Parma, 23 Settembre 2010 LHCf status report Oscar Adriani Università degli Studi di Firenze INFN Sezione di Firenze

Oscar Adriani 23/09/10 Experimental set-up Detectors installed in the TAN region, 140 m away from the Interaction Point 1  Here the beam pipe splits in 2 separate tubes.  Charged particle are swept away by magnets  We cover up to y   I NTERACTION POINT IP1 (ATLAS) Detector II Tungsten Scintillator Silicon  strips Detector I Tungsten Scintillator Scintillating fibers Charged particles Neutral particles Beam pipe Protons 140 m n π0π0 γ γ 8 cm6 cm

Oscar Adriani 23/09/10 LHCf : Monte Carlo discrimination 10 6 /10 7 generated LHC interactions at 7+7 TeV  1 minute 29 cm -2 s -1 luminosity  n 

Oscar Adriani 23/09/10 LHCf Operations at 900 GeV 06 Dec – 15 Dec hours for physics ~5x10 5 collisions at IP1 ~2,800 shower events in Arm1 ~3,700 shower events in Arm2 02 May – 27 May hours for physics ~5.5x10 6 collisions at IP1 (Statistics x 11 wrt 2009) ~44,000 shower events in Arm1 ~63,000 shower events in Arm2 Beam Gas significantly reduced wrt 2009

Oscar Adriani 23/09/ vs Very big reduction in the Beam Gas / Bunch crossing ratio!!!! Very big increase of the ‘signals/noise’ ratio due to higher intensity

Oscar Adriani 23/09/10 Arm1 Spectra at 900 GeV MC normalized to the total number of events in the 2 towers,without PID. Only one normalization factor common to all models Preliminary Only statistical errors are quoted

Oscar Adriani 23/09/10 Arm2 Spectra at 900 GeV MC normalized to the total number of events in the 2 towers,without PID. Only one normalization factor common to all models Preliminary Only statistical errors are quoted

Oscar Adriani 23/09/10 LHCf 2010 runs (mainly at 7 TeV) Detector shows good performance with stable quality. –Energy scale calibration with the  0 peak!!!! –Good stability < ±1% level. –We started to have some radiation problems in the last periods. Thanks a lot to all LHC people for providing us 100  rad crossing angle!!! –Very important for physics to enlarge the P T acceptance Detectors were removed on July 20, 2010

Oscar Adriani 23/09/10 Acceptance gain due to Crossing Angle Arm1 No crossing angle 100  rad crossing angle A very significant gain in acceptance is clearly visible!

Oscar Adriani 23/09/10 Operation at 7 TeV Without crossing angle (30/03 – 05/06) With 100  rad crossing angle (25/06 – 20/07) Runs are taken in many different vertical position and with/without Xing angle

Oscar Adriani 23/09/10 7 TeV collisions Y-view of silicon strip X-view of silicon strip Transition curve in towers 1 TeV gamma-ray Arm2

Oscar Adriani 23/09/10  0 at 7 TeV Arm2 event display Silicon layers Scintillator layers Tower 32mm 25mm Robust sample Good energy calibrator 25 mm tower 32 mm tower

Oscar Adriani 23/09/10 Beam position analysis: LHCf vs BPM

Oscar Adriani 23/09/10  M/M=6.3MeV/135MeV=4.7%  0 mass and energy spectrum (Arm1) Please note the Very High Energy! Preliminary

Oscar Adriani 23/09/10  0 mass and energy spectrum (Arm2)  M/M=2.3% Using only data taken before April 13 th Preliminary

Oscar Adriani 23/09/10 Particle ID: L90%

Oscar Adriani 23/09/10 PID study Energy spectra with not PID biased By fitting the L90% distribution with the superposition of 2 components (gamma-rays and hadrons), the efficiency and purity can be estimated from the data themselves. Before the correction After the correction

Oscar Adriani 23/09/10 Measured Spectra at 7TeV preliminary Gamma-ray like Hadron like Arm2 preliminary Gamma-ray like Hadron like Arm1 Very high statistics !! only 2% of all data

Oscar Adriani 23/09/10 Arm1/Arm2 Comparison Red : Arm1 Blue : Arm2 Same geometrical regions and same runs are selected Correction for different livetimes

Oscar Adriani 23/09/10  search All data taken with zero-crossing angle and low luminosity In the High Lumi/High Pile Up runs we don’t see  (combinatorial background)

Oscar Adriani 23/09/10 Luminosity with VdM scan with Front Counter Data σ x & σ y are measured in VdM scan (May 9 th ) independently from interaction model or detector Calculate luminosity with this VdM scan Calculate “FC rate  Luminosity” Conversion Factor to be independent from MC

Oscar Adriani 23/09/10 VdM scan May 9 th, 2010 FC rate of arm1 / 1000 Beam position - start of scan +0.3mm Beam position - end of scan +0.3mm ScanFC1FC2FC1&2ATLAS Scan μ m59.9 μ m58.4 μ m59.1 μ m Scan μ m60.3 μ m59.1 μ m59.3 μ m  x measured by FC Horizontal scan Lumi measured perfectly compatible with Atlas! +

Oscar Adriani 23/09/10 Radiation Damage 3% Dose measured by the dosimeters behind the calorimeters  0 mass peak

Oscar Adriani 23/09/10 LHCf removal LHCf has completed the basic physics program at 7 TeV LHCf has been removed on July 20 th, during a short technical stop (a little bit  ) Laser calibrations were done for few weeks after the removal (Annealing) Test beam is foreseen from October 15 to 28 –3 days main users –10 days parasitic run

