the lhcf experiment verification of uhecr interaction by lhc

Y.Itow, The LHCf experiment AIU08@KEK 14 / 03 / 2008

The LHCf experiment

Verification of UHECR interaction by LHC

Yoshitaka Itow

Solar-Terrestrial Environment Laboratory, Nagoya University

For the LHCf collaboration


102010151010 (eV)

1 particle / m2s

Knee1 particle / m2year

Ankle1 particle / km2year

High EnergyCosmic Ray Observations

Extensive Air Showerexperiments


Air Florescence telescope (FD)

Surface Detectors (SD)


AGASA (SD)

HiRes (FD)

AUGER (SD+FD)TA (SD+FD)

3000km2760km2

100km2


GZK or not ?

AUGER ICRC07

GZK cut off ? AUGER sees transition of spectrum index, however.. Discrepancy among existing experiments ? Energy scale? Composition ? Arrival direction ?

T.Yamamoto et al ICRC07,astro-ph/0707.2638


Arrival directions of UHECRs in AUGER

UHECR = proton ?

Science 318 938 (2007)

27 UHECRs w/ E>5.7×1019eV have correlation to AGNs with 3.1 deg error circles.


Composition at GZK region

QGSJETII-03 : proton

QGSJETII03 : Iron

SIBYL2.1 : proton

SIBYL2.1 : Iron

p or Fe ? is important to understand origin

M.Unger et al ICRC07,astro-ph/0706.1495


Model dependence of air shower development

Atm. depth

#o

f p

art

icle

s

AUGER alt.　

Model dependence　

J.Knapp Astropart. Phys.19 (2003) 77 Surface detector would get uncertainty of E-scale (AGASA claims 20%)

Florescence should be OK ( a few %) for E-scale But FD SD problem

Composition uncertainty


① Inelastic cross section

② Forward energy spectrum (or Inelasticity k )

Shower development vs ① and (degenerated)②

If large k rapid developmentIf small k deep penetrating

If large rapid developmentIf small deep penetrating


Forward production spectra vs Shower curve

Half of shower particles comes from large XF

Measurement at very forward region is needed


Better understanding of UHECR air shower Inelastic cross section

Total and elastic cross section at LHC provided by diffractive proton measurement in “Roman-pod” experiments (i.e.TOTEM)

Low energy hadron interaction models should be also refined Forward production spectrum

Dominated by soft hadronic processes which are poorly known Need measurement by a zero-degree calorimeter

The LHCf experiment

Dedicated detector at LHC covering very forward

psuedorapidityη = −ln(tan( θ/ 2 ))

8.0 < <　∞

p pθ


IP1, ATLAS, LHCf

IP5, CMS

IP2, ALICE IP8, LHCb

LHC: 7TeV+7TeV collision 1017eV at lab frame First collision at 2008

LHCf experiment Measurement of and n at 0 deg at 1017eV Discriminate models (QGSJET, SIBYLL,EPOS etc.) Calibrate XF, PT, inelasticity etc. at 1017eV Dedicated detectors located at +-140m at IP1


The LHCf Collaboration

ITALYITALYFirenze University and INFN:Firenze University and INFN: O.Adriani,, L.Bonechi, O.Adriani,, L.Bonechi, M.Bongi, G.Castellini, M.Bongi, G.Castellini, R.D’Alessandro, P.PapiniR.D’Alessandro, P.PapiniCatania University and Catania University and INFN:INFN: A.Tricomi A.Tricomi

JAPAN:JAPAN:STE Laboratory Nagoya University:STE Laboratory Nagoya University:K.Fukui, Y.Itow, T.Mase, K.Fukui, Y.Itow, T.Mase, K.Masuda, Y. Matsubara, K.Masuda, Y. Matsubara, H.Menjo,T.Sako, K.Taki, H. H.Menjo,T.Sako, K.Taki, H. WatanabeWatanabeShibaura Institute of Technology:Shibaura Institute of Technology: K.YoshidaK.YoshidaKanagawa University: Kanagawa University: T.Tamura, T.Tamura, K.Tanaka K.Tanaka Konan University: Konan University: Y.MurakiY.MurakiWaseda University:Waseda University: K.Kasahara, K.Kasahara, K.Mizuishi, Y.Shimizu, S.ToriiK.Mizuishi, Y.Shimizu, S.Torii

SPAINSPAINIFIC Valencia:IFIC Valencia: A.Fauss, A.Fauss, J.VelascoJ.Velasco

FRANCEFRANCEEcole Politechnique Paris:Ecole Politechnique Paris:M. HaguenauerM. Haguenauer

USAUSALBNL Berkeley:LBNL Berkeley:W. TurnerW. Turner

CERNCERND.Macina, A.L. PerrotD.Macina, A.L. Perrot


Letter Of Intent: May 2004Letter Of Intent: May 2004Technical report: September 2005Technical report: September 2005Technical Design Report: February 2006Technical Design Report: February 2006LHCC approval: June 7LHCC approval: June 7thth, 2006, 2006

Detector assembly,beam test: 2007Detector assembly,beam test: 2007Installation in the LHC tunnel: Feb 2008 Installation in the LHC tunnel: Feb 2008

The 6th approved experiment at LHC


LHCf experimental site

ATLAS

140m

LHCf Detector

IP1

140m95mm

Compact calorimeter

TAN absorber


Detector #1

16 scintillator 16 scintillator layers (3 mm layers (3 mm

thick)thick)

Trigger and Trigger and energy profile energy profile measurementsmeasurements

AbsorberAbsorber

22 tungsten layers 7mm thick 22 tungsten layers 7mm thick 4 44 X4 X00 (1.6 (1.6 II)) in totalin total

(W: X(W: X00 = 3.5mm, R = 3.5mm, RMM = = 9mm)9mm)

4 pairs of4 pairs of scintillating fiber la scintillating fiber layers yers for tracking purpose (6, for tracking purpose (6, 10, 30, 42 r.l.)10, 30, 42 r.l.)

