HCP, Toronto, August 23-27, 2010 Other experiments at LHC: LHCf, MoEDAL, Totem Oscar Adriani...

HCP, Toronto, August 23-27, 2010

Other experiments at LHC:

LHCf, MoEDAL, Totem

Oscar AdrianiUniversità degli Studi di

FirenzeINFN Sezione di Firenze

Oscar Adriani Other experiments at LHC Toronto, August 27, 2010

David(s) vs Goliath

But also David(s) are able to do very good physics!!!!


‘Traditional style’ particle physics detectorOnline DAQ systemLocated in the forward/very forward region

Nuclear Track Detector based experimentDetector is:

• Exposed• Removed• Off-line analyzed

Totem

LHCf

MoEDAL


LHCf & Totem

Dedicated forward/very forward experiments


How to access Forward/Very Forward Region at LHC?

Charged particles

Neutral particles

Beam pipe

Surrounding the beam pipe far away from IP with detectorsSimple way, but still miss very very forward particles

Approach #1 used by Totem


Neutral particles

Beam pipe

Charged particles

Install detectors (movable!) inside the beam pipe very far away from the IPChallenging but ideal for charged particle


Approach #2 used by Totem


Detectors can be installed where the single beam pipe splitsIn 2 separate beam pipes, 140 m away from the IPAll neutral particle produced can be measured

Charged particles

Neutral particles Beam pipe


Approach used by LHCf (and in general by the others Zero Degree Calorimeters)


Pseudo rapidity coverage at LHC

Pseudorapidity: = - ln (tan/2)

All phase space covered thanks to dedicated forward detectors!And most of the energy is concentrated in the forward regions!

Particle flow

Energy flow


TotemTotem


T1:3.1 << 4.7

T2: 5.3 < < 6.5

T1 T2 CASTOR (CMS)

Roman Pot @147 m Roman Pot @220 m

10.5m

14m

Totem experimental layout


T1 TelescopeT1 TelescopeCathode Strip Chambers (CSC)3.1 < || < 4.75 planes with measurement of three coordinates per plane, ~ 1 mmPrimary vertex reconstruction (beam-gas interaction removal)Trigger with anode wires

Both arms are completely assembled and equipped in the test beam line H8.

Successfully tested with pion and muon beams in May – June 2010Both telescope arms not yet installed but ready for installation

chamber frames

~3 m

1 arm

stripstrip

wire

0.8 1.1 m

¼ of T1


T2 Telescope Gas Electron Multiplier (GEM) 5.3 < || < 6.5 10 half-planes @ 13.5 m from

IP5 Half-plane:

512 strips (width 80 µm, pitch of 400 µm), radial coordinate

65*24=1560 pads (2x2 mm2 -> 7x7 mm2), radial and azimuth coord.

Resolution: (R) ~ 100 µm, () ~ 1°

Primary vertex reconstruction (beam-gas interaction removal)

Trigger using (super) pads

All T2 chambers on both sides of IP5 installed and operational (data & trigger)

40 cm

pads

strips


T2: Preliminary Distribution

(with detector efficiency)

T2 acceptance


14

Roman PotsRoman PotsMeasurement of very small proton scattering angles (few µrad)Vertical and horizontal pots mounted as close as possible to the beamBPM fixed to the structure gives precise position of the beam

All 12 Roman Pots at ±220 m from IP5 are operational (data with active triggers)RP147 detector assemblies to be installed during next winter technical stop.

