Future perspectives of
the ALICE experimentand detector upgrade
Hiroshi Masui for the ALICE collaboration
University of Tsukuba!
The 5th Asian Triangle Heavy Ion Conference 2014,
Osaka, Japan, Aug. 5-8, 2014

H. Masui / Univ. of Tsukuba

1Outline• Current ALICE experiment‣ Upgrade during Long Shutdown 1 (LS1) in 2014; Di-jet CALorimeter(DCAL)!

• ALICE future physics programs‣ Focus on long term physics after LS2!

• ALICE detector upgrade (selected)‣ Core upgrade during LS2 in 2018-2019; Time Projection Chamber(TPC), Inner Tracking Systems (ITS)!

• Summary and outlook
H. Masui / Univ. of Tsukuba2Current ALICE detectors• Efficient tracking, particle identification,vertexing down to ~100 MeV/c in pT
H. Masui / Univ. of Tsukuba

3

4

5

6

7

8

9

10

Figureillustrates
M(Kπ)38(GeV/c 2 ) the performance of the TOF detector by showing the measured veloci
bution as a function of momentum (measured by the TPC). The background is due to trac
50: Invariant mass distribution of Kπ candidate pairs for reconstruction of the incorrectly
D0 →Kπ decay,
with toandTOF hits in high-multiplicity Pb–Pb collisions. The distribution ismatchedpMC (GeV/c)Fig.
without particle identification, before (left panel) and after (right panel) background subtraction.
T
p–Pb collisions (Fig. 39), showing that the background is not related to the resolution of th
tector, but is rather an effect of track density and the fraction of mismatched tracks. This isin Fig. 40 where the β distribution is shown for a narrow momentum band. The pion, kaon,om
the primary interaction vertex. Two setsof cuts on theof the ALICE Experiment
The ALICE Collaboration
peaks are nearly unchanged but the level of background due to mismatched tracks is higher
The fraction of mismatched tracks above 1 GeV/c in Pb–Pb events is closely related to thevertex are shown: “loose” with |d0,z | < 3 cm, d0,xy < 3 cm

M(Kπ) (GeV/ c 2 )Current performance
TPC

ITS
−1

600

TOF β

ITS dE /dx (keV/300 µm)

50 GeV/cpT ) cm.
700

TOF

Pb-Pb sNN= 2.76 TeV

the productsof decays and of secondary interactions
500
ed by cuts on the longitudinal and transverse distances
400p
The dedicated reconstructionof secondary tracks is the
K
300

104

1.1
1
0.9
0.8

e
π
K

103

p
d

0.7

102

0.6
0.5

π

200

p-Pb sNN = 5.02 TeV

0.4

10
e transverse
0.3
edistance to the primary vertex for identified
100
0.2
simulation.
The contribution from the vertex resolution
0
0.07 0.1
0.2 0.3 0.4
2
3 4 5
1
0.1
1
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
ws the same quantity for all charged pparticle
tracks for(GeV/c )p (GeV/c )ibutionof the energy-loss
signal inan
the ITS
as a function of momentum.
the energy loss andch.
One
can noticeimprovementof theBothresolution
inFig. 39: Distribution of β as measured by the TOF detector as a function of momentum for particles re
ere measured by the ITS alone.
Fig. 51: Measured dE/dx signal in the ALICE TPC versus magnetic rigidity, together with the expected curves
ermined vertex for higher multiplicities.
in p–Pb interactions. The background of mismatched tracks is lower than in Pb–Pb.
for negatively-charged particles. The inset panel shows the TOF mass measurement which provides additionalvertexing

TPC dE /dx d(arb. units)
resolution (µm)
0,xyhe particle velocity, γ is the Lorentz factor, and P1−5 are fit parameters. Figure 334 shows
separation between He and 4 He for tracks with p/Z > 2.3 GeV/c.
d dE/dx vs. particle momentum in the TPC, demonstrating the clear separation between
300 The lines correspond to the parametrization. While at low momenta
particle species.
c) particles can be identified on a track-by-track basis, at higher momenta particles canated on a statistical basis via multi-Gaussian fits. Indeed, with long tracks (" 130 samples)truncated-mean
250method the resulting dE/dx peak shape is Gaussian down to at least 3 orders
59.

