Overview and recent results of LHCf

OverviewandrecentresultsofLHCf
TakashiSAKO
(KMI/ISEE,NagoyaUniversity)
fortheLHCfCollaboraCon
26-Oct-2015
TeVPA2015,Kashiwa
1
HECRComposi+on
PAO,PRD90,122005(2014)
TA,APP64,49-62(2015)
ü  AirshowerobservaConsdetermine<Xmax>vs.energy
ü  ModelpredicConstobecompareddifferatthelevelof
experimentaluncertainCes
ü  Modelsmustbetestedbyacceleratorexperiments
2
Cosmic-rayspectrumandcolliderenergy
（D’Enterriaetal.,APP,35,98-113,2011）
RHIC
LHC
FCC
Endofgalac+cCRand
transi+ontoextra-galCR
Ankle
Knee:endofgalac+cprotonCR
(GZK)cutoff:
endofCRspectrum
3
LHCEra(T.Pierog,HESZ2015)
LHC
Tevatron
ü  Goodagreementbetweenpost-LHCmodels,QGSII-04andEPOS-LHC
ü  NoupdateinSIBYLL,butverygoodagreementwiththeothers.By
4
chance???
Parameterstocharacterize
hadronicinterac+on
1.σine（λint）
2.ParCcleproducCon
MulCmesonproducCon
Leadingbaryon
π-
elasCcity(Ebaryon/E0)
Baryonspectrum
π+
π0
3.Nucleareffect
(Baryon-BaryonproducCon)
γ
nucleon
inelasCcity(Emeson/E0=1-elasCcity)
mulCplicity
Mesonspectrum
4.π–AinteracCon
5
Parameterstocharacterize
hadronicinterac+on
1.σine（λint）
2.ParCcleproducCon
MulCmesonproducCon
Leadingbaryon
π-
elasCcity(Ebaryon/E0)
Baryonspectrum
π+
π0
3.Nucleareffect
(Baryon-BaryonproducCon)
γ
nucleon
inelasCcity(Emeson/E0=1-elasCcity)
mulCplicity
Mesonspectrum
4.π–AinteracCon
6
ForwardPar+cleProduc+on
η=7
(photons≅π0->γγ)
ü  √s=14TeVp-pcollision(QGSJETII-03)
ü  TypicalpT≈1GeV/c
=>high-EparCclesareemipedforward
pseudorapidity:η=-ln(tan(θ/2))
7
ForwardPar+cleProduc+on
ü  √s=14TeVp-pcollision(QGSJETII-03)
ü  TypicalpT≈1GeV/c
=>high-EparCclesareemipedforward
LHCfcoverage
η=7
(photons≅π0->γγ)
η=8.4=>θ=440μrad
8
TheLHCfCollabora+on
*,**Y.Itow, *Y.Makino, *K.Masuda, *Y.Matsubara, *E.Matsubayashi,
***H.Menjo, *Y.Muraki, *Y.Okuno, *,**T.Sako, *M.Ueno, *Q.D.Zhou
*Institute for
Space-Earth Environmental Research, Nagoya University, Japan
**Kobayashi-Maskawa Institute, Nagoya University, Japan
***Graduate School of Science, Nagoya University, Japan
Shibaura Institute of Technology, Japan
K.Yoshida
T.Iwata, K.Kasahara, T.Suzuki, S.Torii
Waseda University, Japan
Y.Shimizu, T.Tamura Kanagawa University, Japan
N.Sakurai
Tokushima University, Japan
M.Haguenauer
Ecole Polytechnique, France
W.C.Turner
LBNL, Berkeley, USA
O.Adriani, E.Berti, L.Bonechi, M.Bongi, G.Castellini, R.D’Alessandro,
P.Papini, S.Ricciarini, A.Tiberio
INFN, Univ. di Firenze, Italy
A.Tricomi
A-L.Perrot
INFN, Univ. di Catania, Italy
CERN, Switzerland
9
TheLHCforwardexperiment
LHCf Arm#1
ATLAS
140m
Twoindependentdetectorsat
eithersideofIP1(Arm#1,Arm#2)
Beam
96mm
Beampipe
ChargedparCcles(+)
Neutral
par+cles
LHCf Arm#2
ChargedparCcles(-)
ü  AllchargedparCclesaresweptbydipolemagnet
ü  NeutralparCcles(photonsandneutrons)arriveatLHCf
ü  η>8.4(toinfinity)iscovered
10
LHCfDetectors
ü  Imagingsamplingshowercalorimeters
ü  TwocalorimetertowersineachofArm1andArm2
ü  Eachtowerhas44r.l.ofTungsten,16samplingscinCllatorand4
posiConsensiCvelayers
Arm#1Detector
20mmx20mm+40mmx40mm
4XYSciFi+MAPMT
Arm#2Detector
25mmx25mm+32mmx32mm
4XYSiliconstripdetectors
11
Detectorperformance
Arm2
ΔE/E≈40%
ΔE/E<5%
12
LHCfOpera+onHistory
•  2009-2010
–  Datatakingwith900GeVp-pcollisions
–  Datatakingwith7TeVp-pcollisions
•  2013(onlyArm2)
–  Datatakingwith5.02TeVp-Pbcollisions
–  Datatakingwith2.76TeVp-pcollisions
•  2015
–  Datatakingwith13TeVp-pcollisions
13
Publica+ons
Photon
(EMshower)
Neutron
(hadron
shower)
Beamtest
NIM,A671
(2012)
129-136
JINST,9(2014)
P03016
0.9TeVp-p
PLB,715
(2012)
298-303
7TeVp-p
