Current Status of LHCf Experiment

1. Current status of the LHCf experimentYasushi Muraki (Konan University) • 1. A history on hadron physics • 2. Previous experiment CERN UA7 • 3. Current experiment aｔ LHC: LHCf Measurement of π0 cross-section emitted in a very forward region by the pp collisions at E0=10 17eV

2. Historical debate in the field of cosmic ray physics • Around 1980, there was a big debate in the field of cosmic ray physics • Whether or not the nuclear interaction process is changing at 100 TeV? • Or it just reflects an increase of heavy primary component like Fe in the primary component of cosmic rays. • The data showed only rapid development of the cascade showers in the atmosphere.

3. A typical example of such a debate: • Chacaltaya emulsion group → new interaction process like Centauro • Fuji-Tibet group: increase of iron component • If we can launch again a new heavy calorimeter in the space, we can resolve this problem immediately, but the experiment is very expensive. 1987 in Moscow conference..

4. 1981

5. The CERN UA7 experiment1985-86, Muraki, M. Haguenauer(UA4) et al.

6. Roman pot and Silicon calorimeters are used

8. The energy is calibrated by π0 peakEric Paré et al, Phys. Lett. B242 (1990) 531.

9. Result : Feynman scaling does hold at very forward region at 150TeV

10. New debate in the very high energy region • We must need again by an accelerator experiment. • To establish the GZK cut-off problem, we need a calibration experiment. • To calibrate the Monte Carlo Codes that are often used for the reduction of the incident energy of air showers at LHC.

12. The position of shower maximum Knapp et al, Astroparticle Physics, 19(2003) 77 LHCf Fe incidence UA7

13. How to do it?

14. Y Chamber Detector location

15. LHCf two kinds of tower calorimeter Arm#1Arm#2 SciFi x-y layer Si microstrip x-y layer Scintillator 25cm W plates

16. Arm#1 during assembly 32 PMTs + 8 MAPTs Light guides Tower calorimeters

17. independent detectors on both sides of IPX Detector I Tungsten Scintillator Scintillating fibers Detector II Tungsten Scintillator Silicon mstrips INTERACTION POINT 140 m 140 m Beam line • Redundancy • Background rejection (especially beam-gas) • Physics single diffractive/double diffractive

18. Transverse projection of LHCfand beam pipe acceptance (coverage)

19. Two calorimeters are lifted up and down by the manipulators IP1 140m away LHCf Arm#1 TAN

20. Monte Carlo g ray energy spectrum 106 generated LHC interactions  1 minute exposure

21. The LHCf experiment (Apr. 2008-) K.Fukui, Y.Itow, T.Mase, K.Masuda, Y.Matsubara, H.Menjo, T.Sako, K.Taki Solar-Terrestrial Environment Laboratory, Nagoya University, Japan K.Yoshida Shibaura Institute of Technology, Japan K.Kasahara, M.Mizuishi, S.Torii Waseda University, Japan T.Tamura Kanagawa University, Japan Y.Muraki Konan University Y.Shimizu ICRC, University of Tokyo, Japan M.Haguenauer Ecole Polytechnique, France W.C.Turner LBNL, Berkeley, USA O.Adriani, L.Bonechi, M.Bongi, R.D’Alessandro, M.Grandi, P.Papini, S.Ricciarini, G.Castellini, A. Viciani INFN, Univ. di Firenze, Italy A.Tricomi INFN, Univ. di Catania, Italy J.Velasco, A.Faus IFIC, Centro Mixto CSIC-UVEG, Spain D.Macina, A-L.Perrot CERN, Switzerland

22. IP5, CMS IP1, ATLAS, LHCf IP8, LHCb IP2, ALICE

23. Current status of the LHCf experiment • The two detectors have been installed now at the collision point IP1. • The beam will circulate in the 28km tunnel on September 10th (Today! ). • The beams will make collisions within one month. • The beams will be accelerated to 5TeV until the end of this year. √ s=10 TeV

24. September 10 • Before we startBeam down the lines to the TEDs OK (check to TDIs) • All screens in and visible (or easily made so) • Synoptic display and trajectory display • Primary aim: Get 2 109 protons round ring 1 • Get 2 109 protons round ring 2 • Aperture ~clear in both rings • Icing: Inject and dump after > 1 turn • Interleaved injection into both rings (as we did Sunday 24th) • Dreaming: Get 5 109protons to circulate in ring 1 • Get 5 109protons to circulate in ring • R.Bailey, September 2008

25. By R.Bailey, September 2008

26. Concluding remarks ★A very important data will be obtained without change of present LHC projects. ★The data will become extremely useful not only for cosmic ray physics, but also for high energy physics. ★ The data will be used for a long time. • Other remarks ＊We also want to measure N-N or p-N or or N-Fe collisions. ( N= N2 and O2) ＊We also get another important data on neutrons and K0s and the inelesticity. Concluding Remarks

28. We can measure the region ofphotons with XF>0.05 by this experiment.

29. The position of shower maximum Knapp et al, Astroparticle Physics, 19(2003) 77 LHCf Fe incidence UA7

30. The background • The beam gas contamination • We estimate beam-beam: beam-gas = 2 : 1 @ L= 1029 and early stage • but at the later stage = 1: 0.01 @ L= 1029 and later stage • At the beginning, taking account of the acceptance for the beam-gas event by the M.C. calculation, we found that the ratio between • beam-beam : beam-gas = 10 : 1 (contamination is ~10%) • However if we will take arm#1*arm#2 trigger, it will be reduced to 1000:1. • Unfortunately a that time we may loose pure single diffractive event. • Therefore we must repeat the data-taking after machine conditioning. • However the above value is estimated for the high luminosity case and in fact • in the early low luminosity case, the gas in the beam pipe would be not so • much. We must ask a calculation to the CERN vacuum group.

31. Two production cross-sections were assumed for Monte Carlo :A and B.

32. We have made a similar detector what we had proposed and made a test experiment using NA beam line of CERN.The detector was bombarded to the electron, muon and proton beams with energies 50-250 GeV.The position of the beam incidence was measured by the silicon detector.

33. Instrumentation slot (96mm x 60.7mm x 1000mm) IP, +140m ~ 5m At 140m away from the interaction regionthere is a gap of 9cm that can put a small calorimeter

34. We could install an electromagnetic calorimeter there