Calorimeters In Action!! ILC Calorimeter School CCAST & TUHEP, Tsinghua University Apr. 22 – 26 Jae Yu University of Texas at Arlington

Calorimeters In Action!!ILC Calorimeter SchoolCCAST & TUHEP, Tsinghua UniversityApr. 22 26

Jae YuUniversity of Texas at Arlington

ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington

Lecture OutlinePreparation of a HEP experimentPhysics GoalsAccelerators and DetectorsNuTeV CalorimeterPhysics GoalsBeam CharacteristicsDetector and its performanceD CalorimeterPhysics GoalsBeam ChracteristicsDetector and its performance4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Preparation of a HEP ExperimentDecide on physics topics and scientific goals to accomplishExplore accelerators, existing, upgraded or newDefine the necessary detector performance requirements to accomplish the measurements of the topics Define the design parameters and look into available or new technologies to fit the performance parametersPerform Monte Carlo simulations to refine the requirements and test technical feasibilitiesPerform R&D for various detector technologies and construct and test prototypesDesign an integrated detector and test them in the beam to understand, improve and calibrate its performanceConstruction, commissioning, data taking and analysis4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Design Considerations Scientific GoalsWhat are the critical physics questions to answer?Always changing, a moving targetTheoretical predictions based on previous theories and the results of experimental testsPrevious experimental resultsDid we measure certain quantities to a satisfactory precision? Sufficiently low statistical and systematic uncertainties?What can be accomplished at the next level?Are the sources of systematic uncertainties reducible?Can the existing accelerator provide necessary statistical and systematic precisions?Do we need a new accelerator? 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Standard Model Elementary Particle TableSU3XSU(2)xU(1) gauge symmetryPrescribes the following simple and elegant fundamental structure:

Total of 3 families of quarks and leptons with 12 force mediators form the entire universe~0.1mpFamily


Are we all happy with the current theory?Standard Model has been extremely successful under scrutiny EW sector tested very rigorouslyYet, there are outstanding issues lingeringNeutrino masses Now proven that neutrinos oscillateElectroweak symmetry breaking Origin of massSearch for the Higgs particle still on-goingCP violations kTeV and other experimentsWhy are there so wide a range in constituents masses (hierarchy problem)?At what energy does the unification of all forces occur?Is there any other model that describes nature better?Will we find SUSY partner particles?To answer these questions we need The acceleratorThe detector 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Current Status of Higgs SearchesMost optimal central value is below the experimental limit under the SM


Particle AcceleratorsHow can one obtain high energy particles?Cosmic ray Sometimes we observe 1000TeV cosmic raysLow flux and cannot control energies or types of incident particles too wellNeed to look into small distances to probe the fundamental constituents with full control of particle types, energies and fluxesParticle acceleratorsAccelerators need not only to accelerate particles but also toTrack themManeuver themConstrain their motions better than 1mmWhy?Must correct particle paths and momenta to increase fluxes and control momenta4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Role of AcceleratorsAct as a probing toolThe higher the energy The shorter the wavelengthSmaller distance to probeTake us back in time close to the creation of the universeTwo method of accelerator based experiments:Collider Experiments: p`p, e+e-, epCMS Energy = 2sqrt(E1E2)Fixed Target Experiments: Particles on a targetCMS Energy = sqrt(2EMT)Each probes different kinematic phase space4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Particle Accelerator TypesDepending on what the main goals of physics are, one can use various kinds of acceleratorsFixed target experiments: Probe the nature of the nucleons (Structure functions) and measure particle propertiesResults also can be used for producing secondary particles for further accelerations and beam particle selectionsColliders: Probes the interactions between fundamental constituentsHadron colliders: Wide kinematic ranges and high discovery potentialProton-anti-proton: TeVatron at Fermilab, Sp`pS at CERNProton-Proton: Large Hadron Collider at CERN (to turn on late 2009)Lepton colliders: Very narrow kinematic reach and for precision measurementsElectron-positron: LEP at CERN, Petra at DESY, PEP at SLAC, Tristan at KEK, ILC in the med-range futureMuon-anti-muon: Conceptual accelerator in the far futureLepton-hadron colliders: HERA at DESY4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Collider Accelerators Lepton Collider Used primarily for precision measurementsParticles without the internal structures - Point-like particlesMuch lower total cross section than hadron colliders Much cleaner final states CMS energy for each collision well understoodLimited kimematic phase spaceLEP, LEP-II, KEK, PEP-II, ILC4/22/2009*ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington


