+ lhcf: stato e programmi oscar adriani university of florence & infn firenze infn csn1 bologna,...

+

LHCf: stato e programmi

Oscar AdrianiUniversity of Florence & INFN Firenze

INFN CSN1 Bologna, 18 Settembre 2013

O. Adriani LHCf: Stato e Programmi Bologna, 18 Settembre 2013

+Hadronic models tuning after the first LHC data (for VHECR)

PROTON

IRON

Auger Coll. ICRC2011

10191018

Xmax as function of E and particle type

T.Pierog,Cosmic QCD 2013 conference in Paris

Pre LHC Post LHC


+Hadronic models tuning after the first LHC data (for VHECR)

PROTON

IRON

Auger Coll. ICRC2011

10191018

Xmax as function of E and particle type

T.Pierog,Cosmic QCD 2013 conference in Paris

Pre LHC Post LHC

LHC is really useful!!!

!!!!

+


YearBeam

sBeam

energy

Proton equivalent

energy in the LAB (eV)

Setup

2009 p - p450+450

GeV 4.3 1014 Arm1+Arm2

2009/2010 p - p

3.5+3.5 TeV 2.6 1016 Arm1+Arm

2

2013 p – Pb 4 TeVproton

1.3 1016 Arm2

2013 p - p 1.38+1.38 TeV

4.1 1016 Arm2

2015 p - p 6.5+6.5 TeV

9 1016 Arm1+Arm2 upgraded

?p –

light ions

? ? ?

LHCf Physics Program


+

Inclusive photon spectrum analysis at 7 TeV and 900 GeV“Measurement of zero degree single photon energy spectra for √s = 7 TeV proton-proton collisions at LHC“PLB 703 (2011) 128“Measurement of zero degree single photon energy spectra for √s = 900 GeV proton-proton collisions at LHC“PLB 715 (2012) 298

A short review of already published results

Forward p0 spectra at 7 TeV“Measurement of forward neutral pion transverse momentum spectra for √s = 7TeV proton-proton collisions at LHC“PRD 86 (2012) 092001

+


DATA vs MC : comp. 900GeV/7TeV9

00

GeV

7Te

V

η>10.94 8.81<η<8.9

• None of the model nicely agrees with the LHCF data• Here we plot the ratio MC/Data for the various models• > Factor 2 difference

+


DATA : 900GeV vs 7TeV

Preliminary

Data 2010 at √s=900GeV(Normalized by the number of entries in XF > 0.1)Data 2010 at √s=7TeV (η>10.94)

900GeV vs. 7TeVwith the same PT region

Normalized by the number of entries in XF > 0.1 No systematic error is considered in both collision

energies.

XF spectra : 900GeV data vs. 7TeV data

small-η

Coverage of 900GeV and 7TeV results in Feynman-X and PT

Good agreement of XF spectrum shape between 900 GeV and 7 TeV.weak dependence of <pT> on ECMS

+


p0 PT spectra for various y bin: MC/data

EPOS gives the best agreement both for shape and yield.

DPMJET 3.04 QGSJETII-03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145

0 0.6PT[GeV]

0 0.6PT[GeV] 0 0.6PT[GeV] 0 0.6PT[GeV]

0 0.6PT[GeV] 0 0.6PT[GeV]

MC

/Data

MC

/Data


+ p0 analysis at √s=7TeV

1. Thermodynamics (Hagedron, Riv. Nuovo Cim. 6:10, 1 (1983))

2. Numerical integration actually up to the upper bound of histogram

• Systematic uncertainty of LHCf data is 5%.• Compared with the UA7 data (√s=630GeV)

and MC simulations (QGSJET, SIBYLL, EPOS).• Two experimental data mostly appear to lie

along a common curve→ no evident dependence of <pT> on ECMS.

• Smallest dependence on ECMS is found in EPOS and it is consistent with LHCf and UA7.

