the lhcf experiment - center for cosmology and...

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Y.Itow, The LHCf experiment CCAPP seminar@ 10 Jan 2012

The LHCf experiment~ Verification of high energy cosmic rays interactions ~

Yoshitaka ItowSolar-Terrestrial Environment

LaboratoryNagoya University

for the LHCf collaboration

Jan 10, 2012CCAPP Seminar, OSU

Y.Itow, The LHCf experiment CCAPP seminar@ 10Jan 2012

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Micro to Macro : Physics in the scale of 40 order of magnitude

Variety of phenomena Extreme conditionsParticles Solar system Star formation Galaxy Large scale structure

Solar Flare Relativistic jet CMB 10K １00M K

Research core for the universe at all the scaleResearch core for the universe at all the scale

“Complete” research center from particles to the universe


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Comprehensive and global center of research for particle and astrophysics

University’s global research network

All wavelength observatory

Both Lepton / Hadron sector

EISCATNANTENAKARIIRSFMOASUMITSUZAKU

LHC

B-FactoryOPERA

CP violation τ neutrino

MOA

NANTEN

EISCAT

IRSF

SUMIT

LHCOPERA

B-FactorySNT

FERMI (2010~)


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Cosmic rays energy spectrum


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γp

n

pπ＋ μ＋ ν e＋ γ

E = 10 20 eVE 0.8 x 10 20 eV~

Energy spectrum of UHE cosmic rays

KNEE

14TeV

ANKLE

GZK

GZK cut off

7TeV

0.9TeV


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Cause of spectrum index changes

Something changes in ….Accelerations ?Propagations ?Hadronic Interactions ( with air ) ?


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Air Florescence telescope (FD)

Surface Detectors (SD)

Air shower observation

Scintillation lightsShower directionsShower max altitude

Number of particlesArrival timingMuon or EM component

( at given altitude)

EM component (most of energy)

Model uncertainty in hadron interactions at UHE

surfacedetectors

Robust against interaction model.Detector systematics

interaction model dependence.

EM c

ompo

nent

Had

com

pone

nt


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AGASA (SD) HiRes (FD)

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

3000km2

100km2

Airs shower experiments for UHECRs

760km2Thick water Cherenkov (µ sensitive)Thin plastic scinti (EM sensitive)


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Energy spectrum in the GZK region


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Composition in the GZK region

0g/cm2

Xmax


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Unisotropy in the GZK region


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Situation of UHECRs

“GZK”-like cut off feature is confirmed, but…Contradiction in composition measurements, proton or HI ? No significant direction correlations (2 σ) found, but…

Need a conclusive composition measurement


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Impact of shower development uncertainty on E-scale/composition

Atm. depth

#of p

artic

les

AUGER alt.

SD E-scale error

J.Knapp Astropart. Phys.19 (2003) 77

AUGER ICRC09

Composition error

0g/cm2

Xmax


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① Inelastic cross section

② Forward energy spectrum

If large krapid development

If small k deep penetrating

If large σrapid development

If small σdeep penetrating④ 2ndary interactions

③ Inelasticity k= 1 – Elead/Etot

If softershallow development

If harderdeep penetrating

σ inela =73.5±0.6. mb(TOTEM )+1.8-1.3


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Hadron interactions at ultra high energy Accelerator Cosmic rays

√s=14TeV collision at LHC1017eV cosmic rays

Precision improvement

Hint for interaction at ultra-ultra high energy

ECM ~ ( 2 × Elab × Mp ) 1/2


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IP1 : ATLAS, LHCf

IP5 :CMS TOTEM

IP2: ALICE IP8: LHCb, MoEDAL

The seven LHC experiments

Dedicated to 0-deg EM.Verify cosmic ray interaction models.