Collider Accelerators Lepton-HadronPrimarily used for internal nucleon structure measurementsPoint-like particle on a particle of structureCan extend the kinematic space of the structure functions to very low momentum fractionNeeded for high energy experiments such as the LHCVery asymmetric final stateDESY in Germany (HERA)4/22/2009*ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington


Collider Accelerators Hadron ColliderPrimarily used as discovery machinesCollisions between structured particlesHigh total cross sectionsLarge number of eventsMessy final statesFrom spectator quarksMultiple interactions per collisionsMaximum kinematic reach for the given costProbes broad corners of kinematic phase spaceCERN Sp`pS(0.63TeV), Tevatron (2TeV), CERN LHC (14TeV)4/22/2009*ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington


Synchroton AcceleratorsSynchrotons use magnets arranged in a ring-like fashion.Multiple stages of accelerations are needed before reaching over GeV ranges of energiesRF power stations are located through the ring to pump electric energies into the particles4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Relativistic VariablesThe invariant scalar, s, is defined as:

Show that in the CMS frame In the CMS frame

Thus, represents the total available energy of the interaction in the CMS


Jog-your-memory Simple ExerciseDerive the formulae for the available center of mass energy forA fixed target experiment with incoming particle four momentum P1 (E1, P1) (E1>> m1)and the target mass of MTA collider experiment with the two particle four momenta of P1 (E1, P1) and P2 (E2, P2) 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Particle DetectorsSubatomic particles cannot be seen with naked eyes but can be detected through their interactions within matterWhat do you think we need to know first to construct a detector?What kind of particles do we want to detect?Charged particles and neutral particles?What kind of particles are they? EM, Hadrons, Jets, neutrinos?What do we want to measure?Their momentaTrajectoriesEnergiesOrigin of interaction (interaction vertex)EtcTo what precision do we want to measure?Depending on answers to the above questions we use different detection techniques 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Tracking DevicesUsed to provide the traces of charged particles resulting from interactionsAlong with a magnet, provides the curvature of the charged tracks (charge ID) and their momentaUsed to determine the location of the interactions called verticesCan provide secondary vertices resulting from the decay of longer lived particlesSome devices can measure energy losses of particles via radiations and provide additional particle ID informationMuon tracking system sits at the very outside for momentum measurement and identification4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


A Collider Experiment Tracking System (D)800k channel Si vertex detectorProvides precise location of the primary and secondary verticesHigh resolution scintillating fiber tracking systemProvide high resolution position and momentum measurements4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


CalorimetersMagnetic measurement of momentum is not sufficient, why?The precision for angular measurements gets worse as particles momenta increasesIncreasing magnetic field or increasing precision of the tracking device will help but will be expensiveCannot measure neutral particle momentaCharge neutral particles do not leave traces in the trackerHow do we solve this problem?Use a device that measures kinetic energies of particlesCalorimeterA device that absorbs full kinetic energy of a particleProvides the signal proportional to deposited energyCan measure shower shapes with fine granularityMust work as an integral part of the detector4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


