ELENCO PROGRAMMI DI RICERCA PER BORSE DI STUDIO...

PROGETTO FORMATIVO “LA FISICA DELLE PARTICELLE PER ESPLORARE L’UNIVERSO”

ELENCO PROGRAMMI DI RICERCA PER BORSE DI STUDIO TRIMESTRALI

PER LAUREANDI o NEOLAUREATI MAGISTRALI IN FISICA DELLE PARTICELLE

CERN-1 HostingLaboratory Availablestartingdate Contactperson(s)

CERN 1April2019–1June2019 GiulioAielli(CERN)

Scientificprogram Dailyactivity,skillsrequiredandtobeacquired

AssemblyandtestofanewgenerationofRPCdetectorwithintheATLASBIS7/8Project

TheresearchprogramconsistsinassemblingandtestinganewtypeofRPCdetectorandrelatedFEelectronicswithintheBIS7/8projecttobeinstalledinthebarrel-endcaptransitionregionoftheATLASmuonspectrometeraspartofthePhaseIupgradefortheHL-LHC.Thesenewchamberswillimprovetheacceptance(ofabout20%)oftheLVL1muontrigger,itsefficiencyandselectivity.ThenewtypeofRPChasagasgapreducedto1mmandabettertimeresolution.Moreoverthethicknessoftheelectrodesisreducedfrom1.8mmto1.2mmtoincreasethechargefractionthatistransferredtothepickupelectrodesandsoimprovingthesignal-noiseratio.Averyimportantpartofthisprogramisthetestofthefront-endelectronics,basedonanewSiGechipamplifier.

TherequestedskillisabasicknowledgeofhardwareandsoftwaretoolsneededtotesttheRPCchamberwithacosmicraytest-standtoverify:

1)theoverallfunctionalityofthisnewchambersmappingthex-yread-outefficiency;

2)theclustersizetoadjusttheFEelectronicsthreshold;

3)thespatialandtimeresolution


CERN 1April2019–1August2019 HeinzPernegger(CERN)


RadiationhardmonolithicCMOSdetectors

HighlysegmentedmonolithicsiliconpixeldetectorsbuiltinCMOStechnologieshavebeenverysuccessfulinparticleandappliedphysics,buttillnowtheirrangeofapplicationhasbeenlimitedtoeventrateandradiationhardnessmuchlowerthanwhatisrequiredbyforoperationattheHL-LHCandfuturehigh-energycolliders.Monolithicdevices,builtonahighresistivitysubstratewithasizeabledepletedregionforchargecollection,promisetobeabreakthroughforchargedparticledetection,providinghighratecapabilitiesandradiationhardness,accompaniedbylowercostandpowerconsumptionwithrespecttohybridpixeldetectors.PrototypesusingsensordesignsmeanttoguaranteeshortcollectiontimeandhighsignalefficiencyareinproductionintheTowerJazz180nmprocess.Theyalsoincludethenecessarycomponentstobuildahigh-ratereadoutarchitecture.Afteraninitialcharacterization,theseprototypeswillundergoanextensivestudytoassesstheirperformanceafterirradiationandtheirsensitivitytosingleeventeffects.ThecandidatewilljointheCERNteaminthemeasurementofthedetectorproperties,inparticulartheefficiency,noise,uniformityofresponseandtimeresolutionfordifferentdetectordesigns.

Theactivitywillmainlyconsistoflaboratorymeasurementsandtheassociateddataanalysis.Prototypesensorsirradiatedwithdifferenceparticles(neutron,protonandphoton)willbeprovidedandtheirresponsetodifferentradiationsourcetested.Theactivitywillincludealsodataanalysisforthemeasurementofefficiencyandresolutionintestbeamdatacollectinginotherlaboratories.Basicknowledgeofelectronicslaboratorypracticeisrequired.Programmingskillswillbebeneficialbothforthemeasurementsanddataanalysis.


CERN 1March2019–1October2019 PaoloMastrandrea(CERN)


CommissioningoftheFastTrackerAssociativeMemory

ThestudentwilljointheteamcommissioningtheFast-Tracker(FTK)triggerprocessoratCERN.FTKisoneoftheATLAStriggerupgrades.TheFTKwillbeunderintensecommissioningactivitiesalsoduringthelongshutdown(LS2)periodwiththegoaltohavethesystemreadyforATLASintegrationrunsplannedfor2020.

TheFTKwillreconstructalltheinnerdetectortrackswithtransversemomentumlargerthan1GeVattheinputrateoftheHighLevelTriggergreatlyincreasingthephysicsreachforb-jetandtau-leptonsignatures.Moreoveritwillallowmultiplevertexreconstructionattriggerlevelreinforcingpile-upsuppressionstrategies.FTKisbasedoncustomelectronicboards,associativememoriesandFPGAs.Thecommissioningphaseisinitsintensivephase.Webelievethisisaveryformativeexperienceforastudenttojointheprojectsinceitwillallowhim/hertoparticipatetothesystemcommissioning.Thecandidatewillbeinvolvedintheoperationoftheelectronicscards,inthedevelopmentofcontrolandmonitoringsoftwareandthedebuggingoftheAssociativeMemoryboard.HewillstudytheFTKperformancesonthefirstrealdataandcomparehisresultswiththoseobtainedonsimulatedsamples.

Thedailyactivitywillinclude:-participationandreporttotheFTKdailyintegrationmeetings-softwaredevelopmentfortheAssociativeMemoryboardonlineandcontrolsoftware-integrationtestingoftheAssociativeMemoryboardfollowedbyanalysisoftheresultswiththerestoftheteamatCERN

TheinitiallyrequiredexpertiseisC++softwareexperience.

Duringtheprogramthestudentwilllearnabout-experiencewithteamwork-howtowritesoftwareinanonlineenvironment-commissioningofatriggerelement


CERN 1April2019–1August2019 GiulianoGustavino(CERN)


Development of new fast Deep Learning algorithms on FPGAs for muon reconstruction and identification in the ATLAS L0 Muon Barrel Trigger

ThefirstlevelhardwaretriggersystemoftheATLASexperimentwillundergoafullupgradeforHL-LHCtostandthechallengingperformancesrequestedwiththeincreasinginstantaneousluminosity.TheLevel-0MuonTriggersystemhastomaintainorincreaseitsdataselectioncapabilityduringHL-LHC,despiteofthehigherdetectorhitrate,cavernbackgroundandtriggerrate.TheResistivePlateChamberdetectorprovidesthemaintriggersourceinthebarrelregionoftheMuonSpectrometer.TheupgradedtriggersystemforeseestosendRPCrawhitdatatotheoff-detectortriggerprocessors,wherethetriggeralgorithmsrunonnewgenerationofField-ProgrammableGateArraysFPGAs.TheFPGArepresentsanoptimalsolutioninthiscontext,becauseofitsflexibility,wideavailabilityoflogicalresourcesandhighprocessingspeed.InthiscontextthestudentwillworkwithintheATLASL0MuonBarreltriggergroup,inthedesignanddeploymentofnovelfasttriggeralgorithmsbasedonstate-of-the-artmachinelearningalgorithms.Inparticulartheworkwillbefocusedintheportingandoptimizationofnewlowprecisiondeepneuralnetwork