• Large ECMS dependence is found in SIBYLL

PLB 242 531 (1990)

ylab = ybeam - y

Submitted to PRD (arXiv:1205.4578).

pT spectra vs best-fit function Average pT vs ylab

YBeam=6.5 for SPSYBeam=8.92 for7 TeV LHC


+

On going analysisNeutrons at 7 TeV pp collisionsThe 2013 p-Pb run

+Muon excess at Pierre Auger Obs.

Pierre Auger Collaboration, ICRC 2011 (arXiv:1107.4804)

Pierog and Werner, PRL 101 (2008) 171101

Auger hybrid analysis• event-by-event MC selection to fit

FD data (top-left)• comparison with SD data vs MC

(top-right)• muon excess in data even for Fe

primary MCEPOS predicts more muon due to larger baryon production => importance of baryon measurement



+ Very big discrepancies

between models Useful measurement!

Performance for neutrons 35% Eres

1mm Position Res. @ 1.5TeV n

And….

Detector performanceis also interaction model dependent.

Unfolding is essential to extract physics results from the measured spectra

The challenge of n analysis

MC

Detector performance

+


L90%L20%

Layer[r.l.]

hadronphoton

projection along the sloped

line

L 90

%

L20%

Shower development in the small

calorimeter tower

Neutron identification

• Particle Identification with high efficiency and small contamination is necessary

• A 2D method based on longitudinal shower development is used

• L20%(L90%): depth in X0 where 20% (90%) of the deposited energy is contained

• L2D=L90%-0.25 L20%

• Mean purity in the 0-10 TeV range: 95%

• Mean efficiency: ~90%

L2D

+


`

Small tower7 TeV pp

Large tower7 TeV pp

Preliminary n spectrum

Unfolding is in progress…..A paper for n performancesis in preparation

No efficiency correctionNo rapidity selectionNo unfoldingNo systematic errors

+


Arm1-Arm2 comparison


+

3.5cm,4.0cm

The 2013 p-Pb run at sNN = 5 TeV(Italian responsibility)

2013 Jan-Feb for p-Pb/Pb-p collisions• Installation of the only Arm2 at one

side (silicon tracker good for multiplicity)

• Data both at p-side (20Jan-1Feb) and Pb-side (1fill, 4Feb), thanks to the swap of the beams

Details of beams and DAQ– L = 1x1029 – 0.5x1029cm-2s-1

– ~200.106 events– b* = 0.8 m, 290 mrad crossig angle– 338p+338Pb bunches (min.DT = 200 ns), 296 colliding at

IP1– 10-20 kHz trig rate downscaled to approximately 700 Hz– 20-40 Hz ATLAS common trig. Coincidence successful! – p-p collisions at 2.76 TeV have also been taken p

Pb

IP8IP2IP1

Arm2

+


Physics in pA

Nuclear effect in the forward particle productionPhoton spectra for different impact parameters

Photon spectra at different η in p-p, p-N and p-Pb collisionsIs p-Pb good test for p-atmosphere?

p-p p-N p-Pb

QGSJET II-04All η8.81<η<8.99η>10.94

(Courtesy of S.Ostapchenko)

Please observe that the impact parameter can be obtained from Atlas Lucid, for ex.!

Frankly sp

eaking……

No big feedback from ATLAS….

+


Impact points and beam center2d distribution of impact point: neutrons are more peaked

DATA

DATA

Determination of the beam center (BC)

2d gaussian fit

𝑥𝐵=(1.07±0.09 )mm

𝑦𝐵=(−1.87 ±0.08 )mm

Coordinates of the beam center with respect to the expected beam center

n

n

2013p-Pb run

p-remnant side

DATA

+


Photon - y

Neutron - x

Neutron - y

Photon - x

PRELIMINARY PRELIMINARY

PRELIMINARY PRELIMINARY

Neutrons are well peaked at the beam center

Forward baryon production is important to understand the muon excess [T. Pierog, K. Werner PRL 101 171101(2008)]

g and n impact point distributions (p-remnant)

+


PRELIMINAR

Y

PRELIMINARY

25 mm

32 mm

Detailed simulations with the available hadronic interaction models are on-going for a comparison with data• Transportation of secondary particles

from IP to detector, beam pipe structure, magnetic fields along the path and detector’s response will be taken into account

