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LHCf: il run con ioni (e i due nuovi risultati…) Oscar Adriani 3 Aprile 2012

LHCf: il run con ioni (e i due nuovi risultati …)

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LHCf: il run con ioni (e i due nuovi risultati …). Oscar Adriani. 3 Aprile 2012. Some historical remarks. LHCf expression of interest for proton/Lead 2012 run Presentation at the LPCC meeting on October 17 th , 2011 Contact with Atlas management - PowerPoint PPT Presentation

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Page 1: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

LHCf: il run con ioni(e i due nuovi risultati…)

Oscar Adriani

3 Aprile 2012

Page 2: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Some historical remarks LHCf expression of interest for proton/Lead 2012 run

Presentation at the LPCC meeting on October 17th, 2011 Contact with Atlas management

Letter of Intent submitted to LHCC on December 4th, 2011 CERN-LHCC-2011-015/LHCC-I-021 04/12/2011

Approved by LHCC in December 2011! The Committee has independently verified

the support of the ATLAS Collaboration, and recommends the acceptance of the Letter of Intent.

And formal approval by RB practically obtained in March 2012!

The plan for LHCf to run during proton-Pb run was agreed by the LHCC and endorsed by the Research Board

Page 3: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Global LHCf physics programLHCf measurement for p-Pb interactions at 3.5TeV proton energy could be easily and finely integrated in the LHCf global campaign.

Period Type Beam energy

LAB proton Energy

(eV)Detector

2009 p - p 450+450 GeV 4.3 1014 Arm1+Ar

m22009/20

10 p - p 3.5+3.5 TeV 2.6 1016 Arm1+Ar

m2

2012 p – Pb 3.5 TeV proton E 1016 Arm2

2014 p - p 7+7 TeV 1017Arm1+Ar

m2 upgraded

Page 4: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

We are simulating protons with energy Ep = 3.5 TeV Energy per nucleon for ion is

“Arm2” geometry considered on both sides of IP1 to study both p-remnant side and Pb-remnant side

No detector response introduced yet (only geometrical considerations and energy smearing)

Results are shown for DPMJET 3.0-5 and EPOS 1.99, 107 events each

140 m 140 m

p-beam

Pb-beam

“Pb-remnant side”

“p-remnant side”

nTeV/nucleo 38.1 pN EAZ

E

What LHCf can measure in the p+Pb run (1)E, pT, spectra of neutral particles

Page 5: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Proton-remnant side - multiplicity

n

Small tower Big tower

Page 6: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Proton-remnant side – photon spectrumSmall tower Big tower

Page 7: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Proton-remnant side – neutron spectrumSmall tower Big tower

35% ENERGY RESOLUTION IS CONSIDERED IN THESE PLOTS

Page 8: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Proton remnant side – Invariant cross section for isolated -rays

Page 9: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

What LHCf can measure in the p+Pb run (2)Study of the Nuclear Modification Factor

Nuclear Modification Factor measured at RHIC (production of p0): strong suppression for small pt at <>=4.

LHCf can extend the measurement at higher energy and for >8.4Very important for CR Physics

Phys. Rev. Lett. 97 (2006) 152302

Page 10: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Proton-remnant side – p0

We can detect p0!

Important tool for energy scale

And also for models check…..

Page 11: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

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

n

Small tower Big tower

Page 12: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Some estimations based on reasonable machine parameters…. Considering machine/physics parameters:

Number of bunches, n = 590 (150 ns spacing) Luminosity up to 1028 cm-2s-1 Interaction cross section 2 barn

PILE-UP effect Around 310-3 interactions per bunch crossing 1% probability for one interaction in 500 ns (typical time

for the development of signals from LHCf scintillators after 200 m cables from TAN to USA15)

Some not interacting bunches required for beam-gas subtraction

Beam gas first estimation indicate no problem Beam Gas/Beam Beam = 3.10-4

Page 13: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Minimum required number of collision: Ncoll = 108 (factor 10 more statistics wrt shown plots) Integrated luminosity Lint = 50 mb-1

2106 single photons expected on p-remnant side

35000 p0 expected on same side

Assuming a pessimistic scenario with luminosity L = 1026 cm-2s-1 : Minimum running time for physics t = 140 h

(6 days)

