The First Results from the LHCf experiment Yoshitaka Itow - - PowerPoint PPT Presentation

Y.Itow, The first results from the LHCf experiment HESI10@ 12 AUG 2010

The First Results from the LHCf experiment

Yoshitaka Itow Solar-Terrestrial Environment Laboratory Nagoya University for the LHCf collaboration

HESI 2010 Aug 10-13, 2010, YITP

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010 IP1 : ATLAS, LHCf IP5 :CMS TOTEM IP2: ALICE IP8: LHCb, MoEDAL

The seven LHC experiments

Dedicated to 0-deg. Verify cosmic ray interaction models

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

K.Fukatsu, Y.Itow, K.Kawade, T.Mase, K.Masuda, Y.Matsubara, G.Mitsuka, K.Noda, T.Sako, K.Suzuki, K.Taki

Solar-Terrestrial Environment Laboratory, Nagoya University, Japan

K.Yoshida

Shibaura Institute of Technology, Japan

K.Kasahara, M.Nakai, Y.Shimizu, T.Suzuki, S.Torii

Waseda University, Japan

T.Tamura

Kanagawa University, Japan

Y.Muraki

Konan University, Japan

Y.Shimizu

ICRR, 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, H.Menjo, P.Papini, S.Ricciarini, G.Castellini

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

The LHCf Collaboration

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

LHCf experimental site

ATLAS

140m

LHCf

IP1

140m 95mm

Compact calorimeter TAN absorber 140m

96mm

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

LHCf: location and detector layout

INTERACTION POINT INTERACTION POINT IP1 (ATLAS) IP1 (ATLAS)

Detector II Detector II Tungsten Tungsten Scintillator Scintillator Silicon Silicon µ µstrips strips Detector I Detector I Tungsten Tungsten Scintillator Scintillator Scintillating Scintillating fibers fibers

Beam line Beam line

140 m 140 m 140 m 140 m 140 m 140 m 140 m 140 m

Arm#1 Detector 20mmx20mm+40mmx40mm 4 SciFi tracking layers

44X0, 1.6 λint

Arm#2 Detector 25mmx25mm+32mmx32mm 4 Silicon strip tracking layers

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

LHCf calorimeters

Arm#2 Detector Arm#1 Detector 9 m m 2 9 m m

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Detector vertical position and acceptance

Remotely changed by a manipulator( w/ accuracy 50 µm)

Distance from neutral center Beam pipe aperture Data taking mode 3 different position To cover PT gap

Garage position when beam tune To prevent unnecessary dose (10-3 of data taking mode)

N L G

All γ from IP

Viewed from Interaction Point Neutral flux center N L

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Very forward EM measurement at LHC

8.4 < η < ∞ Multiplicity Energy Flux All particles neutral

Most of the energy flows into very forward

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Typical detector performance

Gamma-rays (E>100GeV,dE/E<5%) Neutral Hadrons (E>a few 100 GeV,

dE/E~30%)

Neutral Pions (E>700GeV, dE/E<3%)

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Motivation

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Verify hadron interaction models used in air shower simulations at 0-degree in LHC

Uncertainty in air-shower observables QGSJET Ⅰ、

Ⅱ

DPMJET SIBYLL EPOS

…….. E-scale Composition

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

γ

p n p

π

＋ μ ＋

ν e

＋

γ

E = 1

2 0e

V E . 8 x 1

2 0e

V ~

Energy spectrum of UHE cosmic rays

KNEE LHC 14TeV

ANKLE GZK GZK cut off

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Air Florescence telescope (FD) Surface Detectors (SD)

Air shower observation

Scintillation lights Shower directions Shower max altitude Number of particles Arrival timing Muon or EM component ( at given altitude) EM component (most of energy)

Model uncertainty in hadron interactions at UHE

Floresense detectors

Robust against interaction model. Detector systematics interaction model dependence.

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

AGASA (SD) HiRes (FD) TA (SD+FD)

3000km2 100km2

Airs shower experiments for UHECRs

760km2 Thick water Cherenkov (µ sensitive) Thin plastic scinti (EM sensitive)

AUGER (SD+FD)

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

UHECR GZK Problem

~ recent situation ~

1020eV 1018eV 1020eV 1018eV AUGER Xmax HiRes Xmax p p Fe Fe

p or Fe ?