CalorimetersLarge scale calorimeter were developed during 1960sFor energetic cosmic raysFor particles produced in accelerator experimentsHow do EM (photons and electrons) and Hadronic particles deposit their energies?Electrons: via bremsstrahlung followed by a mixture of photon pair production and electron bremsstrahlungPhotons: via electron-positron conversion, followed by bremsstrahlung of electrons and positronsThese processes continue occurring in the secondary particles causing an electromagnetic shower losing all of its energy4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Interaction of Hadrons at High EnergiesHadronic collisions involve very small momentum transfers, small production angles and interaction distance of order 1fmTypical momentum transfer in hadronic collisions are of the order q2 ~ 0.1 (GeV/c)2Mean number of particles produced in hadronic collisions grows logarithmically~3 at 5GeV~12 at 500GeVHigh energy hadrons interact with matter, they break apart nuclei, produce mesons and other hadronsThese secondaries interact through strong forces subsequently in the matter and deposit energy4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Hadron Energy DepositHadrons are massive thus their energy deposit via bremsstrahlung is smallThey lose their energies through multiple nuclear collisionsIncident hadron produces multiple pions and other secondary hadrons in the first collisionThe secondary hadrons then successively undergo nuclear collisionsMean free path for nuclear collisions is called nuclear interaction lengths and is substantially larger than that of EM particlesHadronic shower processes are therefore more erratic than EM shower processesSlow neutron energy deposit also problematic4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Sampling CalorimetersHigh energy particles require large calorimeters to absorb all of their energies and measure them fully in the device (called total absorption calorimeters)Since the number of shower particles is proportional to the energy of the incident particlesOne can deduce the total energy of the particle by measuring only fraction of their energies, as long as the fraction is known Called sampling calorimetersMost the high energy experiments use sampling calorimetersCan measure E with much less detector volume 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


How do particle showers look in detectors?*ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington4/22/2009


Calorimeter Design ConsiderationsFull shower containmentWhat are the expected energies of particles resulting from the interactions?How deep and wide does the calorimeter have to be to contain full shower?What is the necessary energy measurement precision? What sensitive gap technology can allow to accomplish such precision?At what longitudinal frequency do we need to sample?What is the necessary longitudinal and transverse granularity? What is the necessary position resolution?What are the timing structure of the accelerator?What are the particles to be identified in the detector?4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


What are the most distinguishing characteristics of different particles?Electrons: Electromagnetic particleDeposit virtually all of its energy in the electromagnetic section of the calorimeterHas an associated charged track pointing at the clusterPhotonsDeposit virtually all of its energy in the electromagnetic section of the calorimeterNo charged track associated with it4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


What are the most distinguishing characteristics of different particles?Hadronic particles, pions, Kaons, protons, neutrons, etcSome have charge while some others dontDeposit energy throughout both EM and hadronic sections of the calorimeterHadroinc Jets induced from quarks and gluonsMultiple charged and neutral hadrons collimated like a jetDeposit energies throughout the entire calorimeter sectionLeave long and wide hadronic showers in the calorimeterneutrinos: Does not interact in the calorimeter.. How do we measure its energy?We measure its transverse energy using momentum imbalance4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Particle Detection and Identificationelectronphotonjetmuonneutrino -- or any non-interacting particle missing transverse momentumWe know x,y starting momenta is zero, butalong the z axis it is not, so many of our measurements are in the xy plane, or transverse


Monday, Jan. 26, 2009PHYS 1441-002, Spring 2009 Dr. Jaehoon Yu*Computers put together a pictureDigital data


The NuTeV DetectorPhysics goalsBeam characteristicsDetector requirementsNuTeV CalorimeterNuTeV Calorimeter Performance4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*What are neutrinos?Lepton species without electrical chargeOnly affected by weak interactions, no EMHave one helicity we have observed only left-handed neutrinos and right-handed anti-neutrinosThis property led Yang & Lee to parity violation and eventually theory of weak interactionsNo mass prescription in the original SM Now some mass prescription corrections after the strong proof of neutrino oscillationMeasurements show three species only


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Physics With NeutrinosInvestigation of weak interaction regimeOnly interact via weak interaction This is why neutrinos are used to observe NC interactionsMeasurement of weak mixing angleMeasurement of coupling strength e=gsinqWTest for new mediators, such as heavy neutral IVBsMeasurement of SM r parameterIndirect measurement of MW: sin2qW=r(1-MW2/ MZ2)Measurement of proton structure functionsMeasurement of neutrino oscillations


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Neutrino Cross SectionsCharged CurrentNeutral Current


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Neutrino ExperimentsNeutrino cross sections are small ~10-38 EnTo increase statisticsIncrease number of neutrinos Natural or reactor sources will not give you control of beam intensityNeed man-made neutrino beamsIncrease neutrino energyIncrease thickness of material to interact with neutrinos Detectors with dense materialBeam can be made so that it is enriched with a specific flavors of neutrinos, such as nts.How does one do this?


