A Large Ion Collider Experiment

ALICE physics highlights and perspectives
Luciano Musa (CERN)

20th Lomonosov Conference
Mikhail Lomonosov (1711 – 65)

Moscow, 19 - 25 August 2021

1

A Large Ion Collider Experiment

Outline①

Introduction②

Physics highlights③

Preparations for Run 3④

Future perspectives

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

2

A Large Ion Collider Experiment

Outline①

Introduction②

Physics highlights③

Preparations for Run 3④

Future perspectives

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

Other ALICE talks at this conference
Igor Altsybeev

Overview of recent ALICE results on particle
correlations and fluctuations

19.08.A ✓Tatiana
Karavicheva

ALICE upgrade overview for Run 3 and 4 at the
CERN LHC

19.08.A ✓Dmitry Blau

Overview of direct photon and neutral mesons
measurements with ALICE at the LHC

23.08.C

Viktor Riabov

Recent results on light flavor hadronproduction in the ALICE experiment at the LHC

23.08.C

ValeriPozdniakov

Recent results on ultra-peripheral collision
studies with ALICE at LHC

23.08.C

Artem Isakov

Analysis of b jets production in p--Pb and pp at√sNN = 5 TeV with ALICE

23.08.C3

A Large Ion Collider Experiment

The ALICE Collaboration

42 Countries, 173 Institutes
1946 Members
about 1000 signing authors
Russia in ALICE• 174 members• 94 authors• 39 Ph.D. scientists

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

4

A Large Ion Collider Experiment

The ALICE detector (version 1: Run 1 + Run 2)
Central Barrel |h| < 0.9• Tracking• PID• EM-Calorimeters

ITS
EMCAl
TOF

TRD
HMPID

ACORDE (cosmics)
Forward detectors:• AD (diffraction selection)• V0 (trigger, centrality)• V0 (timing, luminosity)• ZDC (centrality, ev. sel.)• FMD (Nch)• PMD (Ng, Nch)
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

TPC

EMCAl + PHOS

Muon Spectrometer-4 < h < -2.5

5

A Large Ion Collider Experiment

ALICE data taking and publications
Run 1 (2009 – 2013)

LS1

Run 2 (2015 – 2018)

LS2

ALICE I

Year(s)√sNN (TeV)

Lint

Pb-Pb

2010, 20112015, 2018

2.76
5.02

~75 µb-1~800 µb-1

Xe-Xe

2017

5.44

~0.3 µb-1

p-Pb

2013
2016

5.02
5.02, 8.16

~15 nb-1~3 nb-1, ~25 nb-1

2009-2013

0.9, 2.76,
7, 8
5.02
13

~200 mb-1, ~100 nb-1
~1.5 pb-1, ~2.5 pb-1
~1.3 pb-1~36 pb-1

Run 1

2015, 20172015-2018

Run 2

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

LS3

Run 4 (2027 – 2029)

ALICE 2

Systempp

Run 3 (2022 – 2024)

352 ALICE papers on arXiv so far

http://alice-publications.web.cern.ch/submitted
6

A Large Ion Collider Experiment

A few physics highlights… focus on new results

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

7

A Large Ion Collider Experiment

Focal point of the experiment: characterize the QGP• Explore the deconfined phase of QCD matter a quark-gluon plasma• LHC Pb-Pb a large energy density (initial e > 15 GeV/fm3) & large volume (~5000 fm3)

Study the time evolution of the collision• Initial stage• Macroscopic properties• Colour deconfinement• Parton interactions• Expansion dynamics• Hadronic phase

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

•
•
•
•
•
•

Light flavour (including light-nuclei) production
Heavy flavour production
Quarkonia
Photons, low-mass dileptons
Jets
Ultra Peripheral Collisions8

A Large Ion Collider Experiment

ALICE Pb+Pb → Pb+Pb+J/ψ

10

Pb

t

8

Pb

s NN = 5.02 TeV

ALICE coherent J/ψ
Impulse approximation
STARLIGHT
EPS09 LO (GKZ)
LTA (GKZ)IIM BG (GM)
IPsat (LM)BGK-I (LS)GG-HS (CCK)b-BK (BCCM)

12dσγ Pb/d|t | (mb c 2 GeV-2)

arXiv:2101.04577
arXiv:2101.04577

14

nuclear effectdσ/dy (mb)

