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News da LHCf

News da LHCf. Oscar Adriani Università degli Studi di Firenze INFN Sezione di Firenze. Arm#2 Detector 25mmx25mm+32mmx32mm 4 Silicon strip tracking layers. Arm#1 Detector 20mmx20mm+40mmx40mm 4 SciFi tracking layers. LHCf: detector overview. Detector II Tungsten Scintillator

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News da LHCf

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  1. News da LHCf Oscar Adriani Università degli Studi di Firenze INFN Sezione di Firenze

  2. Arm#2 Detector 25mmx25mm+32mmx32mm 4 Silicon strip tracking layers Arm#1 Detector 20mmx20mm+40mmx40mm 4 SciFi tracking layers LHCf: detector overview Detector II Tungsten Scintillator Silicon mstrips Detector I Tungsten Scintillator Scintillating fibers INTERACTION POINT IP1 (ATLAS) 140 m 140 m Beam line 44X0, 1.6 lint Oscar Adriani Torino, 17/05/10

  3. Calibrate cosmic ray interactions for very forward energy spectra at LHC energy • Discriminate a good model • Input data for model building Single g p0 neutron Model difference in very forward at 14TeV Oscar Adriani Torino, 17/05/10

  4. LHCf 2010 runs • Successful data taking at 7TeV collisions is ongoing. • Integrated Luminosity ~ 5.0 nb-1 up to May 16, 2010 • ~60M showers and 200K p0s obtained ( arm1+arm2 ). • Detector shows good performance with stable quality. • Energy scale calibration with the p0 peak. • Good stability < ±1% level. Yet no radiation problem. Oscar Adriani Torino, 17/05/10

  5. Statistic plot up to 16 May 2010 Red = Shower Arm1 Blue = p0 Arm1 (x100) Light red=Shower Arm2 Light Blue = p0 Arm2 (x100) Oscar Adriani Torino, 17/05/10

  6. Arm1 7 TeV collisions 1 TeV gamma-ray shower @ Arm2 Transition curve in towers Particle Hit maps X-view of silicon strip Arm2 Y-view of silicon strip Oscar Adriani Torino, 17/05/10

  7. Arm2 event display p0 at 7 TeV Silicon layers 25 mm tower 32 mm tower Scintillator layers • Robust sample • Good energy calibrator Tower 32mm 25mm Oscar Adriani Torino, 17/05/10

  8. Please note the very high energy!!!! DM/M=5.0MeV/135MeV=3.7% Oscar Adriani Torino, 17/05/10

  9. DM/M=3.1MeV/135MeV=2.3% Oscar Adriani Torino, 17/05/10

  10. Quick look at 7TeV collisions (Arm2) Colliding bunch Non-colliding bunch High statistics !! Only <1% of total data are used Very clean data!! BKG due to beam-gas collisions is ~ 1% Oscar Adriani Torino, 17/05/10

  11. Gamma/Hadron at 7 TeV Arm1 Data Small+Large Small+Large Gamma+Hadron Gamma+Hadron Oscar Adriani Torino, 17/05/10

  12. Detector gain stability in Apr 2010 7TeV run Laser gain calibration for scintillator layers ±2% ±1% level stability ! 01/04 15/04 ±2% p0 mass peak 0.045Gy cumulative dose Oscar Adriani Torino, 17/05/10

  13. Arm1 Arm2 Coincidence FC LHCf-CAL ZDC ZDC ZDC BRAN-Sci BRAN-IC Beam pipe Neutral particles TAN Gaussian fit FrontCounter as a good luminosity monitor Stay all the time • FC is working very well for luminosity monitoring (Very useful monitor for the machine) • Continuous monitoring w/ independent DAQ now available. See Page1 “LHCf experiment” • Conversion to “luminosity” from FC rate is now under study by MC Page1 LHCf page lumiscan Oscar Adriani Torino, 17/05/10