StudentactivityatCERN:-DevelopmentofDNNandCNNbasedonternarynetworksforreconstruction,measurementoftransversemomentumandclassificationofmuonsbasedonRPCinformationavailableatL0oftheupgradedATLASbarreltrigger-PortingofthealgorithminsidethelatestgenerationXilinxFPGAsusingavailableHLStoolsforcodesynthesisforFPGA-IntegrationofthedevelopedalgorithmintheFPGAsusedinthepermanenttriggertestsliceoftheATLASexperiment-Evaluationofphysicsperformancesintermsofefficiencyandfakeratesofthedevelopedalgorithms,andtechnicalperformances(FPGAlogicresourceoccupancyandtiming/latency),obtainedwiththedevelopedalgorithms-Daylyreportonprogress/issueswithgroupcollaboratorsandeveryweekintherelevantATLASinvolvedTDAQgroups

architectures(basedonternarydenseandconvnetnetworks)designedtorunonFPGAsandtocopewithsparsedatadevelopedbytheATLASRomeL0MuonBarrelgroup,andtotesttheminthepermanentdetector/triggerslicetestavailableintheATLASfacilityatCERN.

Requiredinitialcompetences:-knowledgeoffundamentalsinparticlephysics-knowledgeoffundamentalsinmachinelearning-basicknowledgeofpythonandCprogramminglanguages-basicsknowledgeofFPGAfunctioningand/orprogrammingwouldbeaplus

CERN-5 Hosting

Laboratory Availablestartingdate Contactperson(s)

CERN 1March2019–1September2019 HideyukiOide(CERN)


StudyofthelongtermstabilityoftheATLASpixeldetector:whatwecanlearnfortheconstructionofanewtracker

TheATLASPixeldetectorhasbeentakingdatawithoutmajorproblemssince2009andisnowapproachingatwo-yearstopduringtheLHCshutdown.Inthisprojectweproposetoperformananalysisofthedamagesinthedetectormodulesinducedbythermalvariationsthepixeldetectorhavesufferedduringthesetenyearsofoperation.Particularattentionwillbeaddressedtostudythefailuresinthebumpsconnectionbetweensensorsandreadoutchips.Thesedamagescanbeeasilyidentifiedasclustersofinefficientpixelslocatedattheedgesofthereadoutchips.Thebumpconnectivitywasmonitoredcloselyduringtheintegrationofthedetector,asbumpswereknowntobeaweakpoint,butitwasneverstudiedasafunctionoftimeandthermalcyclesorotherstressesafterinstallation.DifferencesbetweenInorPbSnbumpsthatarepresentinthedetectorwillalsobeaddressedtocheckifoneismorerobustthantheother.Indeed,theinterestinthebumpconnectivityfailuremodeisnowrevampedduetothestartoftheconstructionofthenewPixeldetectorforeseentoreplacethecurrentoneduringthelongshutdownin2024.Infact,severaltechnologieshavebeendevelopedtojoinwithbumpssensorsandreadout,butrobustnessagainstmechanicalstresses,mainlycomingfromhandlingandthermalcycles,needstobeproven.

Thecandidatewillhavetogetasampleofdatathatcoversthefulldata-takingperiod.Thenhe/shewillhavetoidentify“inefficient”pixelsanddefine“clustersofinefficient”pixels.Oncethesedefinitionsareset,thestudyoftheirbehaviorversustimeandmechanicalstresseswillbepossible.Inparallel,testofbumpsconnectivityundermechanicalstresseswillalsobeperformedonrealdevicesinthenewtrackerassemblyfacility.Inordertoefficientlyworkonthisproject,theapplicantmustbefamiliarwithbasiccomputingskillsofhandlingoflarge-scaledatabase,namelyshellscriptorpythonprogramming.TheapplicantshouldbealsofamiliarwithbasicdataanalysisusingC++andROOT.Familiaritytoimaginganalysisisalsorecommended.


CERN 15February2019–15September2019 EmilioMeschi(CERN)


Trigger-lessreadoutanddataprocessingwithCMSDriftTubechambers

Availabilityoflowcost,highthroughputopticallinksandtheevolutionofFPGAI/Ocapabilitiesandprocessingpowerbroughtadramaticchangeinthedataacquisitionarchitecturesandtriggeringmodels.Ondetectorelectronicscanbereducedtotheminimumrequiredfordigitizationandtime-stamping,databeingthenstreamedinparalleltocentralizedunits,withanasynchronousmergingandprocessing.Suchasolutionrelaxestriggeringconstraints,openinguptoanunbiasedcontinuous,realtimemonitoringandreconstructionofphysicsquantitiesevenbeforetheeventdataarestored.AimingtoexploresolutionsfortheLHCPhase2upgrade,aCMSDriftTubesparechamberhasbeenequippedwithaprototypalreadoutchain,andisbeingoperatedatSX5todemonstratetheeffectivenessoftheupgradedarchitecture,onafirstinstancebydirectcomparisonwiththelegacysystembymimickingtheoriginalbehavior.AfurtherongoingstepforeseestheintegrationwithaCMSDAQ2nodeprototype,whichcarriesappropriatehardwareinterfacestofeedincomingstreameddatatohighlevelprocessingcodeandBigDatatools.

Havingtodealwithaworkingdetector,mostoftheactivitywillfocusonexercisingthedatataking(e.g.latenciesmeasurements),definingperformanceindicatorsandevaluatingdifferentalgorithmsefficienciesthroughcosmicmuonsruns.Existingdetectorperformancemonitoringtoolswillhavetobeadaptedorevolvedaccordingly,alsothroughexcerptsfromthefastreconstructionsoftware(e.g.thepresentCMSHLT).Previousexperiencewithscalabledatahandlingandprocessingtools(e.g.PythonDataAnalysisLibrary)wouldbeuseful,aswellasageneralawarenessofdataacquisitionsystemscomponentsandonlinesoftwarearchitectures.