arXiv:1402.4476 [nucl-ex]
51

ALICE
charged particles

200

200 K

p

180

d

pp s = 7 TeV
Pb-Pb ss = 2.76
TeV
p-Pb
NN = 5.02 TeV
NN

160

150

Pb-Pb sNN = 2.76 TeV

140
120

100

100

80
60
40

T

T

e

50

• PID for wide p range• Efficient low p tracking• Excellent vertexing

π

20

0.2 0
0.3
2
3 4 5 6 7 8 910
201
p (GeV/c)
-1
4
10
1
10
sNN = 2.76 TeV.
)fic energy loss (dE/dx) in the TPC vs. particle momentum in Pb–Pb collisionspat √(GeV/c)w the parametrizations of the expected mean energy loss.

T

primaryvertexfor identified
particle
global for
ITS–TPC
istic rise region,
the dE/dx
exhibits a nearly
constant separation
the different tracks
particleacontribution
wide momentum range.
Due
to
a
dE/dx
resolution
of
about
5.2
%
in
pp
collisions
from the vertex resolution is not subtracted. and

H. Masui / Univ. of Tsukuba

4

Di-jet CALorimeter
DCAL

beam view

PHOS• DCAL - extension of EMCAL acceptance‣ |η|=0.7, Δφ=66o on opposite side of EMCAL → allows hadron-jet, di-jet measurements in ALICE, with R=0.4, up to pT ~ 150 GeV/c‣ Energy resolution ~ 10%/√E• Enhance photon and jet trigger capability• DCAL has already being installed, and will be ready in 2015
H. Masui / Univ. of Tsukuba

5Physics with DCALALICE DCal Addendum to the EMCal TDR

June 2010

with the latter case exhibiting much stronger bias. This suggests (within the qPYTHIA
model) that pion production at ~5 GeV/c may not be strongly biased towards leading jet
fragments.Transverse
Measurements withdistribution
a large dynamic rangein pion scattering
threshold are thereforeof hardverticesneeded, and can only be provided in an efficient way by a fast (Level 1) trigger in the DCal.

DR

calculated in qPythia

June 2010

ALICE DCAL TDR, https://cds.cern.ch/record/1272952

f jet quenching. The DCal, including its fastmeasurement.

ALICE DCal Addendum to the EMCal TDR

June 2010

pion

Figure II.10 Distribution in transverse plane of hard scattering vertices that generate aThard pion moving to the right, for various qhat and pion trigger
ET thresholds.

anti-k , R=0.4
0.5 nb-1

The path length bias for both the trigger jet (generating the pion trigger) and the recoil jet
are shown in Figure II.11, for various qhat and pion trigger thresholds. The reference
distribution (qhat=0) is shown by the black circles. A marked bias of several fm is seen forboth jets. As discussed in section II.2 on RHIC measurements, triggering on a high pT
17

Figure II.10 Distribution in transverse plane of hard scattering vertices that generate a
hard pion moving to the right, for various qhat and pion trigger ET thresholds.

•• Di-jet - energy balance between recoiling jet pairs

0-jet correlation - maximize
Figure II.6 Effectonjet energy
resolution ofin
gapthebetweenmedium
DCal and PHOS, measured
π
jet
path
lengthm measured in EMCal (anti-kT, R = 0.4),
by the di-jet energy balance in EMCal and DCal (anti-kT, R = 0.4 for both EMCal and

The path length bias for both the trigger jet (generating the pion trigger) and the recoil jet
DCal). Left: correlation for EMCal Trigger Jet ET > 90 GeV, for no gap (black),
are shown
T in Figure II.11, for various qhat and pion trigger thresholds. The reference
distribution (qhat=0) is shown by the black circles. A marked bias of several fm is seenforvariousvalues of gap width (red, green, blue), and no DCal (charged tracking only,
both jets. As discussed in section II.2 on RHIC measurements, triggering on a high pTpink). Right: dependence of peak width on EMCal threshold ET. Statistical error bars
17
-1
-1

ve p thresholds of 20 GeV/c (left) and 40
ars show statistical errors expected for one
0.5 nb ).

correspond to 0.5 nb Pb+Pb, though for clarity no quenching effects have been
H. Masui / Univ. of Tsukuba
6

