Compact Muon Solenoid (CMS) Physics, Status, and Plans

1. Bill Gabella and Med Webster QuarkNet 2013 Vanderbilt University Compact Muon Solenoid (CMS) Physics, Status, and Plans

2. Gabella CMS Status Outline • The Standard Model of Particle Physics • The Large Hadron Collider • The Compact Muon Solenoid • Proton on Proton collisions • Higgs Boson, now your run-of-the-mill Standard Model Higgs • Supersymmetry, NOT? • Extra Dimensions • Lead on Lead collisions • centrality, Jet Quenching • ridge in two particle correlations • Large Hadron Collider and CMS plans

3. Particle Physics,aka High-Energy Physics,aka Theory of Fundamental Particles All stable matter is made of protons, neutrons, and electrons. Yes, but protons and neutrons are also made up of Quarks! Gabella CMS Status

4. Gabella CMS Status The Standard Model A good description of fundamental particle interactions, relevant inside the nucleus, at early times in the evolution of the universe, and in man-made and natural collisions of particles. Particles that “carry” the force. Particles that make up Matter. All of the matter and forces in the Universe are made up of: 6 leptons (and 6 anti-leptons), 6 quarks (and 6 anti-quarks), and 12 force carrying particles...ur plus the Higgs boson and don't forget Gravity, and...

5. Gabella CMS Status

6. Gabella CMS Status Ref: http://www.particleadventure.org

7. Gabella CMS Status Cosmic Ray Showers Mostly Protons with high energy hitting the atmosphere... make mostly muons at Earth. Ref: http://www.particleadventure.org

8. Particle Accelerators Large Hadron Collider, p on p Geneva, Switzerland 7, 8, and soon 14 TeV center of mass Tevatron, was p on p-bar Batavia, IL (Chicago)‏ 2 TeV center of mass now lower energy, high intensity p source, also intense neutrino source Ref: www.fnal.gov, www.cern.ch Gabella CMS Status

9. Gabella CMS Status The Large Hadron Collider Proton-on-Proton collider, 2010-11 3.5+3.5 TeV center of mass energy 2012 4+4 TeV plan 2015 7+7 TeV also Lead-on-Lead (aka Heavy Ion) collider and Proton-on-Lead for comparison of the above two

10. Gabella CMS Status The Large Hadron Collider

11. Gabella CMS Status The Large Hadron Collider

12. Large Hadron Collider (LHC)‏ Energies: Linac 50 MeV PSB 1.4 GeV PS 28 GeV SPS 450 GeV LHC 3.5, 4, 7 TeV Ref: Introduction to Accelerators, Elena Wildner, CERN Gabella CMS Status

13. Gabella CMS Status CMS Detector Vanderbilt University (Will Johns) http://www.uscms.org/public_2/about/cms_detector/index.shtml

14. Gabella CMS Status Particles through a CMS slice

15. Gabella CMS Status The Forward and Barrel Pixel Detector Barrel Pixel r = 4.4, 7.3, and 10.2 cm 11520 readout chips, 48 Mpixels Forward Pixel z = +/-34.5, and +/-46.5 cm 4320 readout chips, 18 Mpixels http://www.hep.vanderbilt.edu/ borrowed from Mauro Dinardo docdb 2404

16. Gabella CMS Status CMS - Short Timeline March 2010 --- Started taking data on collisions at 7 TeV. Previous testing done at 0.45 TeV (injection energy) and 1.26 TeV. Low luminosity (intensity) 2010 - 2011 --- Taking data with increasing luminosity (intensity) by both more proton bunches in the rings and more protons in each bunch 2012 --- Running at 8 TeV, and high luminosity July 4, 2012 --- Announce discovery of Higgs-like particle, also seen with the ATLAS detector March 2013 --- Shutdown LHC and detectors for “Long Shutdown 1,” aka LS1. LHC back “on” in 2015 with energy 14 TeV.