EnergyEnergy

Impact point Impact point (())2 towers 2 towers ~~24 cm 24 cm

long stacked long stacked vertically with 5 mm vertically with 5 mm gapgap

Lower:2 cm x 2 cm Lower:2 cm x 2 cm areaarea

Upper: 4 cm x 4 cm Upper: 4 cm x 4 cm areaarea

< 300 < 300 radrad

Compact to prevent multi particle hitsDouble stacks to tag 0 2

~4% for EM~30% for Hadrons

E/E =

Very compact EM shower


Detector # 24 pairs of 4 pairs of silicon microstrip layerssilicon microstrip layers (6, 12, 30, 42 r.l.) for tracking purpose (6, 12, 30, 42 r.l.) for tracking purpose (X and Y) (X and Y) impact pointimpact point

We use LHC styleWe use LHC styleelectronics and readoutelectronics and readout

16 scintillator 16 scintillator layers (3 mm layers (3 mm thick)thick)

Trigger and Trigger and energy profile energy profile measurementsmeasurements

AbsorberAbsorber22 tungsten layers 7mm thick 22 tungsten layers 7mm thick 44 X44 X00 (1.6 (1.6 II) in total) in total

(W: X(W: X00 = 3.5mm, R = 3.5mm, RMM = = 9mm)9mm)

2 towers 24 cm long 2 towers 24 cm long stacked on their edges stacked on their edges and offset from one and offset from one anotheranother

Lower:2.5 cm x 2.5 cmLower:2.5 cm x 2.5 cm

Upper: 3.2 cm x 3.2 cmUpper: 3.2 cm x 3.2 cm < 400 < 400 radrad

Placed opposite side of detector#1


Detectors already in hand and calibrated

Detector #1

Detector #2


Acceptance

“450 rad” 140 rad xing angle“310 rad” 0 rad xing angle

Vertical scanning is available remotely

Beam pipe cut-view

Y.Itow, The LHCf experiment AIU08@KEK 14 / 03 / 2008Monte Carlo Monte Carlo ray energy spectrum ray energy spectrum (5% Energy resolution is taken into account)(5% Energy resolution is taken into account)

101055 events in events in 3min. !3min. ! (@10(@102929 cm cm-2-2ss-1-1 ) )

Shape analysis can discriminate SIBYLL from others (2 =135/67dof)


Energy spectrum of π0 expected from different models

QGSJETII ⇔ DPMJET3 χ2= 106 (C.L. <10-6) ⇔ SIBYLL χ2= 83 (C.L. <10-6)DPMJET3 ⇔ SIBYLL χ2= 28 (C.L.= 0.024) 107events DOF = 17-2=15

10K 0 in 20 min @ L=1029cm-2s-1

m ~ 5%


Model dependence of neutron energy distributionOriginal n energy 30% energy resolution30% energy resolution


Typical event rate of LHCf @L=1029cm-2s-1

For L= 1029 cm-2s-1, ~ 10kHz inelastic collisions

0 hadrons

Rate 670 Hz

(at 2cm tower)

7 Hz 150 Hz

(at 2cm tower)

Time for

10k events

0.34 min. 29.5 min. 28.7 min

30% analysis efficiency Is assumed for hadrons

Very quick measurement !

Y.Itow, The LHCf experiment AIU08@KEK 14 / 03 / 2008From R. Bailey presentation at January 2007 TAN workshop From R. Bailey presentation at January 2007 TAN workshop

Y.Itow, The LHCf experiment AIU08@KEK 14 / 03 / 2008LHCf proposed running scenario 2008 : Phase-I ( During LHC commissioning )

Run since the very beginning of LHC operations (L<1031cm-2s-1, 43 bunches)

First 7TeV collision is expected in summer? 2008 The LHCf detector is not radiation-hard. But still 10Gy/days@L=10

29/cm2s for a week operation will not be a problem.

200? : Phase-II (Dedicated run ) Re-install the detector at the next opportunity of low luminosity ru

n ( Possibly with TOTEM run ) Enlarge covered PT region, more detail study

200? : Phase-III ( possible heavy ion run ) Nuclear effect plays an essential role in “muons” Future extension for p-A, A-A run with upgraded detectors?

So far approved


Status of experiment Final calibration was done by SPS beam test (Sep 07) Both detectors were installed in TAN (Feb08) Doing In-situ calibration and detector commissioning Appear in official LHC web page (open official LHCf web)

See www.stelab.nagoya-u.ac.jp/LHCf Design official LHCf logo


Detector installation (Jan08)

Just 40 min. work


Installed detector in TAN


Summary Analyses of UHECR air showers rely on production m

odels at very forward, which should be experimentally verified at energy as high as possible. Even all current models may be wrong.

LHCf : Dedicated measurements of neutral particles at 0 deg by LHC, providing calibration of interaction models at 1017eV.

Approved parasite measurements by two small sampling calorimeters at +-140m from IP1 during LHC commissioning in 2008

Just “one day” measurement provides good discrimination of various models in the market.

All the detectors and electronics in hand. Calibration by SPS beam has been done. Now installed in LHC.

We are waiting for the LHC 1st collision !

the lhcf experiment verification of uhecr interaction by lhc

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