HALF OF THE RP STATION

Horizontal RP Vertical RP BPM

Roman Pot


RP alignment w.r.t. the Beam Centre

• Alignment is the central problem of Roman Pot measurements:– Done at 450 GeV on the 25th of June 2010

• LHC collimation system produces sharp beam edges:– used to align Roman Pots and to determine the centre of the beam– same procedure as collimator setup

• When both top and bottom pots “feel” the edge:– they are at the same number of sigmas from the beam centre as the

collimator– the beam centre is exactly in the middle between top and bottom

pot Collimator cuts a sharp beam edge

symmetrically to the centre

RP approaches this edge

until it scrapes …

… producing spike in BLM downstream

The second RP approache

s


Totem Physics plans• Early physics plan (2010-2011)

– Physics at s 7 TeV with low * (= 2 - 5 m) optics: • forward charge particles studies with T2• large |t| elastic scattering• high mass SD & CD

– Physics at s 7 TeV with short * = 90 m runs:• early measurement of tot @ 5-6 % • elastic scattering in wider |t|range (|t| > 0.015 GeV2)• SD & CD @ any M• classification of inelastic events:

– inelastic rates– process dependent forward charged multiplicity

• Full physics plan– TOTEM

TOTpp with a precision ~ 1-2%

• Elastic pp scattering in the range 10-3 < |t| ~ (p)2 < 10 GeV2

• Soft diffraction (SD and DPE)• Particle flow in the forward region (cosmic ray MC

validation/tuning)

– TOTEM & CMS• Soft and hard diffraction in SD and DPE (production of jets, bosons,

h.f.)• Central exclusive particle production• Low-x physics• Particle and energy flow in the forward region

Total cross-section

Elastic Scattering

b

Diffraction: soft and hard


p-p Total Cross Sectionp-p Total Cross Section

RPT1&T2


High * optics needed to measure the total pp cross-sectionEarly optics:*=90m (un-squeezing of existing injection optics, |t| > 3 102 GeV2)

Target optics:*=1540m (difficult to have at the beginning – requires special injection optics)

acceptance at very low |t| > 2 103 GeV2

1.5x106

2x109

500

30

1

4000

0.3

* = 90 m

* = 11 m

* = 2 m

11m

90m

1540m

exponential region

Elastic scatteringElastic scattering, exponential , exponential partpart

BSW

*=90m∫Ldt= 0.3pb-1


LHCf


Experimental set-upExperimental set-up

Detectors installed in the TAN Detectors installed in the TAN region, 140 m away from the region, 140 m away from the Interaction Point 1Interaction Point 1Here the beam pipe splits

in 2 separate tubes.Charged particle are swept away by magnets Coverage up to

Charged particlesCharged particles

Neutral particlesNeutral particles

Beam pipeBeam pipe

ProtonsProtons

INTERACTION POINTINTERACTION POINT

IP1 (ATLAS)IP1 (ATLAS)

Detector IIDetector II

TungstenTungsten

ScintillatorScintillator

Silicon Silicon stripsstrips

Detector IDetector I

TungstenTungsten

ScintillatorScintillator

Scintillating Scintillating fibersfibers

140 m140 m 140 m140 m


40mm

20mm

25mm

32mm

The LHCf detectors

Expected Performance Energy resolution (> 100GeV) < 5% for photons 30% for neutrons Position resolution < 200μm (Arm#1) ~40μm (Arm#2)

Sampling and Position-measurement Calorimeters • W (44 r.l , 1.7λI ) and Scintillator x 16 Layers• 4 position measurement layers XY-SciFi(Arm1) and XY-Silicon strip(Arm#2)• Each detector has two calorimetric towers, to allow the 0 reconstruction

Front Counter• Thin scintillators 80x80mm2 to monitor beam condition. • For background rejection of beam-residual gas collisions by coincidence analysis

Arm2Arm2

Arm1Arm1


ATLAS & LHCf

Goliath

David


HECR Open Issues

Difference in the energy scale between different experiments???