17. Gabella CMS Status CMS Recent Results - Higgs July 4, 2012 --- CMS and ATLAS report “Higgs-like particle” at 125 GeV. Too many H->Gamma Gamma events compared to the Standard Model predictions for the Higgs. July 4, 2013 --- The Higgs looks a lot like the Standard Model (SM) Higgs. Right ratio of different events, better statistics. Mass 125.8 GeV +/- 0.5 GeV Now measuring the quantum numbers of the Higgs: consistent with spin 0 (at least not spin 1 nor spin 2); parity consistent with +1

18. Gabella CMS Status

19. Gabella CMS Status Higgs decays into...

20. Gabella CMS Status Higgs to two Z's to Four Leptons borrowing from Higgs Seminar

21. Gabella CMS Status Note the numbers... Black dots are data.

22. Gabella CMS Status CMS (Some) Other Important Results • Supersymmetry • Looking for “missing energy,” i.e. invisible particles, at least to the detector, as are neutrinos. • Currently appears to have eliminated many popular SUSY models; we are left with the 105 parameter full-model (maybe). • Extra-dimensions • Inspired by Super-strings, Randall and Sundrum took the idea of extra-dimensions (spatial) seriously and asked what would accelerators see/measure. • No discovery, putting limits on the models.

23. Gabella CMS Status CMS Heavy Ion Collisions • LHC Collides Pb-208 ions, fully-stripped to +82 charge • in other words, atomic number Z=82, atomic mass A=208, number of neutrons N=126 • For protons we inject at 450 GeV and ramp up to 3.5 TeV • Acceleration is by electric field, so a charged particle with charge Ze would be injected at 450 Z GeV and ramp to 3.5 Z TeV total energy. • The bending magnets determine what energy (really momentum!) that you can have in your ring of radius rho.

24. Gabella CMS Status CMS Heavy Ion Collisions

25. Gabella CMS Status CMS Heavy Ions, some numbers Pb-208 accounts for 52.4% of all stable lead.Z=82, N=126, A=208

26. Gabella CMS Status CMS Heavy Ions - A tutorial well centered or glancing blow = Centrality

27. Gabella CMS Status CMS Heavy Ions - Make a lot of Particles!

28. Gabella CMS Status CMS Heavy Ions - Jet Quenching Main Jet - not modified In a head-on collision, more Jets (q-qbar hadron shower) near the edge of the fireball. Borrowed from Iancu fig 42. Away Jet - highly modified

29. Gabella CMS Status CMS Heavy Ions - Jet Quenching Main Jet - not modified Away Jet - highly modified

30. Gabella CMS Status LHC and CMS Plans Currently the LHC and all the experiments are doing maintenance. Expect to start turning on the LHC in 2015, with data taking my mid-year.

31. Gabella CMS Status LHC and CMS Plans

32. Gabella CMS Status Backup

33. Gabella CMS Status Some Links/References The Standard Model of Particle Physics • http://www.particleadventure.org • Vanderbilt HEP Group http://www.hep.vanderbilt.edu/~focuser/index.php • CMS Public Talks http://cms.web.cern.ch/org/cms-presentations-public • CMS News http://cms.web.cern.ch LHC and Heavy Ions • Ions Pagehttp://lhc-commissioning.web.cern.ch/lhc-commissioning/commissioning-ions.htmhttp://lhc-commissioning.web.cern/lhc-commissioning/commissioning-ions.htm • LHC consolidationshttp://home.web.cern.ch/about/accelerators/large-hadron-colliderhttp://home.web.cern.ch/about/updates/2013/03/lhc-consolidations-step-step-guide

34. Gabella CMS Status Backup

35. Units? 1 eV... Gabella CMS Status

36. Gabella CMS Status

37. Gabella CMS Status LHC Ions, the Numbers 1/4 • LHC Collides Pb-208 ions, fully-stripped to +82 charge • in other words, atomic number Z=82, atomic mass A=208 • For protons we inject at 450 GeV and ramp up to 3.5 TeV • Acceleration is by electric field, so a charged particle with charge Ze could be injected at 450 Z GeV and ramp to 3.5 Z TeV. • The bending magnets determine what energy (really momentum!) that you can have in your ring.

