harvard grant

RENEWAL PROPOSALBudget Years 2006-2008forParticle Physics and Cosmology ResearchbyA Faculty Group inTHE DEPARTMENT OF PHYSICSHARVARD UNIVERSITYCambridge, MassachusettsMay 2005 Grant DE-FG02-91ER40654Between the Department of Energyand thePresident and Fellows of Harvard College HARVARD UNIVERSITY Laboratory forParticle PhysicsandCosmology George Branden burg, Gary Feldman, Andrew Foland, Melissa Franklin, JohnHuth, Masahiro Morii, Christopher Stubbs DOE GrantDE-FG02-91ER40654 1Overview 1.1OurMotiv ation: Fundamen talPhysics ThequesttounderstandthefundamentallawsofNaturestretchesbackovertwomillennia totheancientGreeks.Newton'sdiscoveryofhislawsofmotionthreehundredyearsago showedthattheunderlyingfundamentallawsaremostconciselyandbeautifullydescribed inthelanguageofmathematics, markingthebirthofthemoderneraofphysics.Inthe twentiethcentury,thisjourneycontinuedwithtworevolutionarydevelopments{relativity andquantummechanics{andmuchofthelatterhalfofthetwentiethcenturywasdevoted toanattemptatasynthesisoftheseideas.Thisculminatedinthedevelopmentofthe StandardModelofparticlephysics,describingtheweakandelectromagnetic interactions withinauni¯edframeworkthatprovidesanastonishinglyaccuratedescriptionofthese forcesdowntodistancesaboutahundredththesizeofaproton.Inparallelwiththis,an understanding oftheuniverseonthelargestscalesbeganwiththediscoverythattheuniverse isexpanding.Theobservationofthecosmicmicrowavebackgroundradiationcon¯rmeda centralpredictionofthe\BigBang"cosmology,andprovidedadeeplinkbetweenthestudy ofphysicsatthelargestandsmallestscales. Despitethisprogress,ourdescriptionofthefundamentallawsofNatureremainsself- contradictoryandincomplete.Theessentialquestionsaresimpletostate.Forinstance,how didtheuniversebegin?Isthereauni¯eddescriptionofallforces?Howistheexistenceof gravityreconciledwithquantummechanics?Whatistheoriginofmass?Isouruniverse unique?Doblackholesdestroyinformation?Whataretheoriginsoftheenergyanddark matterthatseemtodominatethedynamicsoftheuniverseonthelargestscales?These questionsareallintimatelyrelated,andFundamentalPhysicsisdevotedtounravelingthese mysteriesandothersattheedgesofourunderstanding ofthefundamentallawsofNature. Thiswillrequireintensivecollaborativee®ortsbetweentheoristsandexperimentalistsin 2 Section 1:LPPC high-energyphysicsandcosmology.HereatHarvardthisworkisbeingundertakenbythe TheoreticalInstituteontheFundamentalLawsofNatureandtheLaboratoryforParticle PhysicsandCosmology(LPPC).Thisproposaldescribesthecurrentprogramsandfuture plansofthephysicistsatLPPC. Weareonthethresholdofanincrediblyexcitingnewerainexperimentalparticlephysics: thenextgenerationofparticleacceleratorswillfullyprobetheweakscale,startingwiththe LargeHadronCollider(LHC)inEurope,settobeginoperationin2007.WeexpecttheLHC willrevealsomefundamentallynewphysicalprinciplesbeyondthestandardmodel.These mightincludethediscoveryofthe¯rstnewspacetimesymmetrysinceEinstein:supersym- metry,additionaldimensionsofspace,orevenobservablee®ectsofstringtheory.Wehave alreadymademajorcontributionstothedevelopmentandconstructionoftheATLASmuon systemattheLHCandhavebeenengagedinthedevelopmentofthecomputinggridthat willbenecessarytoanalyzethevoluminousdataexpectedfromATLAS.Nowweareeagerly anticipatingthesearchfornewphysics. Non-accelerator experimentshavemadetremendousadvancesoverthepastdecadeinthe studyofneutrinooscillations.Wearenowsettoextendourunderstanding oftheseelusive particles,whoseanomalouslylowmassescangiveusawindowonthephysicsofgrand uni¯cationandwhoseCPviolationmaybeinvolvedintheunderstanding ofthematter dominanceoftheuniversethroughleptogenesis.TheHarvardgroupisplayingaleadingrole intheMINOSexperimentandthefutureNOºAexperiment.Theseexperimentsarethe ¯rstandsecondstepsinaprogramtodeterminethemassorderingofneutrinostatesand