QuarkNet: Exploring the Frontiers of High Energy Physics - [PPT Powerpoint] (2024)

QuarkNet: Exploring the Frontiers of High Energy PhysicsBethBeiersdorf

Notre Dame QuarkNet CenterVisionA community of researchersincluding high school teachers, faculty, postdoctoral, graduate andundergraduate students and high school students. Location - Justsouth of NDs campus. - Fully functional research lab. - Housesoffices, lab spaces, and student experimental areas.

QuarkNet Sites Nationwide

Notre Dame QuarkNet CenterAcademic Structure*3-8 week summerresearchPHYS 598Q (teachers) 1-3 creditsPHYS 098Q (students) 1-3creditsacademic year researchPHYS 598R (teachers) 1 creditPHYS 098R(students) 1 creditdiscussion sections, laboratory activity*thanksto effort from K. Newman, J. Maddox, B. Bunker

Science Alive

Student Involvement

Summer, 2000RET Research Experience for Teachers (8weeks)Week12345678

QuarkNet 3 WeeksLunchMorningsAfternoons

QuarkNet StudentsSummer 00

Summer Student Research

QuarkNet Staff and Teachers

Fermilab

The Tevatron

Side View of CFT

Support Cylinder for CFT

Moving in . . .

End View of CFT

CFT Fiber/Waveguide Element

Scintillating Fibers Under Test

Fiber Waveguide Map

Waveguide Bundle Containing 256 Fiber Elements

Sheathing Fiber Waveguides

Optical Connectors

Testing Optical Fibers

Summer Productivity

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Photo Sensors

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Particle Paths

QuarkNet - Summer 2000

CMS Experiment at LHCCERN, Geneva, Switzerland

CMS Plans a working detector in 2005

The CMS Collaboration

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31 Countries146 Institutes1801 Physicists and Engineers

CMS Collaboration

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CountryInstitutesScientists

USA38331

Austria119

Belgium527

Finland628

France5146

Germany575

Greece327

Hungary333

Italy11251

Poland215

Portugal117

Slovakia17

Spain438

CERN1148

Switzerland499

UK586

Russia8197

Armenia16

Belarus431

Bulgaria226

China349

Croatia28

Cyprus13

Estonia14

Georgia213

India534

Korea1431

Pakistan216

Turkey212

Ukraine310

Uzbekistan114

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31 Countries146 Institutes1801 Physicists and Engineers

CMS Collaboration

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CMS Detector Subsystems

What and Where is CERN, LHC, CMS?

European Center for Nuclear Research (CERN)Large HadronCollider(LHC)Compact Muon Solenoid(CMS)

CMS in the Collision Hall TrackerECALHCALMagnetMuon

The Hadron CalorimeterHCAL detects jets from quarks and gluons.Neutrinos are inferred from missing Et.Scintillator + WLS giveshermetic readout for neutrinos

Detection of Fundamental ParticlesSM Fundamental ParticleAppears As (ECAL shower, no track)e e (ECAL shower, with track)(ionization only)g Jet in ECAL+ HCALq = u, d, s Jet (narrow) inECAL+HCALq = c, b Jet (narrow) + Decay Vertex t --> W +b W + beEt missing in ECAL+HCAL-->l + +l Et missing + charged lepton W--> l + l Et missing + charged lepton, Et~M/2 Z --> l+ + l-charged lepton pair --> l + l Et missing in ECAL+HCAL

Dijet Events at the TevatronThe scattering of quarks inside theproton leads to a "jet" of particles traveling in the direction of,and taking the momentum of, the parent quark. Since there is noinitial state Pt, the 2 quarks in the final state are "back toback" in azimuth.

QuarkNet - Is it for you?For more information, contact:BethBeiersdorfND QuarkNet CenterPhysics DepartmentNotre Dame, IN46556(219) [emailprotected] JordanEducationOfficeFermilab, PO Box 500Batavia, IL 60510(630)[emailprotected] website:http://quarknet.fnal.gov

QuarkNet 3 WeeksLunchMorningsAfternoons

Lead Teacher Institute at Fermilab

Student working with lead teacher on CMS HCAL project

September 1999: Initial Meeting for ND Center & WeeklyMeetings during the 99-00 Academic Year

