Transcript LHCf LHCC February 17, 2010 - Istituto Nazionale di Fisica

Parma, 23 Settembre 2010
LHCf status report
Oscar Adriani
Università degli Studi di Firenze
INFN Sezione di Firenze
Detector I
Tungsten
Scintillator
Scintillating fibers
Experimental set-up
Detector II
Tungsten
Scintillator
Silicon mstrips
INTERACTION POINT
IP1 (ATLAS)
140 m
140 m
8 cm
n
γ
6 cm
γ
π0
Detectors installed in the TAN region,
140 m away from the Interaction Point
1
Here the beam pipe splits in 2
separate tubes.
Charged particle are swept
away by magnets
 We cover up to y
Protons
Charged particles
Neutral particles
Beam pipe
Oscar Adriani
23/09/10
LHCf : Monte Carlo discrimination
g
106/107 generated LHC interactions
at 7+7 TeV
1 minute exposure@1029 cm-2s-1 luminosity
n
0
p
Oscar Adriani
23/09/10
LHCf Operations at 900 GeV
06 Dec – 15 Dec 2009
27.7 hours for physics
~5x105 collisions at IP1
~2,800 shower events in Arm1
~3,700 shower events in Arm2
02 May – 27 May 2010
15 hours for physics
~5.5x106 collisions at IP1 (Statistics x 11 wrt 2009)
~44,000 shower events in Arm1
~63,000 shower events in Arm2
Beam Gas significantly reduced wrt 2009
Oscar Adriani
23/09/10
2009 vs 2010
2009
2010
Very big reduction in the Beam Gas / Bunch crossing ratio!!!!
Very big increase of the ‘signals/noise’ ratio due to higher intensity
Oscar Adriani
23/09/10
Arm1 Spectra at 900 GeV
Preliminary
Only statistical errors are quoted
MC normalized to the total
number of events in the 2
towers,without PID.
Only one normalization
factor common to all models
Oscar Adriani
23/09/10
Arm2 Spectra at 900 GeV
Preliminary
Preliminary
Only statistical errors are quoted
MC normalized to the total
number of events in the 2
towers,without PID.
Only one normalization
factor common to all models
Oscar Adriani
23/09/10
LHCf 2010 runs (mainly at 7 TeV)
• Detector shows good performance with stable
quality.
– Energy scale calibration with the p0 peak!!!!
– Good stability < ±1% level.
– We started to have some radiation problems in the last
periods.
• Thanks a lot to all LHC people for providing us 100
mrad crossing angle!!!
– Very important for physics to enlarge the PT acceptance
• Detectors were removed on July 20, 2010
Oscar Adriani
23/09/10
Acceptance gain due to Crossing Angle
No crossing angle
100 mrad crossing angle
Arm1
Arm1
A very significant gain in acceptance is clearly
visible!
Oscar
Adriani
23/09/10
Operation at 7 TeV
Without crossing angle (30/03 – 05/06)
With 100mrad crossing angle (25/06 – 20/07)
Runs are taken in many different vertical position and with/without Xing angle
Oscar Adriani
23/09/10
7 TeV collisions
1 TeV gamma-ray shower @ Arm2
Transition curve in towers
X-view of silicon strip
Y-view of silicon strip
Oscar Adriani
23/09/10
p0 at 7 TeV
Silicon layers
25 mm
tower
32 mm
tower
 Robust sample
 Good energy calibrator
Tower
32mm 25mm
Scintillator layers
Arm2 event display
Oscar Adriani
23/09/10
Beam position analysis: LHCf vs BPM
Oscar Adriani
23/09/10
p0 mass and energy spectrum (Arm1)
Preliminary
Preliminary
Please note the
Very High Energy!
DM/M=6.3MeV/135MeV=4.7%
Preliminary
Oscar Adriani
23/09/10
p0 mass and energy spectrum (Arm2)
Preliminary
DM/M=2.3%
Preliminary
Using only data taken before April 13th
Oscar Adriani
23/09/10
Particle ID: L90%
Oscar Adriani
23/09/10
PID study
Energy spectra with not PID biased
By fitting the L90% distribution with the superposition
of 2 components (gamma-rays and hadrons),
the efficiency and purity can be estimated
from the data themselves.