… and required statistics to complete the p/Pb physics run

Page 14: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Once we have been approved…. We have to do the run!!!!! Technical points:

Installation issues Manpower for Installation, setup and data taking

Please note that Arm2 is ‘more italian than japanese’…. Money for missions (Sblocco SJ, see referee presentation)

4days slot to install

>3 weeks of run

Page 15: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Preparation for 2012 p-Pb run

We have installed multi-pole connectors in tunnel (02/12) We have checked that optical fibers are ok (not damaged by

radiation) (02/12) We are producing a new transportation frame for Arm2+electronics 1-2 experts will stay at CERN from September for DAQ

commissioning One month of 24 hours per day shifts (minimum 8 persons at Cern

for one month, few from Japan and few from Italy) Big manpower is requested…. Please note that Atlas ZDC have already been removed in February

2012, since new detectors are being produced. The hadronic part will be installed behind LHCf on Arm2 side, and em+had part on the other side

Sinergies between LHCf and Atlas are encouraged by LHCC We are working on it

Arm2

Pb

pIP8IP2

IP1Arm2

Page 16: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

16

New configuration Fixing the three sub-systems together

New base plate

Lead block for balance

Page 17: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

A fast spot on 2 new analyses

Page 18: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Submitted to PLB

Measured 900 GeV single spectrum

Page 19: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Type-I Type-IIType-I

Type-II

0 3500 0 3500Ep0(GeV) Ep0(GeV)

PTp0

(GeV

/c)

0

1 1

0

sM=3.7%

LHCf 7TeV p0 analysis

Page 20: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

20

Combined type-I p0 pT spectra (invariant cross section)

DPMJET 3.04 QGSJETII-03 SIBYLL 2.1 EPOS 1.99 PYTHIA 8.145Sys+stat

PTp0(GeV/c)0 0.6

1/N i

nt Ed

3 N/d

p3 1

10-4

8.9<y<9.0 9.0<y<9.2 9.2<y<9.4

9.4<y<9.6 9.6<y<10.0 10.0<y<11.0

Page 21: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Recent Publication (2011-2012)Title journalMonte Carlo study of forward pi0 production spectra to be measured by the LHCf experiment for the purpose of benchmarking hadron interaction models at 10(17)-eV.

Astropart.Phys. 34 (2011) 513

Measurement of zero degree single photon energy spectra for s√ = 7-TeV proton-proton collisions at LHC.

Phys.Lett. B703 (2011) 128

Study of radiation hardness of Gd(2)SiO(5) scintillator for heavy ion beam (Japan only) JINST 6 (2011) T09004 Luminosity determination in s**(1/2) = 7-TeV proton collisions using the LHCf front counter at LHC. JINST 7 (2012) T01003 Calibration of LHCf Calorimeters for Photon Measurement by CERN SPS Test Beam

NIM.   A671 (2012)129

Measurement of zero degree photon energy spectra for √s = 900GeV proton-proton collisions at LHC

Submitted to PLB

Measurement of transverse momentum spectra of forward neutral pions for root s=7TeV proton-proton collisions at LHC

To be submitted

LHCf detector performance during the 2009-2010 LHC run In preparation

Page 22: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

On-going analysis activity and plan

On going activity 7TeV hadron energy spectra g Inelasticity

Italian main analysis task for the near future Full analysis of single (larger , pT, invariant cross

section) Full analysis of p0 (Type-II p0) Feed back to the models and air shower experiments

Future plans Strange particles (Lgp0n, Ksg2p0(4))

Page 23: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Spares slides

Page 24: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Combined type-I p0 pT spectra

Page 25: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

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)

Page 26: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Photons on the proton remnant side Photon energy distrib. in different intervals at sNN

= 7 TeV Comparison of p-p / p-N / p-Pb Enhancement of suppression for heavier nuclei

case QGSJET II-04 SIBYLL 2.1p-p

p-Np-Pb

All s8.81<<8.99

>10.94

Courtesy of S. Ostapchenko

Page 27: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Lead-remnant side – neutron spectrumSmall tower Big tower

35% ENERGY RESOLUTION IS CONSIDERED IN THESE PLOTS

Page 28: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

GSO property(EJ260: plastic scintillator used in the current LHCf detectors)