AGASA Systematics

Total ±18%Hadr Model ~10% (Takeda et al., 2003)

AGASA Systematics

Total ±18%Hadr Model ~10% (Takeda et al., 2003)

M NaganoNew Journal of Physics 11 (2009) 065012

The depth of the maximum of the shower Xmax in

the atmosphere depends on

energy and type of the primary

particle


AlessiaTricomi AlessiaTricomi University and INFN University and INFN

CataniaCatania

Development of atmospheric showersDevelopment of atmospheric showers

LHCLHC

TevatronTevatron

A 100 PeV fixed-target interaction with air has the cm energy of a pp collision at the LHC

AUGERAUGER

Cosmic ray spectrumCosmic ray spectrum

Determination of E and mass of Determination of E and mass of cosmic rays depends on cosmic rays depends on description of primary UHE description of primary UHE interactioninteraction

Hadronic MC’s need tuning with dataHadronic MC’s need tuning with dataThe dominant contribution to the The dominant contribution to the energy flux is in the energy flux is in the very forward very forward region (region ( 0)0)

In this forward region the highest In this forward region the highest energy available measurements of energy available measurements of 00 cross section done by UA7 cross section done by UA7 (E=10(E=101414eV, y= 5÷7)eV, y= 5÷7)

LHCf: use LHCLHCf: use LHC√√s = 14 TeVs = 14 TeVEElablab=10=101717eVeV to calibrate MCsto calibrate MCs


γ

nπ0

Energy spectra and transverse momentum distribution of

• (E>100GeV,E/E<5%)•Neutral Hadrons (E> few 100 GeV, E/E~30%)• 0 (E>700GeV, E/E<3%)

in the pseudo-rapidity range >8.4

What LHCf can measure?


LHCf operation in 2009 & 2010

With Stable Beam at 450 +450 GeV • 42 hours for physics• ~100,000 showers events in Arm1&Arm2

With Stable Beam at 3.5+3.5 TeV150 hours for physics with different setups

Vertical positionBeam crossing angle

~4.108 showers events in Arm1&Arm2~106 0 events in Arm1&Arm2

LHCf completed operation at 900GeV and 7TeV The detectors were removed from the LHC tunnel on 20/07/10 The detectors will be re-installed for operation at 7TeV+7TeV in 2013 after the upgrade of the detector for radiation improvement


Impressive TeV Shower

X Transverse projection

Y Transverse projection

Longitudinal projections


Spectra at 900GeV

preliminary preliminary

preliminarypreliminaryGamma-ray likeGamma-ray like

Gamma-ray likeGamma-ray like Hadron likeHadron like

Hadron likeHadron likeArm1Arm1

Arm2Arm2

Spectra are normalized by number of gamma-ray and hadron like events Detector response for hadrons and systematic errors (mainly absolute energy scale) are under study.

Only statistical errors are shown


0 reconstruction @ 7 TeV

ΔM/M=2.3%

Reconstructed mass @ Arm2

Measured 0 energy spectrum @ Arm2

preliminary

preliminary

An example of 0 event

0’s are a main source of electromagnetic secondaries in high energy collisions.

The mass peak is very useful to confirm the detector performances and to estimate the systematic error of energy scale.


search

0 Candidates

Candidates

• ratio vary a lot among different interaction models. A good handle to probe the hadron interaction models• Another calibration point for more robust energy scale

preliminary


Moedal


Searching for Magnetic Monopoles

MM energy loss

From the experimental point of view:Very highly ionizing particle!

Extended search up to now done both at accelerators and in CR


MoEDAL is located in the LHCbIP, covering the VELO cavern

MoEDAL: Monopole search at LHC: ppppMM

Operating procedure:1) Expose the detector2) Remove it3) Chemical etching to

create the etched cones4) Scan the etched plates

searching for aligned holes, pointing to the IP (x~1cm)

Plastic track edge detector based experiment

mm

m

25 m2 in total

A test detector is already installed

The full MoEDAL will be installed in the next LHC shutdown


Physics Reach for MM Production

Drell-Yan cross-section for magnetic-monopole pair production at the LHC

Exclusion curve for 10fb-1 ( x acceptance=30%)


Conclusions• Interesting physics cases can be studied also

with ‘David like’ detectors optimized for specific measurements– Totem: tot and Diffraction

– LHCf: MC tuning for Cosmic Rays experiments– MoEDAL: Monopole search

• Full support from Cern and LHCCThanks!• Nice physics results are already coming and

more exciting ones will certainly come in the near future

• P.S: Please note: David and Goliath are not ennemies, but nice friends!!!!!