The NuTeV ExperimentNuTeV (E815) was a fixed target Deep Inelastic Scattering (DIS) experiment that used sign selected neutrino beams at FermilabRan in the fixed target run at Fermilab 1996 1997 using 900 GeV protons hitting the targetNuTeV used an improved version of the beam lines and the detector from its previous incarnation, the CCFR experiment in the same beam lineNuTeV used a separate, dedicated beam line for constant in-situ detector calibration4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


NuTeV Scientific Goals Measure sin2qW with a greater precisionNarrow down the Higgs mass range along with precise top quark mass measurements from other experimentsBeam line modification requiredNeed to understand the detector at a greater precisionMeasure proton parton distribution functions to a greater precisionProvide precise knowledge on proton internal structure at high momentum fraction (x) and determine the strong coupling constant with higher precisionGood energy measurementsGood angle measurements4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Proton Structure Function MeasurementsA complete set of Lorentz scalars that parameterize the unknown structure of the protonProperties of the SF lead to parton modelNucleon is composed of point-like constituents, partons, that elastically scatter with neutrinoPartons are identified as quarks and gluons of QCDQCD does not provide parton distributions within protonQCD analysis of SF provides a determination of nucleons valence and sea quark and gluon distributions (PDF) along with the strong coupling constant, as


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Factorization Concepts=f*spfsp


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*How Are PDFs Determined?Measure n-N differential cross sections, correcting for targetCompare them with theoretical x-secFit SFs to measured x-secExtract PDFs from the SF fits Different QCD models could generate different sets of PDFsCTEQ, MRST, GRV, etcFit to Data for SF


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*sin2qW and n-N scatteringIn the electroweak sector of the Standard Model, it is not known a priori what the mixture of electrically neutral electomagnetic and weak mediator is This fractional mixture is given by the mixing angleWithin the on-shell renormalization scheme, sin2qW is:Provides independent measurement of MW & information to pin down MHiggs via higher order loop corrections, in comparable uncertainty to direct measurementsMeasures light quark couplings Sensitive to other types (anomalous) of couplings In other words, sensitive to physics beyond SM New vector bosons, compositeness,n-oscillations, etc


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*How is sin2qW measured?Cross section ratios between NC and CC proportional to sin2qWLlewellyn Smith Formula:(or e)


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Sources of Neutrinos:Atm and otherHigh energy cosmic-ray (He, p, n, etc) interactions in the atmosphereCosmic ray interacts with air moleculesSecondary mesons decayMuons decay again in 2.6msNeutrinos from Big Bang (relic neutrinos)Neutrinos from star explosionsNeutrinos from natural background, resulting from radioactive decays of nucleusNeutrinos from nuclear reactors in power plants


Beam Characteristics NuTeV Fermilabs Fixed Target beam using 900GeV protons hitting the target to generate neutrinosHow can we produce neutrino beams?4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Conventional Neutrino BeamUse large number of protons on target to produce many secondary hadrons (p, K, D, etc) and focus them wellLet p and K decay in-flight for nm beampm+nm (99.99%), Km+nm (63.5%)What percentage of pions will decay in the 540 m decay region when their mean energy are 150GeV?Other flavors of neutrinos are harder to makeLet the beam go through shield and dirt to filter out m and remaining hadrons, except for nDominated by nm


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Improving Experimental UncertaintiesElectron neutrinos, ne, in the beam fakes NC events from CC interactionsIf the production cross section is well known, the effect will be smaller but since majority come from neutral K (KL) whose x-sec is known only to 20%, this is a source of large experimental uncertaintyNeed to come up with a beamline that separates neutrinos from anti-neutrinos


Beam Characteristics NuTeV Fermilabs Fixed Target beam using 900GeV protons hitting the target to generate neutrinosHow can we produce neutrino beams?How can we produce neutrino beams of specific signs (n or `n)?4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*How can we select sign of neutrinos?Neutrinos are electrically neutralNeed to select the charge of the secondary hadrons from the proton interaction on targetNuTeV experiment at Fermilab used a string of magnets called SSQT (Sign Selected Quadrupole Train)Proton beam shot with a 7mr upward incident angleDipoles immediately behind the target bends the particles of right signs toward the detectorWrong charge particles and the remaining protons are dumped


