LHCf and the connection with Cosmic Ray Physics Oscar Adriani Università degli Studi di Firenze INFN Sezione di Firenze

The LHCf Collaboration CERN D.Macina, A.L. Perrot USA LBNL Berkeley: W. Turner FRANCE Ecole Politechnique Paris: M. Haguenauer SPAIN IFIC Valencia: A.Fauss, J.Velasco JAPAN: STE Laboratory Nagoya University: Y.Itow, T.Mase, K.Masuda, Y. Matsubara,H.Matsumoto, G.Mitsuka, Y.Muraki,T.Sako,K.Taki,H. Watanabe Shibaura University Saitama: K.Kasahara Kanagawa University Yokohama: T.Tamura, K.Tanaka Waseda University: Y.Shimizu, S.Torii ITALY Firenze University and INFN: O.Adriani, L.Bonechi, M.Bongi, G.Castellini, R.D’Alessandro, H.Menjo, P.Papini Catania University and INFN: K.Noda, A.Tricomi Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 What is LHCf? The Detectors Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

LHCf: an Astroparticle Experiment at LHC LHCf is the smallest of the six LHC experiments and is a fully dedicated collider experiment for HECR Physics LHCf will use the highest energy particle accelerator to provide useful data to calibrate the hadronic interaction models used in Monte Carlo simulations of atmospheric showers 7TeV+ 7 TeV proton collisions at LHC correspond to ELAB = 1017eV Two independent electromagnetic calorimeters equipped with position sensitive layers, on both sides of IP1 will measure energy and position of g from p0 decays and neutrons produced in pp interaction at LHC Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Experimental set-up INTERACTION POINT IP1 (ATLAS) Detector II Tungsten Scintillator Silicon mstrips Detector I Scintillating fibers 140 m 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 Charged particles Neutral particles Beam pipe Protons Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Arm1 2 towers 24 cm long stacked vertically with a 5 mm gap 4 pairs of scintillating fiber layers for tracking purpose (6, 10, 32, 38 X0.) Absorber 22 tungsten layers 7mm – 14 mm thick (W: X0 = 3.5mm, RM = 9mm) Arm1 16 scintillator layers (3 mm thick) Trigger and energy profile measurements 2 towers 24 cm long stacked vertically with a 5 mm gap Lower: 2 cm x 2 cm area Upper: 4 cm x 4 cm area Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Arm2 4 pairs of silicon microstrip layers (6, 10, 30, 42 X0) for tracking purpose (X and Y directions) Absorber 22 tungsten layers 7mm – 14 mm thick (W: X0 = 3.5mm, RM = 9mm) 16 scintillator layers (3 mm thick) Trigger and energy profile measurements 2 towers 24 cm long stacked on their edges and offset from one another Lower: 2.5 cm x 2.5 cm Upper: 3.2 cm x 3.2 cm Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Double ARM Detectors Arm#1 Detector Arm#2 Detector 290mm 90mm Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

LHCf detectors in the LHC tunnel Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Why LHCf? Physics Motivations Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Ultra High Energy Cosmic Rays Experimental observations: at E>100 TeV only EAS (shower of secondary particles) lateral distribution longitudinal distribution particle type arrival direction Extensive Air Showers Air shower development (particle interaction in the atmosphere) Astrophysical parameters: (primary particles) spectrum composition source distribution origin and propagation Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Cosmic Ray Energy Spectra AGASA Systematics Total ±18% Hadron interaction (QGSJET, SIBYLL) ~10% (Takeda et al., 2003) M Nagano New Journal of Physics 11 (2009) 065012 Difference in the energy scale between different experiments??? Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

HECR composition The depth of the maximum of the shower Xmax in the atmosphere depends on energy and type of the primary particle Different hadronic interaction models give different answers about the composition of HECR IRON PROTON Unger, ECRS 2008 LHC Auger 1018 1019 1020 eV Xmax measurements favours heavier composition as the energy increases Anisotropy would favour proton primaries (AGN correlation still valid?) Alessia Tricomi University and INFN Catania Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Development of atmospheric showers LHC Tevatron A 100 PeV fixed-target interaction with air has the cm energy of a pp collision at the LHC AUGER Cosmic ray spectrum Determination of E and mass of cosmic rays depends on description of primary UHE interaction Hadronic MC’s need tuning with data The dominant contribution to the energy flux is in the very forward region ( 0) In this forward region the highest energy available measurements of p0 cross section done by UA7 (E=1014eV, y= 5÷7) LHCf: use LHC √s = 14 TeVElab=1017eV to calibrate MCs AlessiaTricomi University and INFN Catania Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