After the correction
Before the correction
Oscar Adriani
23/09/10
Measured Spectra at 7TeV
Gamma-ray like
preliminary
Arm1Hadron like
preliminary
Gamma-ray like
preliminary
Arm2
Hadron like
preliminary
Very high statistics !! only 2% of all data
Oscar Adriani
23/09/10
Arm1/Arm2
Comparison
• Same geometrical regions
and same runs are selected
• Correction for different
livetimes
Red : Arm1
Blue : Arm2
Red : Arm1
Blue : Arm2
Oscar Adriani
23/09/10
h search
All data taken
with zero-crossing angle
and low luminosity
In the High Lumi/High Pile Up
runs we don’t see h (combinatorial
background)
Oscar Adriani
23/09/10
Luminosity with VdM scan with Front
Counter Data
f rev n b N1N 2
L
2p x y
σx & σy are measured in VdM scan (May 9th)
independently from interaction model or detector

Calculate luminosity with this VdM scan
Calculate “FC rate  Luminosity” Conversion Factor
to be independent from MC
Oscar Adriani
23/09/10
VdM scan May 9th, 2010
Horizontal scan
FC rate of arm1 / 1000
Beam position - start of scan +0.3mm
Beam position - end of scan +0.3mm
x measured by FC
Scan
FC1
FC2
FC1&2
ATLAS
Scan 005
59.8μm
59.9μm
58.4μm
59.1μm
Scan 006
60.0μm
60.3μm
59.1μm
59.3μm
Lumi measured perfectly compatible with Atlas!
+
Oscar Adriani
23/09/10
Radiation Damage
Dose measured by the dosimeters
behind the calorimeters
p0 mass peak
3%
Oscar Adriani
23/09/10
LHCf removal
• LHCf has completed the basic physics
program at 7 TeV 
• LHCf has been removed on July 20th, during a
short technical stop (a little bit )
• Laser calibrations were done for few weeks
after the removal (Annealing)
• Test beam is foreseen from October 15 to 28
– 3 days main users
– 10 days parasitic run
Oscar Adriani
23/09/10
Future activities (I)
2011
– Replace plastic scintillators with Rad Hard GSO
(prepared by Japan side) in Florence Clean
Rooms
– Produce 2 new silicon modules to replace partly
defective ones + 2 spares
– Modify the silicon layers positions to improve
silicon-only energy resoution
– Test beam at SPS to calibrate Arm1&Arm2
– Test beam at GSI to intercalibrate the Silicon
Pace3 response with relativistic High Z Nuclei
Oscar Adriani
23/09/10
R&D for the detector upgrade.
Plastic scintillators (EJ260)
⇒ GSO scintillators
Scintillating Fibers
⇒ GSO bars
Radiation damage
measured by Ion beams
EJ260
MIP peak
Oscar Adriani
23/09/10
New silicon layers arrangement
8 Silicon Layers 6 6 12 12 18 26 34 42 X0
Oscar Adriani
23/09/10
Future activities (II)
• 2012
– Install the detectors at RHIC?
– RHIC can accelerate:
•
•
•
•
p-p up to 250 GeV/nucleon
Ions up to 100 GeV/nucleon
They have already done deuteron-Gold
They could do p-Light ion
– RHIC beam pipe arrangement
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•
•
•
–
Situation similar to LHC
Single beam pipe split in 2 at 20 m from IP
Space available ~ 10 cm
LHCf can fit very well inside!
p0 can be reconstructed as we are doing in LHC!
• Sqrt(s)min=4 mp d/hdet
• d=20 m, hdet = 8 cm  Sqrt(s)min= 135 GeV
• More news in 2011—> Stay tuned!!!!!!!
Oscar Adriani
23/09/10
Future activities (III)
• 2013-2014
– Re-install Arm1&Arm2 at LHC when the energy
will be raised to 13/14 TeV
– Necessity to mantain the Cern infrastractures:
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Control room
Electronics pool material
Safety infrastructures
Racks in underground areas
Team account
Etc. etc. etc.
