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Exploring Forward Physics at the LHC with James L. Pinfold

Delve into the intricate workings of the Large Hadron Collider (LHC) and its experiments, including ATLAS, CMS, LHCb, ALICE, and TOTEM. Discover the superconducting coils, detectors, and collaborations shaping cutting-edge research in high-energy physics. Follow the LHC's timeline from construction to high luminosity runs, shedding light on phenomena like diffraction, particle collisions, and cosmic rays. Join physicist James L. Pinfold on a journey through the forefront of physics exploration.

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Exploring Forward Physics at the LHC with James L. Pinfold

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  1. Forward Physics at the LHC James L. Pinfold University of Alberta

  2. The LHC Collider The LHC Experiments LHC ring ~26km in circ. 368 SC quads (B/L=223T/m L=3.1m) 1232 SC dipoles (B=8.33T, L=14.2m) Cryogenic system(1.8 K,super fluid He) 27 km of 8T magnets100 m below surface • SCHEDULE • March 2007: Last magnet installed & machine closed March 2007 • Nov. 2007: LHC commissioning run – 1st collisions at Eb =450 GeV) • 2008: First physics (starting in April) run 10 fb-1 L~ 1033 cm-2s-1 • 2009-10: Low luminosity run 20-70 fb-1 L ~10331034cm-2s-1 • 2011-17: High luminosity run at 100 fb-1/year L ~1034 cm-2s-1 James L. Pinfold TAHOE 2007 1

  3. The LHC Experiments ATLAS • ATLAS & CMS Higgs physics, SUSY, EDs… QCD, Top Physics, Heavy-ions • LHCb CP Violation • ALICE Quark-Gluon Plasma • TOTEM Total pp x-section, forward physics • MoEDAL (LoI) Monopole search* • LHCF (LoI) Forward physics, prod. x-sect measurement # ALICE CMS LHCb James L. Pinfold TAHOE 2007 2

  4. The ATLAS Detector Mass –7000 tons Length – 46 m Diameter – 25m Cost ~ 500 MCHF X-sec thru the barrel reveals the typical onion structure of A collider detector Inner Tracker – pixel, silicon strip, TRT 2T solenoidal field, good e/g ID, e/p sep, t/b tag Coverage in |h| - tracker < 2.5, cal < 4.9 LAr EM Calorimeter -- good e/g ID, energy & ETmiss resolution Muon spectrometer – air core toroids B.dl = 2-6Tm (4-8 Tm) James L. Pinfold TAHOE 2007 3

  5. SUPERCONDUCTING COIL Total weight : 12,500 t Overall diameter : 15 m Overall length : 21.6 m Magnetic field : 4 Tesla Silicon Microstrips Pixels The CMS Detector CALORIMETERS ECAL HCAL Scintillating PbWO4 crystals Plastic scintillator/brass sandwich IRON YOKE TRACKER MUON ENDCAPS MUON BARREL Drift Tube ResistivePlate Cathode Strip Chambers (CSC) Chambers ( ) Resistive Plate Chambers (RPC) DTChambers( ) RPC James L. Pinfold TAHOE 2007 4

  6. Status: ATLAS & CMS Detectors • Surface infrastructure in place. • Both detectors on track for first data taking in 2007 • Mostly complete detectors deployed for start. ATLAS Detector Contruction WebCam February 16th 2007 CMS gantry crane tested to 2500T James L. Pinfold TAHOE 2007 5

  7. The LHC Collaborations CMS • ALICE: 30 countries, ~1000 physicists • LHCb: 15 countries, ~600 physicists • LHCf: 3 countries, 3 countries, ~22 physicists • TOTEM Collaboration: 8 countries, 12 Institutions, ~80 physicists 35 nations, ~160 institutions, ~1800 scientists 38 nations, ~174 institutions, ~2030 scientists James L. Pinfold TAHOE 2006 6 James L. Pinfold IVECHRI 2006 6

  8. Astro-Collider Physics– the Synergies Direct Detection of Cosmic Rays in Collider Detectors (CosmoLEPCosmoLHC – so far ACORDE) Forward Collider Physics Few particles with low pT but very high energy (90% of eventrelevant to the understanding of HECR, etc. High PT Collider Physics Involving ETmiss, jet production, lepton ID, etc Relevant to Dark Matter, Extra Dimensions, etc. Astroparticle Physics & Cosmology James L. Pinfold TAHOE 2007 7

  9. Collider & Cosmics Energy Spectrum • Proton-(anti)Proton cross-sections – important for measuring extended air shower development (EAS), every primary particle produces an EAS Knee (~1015eV) I particle/ (m2 year) Ankle(~1018 eV 1 particle/ (km2 century) James L. Pinfold TAHOE 2006 8