Beam Characteristics NuTeV Fermilabs Fixed Target beam using 900GeV protons hitting the target to generate neutrinosHow can we produce neutrino beams?How can we produce neutrino beams of specific signs (n or `n)?Two different beam lines usedNeutrino beam: Fermilabs NC (Neutrino Center) 5 pings of widths 5 ms separated by 0.5 secondsCalibration Beam: NT (Neutrino Test) A 18 second slow spill of continuous beam 1.8 seconds after the last short pulsed neutrino beam 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*How Can Events be Separated?


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Experimental VariableDefine an Experimental Length variable Distinguishes CC from NC experimentally in statistical mannerto theoretical prediction of RnCompare experimentally measured ratio


Detector Requirements NuTeV Large mass in neutrinos path to cause neutrino interactionsNeutrino-nucleon cross section: Anti-neutrino-nucleon cross section:High precision understanding of calorimeter energy resolutionHigh precision interaction position measurement Ability to distinguish CC and NC interactionsTracks of leptons (e and m) from CC interactions for PID Precise momentum measurement of muonsPrecise measurement of hadronic shower energy up to ~150 GeVFine longitudinal segmentationCosmic-ray veto High efficiency, high rejection muon identification and momentum measurements Sensitivity to low energy interactions, such as m MIP energy deposit4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


NuTeV CalorimeterTechnology: Sampling CalorimeterPassive (or absorber) material5cm thick steel platesWhat is the radiation length?What are the functionalities of these steel plates?Active material: 2.5cm thick Liquid Scintillation countersWhat is the liquid scintillator material?Baby oil!!4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


NuTeV Calorimeter, cntdDimension of each unit: 3mx3mNumber of layers: 84 layers of liquid scintillator sandwiched in between two steel plates interspersed with 42 drift chambersReadout technology: PMTs mounted in each of the four corners of the squareEach layer read out independently, giving total of 64 longitudinal sectionsCan one distinguish different particles?Electrons and hadroinc jets? Neutrinos? Muons?4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Calorimeter168 FE plates & 690tons84 Liquid Scintillator42 Drift chambers interspersedThe NuTeV Neutrino DetectorSolid Iron ToroidMeasures Muon momentumDp/p~10%Continuous test beam for in-situ calibration


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*The NuTeV DetectorA picture from 1998. The detector has been dismantled to make room for other experiments, such as D


NuTeV Liquid Scintillation Counter4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Particle incident position dependenceFor structural supportFor light transport


NuTeV Readout Electronics 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*3 different electronics gains to extend dynamic range


NuTeV Detector In-Situ CalibrationsIn-Situ simultaneous calibration beam which followed the neutrino pings by 1.4 s separation18 second long calibration beam spills4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Calibration beam line capable of providing wide range of momenta for various species of particlesElectrons, pions and muonsParticle selection done by the Cerenkov counter just upstream of the detectorBeam momentum measured by an independent set of spectrometer consisting of drift chambers and magnetsBeam was directed to different locations on the detector through a rotating dipole


NuTeV Calibration Beam Line4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Photon converter/ electron generatorfocussingMomentum selectionElectron Momentum selection


NuTeV Hadron Response and Resolution4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Hadron Energy ResolutionHadron Energy Response


NuTeV Calorimeter PerformanceHadron non-linearity 5.9 GeV 190GeV: 3%Hadron energy scale uncertainty: 0.43%Hadron Energy Resolution: Residual Position Dependence of EH:

The D DetectorPhysics goalsBeam characteristicsDetector requirementsNuTeV CalorimeterNuTeV Calorimeter Performance4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Scientific Goals D Top quarkDiscover the top quarkMeasure its properties and production x-sec with high precisionElectroweak Intermediate Vector BosonsMeasure W mass at a higher precisionThe Higgs ParticleNarrow down the mass range using Mt and MW measurementsSearch and discover the Higgs particleSuper-SymmetryDiscover supersymmetric partner particles and measure propertiesQCDMeasure various jet cross sections with higher precision4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Z and W Boson DecaysThe weak vector bosons couples quarks and leptons Thus they decay to a pair of leptons or a pair of quarksSince they are heavy, they decay instantly to the following channels and their branching ratiosZ bosons: MZ=91GeV/c2 W bosons: MW=80GeV/c2