CERN-7 Hosting


CERN 1March2019–1May2019 FrancescoFallavollita(CERN)


Advancedstudiesontheagingofsomegaseousdetectortechnologies

Aprogramisproposedbasedonadvancedlongevitytestsondifferentgaseousdetectortechnologies:Triple-GEMsandRPCs.Thesedetectorswillbeinstalledand/orupgradedinthemuonspectrometeroftheCMSexperimentandareexpectedtooperateefficientlyathighfluxofparticles.Manytraditionallongevitytestshavealreadybeenperformedirradiatingdetectorswithphotonsandcleangasmixtures.Newadvancedtestsarehereproposed.Inthiswork,outgassingofparticularmaterialsiscreated,enhancedandreleasedintothedetectors'inletgaslineinordertocontaminatetheirgasmixture.Thiswouldreproducepollutants’releaseintotheirgasvolumeduringmanyyearsofoperation.Moreover,irradiationofthedetectorswithparticlesofdifferentspecificionizationallowstounderstandhowtheprimarychargedensitycanaffectthedetectorperformancesandtriggerdifferentagingprocesses.CERNlaboratoriesofferthepossibilityofusingvariousradiationsources,includingneutrons,whicharenecessaryforthisprojectandprovideadequateradiationsafety.Moreover,suchlongevitystudiescouldprovideinformationaboutdischargeprobability.Itisexpectedthatabetteraccuracyoftheresultswillbeachievedoveracontinuoustestperiodof4-6monthsbutinterestingoutcomesareforeseenalreadyattheendoftheproposedinternship.

Theactivitywillconsistinthedesign,configurationandmanagementofsmalltestsinwhichdifferenttechnologiesofgaseousdetectorsareexposedtoparticlesofdifferentspecificionizationwiththeaimofcomparinginducedaging.Theagingenvironmentwillbecreatedbypoisoningthegasmixturethroughtheoutgassingofspecificmaterials.Calibrationsanddataanalysiswillalsobenecessaryandtherelatedassociatedcompetenceswillbeinlinewithexperimentalphysics,themanagementofelectroniccircuitsfordataprocessingandthetypicalmethodologyofhighenergyphysics.Aknowledgeofprogramminglanguagesandsoftwareanalysispackageswillbeappreciated.


CERN 1March2019-1September2019 StellaOrfanelliCERN)


SerialPoweringforHL-LHCCMSInnerTracker

TheCMSInnerTrackerforHL-LHCwillbeapixeldetectorpoweredbyusinganinnovativeserialpowering(SP)scheme,forthefirsttimeinaparticlephysicsexperiment.Thismethodallowstofeedthe50kWpowerneededbytheInnerTrackerwithinaverylimitedspaceandwithaminimummaterialbudget,soasnottojeopardizetheexcellentphysicsperformanceofthedetector.TheimplementationoftheSPschemeisachievedthankstoaspecialfunctionalblock,knownasShuntLDO,placedinsidethereadoutchip(ROC).TheShuntLDOisalreadyimplementedonRD53A,theROCprototypechipthatwillbetheR&Dandsystemtestworkhorseinthenextmonths.RefinedShuntLDOprototypeswillalsobesoonavailableasstandaloneASICs.TheShuntLDO,eitherinthestandaloneorintheon-chipversion,needstobefullytestedandcharacterizedalsoaftertheirradiationcampaignreproducingtheharshenvironmentalconditionsoftherunningintheexperiment.Thecharacterizationrequiresthelowlevelstudyofthecircuitbehaviorintermsofregulationcapability(timedomain,frequencyresponse,etc.),withrespecttothetypicalloadvariations.Itwillalsorequiretheverificationofitsfunctionality,intermsofnoiseandstability,withaSPchainwithrealsensorsplusROCassemblies.

Theactivityconsistsofthestudyofatable-topSPchainmadeupofShuntLDOsand/orROCs.Currentsandvoltageswillbemeasuredinvariousconditions,alsointhetime-domainbyusingafastscope;thestudentwillalsoruntheROCDAQsystem,willcalibratethedevices,andthenanalyzetheresultingdatatomeasurenoiseandotherrelevantparameters.Therequiredskillsare:basiclaboratoryexperiencetooperatebenchpowersupplies,laboratoryinstrumentsandthescope;basiccomputingskillstooperateaDAQsystemrunningonaPC;basicprogrammingandROOTcapabilitiesforscripteditinganddataanalysis.

CERN-9 Hosting


CERN 1March2019–1August2019 MarcoLucchini(CERN)


CharacterisationofLYSOmatricesandSiliconPhotomultiplierfortheCMSBarrelMipTimingDetector

CMSisproposingwithintheupgradeprogramforHL-LHCanovelhermetictimingdetectorforchargedparticles(MTD)withatargetresolutionof30ps.Thebarrelpartofthedetector(BTL)willuseassensorssmallLYSOcrystalsreadoutbySiliconPhotomultipliers(SiPM).Duringthelastyear,R&DstudieshavebeencarriedouttooptimizetheBTLdesign.Thereferencedesignnowenvisagesa

3x4x56mm3LYSOcrystal,readoutonbothsidesby3x3mm2SiPM.ThisdesignachievesthetargetresolutionatthebeginoftheHL-LHC,andlimitsthecontributiontothetimeresolutionoftheSiPMdarkcountratethankstothedoubleendedreadout.Severalaspectsstillneedtobestudiedbeforemovingintoapre-productionphaseenvisagedtostartin2020.Weproposetocarryoutsomeofthesestudieswithinthisproject.Optimizationofthefinalsensordesignwillinvolvecharacterizationofcrystalsfromdifferentproducers,systematicstudiesofthematerialusedtowrapcrystalmatrices,studyoftheopticalcross-talkandopticalmatchingbetweentheLYSOandSiPMs.StudiesonirradiatedSiPMsarealsoneededtocharacterizetheperformanceofdifferentpackaging.AllthestudieswillbecarriedoutatthecrystallaboratoryatCERNLab27.

Theselectedcandidatewillperformlaboratorymeasurementsondedicatedcrystalbenches,willanalyzethedataandproducereports.Agoodknowledgeoflaboratoryequipmenttoperformcrystallightyieldmeasurementsispreferential.Knowledgeofananalysisframework(ROOTorpython)isrequired.Thecandidatewillacquireadetailedknowledgeofthedifferentcontributionstothetimeresolutionofasensormadeofascintillatingcrystalandaphotodetector.


