisnotconsidered~0.7

Lorentzmass(vectormass)

Lorentzmass

notrelatedtoanon-localityoftherel.potentials,canbecomparedwiththeeffectivemassinnon-relativistic

appr.

Isospindep.ofLorentzmass,comparewiththatinnon-rel.

DBHFapproachRelativisticapproaches

NN+DBHF

SuccessinNMsaturationproperties

DBHFGMatrix––-Nucleoneffectiveint.

InformationofisospindependenceDiracstructureofGMatrix

Bethe-Salpeterequation

3-dimensionalreduction:(RBBG)

G=V+VgQG

VNNint.(OBEP)gpropergator

Q

Paulioperator

Self-consistentcalculationsimportantG?Us,U0Dirac

eq.s.p.wf

Gmatrix---donotkeepthetrackofrel.structure

Extractthenucleonself-energywithproperisospindep.NewdecompositionofG

DecompositionofDBHFGmatrix

V:OBEP

Gaprojectionmethod(1,)(1,)

Shortrange

m(g/m)2

finite

E.Shiller,H.Muether,EPhys.J.A11(2001)15Nucleonself-energyNucleonself-energyforscattering(kisrelatedwithE)CalculatedinDBHFbyG=V+G

DirectExchange:V

OBEP

Gpseudomeson(1,)(1,)

:vertexa,b

:

isospinindex

singleparticleGreen’sfunctionIsospindep.ofNucleonself-energySingleparticleGreen’sfunctionT

t:

isospinoperator

Directtermsisoscalarisovector

ExchangetermsisoscalarisovectorNucleonpotential

Theopticalpotentialofanucleonthe

nucleonself-energyinthenuclearmedium

Nucleonself-energyinthenuclearmediumwithE>0k–EEincidentenergySelf-Energyofprotonandneutron＝0,.3,.6,1Isospindep.ofeffectivemassinRMF

DiracLorentzNeutron-richasymmetricNM(RMF)

,,

Takingaccountofisovectorscalarmeson

,,,Us

Uo

shouldbeofmomentumandenergydependenceNucleonself-energyinDBHFInneutron-richmatter

Us

UoofneutronsstrongerthanofprotonsDBHF

DiracmassinDBHF:

Lorentzmass:

Isospindep.ofOMPisconsistentwithLanepot.Ma,Rong,Chenetal.,PLB604(04)170B.A.Linucl-th/0404040Summary

IsospindependenceofthenucleoneffectivemassisstudiedinDBHFNewdecompositionofGmatrixisadoptedG=V+G

RMFapproachwithaconstantself-energycannotaccounttheisospindep.ofm*properly

Isospindep.ofeffectivemassThanks

G

UsUo

Singleparticleenergy

R.

Brockmann,R.MachleidtPRC42(90)1965

Momentumdep.ofUs&U0areneglected

workswellinSNM,inconsistentresultsinASNM

wrongsignoftheisospindependenceAsymmetricNM

Inconsequentialresultsforasymmetric

nuclearmatter

UsU0

isospindep.withawrongsignS.Ulrych,H.Muether,Phys.Rev.C56(1997)1788Projectionmethod

Projectionmethod

F.Boersma,R.Malfliet,PRC49(9