Oscar Adriani 23/09/10 Future activities (I) 2011 –Replace plastic scintillators with Rad Hard GSO (prepared by Japan side) in Florence Clean Rooms –Produce 2 new silicon modules to replace partly defective ones + 2 spares –Modify the silicon layers positions to improve silicon-only energy resoution –Test beam at SPS to calibrate Arm1&Arm2 –Test beam at GSI to intercalibrate the Silicon Pace3 response with relativistic High Z Nuclei

Oscar Adriani 23/09/10 R&D for the detector upgrade. Plastic scintillators (EJ260) ⇒ GSO scintillators ⇒ GSO scintillators EJ260 Radiation damage measured by Ion beams Scintillating Fibers ⇒ GSO bars MIP peak

Oscar Adriani 23/09/10 New silicon layers arrangement 8 Silicon Layers X 0

Oscar Adriani 23/09/10 Future activities (II) 2012 –Install the detectors at RHIC? –RHIC can accelerate: p-p up to 250 GeV/nucleon Ions up to 100 GeV/nucleon They have already done deuteron-Gold They could do p-Light ion –RHIC beam pipe arrangement Situation similar to LHC Single beam pipe split in 2 at 20 m from IP Space available ~ 10 cm LHCf can fit very well inside! –  0 can be reconstructed as we are doing in LHC! Sqrt(s) min =4 m  d/h det d=20 m, h det = 8 cm  Sqrt(s) min = 135 GeV More news in 2011—> Stay tuned!!!!!!!

Oscar Adriani 23/09/10 Future activities (III) –Re-install Arm1&Arm2 at LHC when the energy will be raised to 13/14 TeV –Necessity to mantain the Cern infrastractures: Control room Electronics pool material Safety infrastructures Racks in underground areas Team account Etc. etc. etc.

Oscar Adriani 23/09/10 Conclusion LHCf has completed the basic physics program at 7 TeV LHCf was removed from TAN on July 20 th, 2010 Test beam is foreseen in October 2010 The detector will be upgraded during 2011 to improve radiation hardness –GSO will replace plastic scintillator –More energy measurement oriented silicon arrangement RHIC Option for 2012?  Stay Tuned!!!!!!!!!! LHCf will certainly be back in the TAN for the 14 TeV run!

Oscar Adriani 23/09/10 Backup slides

Oscar Adriani 23/09/10 Studies of detector responses layer dE MC (DPMJET3) Measured Silicon Tracker LHCf Detector Beam Pipe Transition curve for 350GeV/c protons Detector response for hadrons by beam test data at SPS done in 2007 LPM effect The radiation length for high energy particles seems to become longer in the heavy matter. - Confirmation of the LPM effect - Effect to the energy reconstruction and PID etc. Transition curve for 1.5TeV γ (MC) presented by SAKO protons with 350GeV/c and 150GeV/c ⇔ LHC: 450GeV+450GeV Presented by MASE

Oscar Adriani 23/09/10 Alessia Tricomi University & INFN Catania The LHCf experiment at LHC ISVHECRI08, Paris 1-6 September 2008 Radiation Damage Studies 30 kGy Expected dose: 100 Gy/day at cm -2 s -1Expected dose: 100 Gy/day at cm -2 s cm -2 s -1 : cm -2 s -1 : 10 kGy 50% light output 50% light output Continous monitor and calibrationwith Laser system!!!Continous monitor and calibrationwith Laser system!!! Scintillating fibers and scintillators 1 kGy

Oscar Adriani 23/09/10 Particle Identification Thick for E.M. interaction (44X 0 ) Thin for hadronic interaction(1.7 ) Longitudinal development of  shower Longitudinal development of Hadron shower Definition of L90% Gamma-rays: L90%<16 r.l x  dE

Oscar Adriani 23/09/10 Results at 900GeV: PID Gamma-rays: L90%<16 r.l x  dE QGSJET2 Data QGSJET2 Data QGSJET2 Data QGSJET2 Data Preliminary

Oscar Adriani 23/09/10 L90%<18X 0 Constant  cut

Oscar Adriani 23/09/10 RHIC Physics Case p-Light Ion –This measurement will allow to directly measuring the characteristic of the HECR-atmosphere interactions, without having to rely on the approximation usually done to go from the p-p collision to the p-nucleus collision (Glauber approximation). p-p –We propose also to run the RHICf experiment in the p- p collisions, to have the possibility to directly check the validity of the Glauber approximation at 200 GeV center of mass energy by comparing the p-p with the p-LI results.

Oscar Adriani 23/09/10 Beam Position Analysis from the LHC data Theoretical center Positive; upward in V outward in H 43m 140m BPMSW IP Offset; bθ Beam position (b) and angle ( θ ) can be determined from the measurements of two BPMSW (beam position monitor) Expected position (neutral center) on the LHCf detector at 140m away can be calculated from these numbers Analysis done by Simon White

Oscar Adriani 23/09/10 FrontCounter as a good luminosity monitor 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 Beam pipe TAN Neutral particles FC LHCf- CAL BRAN-Sci ZDC BRAN-IC Gaussian fit Arm1 Arm2 Coincidence Stay all the time lumiscan Page1 LHCf page

Oscar Adriani 23/09/10 ATLAS online (w/o calibration) VdM scanning