Coherentin Pb-Pb
C heJ/e𝛙 photoproductionJhd c ultra
i peripheral
in Pb-Pbcollisions
UPC

6

arXiv:2101.04623 arXiv:2101.04623
10

ALICE Pb+Pb → Pb+Pb+J/ ψs NN = 5.02 TeV

ALICE coherent J/ ψ, |y|<0.8
Experimental uncorrelated syst. + stat.
Experimental correlated syst.
UPC to γ Pb model uncertainty

1STARlight (Pb form factor)
LTA (nuclear shadowing)b-BK (gluon saturation)

1

Model / Data

Eskola et. al., EPJC 77 (2017) 163

4y

ALI−PUB−479954

2
0

−4

ALI-PUB-479915

•

−3

−2

−1

0

Probing low-x gluon PDFs in the nucleus

2
1.5
1
0

New measurment probing low-x gluon nuclear PDFs

STARlight / Data
LTA / Datab-BK / Data

0.002

0.004

0.006

0.008

0.01
0.012
|t | (GeV2 c -2)|t|| pT2|t| ≈ pT2••

Comparison with the impulse approximation (no nuclear effects) allows-3
for extractionof theshadowing
factor: Rg ~(no0.65nuclear
at x∼10effects)
Comparison
withthegluon
impulseapproximation
allowsextraction ofisthegluontoshadowing
factor:Rg ~ 0.65 at x ~ 10-3
•fort-dependence
sensitive
transverse gluon
distribution
For more details see LHC Seminar by Michal Broz on March 2

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

• First measurement of t-dependence: sensitive to transverse
gluon distribution
talk V. Posdniakov

5
9

A Large Ion Collider Experiment

Neutral pion spectra over 3 pp,
ordersof magnitudenorm.
in unc.
pT 2.6%s = 8 TeV, ALICE
0

Theory, Data
TCM fit

π , |y |< 0.8
Neutral pions measured from pT = 0.3
GeV/c,
with photon conversion and EM calorimeters
2.0 to 200
NLO,
FF:DSS14
PDF:CT10• p-Pb collisions: nuclear modification
1.5 of parton distribution functions:a Low pT: Rp-Pb < 1 due to nuclear shadowing

and EMCal detector

arXiv:2104.03116

a)ss, F.Jurczak

High pT: no significant modification

1.0

1

1.5

10

p− Pb, s NN = 8.16 TeV, ALICE
π0, -1.3 < y < 0.3
η, -1.3 < y < 0.3

2

p 10(GeV/
norm. unc.
3.4% c )T

Rp-Pb = 1 for no nuclear
effects in p-Pb collisions

R pPb

1.0

0.5

π0 CGC, k T fac., FF:DSS LO
π0 FCEL, y = -0.5, gg → gg
π0 NLO, PDF:EPPS16 / CT14 - FF:DSS14
π0 NLO, PDF:nCTEQ15 / CT14 - FF:DSS14b)
0.0
Figure 1: ALICE detector in Run II

0.3

1

2

3 4 56

10

20 30

100

200

Sensitivity to nuclear
shadowing / parton saturation
at low momentum

talk D. Blaup (GeV/c )T

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021
Time Calibration of EMCal ALICE detector

PPSS 27 July 20184 / 1810

A Large Ion Collider ExperimentJ/y dissociation and (re)generation at the LHC

Cartoon from Nature 448, 302–309(2007)

J/ψ suppression reduced at low pT
cc regeneration counterbalances the
suppression by screening in the QGP•

At low pT , modification decreases fromforward to central rapidity•

reflects rapidity dependence of the cc
cross-section (a regeneration probability)

ALI-DER-346483

1

𝑑𝑁/𝑑𝑝% |&'&'
𝑅!! =⟨𝑁"#$$ ⟩ 𝑑𝑁/𝑑𝑝% |((L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

11

A Large Ion Collider Experiment

Suppression of bottomonia in Pb-Pb collisions
arXiv:2011.05758

Varying the binding energy: y(2S) < Y(2S) < J/y < Y(1S)Ȋ 6 DQGȊ 6 5$$LQ3E3E
0.05
0.55
0.65 1.1 GeV)ODWVXSSUHVVLRQYVS
IRUȊ 6 UHFRPELQDWLRQHIIHFWVVPDOO• 䚔Screening
induces a strong
7 suppression of Y production, which is flat vs pT a recombination effects small•