CERN 1March2019-1April2019 SophieMallows(CERN)


SimulationofNeutroninducedbackgroundintheCMSMuondetectors

TheHL-LHCisexpectedtooperatewithapile-uprate5timeshigherthanthecurrentmachine,requiringadedicatedupgradeprogrammeoftheCMSexperiment:newinner&outertrackerinsilicon,anewhigh-granularitycalorimeterfortheendcaps,muonssystemelectronicsimprovementsplusreinforcementandextensionofthemuonsystemendcapwherethehighestbackgroundratesareexpected.Themainsourceofbackgroundinthemuonsystemisduetotheabsorptionofthehighenergyparticlesproducedinpp-collisionsinthehadroncalorimetersandinthemagnetprotectionsystemsofLHCinwhichneutronsareliberated.Theseneutronshaveverylowinteractioncrosssectionandcanliveuptomillisecondsaftertheircreation,travellingmanymetersthroughsteelanddetectorsoftheCMSexperiment,resultingintheCMSexperimentpractically“embedded”inaneutrongas.Theseneutronsuponcaptureemit2.2MeVphotonswhichinducebackgroundhitsinthemuonsystem.Thedesignofthenewendcapcalorimetersisbeingfinalizedaswespeak,afterwhichthebackgroundsinthemuonsystemneedtobere-evaluatedandupdatedw.r.t.thestudiesperformedfortheCMSUpgradeTechnicalProposal(2015).Asafirststepthepp-inducedbackground(neutrons,photons,chargedparticles)needtobeevaluatedwiththeFLUKAcode.

ThestudentwillperformanalysisofdataextractedfromFLUKAsimulationswiththefinaldesignoftheCMSPhase-2detectorandextractneutron,photonandchargedparticlefluxesatthesurfaceoftheupgradedmuondetectors(ME0,GE1/1,GE2/1,RE3/1&RE4/1).She/hewillinteractatCERNwiththeCMSBRILgroup,whoisresponsiblefortheparticletransportsimulationwithFLUKAcode.She/hewillwork&collaborateinaninternationalscientificenvironment.Basicprogrammingskills(C++)arerequired.


CERN 1March2019–1June2019 MaurizioMartinelli(CERN)


SearchforCPviolationinD0àK0

SK-K+ decaysattheLHCbexperiment

The study of Charm hadrons offers a unique opportunity to search for physics beyond the Standard Model in the up-type quark sector. Unknown particles in loop processes may induce significant CP violation effects in addition to the very small predictions from the Standard Model. Additionally, CP violation in charm hadrons is not yet observed and remains an important aspect of the Standard Model seeking clarification. The LHCb experiment collected the world’s largest sample of charm hadrons to date, thanks to the large cc cross-section in pp collisions at LHC.The selected student will work on an analysis searching for CP violation in

the decays of D0àK0

SK-K+ decays, using the LHCb Run2 data. This would be the first time that such analysis is studied at LHCb using a novel technique for hadron colliders, which exploits the variation of CP-odd and CP-even content of the decay with respect to the decay time of the meson. Spending a period at CERN is of primary importance for conducting the analysis efficiently, in order to participate actively to the activities of the Charm working group and to be in close contact with the LHCb charm physics experts on site.

ThecandidatewillworkinclosecontactwithcharmphysicsexpertsfromtheLHCbcollaboration,underthesupervisionofthecharmworkinggroupconvener(MaurizioMartinelli).He/shewilloptimizethealgorithmsaimedatselectingthedecaysofinterest,alsousingmultivariateanalysistechniques.Then,thesensitivitytoCPviolationwillbeassessed.He/shewillhavetheopportunitytopresentregularlyhis/herresultsattheworkinggroupmeetings.BasicknowledgeoftheUNIX/LINUXenvironment,C/C++programminglanguagesandROOT/ROOFITpackagesarerequired.Bytheendofhis/herperiodatCERN,he/shewillhaveknowledgeofadvancedanalysistechniquesemployedinhighenergyphysics,andwillhavedevelopedteamworkingandcommunicationskills.

CERN-12 Hosting


CERN 1September2019–1November2019 GiovanniPassaleva(CERN)


DevelopmentandintegrationofGenerativeAdversarialNetworksfortheUltra-Fast

SimulationframeworkoftheLHCbexperiment

AmongthelargeexperimentsattheLHC,LHCbhasbeendesignedtostudytheheaviesthadronsinNature,containingbandcquarks.Heavyhadronsarecopiouslyproducedintheproton-protoncollisionsattheLHC,andtheirdecaysareefficientlyreconstructedbytheLHCbdetector,resultinginhugeandpuredatasetsthatphysicistsfromallovertheworldanalyzetoidentifydiscrepanciesfromtheStandardModelthatcouldbeinterpretedasevidenceofNewPhysics.Largedatasetsoffertheopportunityofreducingthestatisticaluncertaintytounprecedentedlevels,requiringanoutstandingmodelofthedetectorandofthereconstructionproceduretodistinguishartifactsfromrealphysicseffects.Inpractice,thedetectorresponseisdescribedusinglarge-scaleMonteCarlosimulationstranslatingasimulatedsignalprocess(e.g.aparticledecay)intothesamereconstructedvariablesasavailableforrealdata,bymodellingeverystep:thecollision,thedecays,theradiation-matterinteractionsinthedetector,andtheread-outelectronics.Unfortunately,theavailablecomputingresourceswillneverbesufficienttoperformsuchafullsimulationforsamplesasabundantasthoseexpectedforrealdataduringthefuturerunsoftheLHC.Hence,newFast-Simulationtechnologiesareunderdevelopment.

TheselectedcandidatewillstudyaninnovativeandpromisingapproachbasedontheparametrizationofthedetectorresponseusingDeepNeuralNetworkstrainedinanAdversarialconfiguration(GenerativeAdversarialNetworks,GAN).AninterestingfeatureofthisapproachisthatNeuralNetworkscanbetraineddirectlyonthecollisiondatacollectedtomonitorandcalibratethedetectorresponse,achievinggoodreliabilityforalgorithmsdesignedtobeordersofmagnitudefasterthanthefullsimulation.TheidealcandidatehasexperienceonHighEnergyPhysicsdataanalysis,NeuralNetworksandothermachinelearningtechnologies.He/sheisproficientinPythonandTensorFlow.

