The Big-Bang Machine. Stefan Spanier Physics and Astronomy University of Tennessee, Knoxville. 25 February 2017 Stefan Spanier, The Big Bang Machine

Transcription

1 The Big-Bang Machine Stefan Spanier Physics and Astronomy University of Tennessee, Knoxville 1

2 Accelerator = Microscope Length to be resolved L L 1/Particle Energy Pocket Electron-Accelerator - Energy - + 2

3 Particle Collider Experiment Principle Particle Accelerator provides large kinetic energy Very High Voltage (year 1932) E = m c 2 short lived particle new matter? Particles live long enough to make signals in a detector (material) - create light -generate new particles 3

4 Particle Collider Experiment Principle Measure many particles e.g. their energy more like exists ~10-23 seconds Background Lifetime 1 / Width Signal 4

5 The Standard Model Building Blocks Proton u u hadrons Quarks Leptons d particles Latest addition 1995 Tevatron at Fermilab _ u c t d s b _ d s b u c t e - e e e + mass _ d _ u anti-particles u Anti-proton 5

6 Particles and Forces Franklin, June 1752 Force Charge Electric Force: same sign electrical charges repel each other even at infinite separation Electromagnetic Force: Unification electricity+magnetism Maxwell ~ Distance 2 Coulomb law,

7 Particle Interactions Particle Physics (Quantum Field Theory) Started ~ 1925 Time Photon virtual photon Coupling to Charge + + Range 1 Mass Boson Mass Photon 0 Range Theory works extremely well precision within ten parts in a billion 7

8 Particle Interactions 8

9 Particle Interactions Radioactive Decay Weak Force ~10-15 m e - u ~10-18 m W - e - Neutron Proton d Range 1 Mass Boson Mass W ~ 80 Mass Proton Could the forces be the same? What is the underlying important principle? 9

10 Standard Model Fundamentals The SM is a Quantum Field Theory: describes all interactions as exchange of particles 1) Force laws must apply at all places and times gauge invariance (know how to calibrate) 2) Predicted reaction rates should be finite at all energies renormalizable Turns out: Theories based on principle 1) deliver predictions with high precisions But: To work everywhere the force particles need to be massless!!! 10

11 Noble Price

12 The Higgs Mechanism How particles acquire masses The Higgs particle mass generation Standard Model safe!???? 12

13 Why should it be safe? The Standard Model has ~ 18 (+9) dials (parameters) that are adjusted in agreement with measurements - precisely They are not a fundamental outcome of the present theory = appear to be arbitrary settings - could be linked Arbitrariness is Ignorance we do not know yet the more fundamental theory what is it? 13

14 Standard Model in Everyday Life e.g. the W-boson controls the Sun this weak force process starts the cycle that fuels the Sun: p p p n Set W mass dial to lower value Sun hotter, brighter more UV light W mass is given by Higgs interaction, but not its value e + Deuterium 14

15 The Time Machine 15

16 TimeThe Bigger Picture if this is it ~ 13.7 billion years 1 mev Today ( T= 2.7 K ) Solar system 400,000 yr Galaxy formation 1s 10-8 s Nuclei form (D, He, Li) Quark protons, neutrons form LHC Big Bang s s s 10 3 GeV Higgs acts Particle Desert: Are there more particles? GeV Unification of electroweak and strong force GeV Planck Epoch Why here? ( T~10 32 K ) 16

17 Grand Unification of Forces Minimal Supersymmetric SM develop new theories, e.g. Supersymmety? Simplest super-symmetric model has 105 dials 17

18 The Experiment Smash things together and see what happens! 18

19 How to produce particles at LHC? Proton Collision d u u d u d d d Proton b b u d d u u u d Proton d u Higgs, X, Y d b b 19

20 Higgs Hunt? How do you find one Higgs? If each person is one collision event you need to search ~100 times the number of people on Earth In 2017 there are 7.5 billion people on Earth! Because you need several Higgs and you will miss some you need to do this over an over. 20

21 LHC at CERN The Higgs Mechanism Mont Blanc Airport CERN CMS LHC control room 21

22 LHC Storage Ring LINAC Magnet Need injector, since magnetic field cannot start from zero. RF Beam broken up into bunches ~ 3000 bunches in LHC ~ 100 billion protons/bunch 22

23 The LHC Protons The bottle with hydrogen gas (the protons) ~ 12 liters of gas compressed Airport (1 gram of gas) How often does it need to be refilled? In a year 8 months/year x 120 fills/month CERN x 3 *10 14 protons/fill ~ 3 *10 17 protons / year In the bottle are ~6 *10 23 protons The bottle lasts for 2 Million years! 23

24 LHC RF Cavity Acceleration to full energy takes 20 minutes. 24

25 PS Accelerator Section 25

26 LHC LHC in LEP tunnel Superconducting magnets: 1232 dipole magnets (bending) -T = -271 o C (superfluid Helium) - 100,000 x earth magnetic field superconducting dipole magnet Each beam Circulation time: 89 s Current: ~ 0.6 Ampere Time between collisions: 25 ns Fill time (450 GeV): 7.5 min Acceleration time : 20 min Beam lifetime : several hours 26

27 Beam Protection Energy stored/beam: 360 MJ Energy stored in magnets: 700 GJ The energy per proton is equivalent to using ~70,000 Hiroshima bombs ( Little Boy ) to accelerate a 22 caliber bullet. The energy stored in the beam is equivalent to a small aircraft carrier of mass 10,000 tons traveling at 20 miles/hour. This energy can lighten up a 100W light bulb for 1000 hours. Beam loss is fatal: copper plate 450 GeV beam bunches 27

28 Develop Diamond Detectors Prototype diamond pixel detector readout at UTK (SERF) using radioactive sources Installation of diamond diode detectors near the beam pipe in the CMS detector to continuously monitor the beams in the CMS detector region 28

29 How to detect the Higgs? Every 25ns protons in bunches collide Interactions/crossing = 25 (~1000 charged particles) Simulation in 100,000x earth magnetic field Higgs + 25 other events + - p Higgs p + Z - In CMS collision information corresponds to 100 billion phone calls per second. 29

30 The LHC Collaboration About 10,000 of Earth s inhabitants came together to make it happen. 30

31 The CMS Detector Superconducting coil -270 o C Charged Particle Tracker Photon and Electron Detector Width: 22m Diameter: 15m Weight: 13,000 tons Iron return yoke Muon Detectors Weighs ~25% more than the Eiffel Tower in Paris 31

32 The first force studied carefully by CMS was Gravity 32

33 The CMS Collaboration 33

34 The CMS Detector Superconducting Solenoid E/M Calorimeter Hadron Calorimeter [scintillators & brass] All Silicon Tracker (Pixels and Microstrips) Muon System 34

35 PLT New detector to measure precisely the interaction rate close to LHC beam Grant UTK GradStudent at CERN Collaboration between UTK Princeton, Rutgers, Wisconsin Vanderbilt, CERN, Fermilab Successful measurements since

36 Higgs 4 36

37 But we have only just started to understand the Higgs boson 37

38 we need to look from every angle as there might be something unexpected! 38

39 39

40 40

41 The full picture 41

42 The larger picture 42

43 Probing Gravity Simulation of a black hole event with in CMS Strength of Forces LED al on nti ty avi r G nve o C (1 mm) 1 1/R M* 1 TeV MPlanck N. Arkani Hamed, S. Dimopoulos, G. Dvali (1998). "The Hierarchy problem and new dimensions at a millimeter". Physics Letters B429 : February 2017 No signal in direct searches Stefan Spanier, The Big Bang Machine 43

44 The End 44