How LHCf can calibrate MC? Physics Perfomances Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

LHCf: acceptance on PTg-Eg plane 140 Beam crossing angle Detectable events A vertical beam crossing angle > 0 will increase the acceptance of LHCf EPS 09, Krakow 16-22 July 2009 Alessia Tricomi University and INFN Catania Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

LHCf single g geometrical acceptance Some runs with LHCf vertically shifted few cm will allow to cover the whole kinematical range Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Energy resolution for e/g (Test Beam) For 20mm For 40mm 5% 5% Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

ARM2 Position Resolution (Test beam) 200 GeV electrons Number of event σy=64 mm σx=40 mm Number of event x-pos[mm] y-pos[mm] Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

LHCf : Monte Carlo discrimination 106 generated LHC interactions  1 minute exposure@1029 cm-2s-1 luminosity Discrimination between various models is feasible Quantitative discrimination with the help of a properly defined c2 discriminating variable based on the spectrum shape 14 TeV c.m.energy 5% Energy resolution Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

LHCf: model dependence of neutron energy distribution Original n energy 30% energy resolution 14 TeV c.m. energy Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

g and n spectra at different energies 20 min @ 1029 cm-2s-1 1 min @ 1029 cm-2s-1 1 min @ 1029 cm-2s-1 450 GeV 1 TeV 5 TeV g g g 20 min @ 1029 cm-2s-1 1 min @ 1029 cm-2s-1 1 min @ 1029 cm-2s-1 450 GeV 1 TeV 5 TeV n n n DPMJET3 QGSJET2 QGSJET1 SIBYLL No detector resolution taken into account Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 p0 spectra E2 E1 Gamma2 Gamma1 p0 produced at collision can be extracted by using gamma pair events Powerful tool to calibrate the energy scale and also to eliminate beam-gas BG Emin ~ 700GeV Geometrical Acceptance Peak : 134MeV Sigma: 4.9MeV Cut: 125-145MeV 10mm Lower Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

A different point of view….. The advantage of being forward! Multiplicity@14TeV Energy Flux @14TeV DPMJET3 DPMJET3 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. Low multiplicity !! High energy flux !! Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 When LHCf? NOW!!!!!!!!!!! Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 LHCf Operations in 2009 With stable beams at 900GeV, 06 Dec. – 15 Dec 2.6 hours for commissioning 27.7 hours for physics ~5x105 collisions at IP1 ~2,800 shower events in Arm1 ~3,700 shower events in Arm2 Expected spectra for different hadron interaction model Gamma-ray like @ Arm2 Hadron like @ Arm2 with 107 col. Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Arm2 g event Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Particle Identification A transition curve for Gamma-ray A transition curve for Hadron Thick for E.M. interaction (44X0) Thin for hadronic interaction(1.7l) Definition of L90% L90% @ 20mm cal. of Arm1 MC (QGSJET2) Data Preliminary Gamma-ray like Gamma-rays: L90%<16 r.l. + 0.002 x SdE Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Results at 900GeV shadow of beam pipes Hit map of Gamma-rays Arm1 Background due to beam-residual gas collision is about 10% Red: colliding bunch = collision + BG Blue: single bunch = BG only I shows preliminary resutls in last year operation. in last year, in total LHC had about 10 to 6th collisions at all IPs. We took about 6000 shower events by Arm1 and Arm2 calorimeters. The left figure show the hit map of gamma-ray events. black open circles show events at colliding bunches and red marks shows events at non-colliding bunches. beam and residual gas collisions made these non-colliding bunch events. Black markers have clear cut because of the beam pipe shadow. Left figure show distribution of energy deposit in Arm1 detectors. Red dots shows events at colliding beams and Blue shows events at non-colliding beam events. By subtract with non-colliding beam events, we can see clear collision events. Arm2 Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Comparison of spectra Spatially flat profile in h>8.7 at 900GeV Comparison between calorimeter towers of Arm2 Comparison of spectra Gamma-ray like Hadron like Spatially flat profile in h>8.7 at 900GeV Comparison between two Arms Both detectors give consistent spectra Preliminary Preliminary Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Comparison with MC @ Arm1 MC(QGSJET2) Data Sys.+Sta. Hadron response under study Spectra of MC are normalized by the entries of gamma-ray spectra Data is in good agreement with QGSJET2 MC Checking detector response for hadrons carefully by beam test data with 150GeV, 350GeV protons. Studying systematic errors. for the moment. Sys. of Energy scale (+11% /-5%) Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Comparison with MC @ Arm2 Hadron response under study Adding May 900GeV runs, 100K showers now (Dec09 x15) ! Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 LHCf 2010 runs Successful data taking at 7TeV collisions is ongoing. Integrated Luminosity ~ 10.0 nb-1 up to May 26, 2010 ~120M showers and 400K 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 Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Statistics up to 26 May 2010 Shower Trigger g-like p0 Live time(*) Arm1 60e6 16e6 118,000 96% Arm2 65e6 20e6 280,000 93% Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 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 Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 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 Forward Physics at LHC La Biodola, 28/05/10

