Current status and Current status and plan of the LHCf plan of the LHCf

experimentexperiment(LHCf; Large Hadron Collider (LHCf; Large Hadron Collider

forward)forward)Takashi SAKOTakashi SAKO(Solar-Terrestrial Environment Laboratory, Nagoya (Solar-Terrestrial Environment Laboratory, Nagoya

University, Japan)University, Japan)

for the LHCf collaborationfor the LHCf collaboration

31th International Cosmic Ray Conference, Lodz, Poland

For more details, please go to the posters Sako 75 Performance tested with SPS beam Menjo 221 Pi-zero measurement Ricciarini 318 Siliconstrip detector Taki 935 Background in LHC Nakai 953 Particle identification Mase 1113 Neutron measurement

Target of LHCfTarget of LHCf

To reduce the uncertainty of hadron To reduce the uncertainty of hadron interaction models by using LHCinteraction models by using LHC

LHCf measures LHCf measures neutral particlesneutral particles emitted in emitted in very forwardvery forward (including (including zero degree) in the LHC collisionszero degree) in the LHC collisions

To discriminate existing interaction To discriminate existing interaction models and provide crucial data for models and provide crucial data for future modelsfuture models

Y.Itow, K.Kawade, T.Mase, K.Masuda, Y.Matsubara, G.Mitsuka, T.Sako, K.Taki Solar-Terrestrial Environment Laboratory, Nagoya University, Japan

K.Yoshida Shibaura Institute of Technology, Japan

K.Kasahara, M.Nakai, 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, H.Menjo, 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

The LHCf CollaborationThe LHCf Collaboration

Knapp et al.

Xm

ax (

g/c

m2)

Proton

Iron

Atmospheric depth

Nu

mb

er o

f p

arti

cles

Iron

Proton

Hadron Interaction Hadron Interaction Models and EAS Models and EAS

developmentdevelopment

Measurements of very forward particles using the highest energy accelerator are important to constraint the models

Energy (eV)

Knapp et al., 2003

ATLAS / LHCfLHCb

CMS / TOTEM

ALICE

interaction point 1140m

96mm

Forward Forward measurement at measurement at

LHCLHC

Collision of 7TeV proton + 7TeV proton at LHC corresponds to 1017eV @ lab. System Zero degree instrumentation slot at 140m away from IP

LHCf DetectorsLHCf Detectors

Arm#1 Detector20mmx20mm+40mmx40mm4 XY SciFi+MAPMT

Arm#2 Detector25mmx25mm+32mmx32mm4 XY Silicon strip detectors

Sampling & imaging calorimeters either side of IP1 Two small tower calorimeters in both detectors (Tungsten 44r.l., 1.7λ, 16 plastic scintillator sampling layers, 4 position sensitive layers)

Resolutions at beam test Resolutions at beam test & MC& MC

Energy Resolution at different gains

ΔE/E<5% at E>100 GeV

Position Resolution of SciFi <200μm

Beam Test at CERN SPS compared with MC using EPICS (Poster 75, Sako et al)

Excellent agreement between beam test and MC is obtained

Double Arm DetectorsDouble Arm Detectors

Arm#1 Detector Arm#2 Detector90mm

280mm

62cm

64cm

BABY SIZE DETECTOR!

LHCf detector in the LHC LHCf detector in the LHC tunneltunnel

LHCLHC ｆ ｆ OperationOperation Data taking during the commissioning of LHC at very low luminosity ( typ. L=1029cm-2s-1) － 1kHz single gamma-ray events － 10 Hz π0 →2γ events (after all analysis process) Hour(s) of operation gives sufficient statistics

Expected energy spectra of single gamma-rays100sec @ L=1029cm-2s-1

EPOS 1.99 will join soon

Full MC using DPMJET-III considering trigger, electrical noise, analysis (aperture correction) Histograms; (production)×(geometrical aperture) 103 sec operation at L=1029 is assumed

ππ00 MeasuremenMeasuremen

tt

2210

EEM

Peak=134MeV

σ=4.9MeV

(Poster 221, Menjo et al. for detail)

Drescher, Physical Review D77, 056003 (2008)

New modelsNew models(PICCO, (PICCO, EPOS)EPOS)

Neutron Pi0

Proton

EPOS1.61 EPOS1.61QGSJET-II

QGSJET-II

Possible Realistic Time Possible Realistic Time TableTable

(not official !!)(not official !!)

0.45

7

5

3?

LHCf Operation

Beam Energy (TeV) Lab. Energy (eV)

1.0x1017

5.1x1016

1.8x1016

4.1x1014

2009 2010 2011-

SummarySummary

LHCf can provide critical calibration data LHCf can provide critical calibration data for hadron interaction models used in the for hadron interaction models used in the EAS studyEAS study

Detectors, DAQ of LHCf are readyDetectors, DAQ of LHCf are ready In 2009, data taking at 450GeV, <5TeV In 2009, data taking at 450GeV, <5TeV

collisions will be carried outcollisions will be carried out One day operation gives sufficient data (not One day operation gives sufficient data (not

only statistics, also for systematics study)only statistics, also for systematics study) Simulation studies for <7TeV are in Simulation studies for <7TeV are in

progressprogress 5-7 TeV collisions will be after 20115-7 TeV collisions will be after 2011

Thank YouThank You