MentorsJim BishopDan KarmgardRandy RuchtiMitch WayneQuarkNetStaffPat MooneyCMS/D StaffBarry BaumbaughJeff MarchantMarkVigneaultAdministrationJennifer MaddoxLead TeachersLeRoy Castle, LaPorteDale Wiand, AdamsAssociate TeachersKen Andert, LaLumiereBethBeiersdorf, LaSalleJeff Chorny, LakeShore Helene Douerty, St.JosephMaggie Jensen, GavitTom Loughran, TrinityKevin Johnston*,JimtownRick Roberts*, ClayND QuarkNet Center: Staff

Adams HS visit to ND QuarkNet Center

Teacher ScheduleThree week workshop Mornings: particle physicsinteractive discussionsAfternoons: classroom transfer and researchdiscussions and research activitiesFermilab tours (one withstudents)Five week research experiencePresentation on research workin RET forum

Notre Dame QuarkNet Center

Academic Structure*3-8 week summer researchPHYS 598Q (teachers)1-3 creditsPHYS 098Q (students) 1-3 creditsacademic yearresearchPHYS 598R (teachers) 1 creditPHYS 098R (students) 1creditdiscussion sections, laboratory activity

*thanks to effort from K. Newman, J. Maddox, B. Bunker

High School Students1999D. Dickerson, AdamsD. Saddawi, Adams2000(45 Applicants)R. Bhavsar, AdamsR. Bourke, LaLumiereM. Busk,TrinityZ. Clark, JimtownP. Davenport, Trinity

A. DeCelles, TrinityN. Garg, ClayJ. Martin, ClayS. May, AdamsG.Outlaw, LaSalleR. Ribeiro, TrinityR. Smith, JimtownJ. Tristano,LaLumiereK. Whitaker, LaSalleR. Wiltfong, Riley

Student ScheduleMorning Shift: 7:30am-1:00pmAfternoon Shift:12:00pm-5:30pmwork at QuarkNet Lab or Nieuwland ScienceHallLuncheon interactive physics discussions and/or seminars:12:00pm-1:00pmAt QuarkNet Labdiscussions: Karmgard, Mooney,Ruchtiseminars: Bigi, Cushing, Hildreth, Konigsberg (UFL), Lynker(IUSB), Wayne

LaSalle HS Visit to Fermilab/D0

SummaryIt has been an exciting period of growth for QuarkNetnationally and locally.We have worked extensively with 11 teachersand 15 high school students.The program should grow, now that theword is out.We are now in need of sustaining resources to managethe local program properly.

Sustaining the EffortNSF/DOE FundingQuarkNet out-year fundingRET(research experiences for teachers)Experimental construction funds,D and CMSEndowment or Corporate SponsorshipAEP, Siemens, ?OtherinitiativesNanotechnology Center proposal to NSF by the College ofEngineeringNew Particle Physics initiatives.

CMS

The Physics of the LHC

The Compact Muon Solenoid at the Large Hadron Collider

Dan GreenFermilabUS CMS Project Manager

OutlineWhy do we go to the energy frontier?What is the CMScollaboration? What is the Standard Model? How do we detect thefundamental particles contained in the SM?The Higgs boson is themissing object in the SM periodic table. What is the CMS strategyto discover it?What might we find at CMS in addition to theHiggs?

High Energy Physics-Natural UnitsDimensions are taken to beenergy in HEP. Momentum and mass are given the dimensions ofenergy, pc, mc2. The basic energy unit is the electron Volt, theenergy gained when an electron falls through a potential of 1 Volt= 1.6 x 10 -19 Joule.

The connection between energy and time, position and momentum issupplied by Planck's constant, , where 1 fm = 10-13 cm. Thus,inverse length and inverse time have the units of energy. TheHeisenberg uncertainty relation is

Charge and spin are "quantized"; they only take discrete values,e or . Fermions have spin 1/2, 3/2 ..., while bosons have spin0,1,. The statistics obeyed by fermions and bosons differsprofoundly. Bosons can occupy the same quantum state - e.g.superconductors, laser. Fermions cannot (Pauli Exclusion Principle)- e.g. the shell structure of atoms.

Size and the Energy of the Probe ParticleIn order to "see" anobject of size r one must use "light" with a wavelength l < r.Thus, visible light with l ~ 3000 A ( 1 A = 10-8 cm, ~ size of anatom) can resolve bacteria. Visible light comes from atomictransitions with ~ eV energies ( = 2000 eV*A).

