Announcement of UHECR symposium in Nagoya, Japan

• 10-12 December• Visit http://uhecr2010.icrr.u-tokyo.ac.jp/ for detail• 15-Oct ; abstract deadline

– Mainly invited talks and contribution posters – Some contributions may be selected for oral presentations

• 12-Nov; registration deadline• Contents

– Highlights from PAO, HiRes, TA and future plan– Accelerator results; AirFly, TA ELS, LHCf– Acceleration, Propagation, Multi messenger astrophysics– Panel discussions on technique, UHECR origin, interaction

First Results of LHCf; Very Forward Particles at LHC

Collision

Takashi SAKO(Solar-Terrestrial Environment Laboratory,

Nagoya University, Japan)for the LHCf Collaboration

ICATPP Conference, Villa Olmo, Como, Italy, 7-8 October 2010

UHECR and Hadron Interaction • Recent excellent observations by PAO, HiRes

and TA, but still puzzling in the UHECR origin• Uncertainty in hadron interaction affects in

– Prediction of Xmax– SD observations

• Cross sections of very forward particle emission at as high as possible energy is indispensible

=> LHC forward (LHCf) experiment

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

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

96mm

Experimental Set-up

ATLAS

140m

LHCf Detector(Arm#1)

LHCf Detector (Arm#2)

√s=14TeV proton collision = 1017eV in the lab. frame

Charged particlesCharged particles (+)(+)

Neutral particlesNeutral particlesBeam pipeBeam pipe

ProtonsProtons

Charged particlesCharged particles (-)(-)

LHCf Detectors

Arm#1 Detector20mmx20mm+40mmx40mm4 XY SciFi+MAPMT

Arm#2 Detector25mmx25mm+32mmx32mm4 XY Silicon strip detectors

＊ Imaging sampling shower calorimeters＊ Two independent calorimeters in each detector (Tangsten 44r.l., 1.7λ, sample with plastic scintillators)

ATLAS & LHCf

Expected Results at 14 TeV Collisions(assuming 0.1nb-1 statistics)

Detector response not considered

Summary of Operations in 2009 and 2010With Stable Beam at 900 GeV Total of 42 hours for physics About105 showers events in Arm1+Arm2

With Stable Beam at 7 TeVTotal of 150 hours for physics with different setups

Different vertical position to increase the accessible kinematical rangeRuns with or without beam crossing angle

4·108 shower events in Arm1+Arm2106 0 events in Arm1+Arm2

StatusCompleted program for 900 GeV and 7 TeV

Removed detectors from tunnel in July 2010Post-calibration beam test in October 2010

Upgrade to more rad-hard detectors to operate at 14TeV in 2013

TeV Gamma not from Crab but Underground!

Event sample measured by Arm2 at 30 March 2010

!

Particle Identification

L90% @ 40mm cal. of Arm1

MC (QGSJET2)Data

Preliminary

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

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

Definition of L90%

Criteria for gamma-rays16 r.l. + 0.002 x dE

Gamma-ray like

• L90%; longitudinal position containing 90% of the sum of the shower particles.

• PID bias, Neural Net are in investigation

Hadron like

Energy Spectra at 900GeV

preliminary preliminary

preliminarypreliminaryGamma-ray likeGamma-ray like

Gamma-ray likeGamma-ray like Hadron likeHadron like

Hadron likeHadron likeArm1Arm1

Arm2Arm2

Acceptance is different in two armsNormalized by number events Response for hadrons and systematic error are under study.

Hadron response under study

Only statistical errors are shown

Measured Spectra at 7TeV

preliminary preliminary

Gamma-ray likeGamma-ray likeHadron likeHadron like

Arm2Arm2

preliminarypreliminaryGamma-ray likeGamma-ray like Hadron likeHadron likeArm1Arm1

Very high statistics !! only 2% of all data Comparisons with MC will be available soonCareful study of systematic error is ongoing

Neutral Pions

ΔM/M=2.3%

Energy spectrum (Arm2)

preliminary

preliminary

An example of event (Arm2)

• Pi0’s are a main source of electromagnetic secondaries in high energy collisions.

• The mass peak is very useful to confirm the detector performances and to estimate the systematic error of energy scale.

25mm 32mm

Silicon strip-X view

M/M=2.3%

Reconstructed mass (Arm2)

preliminary

m 140=

R

I.P.1

1(E1)

2(E2)

140mR

14TeV in 2013; Not only highest energy, but energy dependence…

7 TeV10 TeV14 TeV (1017eV@lab.)

SIBYLL

7 TeV10 TeV14 TeV

QGSJET2

Secondary gamma-ray spectra in p-p collisions at different collision energies (normalized to the maximum energy)

SIBYLL predicts perfect scaling while QGSJET2 predicts softening at higher energy

Qualitatively consistent with Xmax prediction

Note: detector aperture

taken into account (biased)

Summary• LHCf has successfully completed operation at

900GeV and 7TeV collisions at LHC• Unprecedented quality of data allows to test

existing hadron interaction models and helps to construct new models

• Operation at 14TeV collisions in 2013 will set more strict limits on the hadron interaction models to extrapolate into higher energy

Analysis of the first result will be finalized soon

Announcement of UHECR symposium in Nagoya, Japan

• 10-12 December• Visit http://uhecr2010.icrr.u-tokyo.ac.jp/ for detail• 15-Oct ; abstract deadline

– Mainly invited talks and contribution posters – Some contributions may be selected for oral presentation

• 12-Nov; registration deadline• Contents

– Highlights from PAO, HiRes, TA and future plan– Accelerator results; AirFly, TA ELS, LHCf– Acceleration, Propagation, Multi messenger astrophysics– Panel discussions on technique, UHECR origin, interaction

Backup

AGASA SystematicsTotal ±18%Hadr Model ~10% (Takeda et al., 2003)

AGASA SystematicsTotal ±18%Hadr Model ~10% (Takeda et al., 2003)

Open Issues on HECR spectrum

M NaganoNew Journal of Physics 11 (2009) 065012

Depth of the max of the shower Xmax in the atmosphere

AUGERHiRes

neutral beam axis

η

∞

8.7

Shadow of beam pipesbetween IP and TAN

IP1,ATLAS Arm1Arm2

Transverse projection of Arm#1

∞

8.4

@ zero crossing angle

@ rad crossing angle

Pseudo-rapidity Coverage

Energy spectra and Transverse momentum distribution of

Multiplicity@14TeV Energy Flux @14TeV

Low multiplicity !! High energy flux !!

simulated by DPMJET3

• Gamma-rays (E>100GeV,dE/E<5%)• Neutral Hadrons (E>a few 100 GeV, dE/E~30%)• Neutral Pions (E>700GeV, dE/E<3%)

at psudo-rapidity range >8.4

ATLAS

LHCf

Eγ – PTγ Correlation plot

Detectable events

140 Beam crossing angle

search0 Candidate

Candidate

• ratio vary a lot among different interaction models. A good handle to probe the hadron interaction models• Another calibration point for more robust energy scale

preliminary

Beam test at SPS Energy Resolution for electrons with 20mm cal.

Position Resolution (Scifi)

Position Resolution (Silicon)

Detector

p,e-,mu

σ=172μmfor 200GeVelectrons σ=40μm

for 200GeVelectrons

- Electrons 50GeV/c – 200GeV/c- Muons 150GeV/c- Protons 150GeV/c, 350GeV/c

Accumulated Events in 2010108 events! LHCf removal