CERN-13 Hosting


CERN 15April2019–1June2019 TatsuyaMasubuchi(UniversityofTokyo)


HiggsbosonHVVcouplingstructureinpp→VH,H→b(bbar)

FiveyearsaftertheHiggsbosondiscovery,ATLASandCMSreportedthissummerthefirstobservationattheLHCfortheHiggsbosondecayinb-quarks.Thecomingyearswillbeveryimportanttoexploitatbestallthepotentialityofthisdecaychannel.MeasurementsofH→b\bar{b}producedinassociationwithavectorbosonV(WorZ)arealreadyprovidinginformationonthestructureoftheHiggscouplingwiththevectorbosons.Inthisprojectwewanttoexploittheuseofkinematicvariables,especiallyathightransversemomentum(whichisparticularlysensitivetophysicsbeyondtheStandardModel)andangularinformationtoextractinformationontheCPpropertiesoftheHVVcouplingstructure.Thesestudieswillcovertheneedsforthefutureanalysisofthepp→VH,H→b\bar{b},optimizingthestrategyforthemeasurement,andinvestigatinghowtocompareandcombinetheresultswiththeotheravailablechannels(Vectorbosonfusion,orHiggsdecaysinWWandZZ).ThesestudieswillbedonecoherentlywiththeplansandrecommendationsoftheLHCHiggsCrossSectionWG.

Month1:learningtheexistingtools/dataformat(i.e.truth-DxAOD,CxAOD);gettingfamiliarwiththeproposedstrategiestoextractinformationfromthepp→VH,H→b\bar{b}channel.Month2:Preparationofsampleswithanomalouscouplings,usingthemostupdatedtools,includingtheproductionofsamplesfordifferentEFTbasis,pseudo-observables,andanomalouscouplings.Month3:Detailedstudiesoftheproposedvariablesondata,optimizationoftheanalysisstrategy,extractionofexpectedresultsandfirstcomparisonswithexistingorplannedresultsinotherchannels.


CERN 1March2019–1August2019 JohannesBernhard(CERN)


Optimizationofamuonbeamtomeasureinthespace-likeregiontheleadinghadroniccorrectionstothemuong-2(theMuonEproject)

Aproposalwaspresentedtomeasurethedifferentialcrosssectionoftheelasticμ−escattering,asafunctionofthetransfermomentumt,todeterminethehadroniccontributiontherunningofα,theelectromagneticconstant.Ahighenergymuonbeamisnecessaryinordertocovertherangeoflarget,wherethehadroniccorrectionsaremeasurable.TheenergyoftheM2muonbeamintheNorthAreaatCERNisadequateforsuchmeasurement.Theparametersofthebeammustbeoptimizedforthewantedapplication,andthelocationoftheμ−edetectormustbespecifiedaccordingly.Theworkprogramwillbe:1.Workonthebeamline:inclosecontactwiththeEN-EAgroup,designindetailbeamopticsforthefinalMuonEexperimentlengthof40m,withoutsignificantinterferencewiththeCOMPASSapparatus.TakeintoaccounttheMuonErequirementsforbeamflux,sizeandmomentumspectrumaswellasHalocontributions.Prepareadetailedlayoutofthebeamlineandexperimentalset-upinsidethelastsectionofthebeamzonePPE211.IncollaborationwithmembersoftheEN-EAteam,performinitialintegrationstudiesandcosting.2.Workonthetestbeamdataanalysis:in2018,largesamplesofdatahavebeentakenwithanapparatusmadebyeightSi-planestrackerandagraphitetarget,locatedbehindCOMPASS.

Thestudentwillparticipateinthedifferentstepsoftheanalysis:selectioncriteriaofelasticevents,anddeterminationofthecross-sectionratiobetweenthetwokinematicalregions,theoneathightandtheoneatlowt.ThestudentisrequiredtohavenotionsofC++andROOT.She/Hewilllearntousethesetoolsextensively,touseGEANT4simulation,tolearntechniquesofanalysis(NN,TMVA,etc).Thefractionoftime(20-30%)dedicatedtosubject2.willhelpthestudenttounderstandtheuseoftheμbeamforthefinalmeasurement.


CERN 1June2019–1July2019 MichaelMoll(CERN)


Trackingparticlesin4Dimensions

Trackingparticlesinspaceandtimeisthenewfrontiersinthedesignofthenextgenerationofexperiments.ThisgoalrequiresthedesignofanewtypeofSiliconsensors,thesocalledUltra-FastSiliconDetectors(UFSD).Thestudentinthisprojectwillbeengagedontwofronts:(1)thestudyoftheradiationhardnessofUFSDintheCERNSiliconlab.and(2)theanalysisoftheimpactonkeyphysicschannelsoftheadditionofaTimingLayertotheCMSdetector.Thestudentwillthereforebenefitfromacombinationofhardwareandsoftwareactivities.AthreemonthstraininginanadvancedSiliconlaboratory,carryingonthecharacterizationoftheradiationhardnessoftheSiliconsensorschosenfortheCMSandATLAStiminglayer,willprovidetothestudentarelevantexperienceforhis/herfutureactivities.Atthesametime,thestudentwillbeengagedinthesimulationgroupoftheCMSTiminglayer,andhe/shewilldevelopthetoolsforevaluatingtheimpactoftheadditionoftheTimingLayerontheCMSphysicsreachatHL-LHC.

ThestudentneedstohavehadaprevioustraininginaSiliconlaboratoryandshe/heshouldhaveabasicunderstandingoftheCMSphysicsanalysisenvironment.AperiodintheCERNSiliconlaboratorywillprovidethestudentwithagoodtraininginthetechniquesneededtocharacterizenewandirradiatedSiliconsensors.Likewise,thesoftwareactivitieswillallowthestudenttomeetandinteractwiththeCMSanalysisteamsandtobeengagedinrelevantsimulationwork.TheworkdaywillbesplitbetweentheCERNSiliconLabandtheanalysiswork,eitherinmeetingorintheoffice.

DESY-1 HostingLaboratory Availablestartingdate Contactperson(s)

CERN 1April2019–1August2019 ChristianSander(DESY)


MeasuringEfficiencyandresolutionofpixelmodulesprototypesforATLASITKupgrade

Theproposedprojectaimstomeasuretheefficiencyandspatialresolutionofvariouskindsofpixeldetectorsbeforeandafterirradiation.Pixelswithvariousdimensionsandtechnologicaldetailsarebeingevaluated,beforeproceedingwithproduction.Primarily,thebaselinehybridsensorswillbetested,bothintheplanarand3Dgeometry.Thesehaveaminimumpitchof50micronsandthicknessrangingfrom100to250microns.AlsomonolithicCMOSsensors,withsamepitchwillbeproducedandtested.AsummerstudentwithadequatebasicknowledgeofrootandNIMinstrumentationcancontributetothedatatakingandtodataanalysistoextractefficiencyandspatialresolutionobtainedusingabeamtelescope.

Initialrequirements:basicknowledgeofrootandstatisticaldataanalysis;basicknowledgeofnuclearinstrumentation:scintillationdetectors,photomultipliers,amplifiers,basicknowledgeofcoincidenceandtriggerconcepts.Aftertheprogrammethestudentwillhavegainedaknowledgeofparticletrackingtechniques,improvedstatisticalanalysismethodsontrackingandfirsthandexperienceofdatatakinganddataanalysis.Thestudentwillalsobeattendingseminarsandlecturesatthehostlaboratory.