ALICE future physics program
Probe

Physics

Observable

Heavy-flavor(charm & bottom)

Thermalization, EoS
Transport coefficient, energy loss

v2 & RAA

Quarkonia(J/ψ, ψ’)

Production mechanisms

yield, v2, RAA

Low mass
di-leptons

Initial temperature, EoS
Chiral phase transition

yield, v2
vector meson spectral function

Jet

Parton energy loss

PID fragmentation function,
Heavy flavor in jets, γ-jet
correlation

Heavy nuclear
statesSearch for exotic bound states(anti-hyper nucleus, H-Dibaryon)

yield• Emphasis on heavy-flavor, low mass di-leptons and heavy
nuclear states at low pT

H. Masui / Univ. of Tsukuba

7Strategy for long term upgrade• Many measurements will focus on low p and very highTbackground observables - trigger is not applicable• Detector upgrade to enhance low p vertexing and tracking
Tcapability, and to take minimum bias data at substantiallyhigher rates‣ Target integrated luminosity: 10 nb-1 in Pb-Pb, 6 pb-1 in p-p‣ Read out ~50kHz Pb-Pb interactions with minimum bias trigger- Complementary to ATLAS and CMS (highly selective triggers)• Upgrade strategy‣ TPC with GEM readout + new pipelined electronics (dead-time free)‣ New ITS, better vertexing with high resolution+low material thickness- Readout electronics for TRD, TOF, PHOS and muon spectrometer- Forward trigger detectors, Muon Forward Tracker- High-Level Trigger (HLT), DAQ and trigger system for high rate
- Integrated online & offline structure; DAQ/HLT/offline (O2 project)
H. Masui / Univ. of Tsukuba

8Physics reach

Table 1.1: Comparison of the physics reach, minimum accessible pT and relative statistical uncertainty, for selected observables between the approved scenario (1 nb 1 of delivered integrated luminosity, out of which 0.1 nb 1
is used for minimum-bias data collection) and the proposed upgrade (10 nb 1 of integrated luminosity, fully exploited in minimum-bias data recording).
ALICE upgrade LOI, http://cds.cern.ch/record/1475243/

Approved
Observable

pAmin
T

(GeV/c)*statisticaluncertainty

Upgrade

**

pUmin
T

(GeV/c)statisticaluncertainty

0
2
0
2
2
1

0.3 % at pAmin
T
1 % at pAmin
T
2.5 % at pAmin
T
20 % at pUmin
T
15 % at pUmin
T
1 % at pAmin
T

0
0
0
0

0.3 % at 1 GeV/c
0.5 % at 1 GeV/c
5 % at 2 GeV/c
10 %

0.3

10 %
10 %
20 %

Heavy Flavour
D meson RAA
D meson from B decays RAA
D meson elliptic flow (v2 = 0.2)
D from B elliptic flow (v2 = 0.1)
Charm baryon-to-meson ratio
Ds meson RAA

10 % at pAmin
T
30 % at pAmin
T
50 % at pAmin
T
not accessible
not accessible
4
15 % at pAmin
T

1
3
1

Charmonia
J/y RAA (forward rapidity)
J/y RAA (mid-rapidity)
J/y elliptic flow (v2 = 0.1)
y(2S) yield

0
0
0
0

1 % at 1 GeV/c
5 % at 1 GeV/c
15 % at 2 GeV/c
30 %Dielectrons

Temperature (intermediate mass)
Elliptic flow (v2 = 0.1)
Low-mass spectral function

not accessible
not accessible
not accessible
Heavy Nuclear States

Hyper(anti)nuclei L4 H yield
4 H yield
Hyper(anti)nuclei LL

35 %not accessible

Luminosity for minimum bias data!