38. Gabella CMS Status LHC Ions, the Numbers 2/4 • A magnetic field B bends a charged particle with momentum P in an arc of radius . • Magnet folks like the constant "magnetic rigidity" • For the LHC ring (and the other injector rings), the B is set by power supplies and magnets and the rho by the vacuum pipe

39. Gabella CMS Status LHC Ions, the Numbers 3/4 • So you will see people post that we are injecting at 450 Z GeV and ramping to 3.5 Z TeV for each Pb nucleus (which is a lot, 36.9 TeV injection and ramp to 287 TeV) • Okay for the physics what is more interesting is the per proton/neutron energy, so per nucleon the numbers are less450 Z/A GeV and ramp to 3.5 Z/A TeV • Z/A is the average charge per nucleon, 0.4 e, and finally, inject at 177 GeV/u ramp to 1.38 TeV/u, and collide at 2.76 TeV/u.

40. Gabella CMS Status LHC Ions, the Numbers 4/4 • Bunch populations, from recent posting, • per bunch charge of 1-1.2e10 ... e's • Count the Pb ions at +82e each, find there are 12-14e7 Pb ions per bunch (below you will see that 7e7 is the design)

41. Gabella CMS Status LHC Ions Injection Chain

42. Gabella CMS Status Pixel Numerology • Barrel has 11520 ROCs, 48 MPxl • Forward has 4320 ROCs, 18 MPxl • 1 ROC has 4160 pixels • Si Sensor pixel size is 100 microns by 150 microns • Fpix has 3 plaquette and 4 plaquette config to its panels: 3 plaquette: 2x5 + 2x4 + 2x3 (ROCs), and the 4 plaquette: 1x5 + 2x4 + 2x3 + 1x2 (ROCs) • Urs shows fpix: (3x24+3x21)/4320 = 2.6% and bpix (3x16+6x8+3)/1152 = 0.9% not working.

43. Gabella CMS Status LHC Ions Physics "Trivia" • Luminosity is limited by the Electron Capture by Pair Production (ECPP) at the IPs. That is, the e- from an e+e- pair produced in the collision is captured by an Pb ion and that ion is lost on collimators leading to a vacuum problem! Limit is 0.5-1e27 cm^-2 s^-1. • Original choice was Pb+53 after the first foil into LEAR. It was found that it had an unexpected short lifetime in the electron cooler, it picked up an e- in a much shorter time than either Pb+52 or +54. Chose +54 state. Pb+53 ends with a 5p^5 orbital---that looks bad!While Pb+52 ends with 5p^4 (all paired) and +54 ends with 5p^6. • Beam Loss Induced Vacuum degradation in LEAR, and the creation of other charge states by Pb+54 interacting with the beam gas, led to a vacuum spec in LEAR of 1e-12 mbar (LHC can be 1e-9mbar).

44. Gabella CMS Status The Standard Model - The Tee Shirt

45. Gabella CMS Status The Standard Model - The Details A pretty equation for the Lagrangian Density of the quantum fields... Photons, W's, Z's bosons, gluons Electrons, Quarks, Neutrinos Higgs “coupled” to leptons Higgs Particle/Field

46. Gabella CMS Status “ In its most explicit form, the Lagranian density of the minimal Standard Model is given by the somewhat uninspiring expression:” A. Connes & M. Marcolli gluons photons W's and Z's

47. Gabella CMS Status Higgs Particle/Field

48. Gabella CMS Status The Standard Model - The Details ...there is more... electrons up quarks

49. Gabella CMS Status CMS Detector “ In its most explicit form, the Lagranian density of the minimal Standard Model is given by the somewhat uninspiring expression:” A. Connes & M. Marcolli Electromagnetic Fields, W's, Z's bosons Electrons, Quarks, Neutrinos Higgs Particle/Field

50. Gabella CMS Status An Event: Higgs to 4 muons http://www.uscms.org/public_2/about/cms_detector/index.shtml