FERMILAB-1 HostingLaboratory Availablestartingdate Contactperson(s)

FERMILAB 1March2019–1April2019 PavelMurat(Fermilab)


ReconstructionofprotonfrommuonnuclearcaptureasMu2enormalizationsource

TheMu2eexperimentaimstodiscovertheconversionofamuonintoanelectronbyimprovingthe

previouslimitbyfourordersofmagnitude(8×10-17

).Theconversionratewillbenormalizedwithrespecttotherateofmuoncaptureinnucleus.

Themuoncapturerateisaround60%ofthemuonstoppingrateanditneedstobedeterminedwithhighprecisionduetotheexpectedlargevariationoftheprotonintensityalongtherunningperiod.ApartlookingforsignificantX-raylineswithadedicatedstoppingmonitordetector(locatedinanexternalregionofMu2e),thepossibilitytouseanin-situeventreconstructionisbeingstudied.

Oneofthemonitoringsourceswithveryhighrateisprovidedbytheprotonsproducedfromde-excitationofthemuonscapturedbythenucleus.Thisratecorrespondsto0.18GHz.Preliminaryprotonreconstructionwiththetrackingsystemindicatesthatthisroadisfeasibleandthattheprotoncountingcouldbesensitivetobeamintensityvariationdowntoaround1ms.Theproposedworkisthatofoptimizingtheprotonreconstructionandevaluatethetimebudgetneededtoperformsuchataskinrealdata.

Requiredknowledge:tohaveareasonable

knowledgeofprogramminglanguages(C,C++)and

Rootpackage.Pre-existing“beginner”expertisein

dataanalysis.

Acquiredknowledge:improvedusage/learningof

C++languageandRootpackage.Improvedcapability

indataanalysis.LearningoftheMu2esoftware,art

frameworkandgridusage.Improved

communicationskills.

Dailyactivity:creationofneededsimulated

samples,developmentofanalysiscode,attendance

/reporttoweeklymeetings(Calorimeter,Software,

Mu2e-general,mu-e+group).


FERMILAB 1March2019–1October2019 FabioRavera(Fermilab)


CMSPhaseIITracker:characterizationoffirstprototypesinlaboratoryand

testbeamsalongwithDAQdevelopment

TheLHCwillbeupgradedtotheHighLuminosity(HL-LHC)inthelate2020tofurtherincreasethediscoverypotentialofthemachine.DuringtheHL-LHCtheinstantaneousluminositymaybeashighas7x1034cm−2s−1inordertocollect10timesmoreproton-protoncollisiondatathanattheLHC.TheHL-LHCupgradewillsetunprecedentedchallengesfromthepointofviewofbothdetectorandelectronicscapabilitiesandradiationhardness.Inordertomaintainitsphysicsreach,theCMSdetectorwillbesignificantlyupgradedandFermilabwillbehaveamajorroleinthedevelopmentoftheTracker.InparticulartheLaboratoryisoneofthemaincentersforthetest,bothinlaboratoryandonbeam,ofthenewTrackerprototypesanditisleadingtheDAQsoftwaredevelopment.

DuringtheactivitythestudentwillbeintegratedintheFermilabteamtestingprototypesanddevelopingtheDAQandtheywillcontributetotheoptimizationofthecalibrationproceduresusedbothfortheproductionandthemonitoringduringthedatataking.ThestudentwillacquireagoodknowledgeoftheelectronicsthatwillbeusedinthePhaseIITracker.TheywillalsohavetheopportunitytopresenttheoutcomeoftheiractivitywithinCMSandthustoacquireaninternationalprofile.

Requiredskills:knowledgeofthelinuxenvironment,goodC++programmingskills,basicknowledgeofelectronics,experienceinlaboratory,capabilityofworkinginateam.


FERMILAB 1March2019–1June2019 BrendanCasey(Fermilab)


MeasurementofthemuonanomalousmagneticmomentintheMuong-2experiment

Thesubjectofthisresearchprogramistheanalysisoftheg-2oscillationfrequencywithintheE989(Muong-2)experimentatFermilab.TheMuong-2experimentaimstomeasuretheanomalousmagneticmomentofthemuontoanunprecedentedaccuracytoverifythecurrentdiscrepancyof3.7σobservedbetweenthetheoreticalpredictionandthevaluemeasuredbythepreviousexperiment(E821atBrookhavenNationalLaboratory),discrepancywhichleavesroomfornewphysicsbeyondtheStandardModel.Thefinalresultoftheexperimentwillbetheratiooftwofrequenciesmeasuredindependently,andwithverydifferenttechniques:themuonprecessionfrequencyrelativetothemomentum(ωa)andthefreeprotonprecessionfrequency(ωa).Bothquantitieshavetobemeasured

withanaccuracyof0.07ppm,thereforefewindependentanalyseswillbeperformedoneachfrequencytocrosscheckcentralvalueandsystematicerrors.Oneoftheωaanalyseswillbeperformedbytheωa-

europagroup,inwhichINFNhasaleadingrole.TheMuong-2experimentcollectedthefirstsetofdataintheperiodMarch-July2018reachingastatisticswhichisalmosttwicetheonecollectedbyE821.WhiletheRun2juststartedinNovember2018,withtheaimofcollecting10timesthestatisticsofE821,ananalysisefforthasstartedtopublishinSummer2019afirstresultwiththesametotalerrorasthecurrentone.Thesuccessfulcandidatewillbeinvolvedindataanalysisandwillcontributetothisfirst,veryimportant,resultwhichwillconfirm,ordisproof,thecurrentdifferencebetweentheoryandexperiment,thusparticipatingtothesearchofphysicsbeyondtheStandardModel.

Theprogramisathree-monthstayatFermilabduringwhichthecandidatewillcontributetothedataanalysisofRun1aswellastothedetectoroperationduringRun2.

Generalconfidencewithparticledetectorsandskillstowardssoftwareactivitiesareprerequisitesofthisresearchprogram.Attheendoftheprogramthestudentwillgaintheexperienceofparticipatingintherealizationandcommissioningofamodernelementaryparticlesexperiment.