* 0.1 nb-1 out of 1 nb-1 delivered luminosity** 10 nb-1 integrated luminosity

3.5 %
20 %

• ALICE will move from an observation to the precision

Table 1.1 illustrates that, with the ALICE upgrade, in some cases (D meson from B decays RAA , D
meson elliptic flow) we will move from an observation to the precision measurement, and other signals(dielectrons) will become accessible.

measurements
withdetector
upgrade1.2.7 Comparison with Other LHC Experiments

The ALICE upgrade and the proposed physics programme build on the demonstrated strengths of the
H. Masui / Univ. of Tsukuba

9

LS2
LS3

starting in 2018 (July)
LHC: starting in 2023 =>injectors: in 2024=>

18 months + 3months BC (Beam Commissioning)
30 months + 3 BC
13 months + 3 BC

ALICE goal beyond LS1
2015

2016

2017

2018

2019

2020

2021

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4

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LHC
Injectors

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Run 5

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LHC schedule approved by CERN management and LHC experiments spokespersons and technical coordinators
Monday 2nd December 2013•

Run 2 (2015-2017): Pb-Pb at ~ 5 TeV (~1-3 nb-1), p-Pb
(energy TBD), p-p at ~ 5 TeV•

Run 3-4: Pb-Pb at 5.5 TeV (~ 10 nb-1 at nominal B field + ~3 nb-1 at reduced B field), p-Pb & p-p at 5.5 TeV

H. Masui / Univ. of Tsukuba

10

TPC


ALICE TPC TDR, https://edms.cern.ch/document/398930/1• AcceptanceCentral Electrode(-100kV)

2E

‣ |η|<0.9, Δφ=2πE- diameter~5m, length~5m• 72 MWPC readout chambers

5m

‣ Outer: 18×2, Inner: 18×2

‣ 557,568 readout cathode pads

• Gas: Ne-CO2 (90-10)&15 mm2
5m

‣ drift field = 400 V/cm

OROC

• Maximum drift time ~ 100 µs• MWPC + Gating Grid Operation

n1)

s

on

Readoutchamber

114cm

IROC

‣ Rate limitation < 3.5 kHz

50cm
H. Masui / Univ. of Tsukuba

11

TPC with GEM readout
The ALICE Collaboration

inner diameter: 50 µm
outer diameter: 70 µm
pitch: 140 µm• A continuous, untriggered readoutof the TPC in Pb-Pb collision at
50 kHz rate

‣ MWPC readout leads to massive

charge accumulation in the drift volume
due to back-drifting ionsFigure 4.1: Electron microscope photograph of standard GEM foil with hole pitch 140 µm.
Figure 4.1: Electron microscope photograph of standard GEM foil with hole pitch 140 µm.

• GEM readout‣ Reduction of ion back-flow (IBF)‣ High rate capability‣ No ion tail

• Requirement for ALICE GEM TPC

re 4.2: Garfield / Magboltz simulation of charge dynamics for electrons (two in this simulation) entering into a GEM
hole/ [4].
Electron simulation
drift paths areofshownas light
lines, ion
paths as dark
Dotssimulation)
mark places where
ionization
Garfield
Magboltz
chargedynamics
fordriftelectrons(twolines.
in thisentering
into a GEM(multiplication)
processes
haveoccurred.
The lines,
paths have
beenpaths
projected
ontolines.
the crosssectionhole [4].
Electron drift
paths areshown
as light
ion drift
as darkDotsmarkplane.
places where ionization‣ IBF < 1% at gain = 2000

‣ Cluster energy resolution <12% for 55Fe
‣ Stable operation at high rate
H. Masui / Univ. of Tsukuba

12

T

for global tracks combining tracking in ITS and TPC. The good agreement of the simulated data shiown
in Fig. 7.2 (left panel) with the measured p–Pb data shown in Fig. 7.1 indicates a thorough understandingof material budget and detector response.

Expected performance
MWPC

TPC + vertex

TPC only tracks

0.014
0.012

TPC constrained tracks
TPC+ITS combined tracks

GEM

The ALICE Collaboration
TPC only tracks
TPC constrained tracks

T

0.012

T

86

0.014

m1/p (GeV/c)

m1/p (GeV/c)-1-1

ALICE TPC upgrade, http://cds.cern.ch/record/1622286

TPC+ITS combined tracks

0.01
0.01
centralevent (simulated with Pythia) in order to enhance thefraction of high-pT particles. Naturally, in
this0.008
simulation the actual tracks seen from the pileup eventsare constrained by the readout time window
0.008
defined by the central event.
0.006