GSO EJ-260density(g/cm3) 6.71 1.023

r.l.(cm) 1.38 14.2decay time(ns) 30-60 9.6

Fluorescence(NaI=100) 20 19.6

λem(nm) 430 490Refractive(@λem) 1.85 1.58

tolerance(Gy) 106 100melting point(℃) 1950 ー

Fast among inorganic scintillators

Best in the known scintillators

Identical to the current scintillators

Similar to the current scintillators

Heavy; reason to reduce 3->1mm

Light collection may differ

Page 29: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Uniformity test using C beam at HIMAC(preliminary results from quick analysis)

PMT via fiber bundle

PMT via fiber bundle

No particle due to the beam pipe

• Scan examples for a 20mmx20mm and a 40mmx40mm GSO plates

• All scintillators of Arm1 were mapped by C beam

• Similar uniformity to the current detector is obtained

mm

mm mm

mm

Page 30: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

New structure

GSO bar bundle and quartz fiber light guide

GSO plate and light guide packed in a new holder

GSO plates and bars as calorimeters, but without Tungsten absorber layers

Page 31: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

GSO bars cross talk and attenuation

Attenuation and cross talk are acceptable to determine the position of single particle shower and multihit identification

For multihit analysis, further study is necessary Paint between the bars reduces cross talk, but worsens attenuation and its bar-

to-bar variation

No paint between bars

-30%/35mm

10%

0%

Irradiated bar (100%)

Attenuation along the longest 40mm bar Cross talk

Page 32: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Estimation of Beam Gas background Input from p-p collisions (Data set used for the photon paper).

Luminosity per bunch (L/n) : 2x1028 cm-2s-1/bunch Intensity per bunch (I/n)  : 2x1010 protons/bunch Total detected events in 25mm tower at non-bunch crossing : 101 photon events (for

non crossing bunches) DAQ live time : ~ 8x103 sec -> Event rate of beam gas per bunch = 101/8000/3 = 0.004 Hz

Inputs from p-Pb (assumptions) Luminosity per bunches (L/n) : 1.7x1025 cm-2s-1/bunch (L=1028, n=590) Inelastic cross section  : 2 barn Expected collision rate : 34 Hz Expected photon detection rate in 25mm : 0.34 Hz (assuming acceptance=0.01)

Estimation of beam-gas background for p-Pb Assuming as the optics for p-Pb is same as one for p-p (same beta, same emittance),

the relative intensity is estimated by using L/n. (I/n)pPb / (I/n)pp ~ 0.03 The beam-gas background rate should be proportional to the intensity per

bunc, so it is estimated as 0.03 x 0.004 Hz = 10-4 Hz

As conclusion, the N/S in p-Pb is estimated as 10-4 / 0.34 = 3x10-4 Negligible!!!!

Page 33: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Few details about the LHCf Arm2 detector

Performances Energy resolution (> 100 GeV): < 3% for 1 TeV photons and 30% for neutrons Position resolution for photons: 40μm (Arm#2)

Sampling and imaging E.M. calorimeter Absorber: W (44 r.l , 1.55λI )

Energy measurement: plastic scintillator tiles 4 tracking layers for imaging: XY-Silicon strip(Arm#2) Each detector has two calorimeter towers, which allow to reconstruct p0 Front Counters

• thin scintillators 80x80 mm2 • monitoring of beam condition •Van der Meer scan 25mm

32mm

Arm2

Page 34: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

LHCf physics program for p-Pb run

Important information for the study of the interaction of UHECR in the Earth atmosphere Comparison with hadronic interaction models Study of the Nuclear Modification Factor Inelasticity

Precise measurement of of E, and pT distributions for pseudo-rapidity > 8.4 both for p and Pb remnant Single Neutral pions Neutrons

WHY

HOW

Page 35: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

Lead-remnant side – photon spectrumSmall tower Big tower

Page 36: LHCf:  il  run con  ioni (e  i  due  nuovi risultati …)

LHCf plans for the p/Pb run We will run with only one detector

Arm2 (W/scint. e.m. calorimeter + m-strip silicon) Only on one side of IP1 (on IP2 side, compatible

with the preferred machine setup: Beam1=p, Beam2=Pb)

Minimal interference with Atlas Installation during the technical

shutdown at the end of the p/p 2012 run