Structure of the Particle-Hole Amplitudes in No-core Shell Model Wave Functions无核壳模型波函数中粒子空穴振幅的结构

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1、StructureoftheParticle-HoleAmplitudesinNo-coreShellModelWaveFunctionsA.C.Hayes1,A.A.Kwiatkowski21TheoreticalDivision,LosAlamosNationalLaboratory,LosAlamos,NewMexico875452NationalSuperconductingCyclotronLaboratory,MichiganStateUniversity,EastLansing,Mic

2、higan48824612Westudythestructureoftheno-coreshellmodelwavefunctionsforLiandCbyinvestigatingthegroundstateandfirstexcitedstateelectronscatteringchargeformfactors.Inbothnuclei,largeparticle-hole(ph)amplitudesinthewavefunctionsappearwiththeoppositesigntoth

3、atneededto′reproducetheshapeofthe(e,e)formfactors,thechargeradii,andtheB(E2)valuesforthelowesttwostates.Thedifferenceinsignappearstoarisemainlyfromthemonopole∆¯hω=2matrixelementsofthekineticandpotentialenergy(T+V)thattransformundertheharmonicoscillatorS

4、U(3)symmetriesas(λ,µ)=(2,0).Thesearedifficulttodetermineself-consistently,buttheyhaveastrongeffectonthestructureofthelow-lyingstatesandonthegiantmonopoleandquadrupoleresonances.TheLee-Suzukitransformation,usedtoaccountfortherestrictednatureofthespaceinter

5、msofaneffectiveinteraction,introduceslargehigher-order∆¯hω=n,n>2,phamplitudesinthewavefunctions.Thelatterphexcitationsaggravatethedisagreementbetweentheexperimentaland′predicted(e,e)formfactorswithincreasingmodelspaces,especiallyathighmomentumtransfers.

6、6ForsufficientlylargemodelspacesthesituationbeginstoresolveitselfforLi,buttheconvergenceisslow.Aprescriptiontoconstrainthephexcitationswouldlikelyaccelerateconvergenceofthecalculations.PACSnumbers:21.60.-n,21.60.Cs,21.60.De,24.30.Cz,25.30.Bf,25.30.DhI.IN

7、TRODUCTIONtwo-bodymeson-exchangecurrentsdonotcontributesig-nificantlytotheformfactorsbelowabout2fm−1[8].Inall(e,e′)calculationspresentedhereweuseabareone-Theabinitiono-coreshellmodel(NCSM)permitscal-bodyoperator;asdiscussedbelow,theintroductionofculatio

8、nsofwavefunctionsinverylargemodel-spaceaneffectiveoperator(tocompensateforthetruncatedsizesfornucleiatthebeginningofthep-shell.For6Limodelspace)doesnotsignificantlyaffectourconclusions.calculationsupto16¯hωhavebeenachieved[1].AmongOurfirstm