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

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

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

Oscar Adriani Torino, 17/05/10 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

Statistic plot up to 16 May 2010 Red = Shower Arm1 Blue = p0 Arm1 (x100) Light red=Shower Arm2 Light Blue = p0 Arm2 (x100) Shower Trigger g-like p0 Live time(*) Arm1 29,515,720 8.0e6 59,000 96% Arm2 33,230,720 1.0e7 140,000 93% Oscar Adriani Torino, 17/05/10

Oscar Adriani Torino, 17/05/10 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

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

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

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

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

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

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 cumulative dose 0.045Gy Oscar Adriani Torino, 17/05/10

FrontCounter as a good luminosity monitor Stay all the time Beam pipe TAN Neutral particles FC LHCf-CAL BRAN-Sci ZDC BRAN-IC Page1 LHCf page 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 Gaussian fit Arm1 Arm2 Coincidence lumiscan Oscar Adriani Torino, 17/05/10

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

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

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

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

Oscar Adriani Torino, 17/05/10 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

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

Preliminary spectra from 900GeV runs in 2009 Normalized by gamma-like entry MC(QGSJET2) Data Hadron response under study Sys.+Sta. 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 Adding May 900GeV runs, 100K showers now (Dec09 x15) ! Oscar Adriani Torino, 17/05/10

Oscar Adriani Torino, 17/05/10 Plan for coming months 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) Typical unit 10K p0 w/ ~1nb-1 Oscar Adriani Torino, 17/05/10

Study of h in a high statistics sample QGSJET2 h 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 Oscar Adriani Torino, 17/05/10

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

Oscar Adriani Torino, 17/05/10

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

Oscar Adriani Torino, 17/05/10 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

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

Oscar Adriani Torino, 17/05/10

Both detectors working without any biases 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

Oscar Adriani Torino, 17/05/10 -Front Counter- Thin scintillators with 8x8cm2 acceptance, which have been installed in front of each main detector. Schematic view of Front counter We have a sub-detector with thin scintillator layers, we call Front Counter. Front Counter has much larger acceptance than calorimeters. It’s useful to monitor collisions and for background rejection of beam and residual gas collisions by coincidence analysis of both size. To monitor beam condition. For background rejection of beam-residual gas collisions by coincidence analysis Oscar Adriani Torino, 17/05/10

Summary of Expected number of events QGSJET2 SIBYLL DPMJET3 Pythia h p0 h/ p0 Arm1 (Normal) 0.08 46.9 0.002 0.01 46.7 0.0002 75.5 0.0001 (-20mm) 7.35 238.4 0.031 0.21 191.9 0.0011 1.05 310.7 0.0034 Arm2 1.6 123.7 0.012 0.10 110.8 0.0009 0.24 177.5 0.0014 0.15 150 0.0010 (-10mm) 3.36 191.3 0.018 165.1 0.0013 0.47 268.5 0.0016 0.1 169 0.00059 Oscar Adriani Torino, 17/05/10

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. Next, I present what we can measure. We can measure energy spectra and transverse momentum distribution of gamma-ray with more than 100GeV and neutral hadrons it’s mainly neutrons with more than a few hundreds GeV, and neutral pions with more than 700GeV at rapidity range from 8.4 to infinity. because we don’t have own central detectors and LHCf trigger is completely independent on ATLAS trigger, so LHCf can measure only inclusive spectra . However we are recording ATLAS event ID number event by event, so it is possible to identify coincidence events with ATLAS event and to analyze with ATALS in future. Multiplicity@14TeV Energy Flux @14TeV High energy flux !! Low multiplicity !! Oscar Adriani Torino, 17/05/10 simulated by DPMJET3

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!!! The LHCf experiment at LHC ISVHECRI08, Paris 1-6 September 2008 1 kGy Alessia Tricomi University & INFN Catania 30 kGy Oscar Adriani Torino, 17/05/10

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

Oscar Adriani Torino, 17/05/10