In this paper we study the possibility of probing for the absolute neutrino mass and its variation with short Gamma Ray Burst (GRB). We have calculated the flight time difference between a massive neutrino and a photon in two different approaches to mass v

TestingMassVaryingNeutrinoWithShortGammaRayBurst

InstituteofHighEnergyPhysics,ChineseAcademyofSciences,

P.O.Box918-4,Beijing100049,P.R.Chinaand

b

DepartmentofAstronomy,NanjingUniversity,Nanjing210093,P.R.China

Inthispaperwestudythepossibilityofprobingfortheabsoluteneutrinomassandits

variationwithshortGammaRayBurst(GRB).Wehavecalculatedthe ighttimedi erencebetweenamassiveneutrinoandaphotonintwodi erentapproachestomassvaryingneutrinos.Firstlyweparametrizetheneutrinomassasafunctionofredshiftinamodelindependentway,thenweconsidertwospeci cmodelswheretheneutrinomassvariesduringtheevolutionoftheQuintessence elds.Ourcalculationsshowingeneralthevalueofthetimedelayischangedsubstantiallyrelativetoaconstantneutrinomass.Furthermoreournumericalresultsshowthatthe ighttimedelayinthesemodelsisexpectedtobelargerthanthedurationtimeoftheshortGRB,whichopensapossibilityoftestingthescenarioofmassvaryingneutrinowiththeshortGRB.

a

HongLia, ZigaoDaib,andXinminZhanga

arXiv:hep-ph/0411228v1 17 Nov 2004

IntherecentyearsastronomicalobservationsshowthattheUniverseisspatiallyacceleratingatthepresenttime[1].Thesimplestaccountofthiscosmicaccelera-tionseemstobearemnantsmallcosmologicalconstant,butitsu ersfromthedi cultiesassociatedwiththe netuningandcoincidenceproblem,somanyphysicistsareattractedwiththeideathattheaccelerationisdrivenbydynamicalscalar elds,suchasQuintessence.Inmodelsofdarkenergywitharemnantsmallcosmologicalcon-4

stantor(trueorfalse)vacuumenergyρ～(2×10 3ev).Thisenergyscale～10 3evissmallerthantheenergyscalesinparticlephysics,butinterestinglyiscompara-bletotheneutrinomasses.Thisindicatesapossibleconnectionbetweentheneutrinosandthedarkenergy.Furthermore,inQuintessence-likemodelsmQ～10 33eV,whichsurprisinglyisalsoconnectedtotheneutrinomassesviaasee-sawformulamQ～m2ν/MplwithMpltheplanckmass.

Istherereallyanyconnectionsbetweentheneutrinosanddarkenergy?Giventheargumentsaboveitisquiteinterestingtomakesuchaspeculationonthisconnec-tion.Ifyes,howeverintermsofthelanguageoftheparticlephysicsitrequirestheexistenceofnewdynam-icsandnewinteractionsbetweentheneutrinoandthedarkenergysector.Recentlytherearesomestudiesintheliteratureonthepossiblerealizationofthemodelsonneutrinosanddarkenergy[2,3,4,5,6,7,8,9,10,11].Oneoftheinterestingpredictionsofthesemodels[12]isthatneutrinomassesarenotconstant,butvaryasafunc-tionoftimeduringtheevolutionoftheuniverse.Inthispaperwestudythepossibilityoftestingthisscenarioofmassvaryingneutrinoswiththegammarayburst.Therearestrongevidencesforthenon-vanishingneu-trinomassesfromtheneutrinooscillationexperiments,howevertheneutrinomassesgivenbythesolarneutri-nosandatmosphereneutrinosexperimentsarenotthe

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