To resolve a virus, the electron microscope with keV energieswas developed, leading to an increase of ~ 1000 in resolvingpower.

To resolve the nucleus, 105 time smaller than the atom one needsprobes in the GeV (109 eV) range. The size of a proton is ~ 1 fm =10-13 cm.

The large Hadron Collider (LHC) at the CERN will explore Natureat the TeV scale or down to distances ~ 0.0002 fm.

CMS Tracking SystemThe Higgs is weakly coupled to ordinarymatter. Thus, high interaction rates are required. The CMS pixel Sisystem has ~ 100 million elements so as to accommodate theresulting track densities..Si pixels + Si Strips - an all Sidetector is demanded by the high luminosity required to do thePhysics of the LHC

If MH < 160 GeV use H --> ZZ --> 4e or 4Fully activecrystals are the best resolution possible needed for 2 photondecays of the Higgs.

Theory

Particle Physics in the 20th CenturyThe e- was discovered byThompson ~ 1900. The nucleus was discovered by Rutherford in ~1920. The e+, the first antiparticle, was found in ~ 1930. The m ,indicating a second generation, was discovered in ~ 1936.

There was an explosion of baryons and mesons discovered in the1950s and 1960s. They were classified in a "periodic table" usingthe SU(3) symmetry group, whose physical realization was pointlike, strongly interacting, fractionally charged "quarks". Directevidence for quarks and gluons came in the early 1970s.

The exposition of the 3 generations of quarks and leptons isonly just, 1996, completed. In the mid 1980s the unification of theweak and electromagnetic force was confirmed by the W and Zdiscoveries.

The LHC, starting in 2005, will be THE tool to explore theorigin of the breaking of the electroweak symmetry (Higgs field?)and the origin of mass itself.

Electro - Weak UnificationThe weak interactions are responsiblefor nuclear beta decay. The observed rates are slow, indicatingweak effective coupling. The decays of the nuclei, n, and m areparametrized as an effective 4 fermion interaction with coupling, G~ 10-5 GeV-2, Gm ~ G2Mm5.The weak SU(2) gauge bosons, W+ Zo W- ,acquire a mass by interacting with the "Higgs boson vacuumexpectation value" of the field, while the U(1) photon, g , remainsmassless. MW ~ gWThe SU(2) and U(1) couplings are "unified" in thate = gWsin(qW). The parameter qW can be measured by studying thescattering of n + p, since this is a purely weak interactionprocess.The coupling gW can be connected to G by noting that the 4fermion Feynman diagram can be related to the effective 4 fermioninteraction by the Feynman "propagator", G ~ gW2/MW2. Thus, from Gand sin(qW) one can predict MW. The result, MW ~ 80 GeV wasconfirmed at CERN in the pp collider. The vacuum Higgs field has ~250 GeV.

The Standard Model of Elementary Particle PhysicsMatter consistsof half integral spin fermions. The strongly interacting fermionsare called quarks. The fermions with electroweak interactions arecalled leptons. The uncharged leptons are called neutrinos.Theforces are carried by integral spin bosons. The strong force iscarried by 8 gluons (g), the electromagnetic force by the photon(), and the weak interaction by the W+ Zo and W-. The g and aremassless, while the W and Z have ~ 80, 91 GeV mass.J = 1g,,W+,Zo,W-Force CarriersJ = 1/2udcstbeeQ/e=2/3-1/310QuarksLeptons

A FNAL Collider (D0) EventThe D0 detector has 3 main detectorsystems; ionization tracking,liquid argon calorimetry ( EM , e ,and HAD , jets ,), and magnetized steel + ionization tracker muon ,m , detection/identification. This event has jets, a muon, anelectron and missing energy , n.

A FNAL Collider (CDF) EventThe CDF detector has 3 main detectorsystems; tracking - Si + ionization in a magnetic field,scintillator sampling calorimetry, (EM - e, g and HAD - h), andionization tracking for muon measurements. Missing energy indicatesn in the final state.Si vertex detectors allow one to identify band c quarks in the event.

W --> e + at the TevatronThe W gauge bosons can decay intoquark-antiquarks, e.g. u + d, or into lepton pairs, e + ne, m + nm,t+ nt. There can also be radiation associated with the W, gluonswhich evolve into jets.