  10. Forward Physics Program • Soft & Hard diffraction • Total cross section and elastic scattering (TOTEM, precision of O(1)%) • Gap survival dynamics, multi-gap events, odderon, etc. • Diffractive structure: Production of jets, W, J/, b, t, hard photons • Double Pomeron Exchange events as a gluon factory (anomalous W,Z production?) • Diffractive Higgs production, SUSY & other exotics & exclusive processes • Low-x Dynamics • Parton saturation, proton structure, multi-parton scattering… • New Forward Physics phenomena • New phenomena such as DCCs, incoherent pion emission, Centauro’s • Strong interest from cosmic rays community • Forward energy and particle flows/minimum bias event structure • LHC as a photon collider - two-photon interactions & peripheral collisions • Use QED processes to determine the luminosity to ~1% (ppppee/) • Forward physics in pA and AA collisions James L. Pinfold TAHOE 2007 9

  11. Diffraction & Forward Physics at LHC TOTEM: Approved July ‘04 • TOTEM stand alone • Elastic scattering, total pp cross section and soft diffraction. CMS: • EOI submitted in Jan. 2004 • Diffraction with TOTEM Roman Pots and/or rapidity gaps • TP in preparation for new forward detectors (CASTOR, ZDC,+…) • Diffractive and low-x physics part of CMS physics program (low + high ) CMS+TOTEM: • Prepared common LOI due in Summer 2006 • Full diffractive program with central activity with TOTEM as a CMS subdetector ATLAS: • LOI submitted (March 04). • RP detectors to measure elastic scattering/ total cross sections/luminosity. Diffraction will be looked at later • LUCID and the ATLAS ZDC approved for installation in 2007 LHCf: Approved by LHCC in 2006 FP420: Collaboration for R&D and feasibility study for detectors at 420 m James L. Pinfold TAHOE 2007 10

  12. LHC Experiments: pT- coverage • The base line LHC experiments will cover the central rapidity region. • TOTEM+ CMS will complement the coverage in the forward region • ALICE & LHCb have restricted eta coverage wrt to ATLAS & CMS James L. Pinfold TAHOE 2007 11

  13. ATLAS Coverage in Forward Direction Breaking news: LUCID and the ZDC recently approved for installation in 2007 ZDC Proposed James L. Pinfold TAHOE 2007 12

  14. CMS Coverage in Forward Direction ZDC CASTOR 5.25<<6.5 Tungsten/quartz plates 1 TeV n shower in ZDC Tungsten/quartz fibres  CASTOR Calorimeter ZDC Calorimeter (at 140 m) Common runs planned with TOTEM: Roman Pots and T1/T2 James L. Pinfold TAHOE 2007 13

  15. CMS+TOTEM: a “Full” Coverage Detector CMS/TOTEM will be the largest acceptance detector ever built at a hadron collider +ZDC James L. Pinfold TAHOE 2007 14

  16. The FP420 Project TOTEM / ATLAS RPs FP420 CMS/ATLAS • Extend the acceptance for leading proton tagging • Combine information from central detector and RP @ 220m • Exclusive central Higgs prod. pp  p H p: 3-10fb • Inclusive central Higgs prod. pp  p+X+H+Y+p: 50-200 fb • Reconstruction of the central mass: FP420: R&D fully funded • TDR to ATLAS/CMS by 1st -half of ‘07 then to the LHCC. Installation ~’08-’09? M = O(1.0 - 2.0) GeV James L. Pinfold TAHOE 2007 15

  17. LHCf Experiment • LHCf: measurement of photons and neutral pions in the very forward region of LHC • Add an EM calorimeter at 140 m from the Interaction Point (of ATLAS) (Scintillating fiber /Tungsten calorimeter + Silicon strip det. Calorimeter) • At the LHC the 14 TeV Ecm translates to a 1017 eV Lab. Energy - by comparing experimental results with MC predictions one can tune MC used in cosmic ray EAS simulation. 400 GeV photon I TeV neutron James L. Pinfold TAHOE 2007 16

  18. LHC Forward Physics & Cosmic Rays • Measurement of forward hadronic particle production at the LHC will play a key role in understanding UHECR EAS where major in uncertainties in our understanding still exist • The NEEDS workshop (Karlsruhre 2002) listed the hadronic interaction data (pp/pA/ AA) required from collider measurements: • Precise measurement of stot& sinel. p-p x-sec • Energy distribution of leading FS nucleon • Measurement of sdiff/sinel • Inclusive p-spectra in the frag. region xF >0.1 • The phenomenological models describing non-perturbative QCD hadronic multi-particle production in HECR simulation,are: • Low/medium energy: GHEISHA, FLUKA, UrQMD, TARGET, HADRIN, etc • High energy: DPMJETII.5 &III, neXus 3.0, QGSjet 01, SIBYLL 2.1, etc • The models describe the Tevatron well - but LHC model predictions reveal large discrepancies in extrapolation ET (LHC) E(LHC) James L. Pinfold TAHOE 2007 17