  14. Next Step for the analysis (in progress) • Understand where LHCf is wrt Beam!!!! • Crucial for the Pt spectra measurements • We are using/planning to use: • Survey measurements • Internal LHCf alignment • Position of the vertical manipulator • Beam spot position from Atlas (Many thanks!!!) • Reconstructed center of the neutral particle flux from LHCf position sensitive detectors • Caution: Beam crossing is not stable • Fill/Fill difference • Inside-fill difference Oscar Adriani Torino, 17/05/10

  15. Reconstruction of the beam center X View Make use of the silicon infos Alghoritm optimized for online monitor 270 mm resolution Y View 240 mm resolution Oscar Adriani Torino, 17/05/10

  16. E-q distribution for g-like shower at 7TeV Measurement distribution of Arm2 (not corrected by geometrical acceptance) • Data : only first collisions (30/03/2010) 38,000 shower trigger • Assumed the beam center is at (X,Y)=(3.0mm, 0.0mm). Geometrical acceptance Preliminary Oscar Adriani Torino, 17/05/10

  17. p0 PT Distribution at 7 TeV • Data : #fill 1058 (24/04/2010) • Assumed the beam center is at (X,Y)=(3.0mm, 0.0mm). • Measurement distribution without correction of geometrical acceptance Oscar Adriani Torino, 17/05/10

  18. Analysis of 900GeV runs in 2009 • Stable beams at 900GeV, 06.Dec. – 15.Dec (27.7 hours) • 2,800 and 3,700 showers in Arm1 and Arm2, for ~5e5 collisions at IP1 • Progress in Analysis since last LHCC • Refine analysis tools and fix final data sets for Dec09 run. • Absolute energy calibration by p0 peak at 7TeV Expected spectra with each hadron interaction model Gamma-ray like @ Arm2 Hadron like @ Arm2 with 107 col. Oscar Adriani Torino, 17/05/10

  19. Particle Identification • Clear discrimination between g and hadron showers based on shower transition curves. • Basic agreement in the PID parameter (L90) distribution • Checking systematics for SPS calibration data (50-200GeV for electrons, 150, 350 GeV for protons) L90% @ 20mm cal. MC (QGSJET2) Data hadron-like g-like Oscar Adriani Torino, 17/05/10

  20. Preliminary spectra from 900GeV runs in 2009 Normalized by gamma-like entry • Reasonable agreement with MC • Conservative systematic error for energy scale +10% -4% assigned • Checking detector response for hadron showers by SPS 350,150GeV p data MC(QGSJET2) Data Hadron response under study Sys.+Sta. Adding May 900GeV runs, 100K showers now (Dec09 x15) ! Oscar Adriani Torino, 17/05/10

  21. Plan for coming months Typical unit 10K p0 w/ ~1nb-1 • Nominal data taking at 7TeV • Vertically shift Arm1&Arm2 • Few runs for checking systematics with a few different configuration (HV, trig threshold, etc..) • High statistic with 1 or 2 settings (for h meson, etc. ) • Possible beam crossing angle run (140mrad) at 7 TeV • Enhance rapidity coverage; h >8.7 g h>8.4 • Important to check flux center moving downward w.r.t. crossing angle • Finally, LHCf de-installation • When luminosity becomes too high ( >1031cm-2s-1, or 2pb-1) Oscar Adriani Torino, 17/05/10

  22. Study of h in a high statistics sample • Next milestone: h meson • h/p0 ratio or h production spectra vary a lot among different interaction models. A good handle to probe the models, though irrelevant to air shower development. • Another calibration point for more robust energy scale • Typical h/p0 =10-3~10-4 at 7TeV. Good to collect ~1M p0 (~100nb-1) • Strangeness production (K0, L) is under study QGSJET2 h Oscar Adriani Torino, 17/05/10