p0 mass and energy spectrum (Arm1) Please note the very high energy!!!! DM/M=6.7MeV/135MeV=5.0% Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

p0 mass and energy spectrum (Arm) DM/M=3.1MeV/135MeV=2.3% Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

Which is the future of LHCf? Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 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 Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

Crossing angle for LHCf 7 TeV run Shown in 99th LHCC, Sep2009 Distance from neutral center Aperture of Beam pipe 3.5+3.5TeV All g from IP a=140mrad 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 A crossing angle during LHCf run is very helpful for physics! LHCf can measure crossing angle by fitting shower center (DY~ 1mm for 100sec@L=1029gDa~7mrad) Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

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 Mid July After removal, beam calibration again by a SPS test beam. Revisit LHC at the next energy upgrade with rad-hard detector Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Improve the radiation resistance of LHCf Basic idea: Replace the plastic scintillator with more RadHard scintillators GSO Rearrange the order of silicon sensors to improve the silicon energy measurement Cross check for scintillator measurement Go back in the 20xx for 7+7 TeV run 20mm 1mm thick A new GSO scintillator layer Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 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 Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Backup slides Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

Results on radiation damage The dose approximately scale as E3 Energy (TeV) Dose rate (Gy/hour at 1029cm-2s-1) Dose rate (Gy/nb-1) Time to reach 1KGy at 1029cm-2s-1 (days) Integrated lumi to reach 1KGy (nb-1) 0.45+0.45 4.6•10-4 1.27•10-3 9140 7.9•105 3+3 1.3•10-1 0.35 330 2.9•103 5+5 6.1•10-1 1.7 68 590 7+7 1.6 4.3 27 230 Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

Energy flux in front of LHCf detector Energy flux for 7TeV 3 orders of magnitude reduction in dose from running to garage positions GeV/s/cm2 Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 -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 Forward Physics at LHC La Biodola, 28/05/10

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 Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 New Models PICCO EPOS Drescher, Physical Review D77, 056003 (2008) p0 Neutron Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Transverse projection in TAN slot ARM1: Maximization of the acceptance for vertical beam displacement (crossing angle>0) ARM2: Maximization of the acceptance in R (distance from beam center) Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

p0 spectra and model discrimination Reconstructed spectrum in good agreement with the original π0 production spectrum (DPMJETⅢ) Systematic errors mainly due to the uncertainty of the absolute energy scale of the calorimeters. ±5% uncertainty were conservatively assumed 20 min @ 1029 cm-2s-1 Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Arm1 g event Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Gamma/Hadron at 7 TeV Arm1 Data Small+Large Small+Large Gamma+Hadron Gamma+Hadron Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10

Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10 Arm2 neutron event Oscar Adriani Forward Physics at LHC La Biodola, 28/05/10