  19. 1st ATLAS/CMS Data–Cosmic Rays! Cosmic muons observed byCMSat IP5 (recorded by hadron barrel calorimeter) Cosmic ray muons observed in the ATLAS Tile Calorimeter James L. Pinfold TAHOE 2007 18

  20. EXTRA SLIDES

  21. LOW X AT THE LHC LHC: due to the high energy can reach small values of Bjorken-x in structure of the proton F(x,Q2) Processes:  Drell-Yan  Prompt photon production  Jet production  W production If rapidities below 5 and masses below 10 GeV can be Covered--> x down to 10-6-10-7 Possible with T2 upgrade in TOTEM (calorimeter, tracker) 5<< 6.7 ! Proton structure at low-x !! Parton saturation effects?

  22. The p-p Total Cross-section • The ATLAS approach is to measure elastic scattering down to such small t-values that the cross section becomes sensitive to the EM amp. via the Coulomb interference term. • In this case an additional valuable constraint is available from the well-known EM amplitude, as can be seen from: that describes elastic scattering at small t • sT, L and the slope parameter b can be determined by a fit to the above expression • At 7 TeV the strong amplitude is equal to the EM amplitude for |t| = 0.00065 GeV2. This corresponds to a scattering angle of 3.5 µrad – thus we need special beam optics • LHC measurement of sTOT expected to be at the 1% level – useful in the extrapolation up to HECR energies 10% difference in measurements of Tevatron Expts: (log s) James L. Pinfold IVECHRI 2006 14

  23. LHC Operation in a Normal Year LHC OPERATION • 140-180 days of running per year • 100-120 days of p-p collisions per year • 4 x 106s of proton luminosity running per year. • Around 40 days of heavy-ion (30 days) and TOTEM running per year HEAVY ION PROGRAM (at present) • LHC Phase I: Collisions with Pb ions “baseline programme” • LHC Phase II: Collisions with lighter ions (A-A collisions –Cand’s: He, O, Ar, Kr, In) • LHC Upgrade Programme: so-called hybrid collisions (e.g. p-A collisions - Pb, Ar, 0) James L. Pinfold IVECHRI 2006 3

  24. The Experimental Challenge • High interaction rate • pp interaction rate 109 interactions/s • Only ~100 events chosen out of 40 MHz event rate • Level-1 trigger decision will take 2-3 ms Electronics needs to store data locally (pipelining) • Large particle multiplicity • <23> superposed events in each crossing • ~100 tracks stream into the detector each 25 ns Need highly granular detectors with good time resolution for low occupancy • Very good muon ID and momentum measurement trigger efficiently and measure the sign of a few TeV muons • Good energy resolution in the EM calorimetry (eg for Hgg) ~0.5% @ ET~50 GeV • Precise inner tracking for good mom. resolution & vertexing (b-decays ~10 better momentum resolution than at LEP • Hermetic calorimeter Good ETmiss resolution • High Radiation levels (10MRads/yr & 1014 n’s/cm2/yr in the Forward reg) Need radiation hard detectors and electronics James L. Pinfold TAHOE 2007 7

  25. ATLAS Coverage in Forward Direction ) ZDC FP420 Inst-TAS Inst-TAS

  26. CMS Coverage in Forward Direction CASTOR 1 TeV shower in CASTOR ZDC

  27. LHCb & ALICE Coverage in Forward Direction ALICE: || < 0.9: charged & neutral E,p measurement and ID 2.4 <  < 4: muon measurement -5.4<  < 3: charged multiplicity 2.3 <  < 3.5: photon multiplicity Zero Degree Calorimeters at ~  100 m LHCb: 1.9 <  < 4.9: charged & neutral E, p measure & ID to ~ 200 GeV James Pinfold ATLAS Physics tutorial June 2003 16

  28. ZDC Tungsten/ quartz fibres

  29. The Triggering & Data Challenge Trigger system - Real time multi-level trigger to filter out background and reduce data volume 40 MHz (40 TB/s) Level 1 – special hardware processors 75 KHz (75 GB/s) Level 2 – embedded processors + PC farms 1-KHz (1-GB/s) Level 3 – PC farms 100 Hz (100 MB/s) Data recording and offline analysis Data recording rate for ATLAS ~0.1 GB/s ~1 PetaByte / LHCyear James L. Pinfold TAHOE 2007 9

  30. ATLAS & CMS Collab. Group Photo

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