  23. Crossing angle for LHCf 7 TeV run Shown in 99th LHCC, Sep2009 a=140mrad Distance from neutral center Aperture of Beam pipe 3.5+3.5TeV All g from IP 2cm No crossing With 140mrad crossing angle, neutral flux center is lowered by 2cm. Rapidity coverage: >8.7 g >8.4. • w/o crossing : 30%acc. @Xf = 0.22 • w 140mrad : 50%acc. @Xf = 0.22 • If possible, it is nice to have a crossing angle during LHCf run. • LHCf can measure crossing angle by fitting shower center (DY~ 1mm for 100sec@L=1029gDa~7mrad) to be distributed by DIP. Oscar Adriani Torino, 17/05/10

  24. Oscar Adriani Torino, 17/05/10

  25. LHCf removal and toward the phase-2 • When luminosity become too high (>1031 cm-2s-1, 2 pb-1), LHCf will go out from the TAN (Radiation damage at plastc scinitillator ~1kGy@2pb-1 for 20% degradation) • De-installation work should be quickly done during monthly Technical Stop. • Not earlier than the next Technical Stop in June. We’d like to revisit the scheduling issue when LHC luminosity profile gets clearer in June. • After removal, beam calibration again by a SPS test beam. • Revisit LHC at the next energy upgrade. R&D and fabrication of rad-hard GSO scinitillator are on-going for the “phase-2” LHCf detector. 1mm thick 20mm A new GSO scintillator layer 20mm Oscar Adriani Torino, 17/05/10

  26. Summary • LHCf has started physics program very successfully. • 100K showers at 900GeV • 60M showers and 200K p0 at 7TeV • Detectors work beautifully without any serious trouble. • Very clean! Negligible beam-gas background • The p0 peak demonstrates good performance as expected. • As luminosity is growing up, high stat run and other optional runs are under discussion • High stat run for h mesons • Crossing angle commission f important step to “phase-2” • Rapid progress in analysis. Almost ready to publish physics ! • 900GeV results (2009&2010) and 7TeV results • Finalizing SPS test beam data to confirm energy scale, PID and hadron shower response at a few 100 GeV. Oscar Adriani Torino, 17/05/10

  27. Backup slides Oscar Adriani Torino, 17/05/10

  28. Oscar Adriani Torino, 17/05/10

  29. Comparison between tower calorimeter towers of Arm2 Comparison of spectra Gamma-ray like Hadron like Flat spectra in h>8.7 at 900GeV Comparison between two Arms Both detectors working without any biases Oscar Adriani Torino, 17/05/10

  30. -Front Counter- • Thin scintillators with 8x8cm2 acceptance, which have been installed in front of each main detector. Schematic view of Front counter • To monitor beam condition. • For background rejection of beam-residual gas collisions by coincidence analysis Oscar Adriani Torino, 17/05/10

  31. Summary of Expected number of events Oscar Adriani Torino, 17/05/10

  32. LHCf can measure Energy spectra and Transverse momentum distribution of • Gamma-rays (E>100GeV,dE/E<5%) • Neutral Hadrons (E>a few 100 GeV, dE/E~30%) • Neutral Pions (E>700GeV, dE/E<3%) at psudo-rapidity range >8.4 The Aim is to calibrate hadron interaction models for ultra high energy cosmic ray physics. Multiplicity@14TeV Energy Flux @14TeV High energy flux !! Low multiplicity !! simulated by DPMJET3 Oscar Adriani Torino, 17/05/10

  33. Radiation Damage Studies Scintillating fibers and scintillators • Expected dose: 100 Gy/day at 1030 cm-2s-1 • Fewmonths @ 1030 cm-2s-1: 10 kGy • 50% light output • Continous monitor and calibrationwith Laser system!!! 30 kGy 1 kGy The LHCf experiment at LHC ISVHECRI08, Paris 1-6 September 2008 Alessia Tricomi University & INFN Catania Oscar Adriani Torino, 17/05/10

  34. Comparing fill# 1031with ATLAS ATLAS lumi http://xxxxxxxx ×1026 L*FC 1.7E+27 1.3E+27 L*FC is smaller than by 24% Difference may come from interaction model detector MC tuning Oscar Adriani Torino, 17/05/10

  35. Oscar Adriani Torino, 17/05/10

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