G-factor - chemeurope.com

For the acceleration-related quantity in mechanics, see g-force. A g-factor (also called g value or dimensionless magnetic moment) is a dimensionless quantity ... Mywatchlist my.chemeurope.com  Withanaccoutformy.chemeurope.comyoucanalwaysseeeverythingataglance–andyoucanconfigureyourownwebsiteandindividualnewsletter. Mywatchlist Mysavedsearches Mysavedtopics Mynewsletter Registerfreeofcharge Login  Keeploggedin Forgotyourpassword? Touseallfunctionsofthispage,pleaseactivatecookiesinyourbrowser. Login Register   DeutschEnglishFrançaisEspañol HomeEncyclopediaG-factor G-factor Template:DISPLAYTITLE:g-factor Fortheacceleration-relatedquantityinmechanics,seeg-force. Ag-factor(alsocalledgvalueordimensionlessmagneticmoment)isadimensionlessquantitywhichcharacterizesthemagneticmomentandgyromagneticratioofaparticleornucleus.Itisessentiallyaproportionalityconstantthatrelatestheobservedmagneticmomentμofaparticletotheappropriateangularmomentumquantumnumberandthefundamentalquantumunitofmagnetism,theBohrmagneton. Additionalrecommendedknowledge WhatistheSensitivityofmyBalance? Weighingtherightway DailyVisualBalanceCheck Contents 1Electrong-factors 1.1Electronsping-factor 1.2Electronorbitalg-factor 1.3Landég-factor 2NucleonandNucleusg-factors 3Muong-factor 4Measuredg-factorValues 5Notesandreferences 6Seealso Electrong-factors Therearethreemagneticmomentsassociatedwithanelectron:Onefromitsspinangularmomentum,onefromitsorbitalangularmomentum,andonefromitstotalangularmomentum(thequantum-mechanicalsumofthosetwocomponents).Correspondingtothesethreemomentsarethreedifferentg-factors: Electronsping-factor Themostfamousoftheseistheelectronsping-factor,gS(moreoftencalledsimplytheelectrong-factor,ge),definedby whereμSisthetotalmagneticmomentresultingfromthespinofanelectron,Sisthemagnitudeofitsspinangularmomentum,andμBistheBohrmagneton.Thez-componentofthemagneticmomentthenbecomes ThevaluegSisroughlyequaltotwo,andisknowntoextraordinaryaccuracy.[1][2]Thereasonitisnotpreciselytwoisexplainedbyquantumelectrodynamics.[3] Electronorbitalg-factor Secondly,theelectronorbitalg-factor,gL,isdefinedby whereμListhetotalmagneticmomentresultingfromtheorbitalangularmomentumofanelectron,Listhemagnitudeofitsorbitalangularmomentum,andμBistheBohrmagneton.ThevalueofgLisexactlyequaltoone,byaquantum-mechanicalargumentanalogoustothederivationoftheclassicalmagnetogyricratio.Foranelectroninanorbitalwithamagneticquantumnumberml,thez-componentoftheorbitalangularmomentumis which,sincegL=1,isjustμBml Landég-factor Thirdly,theLandég-factor,gJ,isdefinedby whereμisthetotalmagneticmomentresultingfrombothspinandorbitalangularmomentumofanelectron,J=L+Sisitstotalangularmomentum,andμBistheBohrmagneton.ThevalueofgJisrelatedtogLandgSbyaquantum-mechanicalargument;seethearticleLandég-factor. NucleonandNucleusg-factors Protons,neutrons,andmanynucleihavespinandmagneticmoments,andthereforeassociatedg-factors.Theformulaconventionallyusedis whereμisthemagneticmomentresultingfromthenuclearspin,Iisthenuclearspinangularmomentum,andμpisthenuclearmagneton. Muong-factor Themuon,liketheelectronhasag-factorfromitsspin,givenbytheequation whereμisthemagneticmomentresultingfromthemuon’sspin,Sisthespinangularmomentum,andmμisthemuonmass.   Themuong-factorcanbeaffectedbyphysicsbeyondtheStandardModel,sohasbeenmeasuredveryprecisely,inparticularattheBrookhavenNationalLaboratory.AsofNovember2006,theexperimentallymeasuredvalueis2.0023318416withanuncertainyof0.0000000013,comparedtothetheoreticalpredictionof2.0023318361withanuncertaintyof0.0000000010[4].Thisisadifferenceof3.4standarddeviations,suggestingbeyond-the-Standard-Modelphysicsmaybehavinganeffect. Measuredg-factorValues ElementaryParticleg-factorUncertainty Electronge 2.00231930436220.0000000000015 Neutrongn 3.826085460.00000090 Protongp 5.5856947010.000000056 Muongμ 2.00233183960.0000000012 CurrentlyacceptedNISTg-factorvalues[1] Itshouldbenotedthattheelectrong-factorisoneofthemostpreciselymeasuredvaluesinphysics,withitsuncertaintybeginningatthetwelfthdecimalplace. Notesandreferences ^SeeCERNcourierarticle ^BOdom,DHanneke,BD'UrsoandGGabrielse(2006)."Newmeasurementoftheelectronmagneticmomentusingaone-electronquantumcyclotron".PhysicalReviewLetters97(3):030801.doi:10.1103/PhysRevLett.97.030801. ^SJBrodsky,VAFranke,JRHiller,GMcCartor,SAPastonandEVProkhvatilov(2004)."Anonperturbativecalculationoftheelectron'smagneticmoment".NuclearPhysicsB703(1-2):333-362.doi:10.1016/j.nuclphysb.2004.10.027. ^ Hagiwara,K.;Martin,A.D.andNomura,DaisukeandTeubner,T.(2006)."Improvedpredictionsforg-2ofthemuonandalpha(QED)(M(Z)**2)". Seealso anomalousmagneticdipolemoment Electronmagneticdipolemoment Category:Atomicphysics   ThisarticleislicensedundertheGNUFreeDocumentationLicense.ItusesmaterialfromtheWikipediaarticle"G-factor".AlistofauthorsisavailableinWikipedia. TopicsA-Z 0-9 a b c d e f g h i j k l m n o p q r s t u v w x y z Alltopics Totop Aboutchemeurope.com Readwhatyouneedtoknowaboutourindustryportalchemeurope.com. findoutmore > AboutLUMITOS FindoutmoreaboutthecompanyLUMITOSandourteam. findoutmore > AdvertisewithLUMITOS FindouthowLUMITOSsupportsyouwithonlinemarketing. findoutmore > TheLUMITOSindustryportals ©1997-2022LUMITOSAG,Allrightsreserved Imprint | TermsandConditions | Dataprotectionpolicy https://www.chemeurope.com/en/encyclopedia/G-factor.html ©1997-2022LUMITOSAG Determinationof4productpropertiesinlessthan20sec Encyclopedia Yourbrowserisnotcurrent.MicrosoftInternetExplorer6.0doesnotsupportsomefunctionsonChemie.DE