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Precision Z/W Measurement StrategyThe weak vector bosons have masses of 91 GeV/c2 for Z and 80 GeV/c2 for Wqqbar (2 jets of particles) the largest x-sec, the multi-jet final states are also the most abundant in collisionsBackground is too large to carry out a meaningful searchThe best channels are using leptonic decay channels of the bosonsThe final states containing electrons and muons are the cleanestSo what do we look for as signature of the bosons?For Z-bosons: Two isolated electrons or muons with large transverse momenta (PT) For W bosons: One isolated electron or muon with a large transverse momentum along with a signature of high PT neutrino (Large missing ET).


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*W and Z event kinematic propertiesdots: Datahistogram: MCETETeMTpTwdiEM Invariant mass (GeV)

Ze+e- cross-section


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Cross Section: W(en) +XTransverse momentum distribution of electrons in W+X events


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*W Transverse Mass DistributionTransverse mass is defined as


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*A W e+n Event


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Z e+e-+2jets Event


Invariant Mass Distributions: Z(ee) +XInvariant mass distribution of electrons in Z+X events 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


How does the top quark final state look?Top quarks produced in pairs with anti-top most of the timeThe top decays through electro-weak process, coupled with a W IVB and a b-quark, highest CKM coupling and Depending on how Ws decay, many final state particle combinations possibleBoth Ws decay leptonically 2 b-quark jets + 2 leptons + 2 neutrinosOne W decay leptonically and the other decay hadronically 2 b-quark jets + one lepton + one neutrino + 2 light quark jetsBoth Ws decay hadronically resulting in 6 jets in the final state4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Simple ExerciseDraw Feynman diagrams of each of the following t`t final states and compute the branching ratios. di-lepton Lepton+jets Six jets

4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*The Higgs MechanismRecovery from a spontaneously broken electroweak symmetry gives masses to gauge fields (W and Z) and produce a massive scalar bosonThe gauge vector bosons become massive (W and Z) The massive scalar boson produced through this spontaneous EW symmetry breaking is the Higgs particleIn SM, the Higgs boson is a ramification of the mechanism that gives masses to weak vector bosons, leptons and quarksThe Higgs Mechanism


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Higgs Production Processes at Hadron CollidersGluon fusion: WW, ZZ Fusion: Higgs-strahlung off W,Z: Higgs Bremsstrahlung off top:


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Hadron Collider SM Higgs Production sLHCTevatronWe use WHen+b`b channel for search for Higgs


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*For MH130GeV


Standard Model Higgs ChannelsmH < 130-140 GeV WH l b`b backgrounds Wb`b, WZ, t`t, single tfactor ~ 1.3 improvement in S/B with neural network possibility to exploit angular distributions (WH vs. Wbb) Parke and Veseli, hep-ph/9903231WH qq b`b overwhelmed by QCD backgroundZH l`l b`b backgrounds Zb`b, ZZ, t`tZH ` b`b backgrounds QCD, Zb`b, ZZ, t`t requires relatively soft missing ET trigger (35 GeV?)4/22/2009*ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington


Standard Model Higgs ChannelsmH > 130-140 GeVgg H WW* /ZZ* backgrounds Drell-Yan, WW, WZ, ZZ, t`t, tW, signal:background ratio ~ 7 10-3 !Angular cuts to separate signal from irreducible WW background4/22/2009*ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*How do we find a presence of a b-quark?Use finite lifetime of mesons containing b-quarks within a particle jets.