0.006

Figure 7.4 shows that the TPC standalone tracking efficiency at the different interaction rates is essentiallythe same for the current TPC and for the GEM TPC.0.004
In these data, the lower bound scenario (central
0.004
event at Rint = 20 kHz) corresponds to an equivalent multiplicity dNch /dh|equiv = 2500, while the most
0.002 to dN /dh|
0.002 scenario (central event at Rint = 70 kHz) corresponds
extremechequiv = 5000. Figure 7.5 shows
the resolution in 1/pT for the GEM TPC for these different scenarios. The tracking performance is00
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
0 0.050.1 0.15 by
0.2 the0.25additional
0.3 0.35 0.4
0.45load.
0.5
essentially
unaffected
track
1/pT (GeV/c)-1

1/pT (GeV/c)-1

TPC tracking efficiency

TPC tracking efficiency

Figure 7.2: 1Resolution in 1/pT as a function of 1/pT for MWPC (left 1panel) and GEM readout (right panel). The open red
squares are for tracks based on TPC information only, while the closed blue squares show TPC track fits including
the vertex point. The open black squares show the result for combined fits to TPC and ITS track points.
0.995

0.995

The deterioration of the resolution for TPC-only tracks is consistent with the slightly worse position
resolution
the GEM-based readout chambers as compared
0.99 due to the narrower pad response function for 0.99
to the present MWPCs (see Sec. 4.5). However, in most of the acceptance region |h| < 0.9 clusters withsignals on more than one pad dominate, as shown in Fig.0.985
4.16.
0.985

central event at 20kHz
central event at 30kHz
central event at 40kHz
central
event
at
40kHz
0.98
0.98
central(1eventcentral
event
at
50kHz
The relative dE/dx resolution sdE/dx /hdE/dxi for isolated electron and pion tracks< at
p 50kHz< 6 GeV/c)central
event
at
60kHz
central event at 60kHz
GEM
MWPC
at 70kHzwas measured
with a triple-GEM
IROC
at the CERN PS test beam. central
The eventresults
reported incentralevent atprototype
70kHz
event at 20kHz
7.2.3 Particle identification central
performancecentralevent at 30kHz

0.975
0.975 show that the dE/dx resolution observed with
Sec. 5.2.6
theis compatible
withthat of
0 GEM
0.5 IROC
1
1.5
2
2.5
3
3.5
4 the
0
0.5
1
1.5
2
2.5
3
3.5
4
-1
-1
1/pT (GeV/c)
1/pT (GeV/c)
MWPC IROCs. This behavior is confirmedin the simulation: Figure 7.3 (left panel) shows
the dE/dx
resolution
a function
the momentum
MWPC
and GEM
readout
at low
track In
multiplicity.
Figure 7.4:as
TPC
standalone oftracking
efficiency for for
MWPC(left panel)
and GEM(right panel)readout.
the simulated Onlydata
a small difference
betweenand
GEMareisembedded
observed.
central events(hdNchMWPC/dhi scaled
to 2000)
in the avereage background given by minimum bias events• Preserve the present TPC performance with GEM upgrade(hdNch /dhi scaled to 500) at different interaction rates.

Figure 7.6 compares the dE/dx resolution for MWPC and GEM readout at different interaction rates. For
H. Masui / Univ. of Tsukuba

13

accumulated in a typical yearly heavy-ion run (⇠ 3 nb 1 ) with the current (left) and upgraded (right)
TPC.

Low mass di-leptons
PbPb @ sNN = 5.5 TeV
0 - 10%, 2.5E7 events-1

10|ye| < 0.84
peT > 0.2 GeV/c
0.0 < p < 3.0
t,ee

-2

10

Sum
Rapp in-medium SF
Rapp QGP
cocktail w/o ρ (± 10%)cc → ee (± 20%)
2.5E7 'measured'
Syst. err. bkg. (± 0.25%)

ALICE simulation
Current rate
New ITSB = 0.2T

10-3

dN/dMeedy (GeV-1)

dN/dMeedy (GeV-1)

ALICE TPC upgrade, http://cds.cern.ch/record/1622286
PbPb @ sNN = 5.5 TeV
-1

10

-2

10-5

10-5

10-6
0

10-6
0

1.5

2

2.5
Mee (GeV/c2)t,ee

ALICE simulation
High rate
New ITSB = 0.2T

10-3
10-4

1

|ye| < 0.84
peT > 0.2 GeV/c
0.0 < p < 3.0

10

10-4

0.5

0 - 10%, 2.5E9 events

Sum
Rapp in-medium SF
Rapp QGP
cocktail w/o ρ (± 10%)cc → ee (± 20%)
2.5E9 'measured'
Syst. err. bkg. (± 0.25%)