Vertical bars: statistical errors

p-Pb run: g spectra

+


PRELIMINARY

PRELIMINAR

Y

p-Pb run: p0

+


The status of the upgrades Arm1 and Arm2 are currently dismounted in Florence

Calorimeter radiation hardening by replacing plastic scintillator with GSO is in progress

Production and laboratory tests of the new scintillators in Japan is finished both for Arm1 and Arm2

Beam test at Ion facility (HIMAC) has been done in August 2013

Upgrade of the silicon positioning measurement system under way Rearranging Silicon layers for independent precise energy

measurement Increase the dynamic range to reduce saturation effects New silicon hybrids and Kaptons are ready The assembly of new silicon modules is starting

Test Beam at LNS for the absolute energy calibration of the silicon system has been assigned for 2014

Summer 2014: assembly of Arm1 and Arm2 in Florence

Test beam at SPS in Autumn 2014

Re-installation in LHC at the end of 2014

+Silicon Calibration program at LNS Aim of the test

1. Absolute energy calibration of one silicon module by measuring the output signal vs deposited energy

2. Relative energy calibration of all PACE3 chips (96) for all the eight silicon modules

3. Scan one module at different X-Y positions to check for systematic effects

To calibrate the silicon response we need to use different species of highly penetrating ions, allowing to span the whole energy range measurable with the PACE3 chips

To select the ions that show a constant energy loss whilst traversing the module we have set-up a simulation of the silicon detector module using the SRIM package

1 MIP = 0.043 eV/APACE3 saturation ~600 MIP

16O 62 MeV/A12C 62 MeV/A

23

silic

on

silic

on

+1. Absolute energy calibration One module is centered on the beam spot and a scan with different energies/sources is done to cover the whole dynamic range from ~ 5-10% to 120% of PACE3 chip (10K events per point)Beam energies/source are a compromise between the need to cover the full range and the availability and feasibility of the test at the LNS facilitiesOnly gaseous sources have been selected and only two different energies

Intensity < 104-106 pps

Ion source

Energy BTU Set-up time

20Ne 45 MeV/A

0.25 2 hours

16O 45 MeV/A

0.25 2 hours

14N 45 MeV/A

0.25 2 hours

4He 45 MeV/A

0.25 2 hours

13C 45 MeV/A

0.25 2 hours

24

+2. Relative calibration of each PACE3 chip A position scan (X-scan) through the 12 PACE3 x 8 modules should be done with an ion beam able to give ~ 0.2-0.3 PACE3 saturation (12C 45MeV/A or 13C 62 MeV/A or 14N 62 MeV/A are equivalent)

10K events per position (10 minutes each including set-up time)

Beam spot size ~ 2-3 mm is required

CS beam

y-stage

Support box

To DAQsystem

x-stageSilicon module

Flat cable

2 BTU RequiredIntensity < 104-106 pps

25

+3. Position scan along one strip – Y scan A position scan along one strip should be done with same beam as point 2.

Useful to check for possible inhomogeneity due to the strip geometry

10 K events x 6 positions every 10 mm (60 mm long strip) for 10 minutes each including set-up time

Beam spot size ~ 2-3 mm is required

CS beam

y-stage

Support box

To DAQsystem

x-stageSilicon module

Flat cable

<0.5 BTU RequiredIntensity < 104-106 pps

26

+ LNS panel evaluation

Preferred period: Beginning of run period (May 2014)

27

LHCf-SiCal

The PAC has been convinced that absolute energy calibration of the LHCf silicon detectors is important. The collaboration did an effort to reduce beam preparation in their final demand. 4 BTU of 45 A.MeV beams are allocated: 0.25x (20Ne, 16O, 14N, 4He, 13C) BTU plus 2.75 BTU of 13C.

Beam attribution: 4 BTU (45 A.MeV, see text)

+


p-p at 13TeV (2015)

Main target: measurement at the LHC design energy.Study of energy scaling by comparison with √s = 900 GeV and 7 TeV data Upgrade of the detectors for radiation hardness.

p-light ions (O, N) at the LHC (2019?)It allows studying HECR collisions with atmospheric nuclei.