KEK-1 Hosting


KEK 1March–1April2019 HiroyukiNakayama(KEK)


InitialoperationandfirstdataanalysisofthefullBelleIIdiamond-detector

TheprogramfocusesonearlyoperationsanddataanalysisofthefullBelleIIdiamond-detectorsystemforradiationmonitoringandbeamabort.TheSuperKEKBelectron-positroncolliderwillprovidetheBelleIIdetectorwithunprecedentedluminosity,yielding50xmoredatathanatpreviousB-factories.ThispositionsBelleIIattheforefrontofindirectsearchesfornon-standard-modelphysicsinthenextdecade.“Phase3”operations(Mar-Jul2019)aimatcommissioningtheacceleratorandthefulldetectorforphysics.Highcollisionintensityimplieshigherbeam-inducedradiation.Radiationcandamagethevertexdetector,whichisessentialfortheBelleIIprogram.EarlyPhase3willbekeyforcharacterizingtheradiationenvironmentinthevertex-detectorandoptimizingstrategiesforprotectingthesensitivecomponents.Thisisthetaskofthediamonddetectors,whichmonitorinstantaneousdose-rates,recordintegrateddoses,andtriggerbeamaborts.Diamondsensorsoperateeffectivelyassolid-stateionization-chambers,providingmeasurementsofpA-nAcurrentsproportionaltothedoserates.In-situmonitoringofnoise,pedestals,radiationratesalongwithtimelyoperationimprovementsthatmirrorthechangingdata-takingconditionswillbeessentialinPhase3.Eightsensorsreadbypurpose-builtelectronicswereoperatedlastyearinapreliminarycommissioning.Thesystemisnowcompletewithtwelveadditionalsensorstoprotectthedetectorandtheneighboringsuperconductingquadrupole-magnets.Thereadoutelectronicsisalsobeingupgradedtoallowformultiple-diamondlogictowardmoreflexiblebeam-aborttriggers.

Thecandidatewillcontributetodailyoperationsandwillanalyzediamonddata,incorrelationwithdetectorandacceleratordata,toidentifysourcesofradiationandmitigaterisks.ThefluidconditionsassociatedwiththecommissioningandtheneedfortimelyandclosecollaborationwithdetectorandSuperKEKBexpertsrequirecontinuouspresenceonsite.Requiredskillsincludebasicknowledgeoftheinteractionofparticleswithmatterandfamiliaritywithstandardlabequipment,programming,

anddata-analysispackages,alongwithcommunicationcapabilities.Thecandidatewillrefinetheseskillsinarealresearchenvironmentduringthemostintenseandexcitingtimeforanexperiment.

KEK-2 Hosting


KEK 1March2019–1May2019 KatsuroNakamura(KEK)


OperationandCommissioningoftheBelle-IISiliconVertexDetectorforitsfirstphysics

runattheSuperKEKBaccelerator

ASiliconVertexDetector(SVD)isthecentralpartofthetrackingsystemoftheBelleIIexperiment,crucialtoperformaprecisemeasurementofthepositionofthedecayvertices,withthecapabilityofreconstructionoflowmomentumtracks.TheSVDiscomposedoffourlayersof300um-thickdouble-sidedsiliconstripdetectors(DSSD),coveringthepolaranglefrom17to150degreesandradiusfrom39to135mm.TheconstructionandassemblyoftheSVDladdersonthesupportstructurehasbeenrecentlycompletedandthefullSVDisnowinstalledinsidetheBelleIIdetector.Inspring2019SuperKEKBwillstartthefirstphysicsrunwiththenewcompletevertexdetectorinstalled.TheparticipationtotheoperationandcommissioningoftheSVDduringthefirstmonthswithbeamswillbeanextremelyvaluableandexcitingexperienceforayoungresearcher.Severaldifferentimportantaspectscanbecoveredduringthisproject:fromthemonitoringofthedetectorstabilityduringdatataking(includingtheevolutionofthecalibrationconstantsandnumberofdefectivestrips),tothestudyofthedetectorperformanceandtheirdependenceonmachinebackground.

Thestudentwillwork,insideateamofexpertsandassistedbyatutor,participatingtotheoperationandcommissioningoftheSVD.He/shewilllearnhowtoacquirethecalibrationconstantsoftheSVD(noiseandgain),usingthestandardDAQsystemoftheexperiment,andwillcollaboratetothesetupoftheSWtoolsneededtostudythestabilityofthecalibrationconstantsandtheevolutionofthedefectivestripsofthedetector.He/shewillbeinvolvedintheofflineanalysistheSVDdata,takenduringphysicsruns,tostudythedetectorperformanceanditsdependenceonmachinebackgroundconditions.Thisanalysiswillconcernclusterchargeandtimereconstruction,aswellasreconstructionefficiencyofSVDhits.Therequiredskillsarebasicknowledgeofthemostpopularoperatingsystems.SomeexperiencewiththeROOTanalysissoftwareisdesirable.Programofstudyorthesisinexperimentalhighenergyphysicsispreferred.

BEPC-1 HostingLaboratory Availablestartingdate Contactperson(s)

BEPC 1May2019–1September2019 IlariaBalossino(INFNFerrara)


CommissioningoftheCylindricalGEMInnerTrackerfortheBESIIIIexperiment

TheBESIIIexperimentisplayingaleadingroleinthestudyofcharmoniumphysics,lighthadronsstudies,andexoticsearchesowingtothehighperformanceoftheleptoncolliderBEPCII.TheBESIIIdatatakingwillexceedtheoriginalterms;anupgradeprogramison-goingfromboththedetectorandtheacceleratorsides.OnespectrometercoreupgradeisthereplacementofthepresentinnertrackerwithanewdetectorbasedonCylindricalGEM(GasElectronMultiplier)technologywithchargeandtimereadout.TheCGEM-ITiscomposedofthreeconcentriclayersoftriple-GEM.Thelayershavebeendesigned,builtandtestedinItaly,andhavebeenfinallyshippedtoIHEPseparatelyattheendof2018forthefinalassembly.TheinstallationisforeseenforSummer2019.Beforetheinstallation,alongstandalonecosmicrunwillbeperformedtotestthefullreadoutchain,theslow-controlsystem,andassesstheperformanceusinganexternaltrackingsystem.Aftertheremovalofthepresentinnertracker,theCGEM-ITwillentertheBESIIIpitreadyforthefinalinsertioninsidetheBESIIIspectrometer.Aftertheinstallation,thecommissioningwillproceedwithafullspectrometercosmicdatatakingtocompletethefinalalignment.

Theactivityplancanbemodifiedaccordingtotheavailabilityofthecandidateduringanyperiodoftheyear.Thecandidatewillcontributetothecommissioningofthedetectorinoneofthemaintasks,supervisedbytheINFNadvisor.

Knowledgeoflaboratoryinstrumentation,C++programmingskills,particlephysicsdetectoroperationarerequiredatbasiclevel.KnowledgeoftheMicroPatternGasDetectorisdesirable.Thecandidatewillbepartofaninternationalcollaboration.Thecandidatewilllearnfromdirectexperienceinthelaboratoryadvancetechniquesintheoperationofahighlytechnologicaldetector,providingaboosttohis/herstudy.