0.5

1

1.5

2

2.5
Mee (GeV/c2)• Significant improvement on statistical uncertainty with TPC

pFigure 1.1: Inclusive e+ e invariant mass spectrum for 0 – 10 % most central Pb–Pb collisions at sNN = 5.5 TeV, assuming
2.5 · 107 events (left panel) and 2.5 · 109 events (right panel). The spectra include a set of tight primary track cuts
based on the new ITS system to suppress leptons from charm decays. Also shown are curves that represent thecontributions from light hadrons (blue), charm (magenta) and thermal radiation from a hadronic gas (red) and a‣ Dalitz
decay,QGP (orange).
The conversion
figures are from [2].and charm rejection by ITS, electron(and ITS) upgrade for low mass di-lepton measurement
identification by TPC+TOF → reduce systematic uncertainty

H. Masui / Univ. of Tsukuba

14

ITS

Present ITS• Present ITS - 6 cylindrical layers‣ 2 layers each of SPD (Silicon Pixel Detector), SDD (Silicon Drift

Detector) and SSD (double sided Silicon Strip Detector)

onsists‣ of
6 cylindricalsilicon detectors – 2 layers each ofRatelimitation ~1layers
kHz in of
Pb-Pb
Detector(SPD),
SiliconDrift Detector(SDD)
andatdouble‣ Poorstatisticalprecisionfor charmed
mesonslow pT sided
Strip Detector‣ Cannot (SSD)
reconstruct charmed baryons in Pb-Pb collisions
Quark Matter 2014, Darm stadt | May 21, 2014 | Sabyasachi Siddhanta
H. Masui / Univ. of Tsukuba

415

Design goals of ITS upgrade
1.3 Upgrade overview

7

Parameter

Present
ITS

New
ITS

Pseudorapidity
acceptance|η| < 0.9

|η| < 1.22

Radius of innermost layer

39 mm~23 mmSi thickness~350 µm~50 µmPixel size

50µmx425µm

O(20µmx30µm)

Material budget
per layer~1.1%X0~0.3-0.8%X0

Max. ratein Pb+Pb~1 kHz~100 kHz,QQHU%DUUHO2XWHU%DUUHO%HDPSLSH

C

Figure 1.1: Layout of the new ITS detector.

• 7 layers of Monolithic Active Pixel Sensors

a particle was crossing a pixel is read out. The main functional elements of the new ITS are
introduced in the following section, while its main geometrical parameters are listed in Tab. 1.1.
As will be shown in Chap. 7, a new silicon tracker featuring the characteristics listed above
will enable the track position resolution at the primary vertex to be improved by a factorof three or greater.
The standalone
efficiency
would
be comparable
what canbe reduced material budget
Smallerradiustracking
of innermostlayer,
smallertopixel
size,
presently achieved by combining the information of the ITS and the TPC, but extended tomuch lower values of transverse momentum. The relative momentum resolution of the silicon
T to 20 GeV/c.
T
tracker standalone would be about 4 % up to 2 GeV/c and remain below 6 % up

‣ Improve a factor of 3-5 impact parameter resolution-‣ Improve tracking efficiency and p resolution at low p-

number of layers & granularity
1.3.2 DetectorIncreaselayout overview‣ Fast readout & easy maintenance

The geometry and requirements of the new ITS provide a natural grouping of the seven layers
in two separate barrels (Inner Barrel and Outer Barrel), each with di↵erent specifications, as
shown in Figs. 1.1 and 1.2. The Inner Barrel consists of the three innermost layers, also referred
to as Inner Layers (Layers 0 to 2), while the Outer Barrel contains the four outermost layers,

H. Masui / Univ. of Tsukuba

16

Expected performance
ALICE ITS upgrade, http://cds.cern.ch/record/1625842/
300

in rφ

in z

Standalone tracking efficiency

90

Current ITS

250

80

IB: X/X0= 0.3%; OB: X/X0= 0.8%
200

IB: X/X0= 0.3%; OB: X/X0= 1.0%
IB: X/X0= 0.3%;OB: X/X0= 1.2%

150

70
Efficiency (%)

Pointing Resolution, σ (µm)