RHICf experiment at RHICLower collision energy, ion collisions.LOI to the RHIC committee submitted

p-p collisions:• Max. √s = 500 GeV• Polarized beams Ion collisions:• Au-Au, d-Au • Max. √s = 200 GeV• Possible, d-O,N (p-

O,N) Cosmic ray – Air @ knee energy.

10cm

detector

LHCf: future plan

+

Nuclear modification factor at d-Au 200GeV

Physics of RHICf Energy Scaling of Very Forward at p-p √s=500GeV Measurement at p-light ion collisions (p-O) √sNN=200GeV Asymmetry of Forward Neutron with polarized beams

LOI submitted to the RHIC committee and nicely appreciated

Physics of RHICf


+ Conclusions

We have published spectra of photons and neutral pions for pp interactions at s = 900 GeV and s = 5 TeV None of the hadronic interaction models that we have considered can reproduce the data within

the errors, but data lie anyway between the models On-going data analysis for the hadronic component (neutrons)

p-Pb run at the beginning of 2013 Successful data taking in p-remnant and Pb remnant side Common operations with ATLAS (trigger exchange) On-going data analysis (some hints for interesting results!!!)

Future plan Continue and finalize the on-going data analysis (start also ATLAS/LHCf common analysis) Complete the upgrade of the detectors for radiation hardness Beam test at LNS for silicon calibration Data taking for pp collisions at s = 13 TeV (2015) Run p-light ions at LHC (2019?) Operations at RHIC (p-O or p-N at lower energies)

E …. Buon lavoro alla nuova responsabile nazionale A. Tricomi!!!!!


+

Backups

+


Proceedings in 2013

+


Conferences in 2013

+

xF = E/E0

Playing a game with air shower (effect of forward meson spectra)

E=E1+E2

E1E

2

xF = E/E0

pT

• DPMJET3 always over-predicts production• Filtering DPMJET3 mesons

• according to an empirical probability function, divide mesons into two with keeping pT

• Fraction of mesons escape out of LHCf acceptance

• This process• Holds cross section• Holds elasticity/inelasticity• Holds energy conservation• Changes multiplicity• Does not conserve charge event-by-event



+ An example of filtering

π0 spectrum

photon spectrum

DPMJET3+filter

2.5x1016 eV proton

~30g/cm2

Vertical Depth (g/cm2)

AUGER, ICRC 2011

EPS-HEP 2013 July 18-24


+η

∞

8.5

What LHCf can measure

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%)• π0 (E>600GeV, dE/E<3%)

at pseudo-rapidity range >8.4

Front view of calorimeters @ 100μrad crossing angle

beam pipe shadow

+


Comparison wrt MC Models at 7 TeV

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

Gray hatch : Systematic Errors

Magenta hatch: MC Statistical errors

+


Comparison wrt MC Models at 900 GeV


+h Mass

Arm2 detector, all runs with zero crossing angleTrue h Mass: 547.9 MeVMC Reconstructed h Mass peak: 548.5 ± 1.0 MeVData Reconstructed h Mass peak: 562.2 ± 1.8 MeV (2.6% shift)


+Type-I Type-II

Type-II at small tower

Type-II at large tower

Type-ILHCf-Arm1

Type-IILHCf-Arm1

LHCf-Arm1Data 2010

BG

Signal

Preliminary

•Large angle•Simple•Clean•High-stat.

•Small angle•large BG•Low-stat., but can cover•High-E•Large-PT

π0 analysis at √s=7TeVSubmitted to PRD (arXiv:1205.4578).

+


p0 Data vs MC

+


p0 Data vs MC dpmjet 3.04 & pythia 8.145

show overall agreement with LHCf data for 9.2<y<9.6 and pT <0.25 GeV/c, while the expected p0 production rates by both models exceed the LHCf data as pT becomes large

sibyll 2.1 predicts harder pion spectra than data, but the expected p0 yield is generally small

qgsjet II-03 predicts p0 spectra softer than LHCf data

epos 1.99 shows the best overall agreement with the LHCf data.

behaves softer in the low pT region, pT < 0.4GeV/c in 9.0<y<9.4 and pT <0.3GeV/c in 9.4<y<9.6

behaves harder in the large pT region.