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Recent input for cosmic ray interactions from LHC data

Charged hadron multiplicityInelastic cross section


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Very forward : Majority of energy flow

8.4 < η < ∞

Multiplicity Energy Flux

All particles

neutral

Most of the energy flows into very forward( Particles XF > 0.1 gives 50% of shower particles )

Rapidity : η = -ln ( tan θ/2 ) , θ: a polar angle of a produced particle


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The LHCf collaborationThe LHCf collaborationK.Fukatsu, T.Iso, Y.Itow, K.Kawade, T.Mase, K.Masuda, Y.Matsubara, G.Mitsuka, Y.Muraki, T.Sako, K.Suzuki, K.Taki Solar-Terrestrial Environment Laboratory, Nagoya Univ.H.Menjo Kobayashi-Maskawa Institute, Nagoya Univ.K.Yoshida Shibaura Institute of TechnologyK.Kasahara, T.Suzuki, S.Torii Waseda Univ.Y.Shimizu JAXAT.Tamura Kanagawa University

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

INFN, Univ. di Firenze, Italy

K.Noda, A.Tricomi INFN, Univ. di Catania, Italy

J.Velasco, A.Faus IFIC, Centro Mixto CSIC-UVEG, Spain

A-L.Perrot CERN, Switzerland


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LHCf experimental site

ATLAS

140m

LHCf

IP1

140m95mm

Compact calorimeter

TAN absorber

140m96mm


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LHCf: location and detector layoutINTERACTION POINTINTERACTION POINT

IP1 (ATLAS)IP1 (ATLAS)

Detector IIDetector II

TungstenTungsten

ScintillatorScintillator

Silicon Silicon µµstripsstrips

Detector IDetector I

TungstenTungsten

ScintillatorScintillator

ScintillatingScintillating fibersfibers

Arm#1 Detector20mmx20mm+40mmx40mm4 SciFi tracking layers

44X0, 1.6 λint

Arm#2 Detector25mmx25mm+32mmx32mm4 Silicon strip tracking layers

140 m 140 m

n π0

γ

γ

8 cm 6 cm

Front Counter Front Counter


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LHCf calorimeters

Arm#2 DetectorArm#1 Detector 90mm290mm


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ATLAS & LHCf

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Acceptance of LHCf

pp 7TeV, EPOS

γθ[μrad]

0

310

Projected edge of beam pipe

Viewed from IP1(red:Arm1, blue:Arm2)


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LHCf as EM shower calorimeter

EM shower is well contained longitudinallyLateral leakage-out is not negligible

Simple correction using incident positionIdentification of multi-shower event using position detectors 25


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Forward E spectra forseen at 14TeV (MC for ~0.1nb-1)

π0single γ

m 140=R

θ

I.P.1θ

γ1(E1)

γ2(E2)

140mR


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Forward E spectra forseen at 14TeV (MC for ~0.1nb-1)

Neutrons (w/ 30% resolution)Neutrons (true energy)


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Brief history of LHCfMay 2004 LOI

Feb 2006 TDR

June 2006 LHCC approved

Jan 2008 Installation

Aug 2007SPS beam test

Sep 20081st LHC beam

Jul 2006construction

Mar 20101st 7TeV run

Dec 20091st 900GeV run Jul 2010

Detector removal


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DATA15 May 2010 17:45‐21:23, at Low Luminosity 6x1028cm‐2s‐1, no beam crossing angle

0.68 nb‐1 for Arm1, 0.53nb‐1 for Arm2

MC

DPMJET3.0４, QGSJETII03, SYBILL2.1, EPOS1.99PYTHIA 8.145 with the default parameters.107 inelastic p-p collisions by each model.

Analysis Two pseudo-rapidity, η>10.94 and 8.81<η<8.9.No correction for geometrical acceptance.Combine spectra between Arm1 and Arm2.Normalized by number of inelastic collisionswith assumption as σ inela = 71.5mb.(c.f. 73.5±0.6. mb by TOTEM )

The single photon energy spectra at 0 degree

+1.8-1.3

(O.Adriani et al., PLB703 (2011) 128-134

Arm1 Arm2


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Event sample Longitudinal development measured by scintillator layers

Lateral distribution measured by silicon detectorsX-view

Y-view

25mm Tower 32mm Tower

600GeV photon

420GeV photon

Hit position,Multi-hit search.