BEPC-2 HostingLaboratory Availablestartingdate Contactperson(s)

BEPC 1April2019–1August2019 RinaldoBaldini(INFNFrascati)


MeasurementoftherelativephasebetweenEMandstrongamplitudesinψ(2s)→

ppbar,lldecays

An unexpected relative phase |∆Φ|=90° between strong and EM decay amplitudes of J/ψ has been observed. Such evidence could be compatible with the unconventional hypothesis of a J/ψ being combination of two resonances, one decaying through EM processes only, one strongly. Recent and unprecedented data available from BESIII, collected within the 2018 ψ(2S) scan, could shed light on the underlying processes. A measurement proposed by the Italian researchers, since the investigation of the relative phase is the core of the INFN BESIII analyses. The two-stage program will focus first on the reconstruction of pure strongly decays: ψ(2S)→ppbar. The candidate will investigate the EM and strong amplitudes no-interference scenario, taking advantage of the newly collected BESIII data and of the tools originally developed for the J/ψ scan. The investigation will then focus on the completely interfering scenario: lepton pairs production. A confirmation of a double nature of the aforementioned vector charmonium would imply that something significant is missing in the understanding of the Zweig rule. The additional existing question of whether this double nature also extends to the exotic charmonium states of the Y family could most likely only be clarified exploiting the enormous datasets expected from BELLEII.

C++/ROOT programming skills, intermediate English are prerequisites. Experience in data analysis, not necessarily in particle physics, is welcomed. The candidate must first select in the ψ(2S) scan dataset ppbar/ll events from both ψ(2S)→ppbar,ll decays and continuum; then, produce and exploit Montecarlo simulations to evaluate |∆Φ|. The candidate will gain deep understanding of a complex generation, simulation, reconstruction and analysis framework as the BESIII one. The extended direct interaction at BEPC with highest experts in the field, both on the experimental and theoretical sides, as Rinaldo Baldini, will strongly boost candidate’s skills in both data analysis and understanding the underlying physics.

PSI-1 HostingLaboratory Availablestartingdate Contactperson(s)

PSI 1March2019–1June2019 StephanRitt(PSI)


CommissioningoftheMEGIIexperimentdriftchamber

TheMEGIIexperimentissearchingfortheleptonflavorviolatingdecayμ→eγwithunprecedentedsensitivities.Thecylindricaldriftchamberplaysacrucialroleinthebackgroundsuppressionbyperforminganunprecedentedprecisepositrontrackinginanultralowmassdriftchamber.Thedetectorisbeingcommissionedinfall2018andissupposedtobereadytolookatthefirstpositrontracksin2019.ThecontractholderwillbeinvolvedinthefinalstepsofdriftchamberHWcommissioningand,inparallel,inthedevelopmentandoptimizationofsignalprocessingcodesanddetectorcalibrationtechniques.She/hewillbenefitofdeepinteractionswithlocalexpertsandothercollaborationmembersinthedevelopmentofsoftwareprogramsfordataacquisition,detectorcalibrationandmonitoringandwillbeanactivememberofanalysisgroupsfordatacollectedduringthebeamtestsenvisagedforsummer2019.Cosmicrayswillbeusedtocalibratethechamberinthefirsthalfofthecontractperiod.Thecalibrationwillconsistintimeandgainfactorsassessmentandtheobtainedresultswillbecomparedwiththeperformancemeasuredbymeansofmuonandpositronbeaminducedevents.Thebeamwillbe

availablesinceJulythe1st2019.

Atthebeginningoftheactivitythecontractholdermusthaveagoodknowledgeofparticledetectorsandespeciallyofdriftchambersandagoodautonomyintheuseofanalysissoftware.ExperienceinC++programmingisalsorequired.Duringthecontractperiodshe/hewillacquireskillsandexperienceaboutthesettingupandstartingupproceduresofanewexperimentandonthesignalhandling,forrealandcalibrationeventstoo.She/hewillalsoacquireadeepknowledgeofthestructureofdataacquisitionandtriggersystemsandofon-linesoftware.

PSI-2 HostingLaboratory Availablestartingdate Contactperson(s)

PSI 1March2019–12019 AngelaPapa(PSI)


LightneutralbosonsearchwiththeMEGIIdetector

Darkmatterisoneofthebigunknowninthecontextofmodernscienceandisattractingalotofeffortinsidethescientificcommunity.Amongpossiblecandidatesthereareshortlivedlightneutralbosons;recentlyseveralattemptshavebeendonetoobservesuchparticlesinthemassrangeof10MeV-10GeVbutsofarnoevidencehasbeenfound.Inthenearfuturenewexperimentsareexpectedtoextendthoselimitsinaregionofcouplingsand/ormassesunexploredsofar.Newapproachestosearchforthatincludenuclearreactionstudies.

Recentlyanevidenceforananomalyintheinternalpaircreationangulardistributionin

transitions7Li(p,e+e-)8Be,possiblyduetoanewneutralbosonhasbeenclaimed.TheMEG

experimenthassetthemoststringentlimitontheμ®egdecay:BR(μ®eg<4.2x10-13)@90%C.L.Anupgradeoftheexperiment(MEGII)isongoingtoincreasethesensitivitybyoneorderofmagnitude.Theupgradeincludesacompletelynewre-designedandhighlyperformingspectrometerthattogetherwiththeavailabilityof1MVCockcroft-Walton(C-W)acceleratorused

forMEGIIcalibrations,offertheopportunitytostudythe7Li(p,e+e-)8Bereactionwithhigherstatisticsandincreaseddetectorresolutionstoeitherconfirmortorejecttheanomaly.

ThestudentwillcollaborateinperformingMonteCarlosimulationsintheGEANT4MEGIIsoft-wareframeworktooptimizethetrackingreconstructionalgorithmforthee+e-pair,todefinethetriggerstrategyandtosetthefinalsensitivitythatcanbeachieved.He/ShewillbealsoinvolvedinsettinguptheexperimentalapparatusincludingthepreparationandthetestofnewC-WLiandLiFtargetstobeusedintheexperiment.

Requiredknowledge:goodknowledgeofEnglish,C++,possiblybasicknowledgeofROOT.BytheendoftheprogramthestudentwillgaingoodexpertiseinGEANT4,ROOTandexperimentaltechniques.

Date post:	10-Jun-2020
Category:	Documents
Upload:	others
View:	0 times
Download:	0 times

ELENCO PROGRAMMI DI RICERCA PER BORSE DI STUDIO...

Documents