Z --> e + e and + Events at the TevatronThe e appear in theEM and not the HAD compartment of the calorimetry, while the mpenetrate thick material.

The Generation of Mass by the Higgs MechanismThe vacuumexpectation value of the Higgs field, , gives mass to the W and Zgauge bosons, MW ~ gW. Thus the Higgs field acts somewhat like the"ether". Similarly the fermions gain a mass by Yukawa interactionswith the Higgs field, mf = gf. Although the couplings are notpredicted, the Higgs field gives us a compact mechanism to generateall the masses in the Universe.

G(H->ff) ~ gf2MH ~ g2(Mf/MW)2MH , g = gW

G(H->WW) ~ g2MH3/MW2 ~ g2(MH/MW)2MH

G ~ MH3 or G/MH ~ MH2 ==> G/MH ~ 1 @ MH ~ 1 TeV

Hgf, W, Z

f, W, Z

Higgs Cross sectionCDF and D0 successfully found the top quark,which has a cross section ~ 10-10 the total cross section.

A 500 GeV Higgs has a cross section ratio of ~ 10-11, whichrequires great rejection power against backgrounds and a highluminosity.

CMS

The CMS Muon SystemThe Higgs decay into ZZ to 4 is preferred forHiggs masses > 160 GeV. Coverage to || < 2.5 is required (> 6 degrees)

Higgs Discovery LimitsThe main final state is ZZ --> 4l.Athigh masses larger branching ratios are needed.At lower masses theZZ* and final states are used.LEP II will set a limit ~ 110 GeV.CMSwill cover the full range from LEPII to 1 TeV.

LEP,CDF D0 Data Indicate Light Higgs

Higgs Mass - Upper LimitIn quantum field theories the constantsare altered in high order processed (e.g. loops). Asking that theHiggs mass be well behaved up to a high mass scale (no new Physics)implies a low mass Higgs.

Progress in HEP Depends on Advancing the Energy Frontier

Theory

Grand Unified TheoriesPerhaps the strong and electroweak forcesare related. In that case leptons and quarks would make transitionsand p would be unstable. The unification mass scale of a GUT mustbe large enough so that the decay rate for p is < the rate limitset by experiment.The coupling constants "run" in quantum fieldtheories due to vacuum fluctuations. For example, in EM the echarge is shielded by virtual fluctuations into e+e- pairs on adistance scale set by, le ~ 1/me. Thus a increases as M decreases,a(0) = 1/137, a(MZ) = 1/128.

Why is charge quantized?

There appears to be approximate unification of the couplings ata mass scale MGUT ~ 1014 GeV.Then we combine quarks and leptonsinto GUT multiplets - the simplest possibility being SU(5).

[d1 d2 d3 e ] = 3(-1/3 ) + 1 + 0 = 0

Since the sum of the projections of a group generator in a groupmultiplet is = 0 (e.g. the angular momentum sum of m), then chargemust be quantized in units of the electron charge.In addition, wesee that quarks must have 1/3 fractional charge because there are 3colors of quarks - SU(3).

GUT Predicts WA GUT has a single gauge coupling constant. Thus,and W must be related. The SU(5) prediction is that sin(W) = e/g =3/8.

This prediction applies at MGUT

Running back down to the Z mass, the prediction becomes; 3/8[1 -109 /18(ln(MGUT/MZ))]1/2

This prediction is in ~ agreement with the measurement of W fromthe W and Z masses.

Why is matter (protons) ~ stable?

There is no gauge motivated conservation law making protonsstable.Indeed, SU(5) relates quarks and leptons and possessesleptoquarks with masses ~ the GUT mass scale.Thus we expect protons(uud) to decay via uu --> e+d , ud --> d. Thus p --> e+oor +Looking at the GUT extrapolation, we find 1/ ~ 40 at a GUT massof ~ 1014 GeV.One dimensional grounds, the proton lifetime shouldbep = 1/p ~ GUT2(Mp/MGUT)4Mp or p ~ 4 x 1031 yr.

The current experimental limit is 1032 yr. The limit is indisagreement with a careful estimate of the p decay lifetime insimple SU(5) GUT models. Thus we need to look a bit harder at thegrand unification scheme.

9 - Why is the Universe made of matter?