Total Energy depositEnergy

Shape PID

π0 mass reconstruction from two photon. Systematic studies

Mπ 0 = Eγ1Eγ 2 ⋅θ


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Reconstruction of π0, η

π0 Candidate

η Candidate

Prelim

inary

Another good energy calibration point.Production yield of η much differs among the models.

Energy scale was determined by CERN SPS 200GeV e beam


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Particle IdentificationdE

Inte

gral

of d

E

Photon Hadron

Calorimeter layers

Calorimeter layers

Elemag: 44r.l.Hadronic: 1.7λ

Calorimeter Depth

L90% Distribution

γ-like Had-like


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Arm1+Arm2 Combined γ spectra

η>10.94 8.99 >η>8.81

1 2 3 (TeV) 1 2 3 (TeV)


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Comparison w/ interaction models

η>10.94 8.99 >η>8.81

1 2 3 (TeV) 1 2 3 (TeV)

DPMJET 3.04 QGSJET II‐03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145


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Comparison w/ interaction models

η>10.94 8.99 >η>8.81

1 2 3 (TeV) 1 2 3 (TeV)

DPMJET 3.04 QGSJET II‐03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145


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Very forward – connection to low-x physics

Very forward region : collision of a low-x parton with a large-x partonSmall-x gluon become dominating in higher energy collision by self interaction.But they may be saturated (Color Glass Condenstation)

Low-x high-xVery forward

Naively CGC-like suppression may occur in very forward at high energy

However situation is more complex(not simple hard parton collsions,

but including soft + semi-hard )

soft semi-hard

hard


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Future direction of LHCfPeriod Type Beam

energyLAB proton Energy (eV) Detector

2009 p - p 450+450 GeV 4.3 1014 Arm1+Arm2

2009/2010 p - p 3.5+3.5 TeV 2.6 1016 Arm1+Arm2

2012 p – Pb 3.5 TeV(proton E) 1016 Arm2

2014 p - p 7+7 TeV 1017 Arm1+Arm2 upgraded


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LHCf takes data every when LHC increases energy

102010171014 eV

14TeV70.5 0.9

KneeGZK

Ankle

AUGER, TATALE

2nd Knee?

HEAT

2.2

0.9, 7 TeV p-Pb ?2010 2011~2012 2015?

LHCf I

2, 14TeV

LHCf IIDetector upgrade

New detector w/ rad-hard GSO scinitillator will be ready.

LHC energy schedule2013~2014?LHC shutdown


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Impact on air shower

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π0 spectrum at Elab = 1019eV

QGSJET II originalArtificial modification

Longitudinal AS development

Ignoring X>0.1 meson

X=E/E0

30g/cm2


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⇔ΔXmax (DPMJETⅢ-QGSJETⅡ) = 36g/cm2

Transition curve for 1017eV proton

π0 reconstructed spectrum

Xmax = 696.6g/cm2 ± 2.3 +15.9, -7.8 g/cm2

statistical systematic

ON

CR

PHYS

OSCAR ADRIANI LHCC MEETING, CERN 23 MARCH 2011


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SummaryLHCf : Dedicated measurements of neutral particles at 0 deg at LHC energy for the verification of cosmic rays interaction models at 1017eV.Phase-I run successfully completed. Analysis on-going.

E spectra for 7Tev single gamma Agreement with models is “so-so”, but none of models really agrees.Analysis is going on for 7TeV pi0, 900GeV gamma, and so on.

Future planRevisit LHC for next energy upgrade at ~2015 with a rad-hard detector. Also p-A run at 2012 ?Possible future LHC A-A runs? R&D in progress.<500GeV runs at RHIC are also very interesting.

UHECR data may hint ultra high energy interactions at beyond-LHC energy. To approach, LHCf will give firm base of understanding at 1017eV.

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