+MC study of n response


E vs. <Evis> at centerPosition resolution

Correction for position dependent shower leakage

Energy resolution (uniform incident on calorimeters)

+


Proton remnant side – Photon spectra

+


Proton remnant side - Neutron spectra


+ Proton-remnant side – p0

We can detect p0!

Important tool for energy scale

And also for models check…..

+Lead-remnant side – multiplicityPlease remind that EPOS does not consider Fermi motion and Nuclear Fragmentation

n

Small tower Big tower


+


Common trigger with ATLAS

LHCf forced to trigger ATLAS

Impact parameter may be determined by ATLAS

Identification of forward-only events

MCimpact parameter vs. # of particles in ATLAS LUCID

+


LHCf: location and detector layout

44X0, 1.6 lint

INTERACTION POINT

IP1 (ATLAS)

Detector IITungsten

ScintillatorSilicon

mstrips

Detector ITungsten

ScintillatorScintillating

fibers140 m 140 m

n π0

γ

γ8 cm 6 cm

Front Counter Front Counter

Arm#1 Detector20mmx20mm+40mmx40mm4 X-Y SciFi tracking layers

Arm#2 Detector25mmx25mm+32mmx32mm4 X-Y Silicon strip tracking layers

Energy resolution: < 5% for photons 30% for neutronsPosition resolution: < 200μm (Arm#1) 40μm (Arm#2)Pseudo-rapidity range:η > 8.7 @ zero Xing angleη > 8.4 @ 140urad

+ Radiation hardness of GSO

No decrease up to 1 MGy

+20% increase over 1 kGy (τ=4.2h recovery)

2 kGy is expected for 350nb-1 @ 14TeV pp)

１ kGyNot irradiated ref. sample

Irradiated sample

τ~4.2h recovery

K. Kawade et al., JINST, 6, T09004, 2011

Dose rate=2 kGy/hour(≈1032cm-2s-1)

+

Silicon sensor

Not used

Normal configuration

New configuration

Readout

ReadoutFloating

Readout

ReadoutGround

Arm2 detector New silicon

Pb (40mm)

e-, 200 GeV/c

Different silicon bonding scheme

The beam test setup

80 mm implant pitch160 mm readout pitch

+ New Silicon Module results (Quick analysis)

Clearly the pulse height in the region of new configuration was reduced by a factor of 1.5 ~ 1.7 (we could naively expect 2)

The modification works fine and increases the silicon dynamic range

#Strip

Normal New

Silicon Lateral distribution

Histogram of peak values


+

④ secondary interactionsnucleon, p

① Inelastic cross section

If large : s rapid developmentIf small :s deep penetrating

② Forward energy spectrum

If softer shallow developmentIf harder deep penetrating

If large k (p0s carry more energy) rapid developmentIf small k (baryons carry more energy) deep penetrating

How accelerator experiments can contribute to VHECR?

③ Inelasticity k=1-Elead/Eavail


+ The Large Hadron Collider (LHC)pp 450GeV+450GeV Elab ~ 2x1014eV

pp 　 3.5TeV+3.5TeV Elab ~ 2.6x1016eVpp 6.5TeV+6.5TeV Elab ~1017eV

ATLAS/LHCfLHCb/MoEDAL

CMS/TOTEM

ALICE

Total cross section ↔ TOTEM, ATLAS, CMS Multiplicity ↔ Central detectors Inelasticity/Secondary spectra ↔ Forward

calorimeters (LHCf, ZDCs)

R. Orava, (2007)

Full rapidity coverage!

+ lhcf: stato e programmi oscar adriani university of florence & infn firenze infn csn1 bologna,...

Documents

gev data

p t gev mcdata

lhc data

p t spectra

gev measurement

gev protonproton collisions

gev vs

tev preliminary data