2.76TeVp-p
5.02TeVp-Pb
13TeVp-p
PLB,703
(2011)
128-134
PLB,750
(2015)
360-366
π0(limited
acceptance)
π0(full
acceptance)
Performance
IJMPA,28
(2013)1330036
PRD,86,
(2012)092001
PRDsubmihed
PRC,89(2014)
065209
Analysisinprogress
physicsresults
performanceresults
14
Forwardneutronspectrain7TeVp-pcollisions
(√s=7TeVp-p；PLB750(2015)360-366)
zerodegree
ü  ZerodegreeproducConisqualitaCvelyexplainedbyQGSJETII
ü  Non-zero-degreeproducCons(largercrosssecCon)are
underesCmatedbypopularQGSJETIIandEPOSmodels
15
π0pzspectrain7TeVp-pcollisions
T
10− 1
10− 2
10− 3
LHCf s=7TeV
10− 4
∫ Ldt=2.64+2.85nb
-1
10− 5
1
(d) 0.6 < p [GeV] < 0.8
T
pz [GeV]
10−1
10−2
10−3
−4
10
10−5
1000 2000
pz [GeV]
3000
(b) 0.2 < p [GeV] < 0.4
T
1/σinel Ed3σ/dp3 [GeV-2]
(a) 0.0 < p [GeV] < 0.2
1/σinel Ed3σ/dp3 [GeV-2]
1
1/σinel Ed3σ/dp3 [GeV-2]
1/σinel Ed3σ/dp3 [GeV-2]
1/σinel Ed3σ/dp3 [GeV-2]
(PRDsubmiped,arXiv:1507.08764[hep-ex])
(e) 0.8 < p [GeV] < 1.0
T
pz [GeV]
11
(c) 0.4 < p [GeV] < 0.6
T
pz [GeV]
LHCf (stat.+syst.)
DPMJET 3.06
QGSJET II-04
SIBYLL 2.1
PYTHIA 8.185
EPOS LHC
1000 2000
pz [GeV]
3000
p
FIG. 5: (color online). Experimental combined pz spectra of the LHCf detector (filled circles) in p + p collisions at s = 716
TeV.
Shaded rectangles indicate the total statistical and systematic uncertainties. The predictions of hadronic interaction models
are shown for comparison (see text for details.)
Energyflowin7TeVp-pcollisions
ü  Post-LHCmodels(EPOS-LHCandQGSJETII-04)wellexplain
theπ0results,butnotforneutrons
ü  DPMJET3explainstheneutronresults,butitisnotrecently
usedforCRsimulaCons
neutron
π0
LHCf
DPM3
QGSII-04
EPOS-LHC
tobecoveredin13TeV
Zerodegree
rapidity(y)
pseudo-rapidity(η)
Blacksolidcircle:LHCfdata(π0,LHCf2012)
Dopedlines:π0energyflowdistribuConofeachmodel
Thickhorizontalline:EnergyflowcalculaCona|erpTcut
17
√sscalingofπ0produc+on
ü  (630GeV−)2.76TeV–7TeV
goodscalingwithinuncertaintes
ü  WidercoverageinyandpTwith
13TeVdata
ü  Wider√scoveragewithRHICf
experimentin2017at√s=510GeV
18
√sscalingofπ0produc+on
ü  (630GeV−)2.76TeV–7TeV
goodscalingwithinuncertaintes
ü  WidercoverageinyandpTwith
13TeVdata
ü  Wider√scoveragewithRHICf
experimentin2017at√s=510GeV
19
13TeVopera+oninJune2015
• 
• 
• 
• 
LHCfphysicsfills:10-13June2015
Totalphysicsdatataking:26.6hours
Observedhighenergy(>100GeV)parCcles:39Mevents
π0candidates:0.5Mevents
20
13TeVopera+oninJune2015
2TeVπ0byArm2
21
13TeVopera+oninJune2015
2TeVπ0byArm2
22
JointanalysiswithATLAS
Wellstudiedbybig
experiments
Invisibleforbigexperimentbut
havinghighenergy
N
n spectrum TS
PYTHIA8simulaCon
18000
16000
Non_diff+Diff
Non_diff
Diff
Diff-like
14000
AllLHCfevents(mixtureofdiffracConandND)
MCTrue;non-diffracCon(ND)
MCTrue;diffracCon
12000
10000
LHCfeventsselectedusingATLASinformaCon,
sameshapetotheTRUEdiffracConevents
8000
6000
4000
2000
0
0
1000 2000 3000 4000 5000 6000 7000 8000
E[GeV]
23
Summary
ü  ColliderdataimprovethehadronicinteracConmodelsusedinthecosmicraystudies
ü  LHCfmeasuresforwardparCclespectra,bothbaryonsandmesons,carrying
alargefracConofcollisionenergy
•  LHCfπ0spectraarewellexplainedbythepost-LHCmodels,EPOS-LHC
andQGSJETII-04
•  LHCfneutronspectrashowexcess,30%inenergyflow,thanthepostLHCmodels
•  LHCfconfirmedscalingofπ0producConat2.76TeVand7TeVdata,
butinalimitedphasespace
ü  13TeVdatatakingin2015wassuccessful
•  Scalingtestwithwiderphasespaceatthehighestenergy
•  MoreinsighttotheprocessbycollaboraCngwithATLAS
ü  LowenergyextensionatRHICisscheduledin2017
•  Wider√scoverageforscalingtest=>importanttoaccess>1017eV
24