AUGER E spectrum TA Xmax

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

① Inelastic cross section ② Forward energy spectrum (or Inelasticity k ) Need both ① and ②

If large k rapid development If small k deep penetrating If large σ rapid development If small σ deep penetrating

LHCｆ is dedicated to ②

① will be give by Roman Pod at LHC

③ 2ndary interactions

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Impact of shower development uncertainty

• n E-scale/composition
• Atm. depth

#of particles

AUGER alt.

E-scale error

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 AUGER ICRC09 Composition error

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Forward E spectra by LHCf @ 14TeV (MC for ~0.1nb-1) π0

single γ

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

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Results from the 1st physics runs

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

2009-2010 run summary

900 GeV run (no crossing angle)

06 Dec. –15 Dec. 2009 (27.7 hrs, 500K collisions)

2.8K / 3.7K single showers at Arm1 / Arm2

02 May – 27 May in 2010 (15hrs, 5.5M collisions)

44K / 63K single showers at Arm1 / Arm2

7 TeV run (0µrad and 100µrad crossing angle)

30 Mar. – 19 July in 2010 (~150hrs, )

172M / 161M single showers at Arm1 / Arm2 345K / 676 K π0s at Arm1 / Arm2

Detectors removal was done at 20 Jul.

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Particle ID

L90% @ 40mm cal. of Arm1

MC (QGSJET2) Data Preliminary

Thick for E.M. interaction (44X0) Thin for hadronic interaction(1.7λ)

A transition curve for Gamma-ray A transition curve for Hadron

Definition of L90%

Gamma-ray like

• ~ 90% efficiency with ~10% contamination

Hadron like

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

900GeV spectra

• Eff. uncorrected, stat.error only

Normalized by total # of events.

Gamma Gamma-

• ray like

ray like Hadron like Hadron like Gamma Gamma-

• ray like

ray like Hadron like Hadron like

Arm1 Arm1 Arm2 Arm2

Preliminary Preliminary

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

7TeV spectra

preliminary preliminary Gamma Gamma-

• ray like

ray like Hadron like Hadron like

Arm1 Arm1

preliminary preliminary Gamma Gamma-

• ray like

ray like Hadron like Hadron like

Arm2 Arm2

Only 2% of data shown. Now study is under going.

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

7TeV data: Typical π0 event

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

7TeV results : π0 reconstruction

σ =6.3MeV (4.7%) σ =3.1MeV (2.3%)

LHCf Preliminary LHCf Preliminary

Arm2 7TeV Arm2 7TeV

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

7TeV results: Reconstruction of η

π0 Candidate

η Candidate

Preliminary

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Next step

Revisit LHC when next energy upgrade (i.e. @14

TeV in 2013)

Detector will be upgraded with rad-hard GCO scintillator

Light ion collision to understand nuclear effects

So far only heavy ions (Pb-Pb) collisions are forseen

( in late 2010) at LHC, in which LHCf will not perticipate.

Feasible study under going to cope with high multiplicity

at 0 degree.

0.5 particle/cm^2 DPMJET3 QGSJET2 3.5TeV/n N- N collisions Mulitiplicity in 0-1cm cone at 140m

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Summary

LHCf : Dedicated measurements of neutral particles

at 0 deg at LHC energy for the verification of cosmic rays interaction models at 1017eV.

Phase-I run completed. Analysis on-going.

900 GeV run : ~ 100K showers in both arms 7 TeV runs : ~300M showers, ~1M π0 in both arms

Revisit LHC for next energy upgrade at ~2013 with

a rad-hard detector.

Possible future Light Ion runs? R&D in progress.

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

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Backup

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Beam-gas backgroud in 900 GeV

2009 2010

Very big reduction in the Beam Gas contribution!!!!

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Gamma‐ray like Hadron like

Both detectors give consistent spectra Spatially flat profile in η>8.7 at 900GeV

Comparison between calorimeter towers of Arm2 Comparison between two Arms

Preliminary Preliminary

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Reconstructed energy spectrum of π0 (@7+7TeV)

Uncertainty of Multi Hit contamination Uncertainty of energy scale ： assumed as ±5% Uncertainty of relative normalization btw 2 pos. <0.1% Uncertainty of neutral beam center <0.1％ Peak=134MeV σ=4.9MeV Cut 125MeV

• 145MeV

Based on ~104 π0 samples at 2 positions Mass cut π0 energy resolution

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Model comparison for 900GeV

with 107 col.

Hadron like @ Arm2

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

MC model discrimination at 7TeV

at 3.5TeV + 3.5TeV pp

γ n

Energy spectra with 30% energy resolution

1.5 x 10 6 collisions

↔

• 3min. exposure @

10 29cm -2s-1

with 5% energy resolution

We w ill see 7TeV collisions tomorrow !!