tomeasureCPviolationintheleptonsector. LikewisetheobservationoftheacceleratingexpansionoftheUniversehasbeenoneof themostsigni¯cantexperimentalresultinfundamentalphysicsofthelastquartercentury, andwehaveyettocometotermswithit.Weintendtoextendourparticipationinthe experimentalandobservationalprojectsthatarebeingundertakentostudythenatureof thedarkenergy.TheseinitiativesincludetheLargeSynopticSurveyTelescope(LSST),a ground-basedfacilitynowinthedesignstage,complementedbynewsatellite-bornefacilities suchastheJointDarkEnergyMission(JDEM).Formanyyearstheoristsassumedthat somedeepprinciplemadethevacuumenergyexactlyzero,but¯veyearsago,cosmological observationsrevealedamajorshock:infacttheuniverseisnowaccelerating,andthemostly likelyexplanationisthatthevacuumenergyisnotzero.MembersofourDarkEnergygroup participatedinthisdiscovery,andwecontinuetoplayaleadershiproleinthisimportant science.Understanding thedarkenergyisoneofthemostpressingoutstandingproblemsin Section 1:LPPC 3 thephysicalsciencestoday,andweintendtobeattheforefrontofthisresearch. Ourgroupshaveparticipatedinanumberofotherexcitingdiscoveriesandopportunities intheexperimentalexplorationoffundamentalphysics.OurCDFgrouphelpedbuildthe CDFdetectorandparticipatedinthediscoveryofthetopquark.Nowtheywillbecontinuing theirinvestigationoftopandbottomquarkphysicsuntilthestartoftheLHC.TheStandard Modelalsopredictsspeci¯cdi®erencesinthebehaviorofmatterandanti-matter,whichwe areactivelystudyingasmembersoftheBaBarcollaboration. 1.2OurApproac h:DiverseTechniques, Shared Infrastructure Wewillusebothastrophysicalandparticlephysicstechniquestoaddressthemostpressing openquestionsinfundamentalphysics.Thesetwoapproacheshaveremarkablysimilar modesofresearch,andcommoninfrastructure needs.Apparatusisdevelopedoncampus andthendeployedtoo®-campusfacilitiesforoperationanddataacquisition.Inbothcases, theprojectstypicallyinvolvelargeinternationalcollaborations.Oncedataareacquired,the resultsarebroughtbacktocampusforre¯nedanalysis.Forbothacceleratorandtelescope projects,datasetsareintheTerabytetoPetabyteregime. OurexperimentalprogramisbasedatHarvard'sLaboratoryforParticlePhysicsand Cosmology(LPPC),whichhascomputingfacilitiesfordataanalysis,engineeringsupport fordetectorR&D,andshopsforthefabricationofdetectorsandtheirreadoutsystems.This yearwechangedournamefromHighEnergyPhysicsLaboratorytore°ectthediversi¯ca- tionofourprogram.Oureducationale®ortsareconcentratedingraduateandpostdoctoral education,wherewearerequestingsupportfortwelveresearchstudents.Inaddition,un- dergraduatestudentsworkonprojectsatLPPCpart-timeduringtheacademicyearand full-timeoverthesummer.Wehaverecentlymovedtonewquarters:ouro±cesandcom- putersarelocatedinhistoricPalfreyHouse,whileourmachineshopandtestlabsarelocated intheformerCambridgeElectronAccelerator.Inseveralyearsweplantobemovinginto alargerandmoremodernspaceintheNWinterdisciplinary sciencebuildingwhichisnow beingbuilt. ThefacultygroupleadingtheLPPCresearchprogramatHarvardincludes: Dr.GeorgeBrandenburgisaSeniorResearchFellowandtheDirectorofLPPC.He hasbeenworkingonbothBABARandATLAS,butwillbefulltimeonATLASasofthis summer.OnATLAShewasresponsibleforthedevelopmentandproductionofmuonsystem front-endelectronics,andwillnowbeconcentratingonmuonsoftwareandthecommissioning ofthemuonsystem. 4 Section 1:LPPC Prof.GaryFeldmanleadsourNeutrinogroupontheMIPP,MINOS,andNOºAexperi- ments.Heisconcentratingallofhisresearche®ortstowardthestudyofneutrinooscillations. Heisservingasco-spokespersonforNOºA. Prof.AndrewFolandiscurrentlydevotinghisfulle®orttocollectionandanalysisofthe datafromtheCDFdetectorattheTevatron.Hehasbeenconcentratingonbuildingthetools andtechniquesfordetailedcharacterization oftopproperties.Overthenextthreeyears, ProfessorFolandwillbetransitioningtotheneutrinophysicse®ortonNOvAasstudents ontheCDFexperiment¯nishtheirtheses. Prof.MelissaFranklinistheChairoftheLPPCFacultyCommittee.Shehasbeen