Backup slides


LHCf : Monte Carlo discrimination @ <14 TeV

γ

n

γ

n


Particle Identification

L90% @ 20mm cal. of Arm1

MC (QGSJET2)Data

Preliminary

Thick for E.M. interaction (44X0) Thin for hadronic interaction(1.7)

A transition curve for Gamma-ray A transition curve for Hadron

Definition of L90%

Gamma-rays:L90%<16 r.l. + 0.002 x dE

Gamma-ray like


Alessia Tricomi Alessia Tricomi University & INFN University & INFN

CataniaCatania

The LHCf experiment at LHC The LHCf experiment at LHC ISVHECRI08, Paris 1-6 ISVHECRI08, Paris 1-6 September 2008September 2008

Radiation Damage StudiesRadiation Damage Studies

30 kGy30 kGy

•Expected dose: 100 Gy/day at 10Expected dose: 100 Gy/day at 103030 cm cm--

22ss-1-1

•Fewmonths @ 10Fewmonths @ 103030 cm cm-2-2ss-1-1: 10 kGy: 10 kGy• 50% light output50% light output•Continous monitor and calibrationwith Continous monitor and calibrationwith

Laser system!!!Laser system!!!

Scintillating fibers and scintillatorsScintillating fibers and scintillators

1 kGy1 kGy


0.5mm

Thin window 0.150mm

10 planes of edgeless detectors

Roman Pot detectors

Beam

Leading proton detection at distances down to 10×(beam) + d

Need “edgeless” detectors that are efficient up to the physical edge to minimize “d”

(beam) ≈ 0.10.6 mm (optics dep.)


28/04/2009 Hubert Niewiadomski, TOTEM

50

µm

66 μm pitch

dead

are

a

Planar technology with CTS(Current Terminating

Structure)I2I1

+-

biasing ring Al

p+

n+

cut edge

current terminating

ring

Al

SiO2

n-type bulkp+

50µm

Si Edgeless Detectors for Si Edgeless Detectors for RPRP

AC coupled microstrips made in planar AC coupled microstrips made in planar technology with novel guard-ring design and technology with novel guard-ring design and biasing schemebiasing scheme

Readout with VFAT chipsReadout with VFAT chips LLeakage current : 60 nA at 200 V (excellent)eakage current : 60 nA at 200 V (excellent) All producedAll produced Installation ongoing: RP220 (147) fully (partially) Installation ongoing: RP220 (147) fully (partially)

equipped by Juneequipped by June

3.5 cm


RP alignment @ 450 GeV

BLM @ 221 mBLM @ 225 m

Start with primary collimator at 4.9 beam edge at 4.9

RP approach (in ≥100m steps)Beam Loss Monitor (BLM)

RP trigger rate

RP 4-5 (-220m) Near – TOP @ 4.9

RP 4-5 (-220m) Near–BOTTOM @ -4.9


A Single Track Event in RP

Near Far

Top Top

Horizontal

Bottom Bottom

Horizontal

transverse view

Top

Hor.


T2 event @ 7TeV


LHC OpticsLHC Optics

– momentum loss

Proton position at RP (x*, y*) is a function of position (x*, y*) and divergence (x

*, y*) at IP:

Beam size and beam divergence at IP5 and at RP

spread of the primary vertex, beam size at RP

beam divergence at IP5 limits the angle measurement precisionx

Proton acceptance is determined by • optical functions, mainly Lx, Ly, Dx

• beam size x, y at RP• internal LHC apertures

RP IP5

measuredreconstructed

RP det.IP5

proton


Combined Combined uuncertainty in ncertainty in tottot

* = 90 m 1540 m• Extrapolation of elastic cross-section to t = 0: ± 4 % ± 0.2 % (Smearing effects due to beam divergence, statistical errors, uncertainty of effective length Leff, RP alignment, model dependent deviations)

