1. Status of the LHCf experiment Alessia Tricomi University and INFN Catania on behalf of the LHCf Collaboration Physics at LHC 2008 29 September – 4 October, 2008 Experiment goals Experiment goals The LHCf detector The LHCf detector Physics performances Physics performances Towards data taking Towards data taking

2. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf: modelling Cosmic Rays at LHC Astrophysical parameters - source type - source distribution - source spectrum - source composition - propagation AGASA x 0.9 HiRes x1.2 Yakutsk x 0.75 Auger x1.2 (not enough) Berezinsky 2007 AGASA Systematics Total ±18% Hadron interaction (QGSJET, SIBYLL) ~10% (QGSJET, SIBYLL) ~10% (Takeda et al., 2003) (Takeda et al., 2003) Difference in the energy scale between different experiments??? IRON PROTON Unger, ECRS 2008 Again different interaction models lead to different conclusions about the composition of the primary cosmic rays and play a fundamental role

3. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf: modelling Cosmic Rays at LHC Astrophysical parameters - source type - source distribution - source spectrum - source composition - propagation LHC Forward Physics - cross section - particle spectra (E, P T,,, X F ) (E, P T,,, X F ) Nuclear Interaction - calibration with data of Monte Carlo used in Cosmic Ray Physics

4. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 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 LHCf firstly proposed to use LHC, the highest energy accelerator s = 14 TeV E lab =10 17 eV to calibrate MC simulation code The dominant contribution to the energy flux is in the very forward region ( 0) In this forward region the highest energy available measurements of 0 cross section done by UA7 (E=10 14 eV, y= 5÷7) p 10 19 eV

5. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 But… Charged particles Neutral particles Beam pipe General purpose detectors (ATLAS, CMS,…) cover only the central region Special detectors to access forward particles are necessary

6. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 How to access Very Forward Physics at LHC? Charged particles Neutral particles Beam pipe Surrounding the beam pipe with detectors Simple way, but still miss very very forward particles

7. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Neutral particles Beam pipe Charged particles Install detectors inside the beam pipe Challenging but ideal for charged particle How to access Very Forward Physics at LHC?

8. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Y shape chamber enables us whole neutral measurements Zero Degree Calorimeters Charged particles Neutral particles Beam pipe How to access Very Forward Physics at LHC? LHCf

9. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Pseudo rapidity in LHC pseudorapidity: = - ln (tan /2)

10. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf location Detectors installed in the TAN region, 140 m away from the Interaction Point 1 Here the beam pipe splits in 2 separate tubes. Here the beam pipe splits in 2 separate tubes. Charged particle are swept away by magnets!!! Charged particle are swept away by magnets!!! We will cover up to y We will cover up to y I NTERACTION POINT IP1 (ATLAS) Beam line Detector II TungstenScintillator Silicon strips Detector I TungstenScintillator Scintillating fibers 140 m

11. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Detector #1 16 scintillator layers (3 mm thick) Trigger and energy profile measurements Absorber 22 tungsten layers 7mm – 14 mm thick (W: X 0 = 3.5mm, R M = 9mm) 4 pairs of scintillating fiber layers for tracking purpose (6, 10, 32, 38 r.l.) Energy Impact point ( ) 2 towers 24 cm long stacked vertically with 5 mm gap Lower: 2 cm x 2 cm area Upper: 4 cm x 4 cm area

12. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Detector # 2 4 pairs of silicon microstrip layers (6, 12, 30, 42 r.l.) for tracking purpose (X and Y directions) We used LHC style electronics and readout 16 scintillator layers (3 mm thick) Trigger and energy profile measurements Absorber 22 tungsten layers 7mm – 14 mm thick (2-4 r.l.) (W: X 0 = 3.5mm, R M = 9mm) 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 Energy Impact point ( )

13. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Double ARM Detectors Arm#1 Detector Arm#2 Detector 90mm 290mm

14. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Detectors in place LHCf Luminosity Monitor (BRAN) Monitor (BRAN) ATLAS ZDC Installation performed in two phases: 1.Pre-Installation (Jan/Apr 2007) Baking out of the beam pipe (200 °C) Baking out of the beam pipe (200 °C) 2.Final Installation (Jan 2008)

15. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Front Counter 2 fixed Front Counters installed in front of Arm1 and Arm2 2 fixed Front Counters installed in front of Arm1 and Arm2 They will not move with Arm1 and Arm2 They will not move with Arm1 and Arm2 They are segmented in 2 x and 2 y slices They are segmented in 2 x and 2 y slices Very useful to check the beam quality and hence decide to move Arm1 and Arm2 in the operating position from the garage position Very useful to check the beam quality and hence decide to move Arm1 and Arm2 in the operating position from the garage position

16. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf Physics performance 1.Single photon spectrum 2. 0 fully reconstructed (1 in each tower) 0 reconstruction is an important tool for energy calibration ( 0 mass constraint) 0 reconstruction is an important tool for energy calibration ( 0 mass constraint) Basic detector requirements: minimum 2 towers ( 0 reconstruction) minimum 2 towers ( 0 reconstruction) Smallest tower on the beam (multiple hits) Smallest tower on the beam (multiple hits) Dimension of the tower Moliere radius Dimension of the tower Moliere radius Maximum acceptance (given the LHC constraints) Maximum acceptance (given the LHC constraints) Simulation Beam Test Unfortunately no LHC data still available Results for the moment based on

17. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf single geometrical acceptance Some runs with LHCf vertically shifted few cm allow to cover the whole kinematical range

18. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf : Monte Carlo discrimination 10 6 generated LHC interactions 10 6 generated LHC interactions 1 Minute exposure@10 29 cm -2 s -1 luminosity Discrimination between various models Discrimination between various models is feasible is feasible Quantitative discrimination with the help of a properly defined 2 discriminating variable based on the spectrum shape (see TDR for details) 5% Energy resolution

19. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf: model dependence of neutron energy distribution Original n energy 30% energy resolution

20. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 New Models Drescher, Physical Review D77, 056003 (2008) 056003 (2008) PICCO EPOS Neutron 0 Proton 29

21. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Energy Resolution Monte Carlo SPS beam test Energy distribution is corrected for leakage correction Distance from Edge N Particles MC predicts that the leakage is energy independent!

22. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 0 reconstruction 0 reconstruction 9.15 m 350 GeV Proton beam Carbon target (6 cm) in the slot used for beam monitor Arm1 Not in scale! >10 7 proton on target (special setting from the SPS people) Dedicated trigger on both towers of the calorimeter has been used (MeV) Preliminary!!!! 250 0 events triggered (in a quite huge background) and on disk 250 0 events triggered (in a quite huge background) and on disk Main problems: low photon energy ( 20 GeV) low photon energy ( 20 GeV) Direct protons in the towers Direct protons in the towers Multi hits in the same tower Multi hits in the same tower Ex: m ~ 8 MeV m ~ 8 MeV m/m ~ 6% m/m ~ 6%Sim: m/m ~ 5% m/m ~ 5%

23. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 ARM2 Position Resolution Number of event σ x =40 m x-pos[mm] y-pos[mm] 200 GeV electrons σ y =64 m

24. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 ARM2-Silicon Energy Resolution E/E ~ 12% E/E ~ 12% No correction/calibration applied ADC 200 GeV electrons SPS beam test data Only silicon energy resolution ~ 10%!!!!! We can use it as a check for the radiation damage of the scintillators

25. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Preparation for data taking The LHCf control room has been prepared and fully equipped in the Atlas area

26. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Dummy event

27. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Communications with LHC Experimental status (On/Off, Gain, etc.) Experimental status (On/Off, Gain, etc.) Detector position (Garage/Operating, position in mm, etc.) Detector position (Garage/Operating, position in mm, etc.) Luminosity rate (Single and Double Arm) Luminosity rate (Single and Double Arm) –Front Counter rate (single Arm, double Arm coincidence) –Small tower rate (single Arm) –Big tower rate (single Arm) –Double Arm coincidence rate (FC.AND.Towers in opposite sides) Horizontal and Vertical position of the Beam (every 10000 events or in the whole RUN) Horizontal and Vertical position of the Beam (every 10000 events or in the whole RUN) Injection Inhibit Injection Inhibit Handshaking signals (Injection, Adjust, Beam Dump) Handshaking signals (Injection, Adjust, Beam Dump) LHCf sends signals to LHC through the DIP system. Link have been tested and it works fine! Important for machine tuning!

28. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 First data: 11 September Not very exciting Physics… But Ready for Data Taking

29. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf: conclusions and plans Compilation of the EAS data is affected by the uncertainty of hadron interaction. Compilation of the EAS data is affected by the uncertainty of hadron interaction. LHCf experiment will provide crucial data of hadron interaction for CR study. LHCf experiment will provide crucial data of hadron interaction for CR study. LHCf can clearly discriminate the existing and new models by measurements of π 0, γ and n thanks to its excellent performances LHCf can clearly discriminate the existing and new models by measurements of π 0, γ and n thanks to its excellent performances –Energy Resolution 5% –Spatial resolution ~40-200 m –Beam crossing angle 0 and/or vertical shifts of LHCf by few cm will allow more complete physics measurements Both Detectors ready to fulfil the run program Both Detectors ready to fulfil the run program So now

30. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf: conclusions and plans We need only to wait LHC restart! Hoping to answer all our questions and to help, thanks to our excellent perfomances, EAS experiments to interpret their data

31. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Back-up slides

32. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 The LHCf Collaboration ITALY Firenze University and INFN: O.Adriani,, L.Bonechi, M.Bongi, G.Castellini, R.DAlessandro, P.Papini, S. Ricciarini, A. Viciani Catania University and INFN: A.Tricomi JAPAN: STE Laboratory Nagoya University: K.Fukui,Y.Itow, T.Mase, K.Masuda,Y.Matsubara, H.Menjo,T.Sako, K.Taki, H. Watanabe Waseda University: K. Kasahara, M. Mizuishi, Y.Shimizu, S.Torii Konan University: Y.Muraki Kanagawa University Yokohama: T.Tamura Shibaura Institute of Technology: K. Yoshida SPAIN IFIC Valencia: A.Fauss, J.Velasco FRANCE Ecole Politechnique Paris: M. Haguenauer USA LBNL Berkeley: W. Turner CERN D.Macina, A.L. Perrot

33. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Cosmic Ray Composition X max favors heavy primary Anisotropy favors light primary (if accept AGN correlation)

34. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Cosmic Ray Composition QGSJET01 SIBYLL 2.1 Kascade Results

35. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 ARM1: Maximization of the acceptance for vertical beam displacement (crossing angle>0) ARM2: Maximization of the acceptance in R (distance from beam center) Transverse projection in TAN slot

36. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Detectable events 140 Beam crossing angle LHCf: acceptance on P T -E plane A vertical beam crossing angle > 0 increases the acceptance of LHCf

37. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 QGSJETII: used model QGSJET: 2 /DOF=107/125 DPMJET3: 2 /DOF=224/125 SYBILL: 2 /DOF=816/125 ray energy spectrum for different positions ray energy spectrum for different positions

38. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 LHCf performances: 0 geometrical acceptance Arm #1 Arm #2

39. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Arm #1 D E/E=5% 200 m m spatial resolution D m/m = 5% LHCf performances: 0 mass resolution

40. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 0 spectra 0 spectra QGSJETII DPMJET3 χ 2 = 106 (C.L. <10 -6 ) DPMJET3 χ 2 = 106 (C.L. <10 -6 ) SIBYLL χ 2 = 83 (C.L. <10 -6 ) SIBYLL χ 2 = 83 (C.L. <10 -6 )DPMJET3 SIBYLL χ 2 = 28 (C.L.= 0.024) SIBYLL χ 2 = 28 (C.L.= 0.024) 10 7 events DOF = 17-2=15 10 7 events DOF = 17-2=15 p 0 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

41. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 rate rate

42. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 rate rate

43. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 The LPM effect Transition curve of a1 TeV photon w/ and w/o LPM to be measured by LHCf w/o LPM w/ LPM

44. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Estimate of the background beam-beam pipe beam-beam pipe E γ (signal) > 200 GeV, OK E γ (signal) > 200 GeV, OK background < 1% background < 1% beam-gas beam-gas It depends on the beam condition It depends on the beam condition background < 1% (under 10 -10 Torr) background < 1% (under 10 -10 Torr) beam halo-beam pipe beam halo-beam pipe It has been newly estimated from the beam loss rate It has been newly estimated from the beam loss rate background < 10% (conservative value) background < 10% (conservative value)

45. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Analysis of Beam Gas events We got 116 FC triggers in 8.275.034 BPTX: N t =116 2.10 9 protons/bunch Total # of protons: N p =1.7 x 10 16 We try to estimate the gas density from this rate: N t =N p * L * * N t =N p * L * * L=effective lenght ~ 100 m =Cross section ~ 80 mbarn = 80 x 10 -31 m 2 =Cross section ~ 80 mbarn = 80 x 10 -31 m 2 We find: = 8.5 x 10 12 H/m 3 = 4.2 x 10 12 H 2 /m 3 From the LHC Project Report #783: = 10 12 H 2 /m 3 From the pressure measurement in April 2008: ~ 10 12 H 2 /m 3 ~ CONSISTENT!!!!!!!!!!!!!

46. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Synchronization with Atlas To have the possibility to identify the events common with Atlas we implemented a synchronization method based on the L1A signal generated by Atlas. To have the possibility to identify the events common with Atlas we implemented a synchronization method based on the L1A signal generated by Atlas. We receive Atlas L1A and we store the time stamp of this signal in our DAQ system. We receive Atlas L1A and we store the time stamp of this signal in our DAQ system. We can really correlate the Atlas events with the LHCf ones! We can really correlate the Atlas events with the LHCf ones! Atlas Bunch ID – LHCf Bunch Id

47. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Beam parameters used for commissioning are good for LHCf!!! Beam parameters used for commissioning are good for LHCf!!! Beam parameter Value # of bunches 43 43 Bunch separation > 2 m sec Crossing angle 0 rad 0 rad 140 m rad downward Luminosity per bunch < 2 x 10 28 cm -2 s -1 < 2 x 10 28 cm -2 s -1 Luminosity < 0.8 x 10 30 cm -2 s -1 < 0.8 x 10 30 cm -2 s -1 Bunch intensity 4x10 10 ppb ( b *=18m) 1x10 10 ppb ( b *= 1m) Optimal LHCf run conditions

48. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 SPS Beam Test LHCfDetectorSilicon Tracker Tracker Moving Table TriggerScintillator CERN : SPS T2 H4 CERN : SPS T2 H4 2006 Aug. 28 – Sep. 4 2006 Aug. 28 – Sep. 4 Incident Particles Incident Particles –Proton 150,350 GeV/c –Electron 50,100, 50,200 GeV/c –Muon 150 GeV/c Setup Test was very successful!!! Analysis is under way for Energy calibration of the calorimeters Energy calibration of the calorimeters Spatial resolution of the tracking systems Spatial resolution of the tracking systems

49. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Energy Resolution Monte Carlo SPS beam test Energy distribution is corrected for leakage correction Distance from Edge N Particles MC predicts that the leakage is energy independent!

50. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 ARM1 Position resolution σ x [mm] σ [mm] Number of event x-pos[mm] y-pos[mm] E[GeV] 200 GeV electrons σ x =172 m m σ y =159 m m

51. Alessia Tricomi University & INFN Catania Status of the LHCf experiment LHC Physics 2008, Split 29 Sept.-4 Oct. 2008 Radiation Damage Studies 30 kGy Expected dose: 100 Gy/day at 10 30 cm -2 s -1 Expected dose: 100 Gy/day at 10 30 cm -2 s -1 Few months @ 10 30 cm -2 s -1 : 10 kGy Few months @ 10 30 cm -2 s -1 : 10 kGy 50% light output 50% light output Continous monitor and calibration with Laser system!!! Continous monitor and calibration with Laser system!!! Scintillating fibers and scintillators