The present state of the Universe is very matter-antimatterasymmetric.

The necessary conditions for such an asymmetry are the CP isviolated, that Baryon number is not conserved, and that theUniverse went through a phase out of thermal equilibrium.

The existence of 3 generations allows for CP violation.

The GUT has, of necessity, baryon non-conserving reactions dueto lepto-quarks.

Thus the possibility to explain the asymmetry exists in GUTs,although agreement with the data, NB/N ~ 10-9, and calculation maynot be plausible.

SUSY and Evolution of It is impossible to maintain the big gapbetween the Higgs mass scale and the GUT mass scale in the presenceof quantum radiative corrections. One way to restore the gap is topostulate a relationship between fermions and bosons. Each SMparticle has a supersymmetric (SUSY) partner with spin 1/2difference. If the mass of the SUSY partners is ~ 1 TeV, then theGUT unification is good - at 1016 GeV

Galactic Rotation CurvesThe rise of v as r (Keplers law) isobserved, but no falloff is observed out to 60 kpc, well beyond theluminous region of typical galaxies. There must be a new darkmatter.

Summary for CMS PhysicsCMS will explore the full (100 - 1000GeV) allowed region of Higgs masses. Precision data indicates thatthe Higgs is light.

The generational regularities in mass and CKM matrix elementswill probably not be informed by data taken at CMS.

There appears to be a GUT scale which indicates new dynamics.The GUT explains charge quantization, the value of W and perhapsthe matter dominance of the Universe and the small values of theneutrino masses. However it fails in p decay and quadraticradiative corrections to Higgs mass scales..

Preserving the scales, (hierarchy problem) can be accomplishedin SUSY. SUSY raises the GUT scale, making the p quasi-stable. TheSUSY LSP provides a candidate to explain the observation ofgalactic dark matter. A local SUSY GUT naturally incorporatesgravity. It can also possibly provide a small cosmologicalconstant. A common GUT coupling and preservation of loopcancellations requires SUSY mass < 1 TeV. CMS will fully explorethis SUSY mass range either proving or disproving this attractivehypothesis.

What will we find at the LHC?There is a single fundamental Higgsscalar field. This appears to be incomplete and unsatisfying.

Another layer of the cosmic onion is uncovered. Quarks and/orleptons are composites of some new point like entity. This ishistorically plausible atoms nuclei nucleons quarks.

There is a deep connection between Lorentz generators and spingenerators. Each known SM particle has a super partner differing byunit in spin. An extended set of Higgs particles exists and a wholenew SUSY spectroscopy exists for us to explore.

The weak interactions become strong. Resonances appear in WW andWZ scattering as in + . A new force manifests itself, leading to anew spectroscopy.

There are more things in heaven and earth than are dreamt of

Pictures +

Teacher and Student Immersion in Physics Research isImportant.QuarkNet is a national program that partners high schoolteachers and students with particle physicists working onexperiments in hadron collider physics.

Working in close association with practitioners, teachers andstudents become immersed in the process of scientific research asit is actually performed, rather than being observers on thesidelines.

Why is the research experience valuable to High SchoolTeachers?How does participating in research impact teaching?Howdoes the research experience impact students?

Who is involved?High School TeachersHigh SchoolStudentsPhysicists

Why is the research experience valuable to High SchoolTeachers?Provides a deeper understanding of PhysicsParticipation inhistoric researchTeachers infused with greater enthusiasm

A key equation:E2 = p2c2 + m2c4New Physics:HiggsBosonsSupersymmetryString TheoryHidden Dimensions

How does participating in research impact teaching?Brings newunderstanding to the classroom instructionCurrent events have apersonal connectionStudents have greater respect for theteacherPositive interaction with other like-minded teachers

FNAL Collider (D ) Event

How are students involved?Classroom visitsField tripsFermiLabSaturday PhysicsScience Alive!Equipment SharingSummer ResearchExperience

Field Trips

How are students chosen?ApplicationsParticipating HighSchoolsJuniors

How does the research experience impact students?Studentquestions take classroom discussions to higher levelsIncreasedinterest in Particle Physics research (Higgs)Deeper understandingof how Physics is performed.

What are the benefits of Research Experiences forTeachers?Feeling a part of current researchUnderstanding ofscientific researchGreater student interestRevitalizedteachingCamaraderie and support

Waveguides