100

100

60

Current ITS

50

IB: X/X0= 0.3%; OB: X/X0= 0.8%

4030

IB: X/X0= 0.3%; OB: X/X0= 1.0%

20

50

IB: X/X0= 0.3%; OB: X/X0= 1.2%

10
0.05

0.1

0.2

0.3
2
3 4 5 6 7 8 910
1Transverse Momentum, p (GeV/c)

0.05

0.1

T

Current ITS
Pointing resolution is improved by a factor of ~3(5)in rφ (z)IB: X/X = 0.3%; OB: X/X = 0.8%
IB: X/X = 0.3%; OB: X/X = 1.0%
direction
10

T
T

T

‣ not affected by variations of material budget
1

•

0.3
2
3 4 5 6 7 8 910
1Transverse Momentum, p (GeV/c)
T

Momentum Resolution, ∆ p /p (%)•

T

Momentum Resolution, ∆ p /p (%)

10

0.2

0

0

0

0

IB: X/X0= 0.3%; OB: X/X0= 1.2%

ITS
Improve Current
efficiency,
particularly in low pT
IB: X/X = 0.3%; OB: X/X = 0.8%
001

IB: X/X0= 0.3%;
OB: X/X= 1.0%range of 92-94% at 200 MeV/c in pT‣ slightly affected,
e.g.
in 0the
IB: X/X0= 0.3%; OB: X/X0= 1.2%

H. Masui / Univ. of Tsukuba

17

Heavy flavor flow

8.2 Heavy flavour
v2

0.6

ALICE

0

0
0.6

Prompt D , D|y|<0.8

0.4

0.4

0.2

0.2

-0.2

2

4

6

8

0.

0.2
0

0.05

-0.2

0.

0

+
Ds , 30-50%
centr.
0.4
Λ+c, 10-40% centr.

0.1

sNN = 2.76 TeV

Centrality 30-50%

Prompt D int|y|<0.8
D0, 30-50% centr.

0.15

0Pb-Pb,± 0.6
Pb-Pb,
L = 10 nb-1

0.2

PRL111, 102301 (2011)

0

0.25

v2

New ITS

v2

Present ITS

0.
Ope

-0.2
ALICE ITS upgrade,

http://cds.cern.ch/record/1625842/ Shaded b

10

12

14

16

18

p (GeV/c)
T

2

4

06
0

82

104 126 148 1610 1812 214 416 6
pT (GeV/c) p (GeV/c)
T

0 , D+ and ⇤ (left) and of D0 an
0+∗+Figure
8.21:
v
of
D
2
c
s
for prompt D , D and D mesons
forPb–Pb colliure 2: v2 as a functionof pT
0statisticalfor Lint = 10 nb 1prompt.
Precision D v2 measurements up
to pTuncertainties~16 GeV/c
feed
down
50%. The central value was obtained with the assumption v2= v2. VCharm v2 down to pT~0 GeV/c with prompt D0
statistical uncertainty, empty boxes the systematicdueandto atheD factormesscaling withuncertainty
hNcoll i for the signal
scaling
For J/
decays, witha dedicatedstudy to asses‣ Beauty v2 can be also measured down
to pfrom
B-decay
T~0BGeV/cthe event-plane
resolution,andshaded
boxes
show
the
uncertainty
fromthewascontr0
carriedout.
Thecentrality
class
10–40
%
found
D
lower significance, because the signal yield and thed-down.

••in 30–50 %.
The v2 measurement
performed using
theH. Masui / canUniv. beof Tsukuba
18

escription of the MFT geometry has been developed and implemented within the AliRoot framerk (which is the ALICE offline official computing code) for a full simulation of the detector reoninformation,
behalf of
ALICE
onse. The entire flow ofstartingfrom Collaboration
the hits generated by the particles up to theonstructed clusters of pixels on the MFT planes, has been described in AliRoot by means ofdicated C++ classes. The final stage of the full simulations is the creation of the global tracks
matching the MUON tracks reconstructed in the Muon Spectrometer to the clusters found in
MFT planes. Future developments will include a standalone tracking, aiming at reconstructall the tracks in the MFT (MFT tracks), and a standalone vertexing, aiming to reconstruct thesition of the primary interaction and secondary vertices including collision pile-up effects. Stanone tracking and vertexing in the MFT will provide additional information improving the event