amemberoftheCDFcollaborationsince1983.Havingworkedonthreedetectors,the plugcalorimeter,thecentralmuonextensionandthecentraloutertracker,andnumerousa physicsanalysesfromearlystudiesoftheZbosonthroughmeasurementsoftheWmassto studiesofthetopquark.Shewillcontinuetocontributetothedatatakingandanaylsisof CDFoverthenextfewyears,whilerampingdownherinvolvement.ProfessorFranklinhas recentlybecomeinterestedinexploringthesubjectofdarkmatteranddarkenergyandis currentlyworkingonaprojectwithProfessorStubbsinvolvingthemeasurementofredshifts ofgalacticclustersinconjunctionwiththeSZGalacticSurveyArray.Overthenextthree yearsshewillmovehermajorresearchfocustodarkmatter/darkenergyasacollaborator ononeofanumberofproposedprojects. Prof.JohnHuthworksonATLASwhereheistheU.S.AssociateProjectManager forPhysicsandComputing.Hisresearchinterestsarethesearchforsupersymmety,extra dimensions,andotherphysicsbeyondthestandardmodel.Heiscurrentlyinthesecond yearofathree-yeartermasPhysicsDepartmentChair. Prof.MasahiroMoriicurrentlyfocuseshisresearchintheanalysisofthephysicsdata fromtheBaBarexperiment.Hewillmaintainhismainresponsibilitywiththeexperiment| coordinationoftheanalysisofBsemileptonicdecays|fortheimmediatefuture.Inthe nextthreeyears,MoriiplanstoincreasehisinvolvementwiththeATLASexperimentasthe BaBarexperimentcompletesitsdatatakingruns. Prof.ChristopherStubbs'researchprogramfocusesontheastrophysicalevidencefor physicsbeyondthestandardmodel,inparticularthepressingopenquestionsofdarkenergy anddarkmatter.Heisplayingascienti¯candtechnicalleadershiproleintheLargeSynoptic SurveyTelescope(LSST),anambitiousground-basedfacilitythatisbeingdesignedtoprobe thenatureofthedarkenergy. Inadditiontothefacultygroupresponsibleforourprogramtherearecurrently¯ve Section 1:LPPC 5 postdoctoralresearchassociates:Dr.KevinBlackwiththeATLASgroup,Drs.Sebastian Grinstein,andJo~aoGuimar~aesdaCostawiththeCDFgroup;Dr.JinweiWuwiththe BABARgroup;andDr.MaylySanchezwiththeNeutrinogroup. 1.3LPPC Shared Facilities TheLaboratoryforParticlePhysicsandCosmologyfacilitiesareavailabletoallthegroups onanequalbasis.Ourengineersandshopsarecapableofdesigningandbuildingstateofthe artdetectorsystemsandtheirassociatedreadoutelectronics.Wehaveproducedprototypes fordetectorR&Daswellascompletemajorsystemsforallofourgroups.Examplesof projectscompletedinthemachineshopincludetheCDFCentralTrackerUpgrade,CDF CentralMuonSystemExtension,aredesignedInteractionRegionforCLEO,andtheNO- MADHadronCalorimeter.WearecurrentlycompletingtheproductionofATLASMuon DriftTubechambers.Theelectronicsshophasproducedreadoutelectronicsformostofour detectors,mostrecentlytheCDFandCLEOsiliconvertexdetectors,thefrontendelectron- icsfortheMINOSfardetector,andatrackingtriggerupgradefortheBABARdetector. WehaverecentlycompletedthereadoutsystemfortheATLASmuondetectorandhave begunworkplanningtheLSSTandNOºAreadoutelectronics.Detailsofcurrentprojects aregiveninthegroupsummaries. TheLPPCengineeringsta®consistsofanelectronicsengineer,Dr.JohnOliver,his assistant,NathanFelt,andanengineeringphysicist,Dr.PeterHurst.Theremaining technicalsta®consistsofanelectronicstechnician,amachinist,andamechanicaltechnician. Theadministrativesta®consistsofthelabdirectorandanadministrativeassistant. Inadditiontoengineeringandshops,LPPChasworkstations,personalcomputers,and associatedperipheralswhichareavailabletoallthegroupsfordataanalysis,documentation, andcommunicationwithcollaborators.Abouthalfofthecomputersarelocatedatour experimentsfortheuseofourpostdocsandstudents.Thisyearwearerequestingfunds expandthelinuxclusterthatisthemaincomputingresourceforallofthegroups.The clustercurrentlyconsistsofeight2.5GHznodestogetherwith4TBytesofRAIDstorage. Finally,LPPChasavideoconferencingsystemforparticipationinmeetingsatotherlabs anduniversities,resultinginsavingsofbothtimeandtravelfunds.