(中国科学院国家天文台)

Flatlargeextradimensions:implicationsforDarkmatterdirectdetectionBoQin(秦波)NationalAstronomicalObservatories,CAS（中国科学院国家天文台）withGlennStarkman(CWRU)&JoeSilk(Oxford)GravityNewtonianNewgravityRFourinteractionsinNatureStronginteraction1Electromagnetic10-2Weakinteraction10-15Gravity10-39Couldgravityplayadominantrolebetweenelementaryparticles?(1)extradimensions(2)darkmatterparticles?(strong,EMforcesabsent)ExtradimensionsThequestionTheoryLargeextradimensions(ADD)EnhanceDM—baryoninteractionExperimentsWIMPDMdirectdetectionsPutlimitonDM—baryoncrosssectioncomparetestSearchesforDarkMatterDirectDetectionIndirectDetectionColliders:LHCFuzzyCDM10-22eV•Axions(CDM)10-6eVWDMkeVMeVCDMMeV•WIMPs(SUSY,neutralino)10-1000GeVDarkmatterdetection2aDMVSdVIndirectDirectnuclearrecoilsnrSNearestMH~0.1pc5xbrighterthanDracoGravity—experimentalGravityhasonlybeenaccuratelymeasuredat~1cmSolarsystem(Pluto)Butwasextrapolated33ordersofmag.downto~10-33cm12orderso.m.,upto1000MpcGravityinlargescales(cosmological)&weakregimes:ModifiedNewtonianDynamics(MOND)Milgrom1983ApJ,Sanders2002,ARA&A,Bekenstein2004PRDa=GM/r2,(aa0)a0~10-8cms-2a=(GMa0)1/2/r,(aa0)PioneerAnomaly:Andersonetal1998PRL,Turyshev2005Am.J.Phys.Negativeenergy?Henry-CouannieretalBulletcluster—EndofMOND?PioneerAnomaly—AMystery?20-70AUap~8*10-8cms-2constant,towardtheSunExperimentaltestsofNewton’slawofgravityatsub-mmscales&SearchesforextradimensionsLongetal.,Nature(2003)Hoyleetal.,PRL(2001);PRD(2004)Chiaverinietal.PRL(2003)(&e.g.hep-ph/0402168forareview)•NodeviationfromNewtonianhasbeenfoundfrom~1cmdownto~20μmGravity—Experimental(smalldistancescales):ExtraDimensions:Klein,Kaluza,1920’•StringtheoryGravitationalbehavioratsmalldistancescales,rR•Sizeofextradimensions:Planckscale~10-33cm•LargeExtraDimensions:3+n+m=9Arkani-Hamed,Dimopoulos&Dvali(ADD)1998,Phys.Lett.BGravity:F~r-(2+n)atrR,R~10(30/n)-17cm(forn=2,R~1mm)Randall&Sundrum(1999)OpensNewWindow:Experimentaltestofstringtheory+Searchesforextradimensions,byprecisemeasurementofgravityatsub-mmscalesADDScenarioSizeoflargeextradimensions:R~10(30/n)-17cm(TeV/MD)1+2/nn=2,R=10-2cm(TeV/MD)2n=3,R=10-7cm(TeV/MD)5/3n=4,R=10-9.5cm(TeV/MD)3/2n=5,R=10-11cm(TeV/MD)7/5n=6,R=10-12cm(TeV/MD)4/3NewFundamentalscale:MD-1~10-17cm,(MD=TeV)1/r2+n—law“New”Gravityin(ADD)largeextradimensionsR:sizeoflargeextradimensionNewtonianNewgravityRGravitationalscatteringcrosssection—Classical122nxnvmGRAA=[(n+1)/(n-1)](n-1)/(n+1)~1422vmGNewtonian:1/r2+n—law“New”Gravity:Gravitationalscatteringcrosssection—Quantum122nxnvmGRAA=[(n+1)/(n-1)](n-1)/(n+1)~1deBrogliewavelengthRorbQ.M.treatmentQ.M.crosssection=2Classicalcrosssection(forbosons)=1/2Classicalcrosssection(forfermions)Conclusions•Largeextradimensions(LED)greatlyenhancegravityinsmalldistancescales•LEDcouldgreatlyincreasethecrosssectionbetweenDMandbaryons•CurrentDMdetectionexperimentsgivestringentconstraintsonflatLED(ADD)•ADDinapparentcontradictionwithDMdirectdetectionlimits•EitherADDscenarioincorrect•orDMmassnotin10GeV-10TeVrange•MeVCDM,orWDM(~keV)?