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Hadron component (neutrons) for different energy Hadron component (neutrons) for different energy

Large difference in cross section (or a γ/n ratio) . Initial accuracy of luminosity 15% by “luminosity scan” would be even enough to discriminate.

DPMJET3 QGSJET2 QGSJET1 SIBYLL

Including 30% E resolution

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Neutral from 3.5TeV/n N+N collisions(DPMJET3)

3.5TeV LHCf aperture

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Expected spectra in N-N collisions

Assuming to measure at the LHCf installation location Gamma spectra at <1cm from 0 degree

• clear difference in QGSJET2 and

DPMJET3 Neutron spectra at <1cm from 0 degree

• dominated by fragmentation

neutron Neutron spectra at 1‐2cm (off center)

• clear difference in high energy part

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Very forward – connection to low-x physics

Very forward region : collision of a low-x parton with a large-x

parton

Small-x gluon become dominating in higher energy collision by

self interaction.

But they may be saturated (Color Glass Condenstation)

Low-x high-x Very forward

Naively CGC-like suppression may

• ccur 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

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Acceptance

Projection of a eliptical beam pipe Beam Crossing Angle = 0 rad. Beam Crossing Angle = 140 urad.

Zero Beam Crossing Angle

⇒ 8.7<η

140urad Beam Crossing Angle

⇒ 8.4<η

＊) psudorapidity： η = - ln (tan θ/2)

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Arm1 detector Scintillator

Tungsten

7mm(2r.l.)

40mm 20mm

SciFi

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Brief history of LHCf

Jul 2006 construction

May 2004 LOI Feb 2006 TDR June 2006 LHCC

approved

Jan 2008 Installation Aug 2007 SPS beam test Sep 2008 1st LHC beam Mar 2010 1st 7TeV run Dec 2009 1st 900GeV run Jul 2010 Detector removal

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Calibration at SPS H4 Beam Test(04,06 and 07)

• p 150,350

p 150,350 GeV/c GeV/c

• e 100,200

e 100,200 GeV/c GeV/c

• µ

µ 150 150 GeV/c GeV/c

• Energy calibration

Energy calibration

• Spatial resolution

Spatial resolution

• PID capability , etc

PID capability , etc… … position energy

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Detectors in place

L H C L H C L H C L H C f f Lum inosity Lum inosity Monitor (BRAN) Monitor (BRAN) ATLAS ZDC ATLAS ZDC Installation perform ed in two phases: Installation perform ed in two phases: 1.

• 1. Pre

Pre -

• Installation (2007)

Installation (2007) Baking out of the beam pipe (200 Baking out of the beam pipe (200 ° °C) C) 2.

• 2. Final Installation (Jan 2008)

Final Installation (Jan 2008)

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Current setup in IP1-TAN (side view)

LHCf Front Counter LHCf Calorimeter BRAN-IC ZDC type1 ZDC type2

Beam pipe

TAN

Neutral particles

Side view

BRAN-Sci

IP1

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

LHCf takes data every when LHC increases energy

AUGER, TA TALE HEAT

1020 1017 1014

eV 7TeV 3.5 5 0.45

Knee GZK Ankle 2nd Knee?

1.1TeV Nov. Dec. 450GeV 1.1TeV 3.5TeV 5TeV Lead 5TeV 2009 2010 2011 7TeV

Detector upgrade LHCf I LHCf II Current detector will be “burned” until 3.5TeV run New detector w/ rad-hard GSO scinitillator will be ready for 5 and 7 TeV runs LHC energy schedule

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Impact of forward spectra on shower development

XF = E/Etot

Half of shower particles comes from large XF γ

Measurement at very forward region is needed

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

The basic sample ; π0

A clean sample against

beam-gas background.

Energy scale can be

checked by data itself

QGSJETII ⇔ DPMJET3χ2= 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

Shape comparison

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Radiation Damage

3%

Slow recovery of light yield with time at the end of fill (Annealing)

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

Energy scale issue; GZK cut off feature in AGASA, HiRes and AUGER （ 2007 summer）

AUGER HiRes AGASA Energy scaling by +-25%

c.f. Energy scale was determined by fluorescence detector for AUGER

• J. Bluemer

@ICRR, Mar. 2008

Y.Itow, The first results from the the LHCf experiment HESI10@ 12 Aug 2010

M.Fukushima@ISVHECRI2010