Oscar Adriani
23/09/10
Conclusion
• LHCf has completed the basic physics program at 7
TeV
• LHCf was removed from TAN on July 20th, 2010
• Test beam is foreseen in October 2010
• The detector will be upgraded during 2011 to
improve radiation hardness
– GSO will replace plastic scintillator
– More energy measurement oriented silicon arrangement
• RHIC Option for 2012?  Stay Tuned!!!!!!!!!!
• LHCf will certainly be back in the TAN for the 14
TeV run!
Oscar Adriani
23/09/10
Backup slides
Oscar Adriani
23/09/10
Studies of detector responses
LPM effect
Transition curve for 1.5TeV γ (MC)
The radiation length for high energy particles
seems to become longer in the heavy matter.
- Confirmation of the LPM effect
- Effect to the energy reconstruction and PID etc.
presented by SAKO
protons with 350GeV/c and 150GeV/c
⇔ LHC: 450GeV+450GeV
Transition curve for 350GeV/c protons
dE
Detector response for hadrons
by beam test data at SPS done in 2007
MC (DPMJET3)
Measured
LHCf
Detector
Beam
Pipe
Presented
by MASE
Silicon Tracker
Oscar Adriani
layer
23/09/10
Radiation Damage Studies
Scintillating fibers and scintillators
•Expected dose: 100 Gy/day at 1030 cm-2s-1
•Fewmonths @ 1030 cm-2s-1: 10 kGy
• 50% light output
•Continous monitor and calibrationwith
Laser system!!!
The LHCf experiment at LHC
ISVHECRI08, Paris 1-6 September
2008
Alessia Tricomi
30Catania
kGy
1 kGyUniversity & INFN
Oscar Adriani
23/09/10
Particle Identification
Longitudinal development of g shower
Longitudinal development of Hadron shower
Thick for E.M. interaction (44X0) Thin for hadronic interaction(1.7l)
Definition of L90%
Gamma-rays:
L90%<16 r.l. + 0.002 x SdE
Oscar Adriani
23/09/10
Results at 900GeV: PID
Preliminary
QGSJET2
Data
Gamma-rays:
L90%<16 r.l. + 0.002 x SdE
QGSJET2
Data
QGSJET2
Data
QGSJET2
Data
Oscar Adriani
23/09/10
L90%<18X0
Constant e cut
Oscar Adriani
23/09/10
RHIC Physics Case
• p-Light Ion
– This measurement will allow to directly measuring
the characteristic of the HECR-atmosphere
interactions, without having to rely on the
approximation usually done to go from the p-p
collision to the p-nucleus collision (Glauber
approximation).
• p-p
– We propose also to run the RHICf experiment in the pp collisions, to have the possibility to directly check
the validity of the Glauber approximation at 200 GeV
center of mass energy by comparing the p-p with the
p-LI results.
Oscar Adriani
23/09/10
Beam Position Analysis from the LHC data
Positive;
upward in V
outward in H
IP
BPMSW
θ
Offset; b
Theoretical center
BPMSW
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•
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43m
140m
Beam position (b) and angle (θ) can be determined from the
measurements of two BPMSW (beam position monitor)
Expected position (neutral center) on the LHCf detector at 140m away
can be calculated from these numbers
Analysis done by Simon White
Oscar Adriani
23/09/10
FrontCounter as a good luminosity monitor
TAN
BRAN-IC
ZDC
BRAN-Sci
ZDC
ZDC
Stay all the time
LHCfCAL
FC
Beam
pipe
Page1
LHCf page
Neutral
particles
• FC is working very well for
luminosity monitoring
(Very useful monitor for
the machine)
• Continuous monitoring w/
independent DAQ now
available. See Page1
“LHCf experiment”
• Conversion to “luminosity”
from FC rate is now under
study by MC
lumiscan
Arm1
Arm2
Coincidence
Gaussian fit
Oscar Adriani
23/09/10
ATLAS online (w/o calibration)
VdM scanning
luminosity
by FC1 data
1.80 ± 0.012
(1028/cm2s)
by FC2 data
1.79 ± 0.012
(1028/cm2s)
by FC1&2
data
1.88 ± 0.019
(1028/cm2s)
Oscar Adriani
23/09/10