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*What do we need to do all this?Smaller Higgs x-sec Need higher rateIncrease CMS energy of the acceleratorIncreased x-secIncreased kinematic reach for higher MHIncreased instantaneous LuminosityIncreased Number of protons and anti-protons, especially anti-protonsIncreased duty factor/efficiencyShorter fill time of anti-protons


Beam Characteristics D Fermilabs Tevatron P Pbar colliderHow is this different operationally from the LHC, a p-p collider?One of the two collider experiments on the Tevatron ringTevatron had the Main Ring booster accelerator circulating beam right on top of the Tevatron beamAccelerates protons up to 150GeVUsed to generate anti-proton beam and accumulate themNow it is replaced by the Main Injector, a separate ringRF Frequency: 50MhZBunch Spacing: 3.5 ms (Run I)/396 ns (Run II)Instantaneous luminosity:~1031/~10334/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*s(tt) ~ 40% higher at 2 TeVdMH ~ 40% per experiment Increase in ratesDecrease in bunch spacingRun II TeVatron Benchmarks

ParametersRun IRunIIa/bLinst (cm-2 sec-1)~10312x1032 ~1033Bunch Spacing3.5 msec396 / 132 nsecECMS(TeV)1.81.98Lint~110pb-12fb-1 / >6fb-1


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*What do we need for the experiment to search for the top and the Higgs and measure IVB precisely?We need to be able to identify isolated leptonsGood electron and muon identificationCharged particle tracking We need to be able to measure transverse momentum wellGood momentum and energy measurementsWe need to be able to measure missing transverse energy wellGood coverage of the energy measurement (hermeticity) to measure transverse momentum imbalance wellIdentify b-quark jets


Detector Requirements D High precision energy and momentum measurementsHigh efficiency and high rejection particle identification, in particular the electrons and muonsHigh efficiency and high rejection neutrino identification and high precision transverse energy measurementsHigh precision jet energy and position measurementsHigh efficiency and high rejection b-jet idenficationCapable of measuring vertex that are ~100mm away from the primary vertex Precision vertex detectorTag and associate leptons with a jet4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*The D DetectorConceived in 1983, construction completed in 1992Weighs 5000 tonsMore than 100 million partsCan inspect 1,700,000 collisions/secondRecords 100 collisions/secondRecords approximately 20 MB/secondRecords 300TB data/yearRecorded over 4x109 events as of Nov. 2008


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Run II D Detector


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Ability to trigger on tracks for quick dicisionMeasure momentum and identify chargeUpgrade tracking & Trigger systemsD Tracking SystemCharged Particle Momentum ResolutionpT/pT ~ 5% @ pT = 10 GeV/c


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*D Silicon Microstrip Detector Covers immediate outside of beam pipe to just before the fiber trackerConsists of Barrels and DisksTotal number of readout channels are 800kExpected Position resolution 10~20mm


Sheet1

BarrelsF-DisksH-Disks

Channels387072258048147456

Modules43214496

Inner R2.7 cm2.6 cm9.5 cm

Outer R9.4 cm10.5 cm26 cm

Sheet2

Sheet3

4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*D Detectormuon systemshieldingelectronics


4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*D DetectorCentral CalorimeterSolenoidFiber TrackerSilicon


ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at ArlingtonSlide *The D CalorimeterThree separate calorimeters:Central and Two End Caps for hermetic coverageConcentric cylinders about the beam axis4/22/2009


D CalorimeterTechnology: Sampling CalorimeterPassive (or absorber) material3mm (central) /4mm (end cap) thick depleted U238 plates in EMWhat is the radiation length of each plate?What is the depth in radiation length to contain over 98% of ET=45 GeV electron energy?10mm thick uranium-niobium alloy in fine hadronic section50mm thick copper plates in coarse hadronic sectionUranium used for compensation of e/pi responsesActive material: 2.6mm Liquid Argon gap surrounding the resistive coated PCB readout boardUsed for energy measurements, p-ID and triggering4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Unit Layer of the D Calorimeter4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*2.6mmHV=+2.5kVGrounded U238/U238 + Nb Alloy/Cu plates


Cell With Readout Electronics4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Calorimeter Data Flow Diagram4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Triggering systemcalibration systemE sum for trigger