• Total elastic rate (strongly correlated with extrapolation): ± 2 % ± 0.1 %• Total inelastic rate: ± 1 % ± 0.8 %

(error dominated by Single Diffractive trigger losses)• Error contribution from (1+2): ± 1.2 %

* = 90 m required for early * = 90 m required for early tottot measurement during the first measurement during the first year of LHC running at 7 TeVyear of LHC running at 7 TeV

Total uncertainty in Total uncertainty in tottot : : ± 5% ± 1÷2 %

Total uncertainty in Total uncertainty in L : L : ± 7 % ± 2 %

20

1

/16 el t

elto

nt

i el

dN dt

N N

2

0

21

/16el inel

el t

N N

dN dt

L


48

T1&T2 + RP provide fully inclusive trigger:

Primary vertex reconstruction to discriminate against beam-gas interactions

TOTEM Trigger efficiency: SD: 82 %, NSD > 99 %

InelasticInelastic event rate event rate NNinelinel

Single Diffractive

Trigger:

Double Diffractive

Trigger:

Central Diffractive

Trigger:

Minimum BiasTrigger:

p

p

p

T1/T2RP RPCMS


TOTEM diffractive TOTEM diffractive protonsprotons’ ’ acceptanceacceptance

Log(-t/GeV2)

Lo

g(-)

Lo

g(-)

Lo

g(-)

Log(-t/GeV2)Log(-t/GeV2)

7 TeV, *= 1535 m7 TeV, *= 90 m

low *

low * : 0.5 – 2 m, L 1033 cm-2s-1

early running: E = 5TeV, * = 3 m

elastic acceptance2 GeV2 < -t < 10 GeV2

resolution() = 16 – 30 µrad() = 1 – 6 10-3

- > 2 % seen

(hard) diffraction, high |t| elastic scattering

* = 90 m

L 1030 cm-2s-1

elastic acceptance3 10-2 GeV2 < -ty < 10 GeV2

resolution() = 1.7 µrad

() = 6 – 15 10-3

all seen, universal optics

diffraction, mid |t| elastic scattering, total cross-section

* = 1535 m

L 1028 – 1029 cm-2s-1

elastic acceptance2 10-3 GeV2 < -ty < 0.5 GeV2

resolution() = 0.3 µrad

() = 2 – 10 10-3

all seen

total cross-section, low |t| elastic scattering

28/04/2009 Hubert Niewiadomski, TOTEM

5TeV, *= 3 m

prelim.


Calibration of MoEDAL NTDs

MoEDAL NTDs have excellent charge resolution

Calibration is performed using heavy -ion beam

• Calibration at high energy heavy-ions sources is preferred eg BNL, CERN• But if these sources are unavailable low energy ion sources can be used eg:

– CHIBA Japan - 300-400 NeV/nucleon– Low energy heavy-ion soures at University de Montreal

• The MoEDAL Collaboration has experience with both types of calibration


Backgrounds• The important background source are nuclei from spallation products from

secondary interactions of particles produced in the primary interaction. – Such interactions take place with nuclei in the material of the detector and the

material surrounding and including the beam pipe.

– Interactions of the colliding beams with residual gas atoms in the beam pipe can also produce highly ionizing spallation products.

• The above sources of background are severely reduced in NTD arrays. Here is how:– The two track resolution of NTDs is extremely good, of the order of 10μms.

Reducing overlap buildup.

– The threshold of CR39, the most sensitive of the NTDs employed by MoEDAL - corresponds to a Z/

• Use of different plastics with different thresholds - Makrofol has a factor of 100 smaller sensitivity to spallation background than CR39

– The requirement of aligned etch pits in a several NTD sheets

– Track pointing to IP to an accuracy of ~1cm

– The different energy loss signature of the Monopole, or highly penetrating electrically charge particles, gives a clear distinction over a stopping spallation product

HCP, Toronto, August 23-27, 2010 Other experiments at LHC: LHCf, MoEDAL, Totem Oscar Adriani...

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