Other detector upgrades

H. Trzaska,

Forward trigger upgrade;
Fast Interaction Trigger (FIT) detector

Muon Forward Tracker (MFT)
ALICE MFT upgrade, http://cds.cern.ch/record/1592659
UPGRADEe scheduled for 2018 will boost the luminosity and collision rate
ut capability of the current forward trigger detectors. They will be
ast Interaction Trigger (FIT). The concept of FIT has evolved from
ined by three ALICE groups: FMD, T0 and V0. FIT will incorporate
erenkov radiators (T0+) and modules with plastic scintillator plates
integrated electronics and readout. Both modules will use MCP. This poster describes the Cherenkov option.

OR CONCEPT

36

FoCal: high-granularity
calorimeter
The ALICE FoCal Collaboration
REQUIRED FUNCTIONALITY FOR FIT
at forward rapidity η~4-5*

ed particles passing through an optical medium with refractive
pad-segments
unity emit a cone of light known as Cherenkov radiation. In case The upgraded trigger detector needs to provide ALICE with:* still in review phase, possibleorwith refractive index n = 1.458 the emission angle of photons isgure 2.1: The MFT planes in a view including the beam pipe design. The Beryllium section of!
Minimum Bias trigger with efficiency comparable to the current V0
installation during LS346.70.
These
forwardare connectedreflected
the ! ! Vertex determination performance atpipe is shownin red, while
the blue emitted
parts are thephotons
Aluminum sections
by thefrom
Aluminum
the level of the current T0
lows
Althoughincludedin focused
the setup considered
for theMCP-PMT
simulations, the to
VZERO
detectortheisthe(brown).
radiator
and
are
on
the
which
ALICE readout & trigger system,
2 Upgrade architecture! Event Multiplicity determination capable of selecting and triggering
shown in this figure.
ally coupledwith special grease. T0+ detector modules andhttp://cds.cern.ch/record/1603472/
on central as well as on semi-central collisions
ibrated with remotely operated fast blue laser (401 nm) delivering!
time resolution of better than 50 ps (current T0 performance)
l splitter and fibers to each MCP-PMT.
!
Precise collision time for TOF (required off line)

Readout & trigger system upgrade

DESCRIPTION

maximize the efficiency for Minimum Bias events requires efficientavailable space with detector modules. The envelopes defined byn are a minimum inner radius of 50-60 mm and a maximum outer
mm. Each MCP-PMT module will be divided into 4 equal parts byz radiator into 4 and arranging the 64 anode sectors into thegroups. As a result, each array on the A and on the C-side will
=80 independent detector units.

Reduced signal latency (to be implemented already during LS1)
tungsten layers!
Event plane determination≈3.5mm thickness!
Reliable and stable operation, capable of handling the LHC´shigher luminosity and bunch crossing frequency after LS2!
Minimal aging over the lifetime of upgraded ALICE!
No after pulses or other spurious signals!
Readout electronics compatible with TOF detector’s DRM&TRM!
Direct feedback to LHC on luminosity and beam condition!
Evaluation and rejection of beam-induced background!

low granularity
pad-layers ≈1cm2,
longitudinally summed
in segments

read-out boards
for pad segments

high granularity pixel-layers
effectively ≈1mm2,
likely using MAPS

DETECTOR EFFICIENCY
H. Masui / Univ. of Tsukuba

Fig. 28: Schematic view of the longitudinal structure of the FoCal-E detector.

19

Summary• DCAL will be ready in 2015

‣ Half of DCAL has been installed in ALICE, other half will be installed

this year‣ Commissioning is on-going• ALICE detector upgrades have been proposed for precision
measurements on rare probes‣ Unique on heavy-flavor, low mass di-leptons in low pT• Inspecting 50 kHz of minimum bias Pb-Pb collisions‣ Key detector upgrades: TPC with GEM readout, ITS, DAQ‣ continuous readout for TPC and ITS & online event reconstruction‣ Significant efforts on detector R&D are on-going

H. Masui / Univ. of Tsukuba

20