D Calorimeter GeometryEM SectionPreceded by 1 2 X0 of material3mm Uranium (U238 depleted) plates + LArTotal of 21 gaps read out in four longitudinal sections2+2+7+10 In which layer is the shower maximum for 40GeV electron?High granularity: DhxDf=0.1x0.1/0.05x0.05 at the shower maximumHadronic Section: Iron/copper + LAr Total of four longitudinal readout layers that cover the depth of 5 7 interaction lengthsTransverse granularity: DhxDf=0.1x0.1Four independent longitudinal readout layers460ns charge collection time



Readout Geometry of the D Calorimeter4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*Projective towers without obviously aligned cracksAngular coverage down to 5o from the beam pipe (|h|

ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at ArlingtonSlide *The D CalorimeterUranium-Liquid ArgonTotal of 50,000 readout channelsCompact, hermetic device Angular coverage to 5o from the beam lineUniform response Stable calibrationcompensating Fully absorbing with relatively small diameter detectorWhere is Jae?

4/22/2009D CC in 1990


Hardware CalibrationRegular calibration runs for constant background noise due to electronics thermal noise + beta rays from U platesRegular electronics gain calibration runs using pulse injection systemConversion between ADC counts and GeV obtained from test beamsMultiple loads of detector stacks exposed to electrons and hadronsRefined using in-situ calibration points4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


In-Situ CalibrationIn-situ calibration helps to minimize remaining effects of detector response variations and understand detector responses to unmeasurable quantities such as missing ETElectromagnetic energy scale: Use known mass resonances to correct for the scales (precision ~0.1%)J/Y ee, Z eeCorrect for overall energy scalea ~1.05Correct for azimuthal non-uniformitiesJet energy scale corrections (precision varies 5 10%)Utilized missing ET projection techniqueAssisted by simulations since jet composition is not known aprioriOut of cone corrections + underlying events



In-Situ electron energy scale calibration 4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*J/ e+e-


D Calorimeter PerformancesSingle particle energy resolutionsEM particles: HadronsJet energy resolution:Absolute EM energy scale precision: 0.1%Response Linearity: Better than 0.5%Average electron ID efficiency: ~85%Jet reconstruction efficiency: >98% for PT>25GeV4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


EpilogueCalorimeters not only measure energies of various particles but also plays a crucial role in particle identificationsDepending on the physics goals, different requirements are applied on the calorimeterPrevious calorimeters such as NuTeV, D, and others have performed marvelously and accomplished a great deal beyond their original goalsPerformance requirements on calorimeters for a Linear Collider is unprecedented A lot of work aheadRequires bright minds like yours to meet the challenge4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Reference TextbooksR. Fernow, Introduction to Experimental Particle Physics, ISBN 0-521037940-7, Cambridge University Press, 1986D. H. Perkins, Introduction to High Energy Physics, 4th Ed., ISBN 0-521-62196-8, Cambridge University Press, 2000D. Griffiths, Introduction to Elementary Particles, ISBN 978-0-471-60386-3, Wiley-VCH, 2004A. Bettini, Introduction to Elementary Particle Physics, ISBN 978-0-521-88021-3, Cambridge University Press, 20084/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


Detector Reference PapersV. M. Abazov et al., D Collaboration, The Upgraded D detector, Nucl. Instrum. Meth. A565, 463 (2006). V.M.Abazov et al., D Collaboration, Determination of the absolute jet energy scale in the D calorimeters, Nucl. Instrum. Meth. A424, 352 (1999). V.M.Abazov et al., D Collaboration,The D upgrade, Nucl. Instrum. Meth. A408, 103 (1998). S. Abachi et al., D Collaboration, The D Detector, Nucl. Instrum. Meth. A338, 185 (1994). S. Abachi et al., D Collaboration, Beam tests of the D uranium liquid argon end calorimeters, Nucl. Instrum. Meth. A324, 53 (1993).D.A. Harris and J. Yu et al., NuTeV Collaboration, Precision Calibration of the NuTeV Calorimeter, Nucl. Instrum. Meth. A447, 377 (2000).4/22/2009ILC Calorimeter School, Tsinghua University J. Yu, Univ. of Texas at Arlington*


**The Run 2 detector. Schematically how it works.SVX and the like.***

Documents

Calorimeters In Action!! ILC Calorimeter School CCAST & TUHEP, Tsinghua University Apr. 22 – 26 Jae Yu University of Texas at Arlington