Υ(2S) (first time!) at forward rapidity - a suppression stronger wrt Y(1S) consistent with lower binding energy䚔 $/,&(GDWDFRPSOHPHQW&06UHVXOWVPRGHOVGRQRWGHVFULEHZHOOWKHȊ 6 WUHQGFORVHWR\ • 䚔Hint
of a decrease of the RAA at large rapidity not described by models
6HTXHQWLDOVXSSUHVVLRQVFHQDULRIRUWKHERWWRPRQLXPIDPLO\
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

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A Large Ion Collider Experiment

loss andof c and b quarks in P
Energy loss and hadronization of c and bEnergy
quarksin hadronization
the QGP (1)0D
Promptvsnon-prompt
RAA consistenLess suppression for (non-prompt) D mesons from B decays than prompt D mesons•••

Quarks and gluons lose energy while traversing the
QGP (RAA < 1)
Energy loss predicted to depend on QGP density,
but also on quark mass
“Dead cone effect” reduces gluon radiation for
high-mass quarks
radiation suppressed for 𝜽C < mQ /E• Also note: first measurement of D meson production
down to zero pT in Pb-Pb• More precise measurement with new ITS in Run 3

R AA

talk Stefano Trogolo
1.6

Pb-Pb, s NN = 5.02 TeV
0-10%, |y |<0.5

1.4

Fir
do

Non-prompt D0

1.2

Prompt D0

1

non-prompt D0
prompt D0

0.8
0.6

D0

Co
(d

0.4
0.2
0
ALI−PREL−332574

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

Non-prompt D0

ALICE Preliminary

10

20

30

40
50
p (GeV/c)T

13

M

A Large Ion Collider Experiment

Energy loss and hadronization of c and b quarks in the QGP (3)RAA(non-prompt D+s ) > RAA(non-prompt D0) consistent with coalescence picture0line with coalescencepicturet D )•in non-prompt
D+S less suppressedthan non-prompt
golo
D0 at low pT
Non-prompt D+s less suppressed than
non-prompt D0 at low pT 0
• enhanced production of B s from beauty
hadronization
via coalescence (50% of D+s from B0s)
0
Points to Bs production via coalescence

25

s
d

s
u

d u
u
d

d

d
s

b
u

d

s

u
d

0
Bs

+
Ds + X

s

s
c

b

0
~50% of D+s from Bs ,~50% from non-strange B

R AA (non-prompt D+s) / R AA (non-prompt D0)

ks in Pb-Pb (4)

5.0
4.5
4.0

ALICE Preliminary
0−10% Pb−Pb, s NN = 5.02 TeV|y | < 0.5

3.5

data

3.0

TAMU

2.5
2.0
1.5
1.0
0.5
0

open markers: pp extrapolated reference

5

10

15

20
25
p (GeV/c )T

TAMU model, He, Fries, Rapp,
PLB 735th (2014) 445

L. Musa (CERN) – 20 Lomonosov Conference - 22 August 2021

ALI−PREL−486723

14

A Large Ion Collider Experiment

QGP expansion: collective flow of hadrons
Flow of identified hadrons in Xe-Xe collisions … similar to Pb-Pb collisions

vn quantify the event

Geometrical elliptical shape à azimuthal modulation in momentum distributions

momentum anisotropy
spatial anisotropy
higher harmonics (v3 v, v4coefficients, …)
εn coefficients
n

v2 –

refle
geom

Flow of identified hadrons in Xe–Xe

V2 – elliptic flow reflects the almond-shaped geometry of the interaction volume
https://arxiv.org/abs/2107.10592
ALICE, arXiv:2107.10592 (2021)

centralityv2

pT < 2-3 GeV/c - clear “mass ordering”
from collective dynamics during hydro expansion 3(heavier hadrons shifted to higher pT by radial flow)

v

v3 –

origi
fluct

3 < pT < 8-10 GeV/c - baryons flow more than mesons
consistent with hadronisation by coalescence
Evolution with pT and centrality similar to Pb-Pb collisions
talk I. Altsybeev
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

15

fundamental prediction of QCD, the dead cone
each step
Define:A Large Ion Collider Experiment

Direct observation of the dead-cone effect in QCD•Iteratively decluster jets with a fully reconstructed D0 amongits constituents0 splittings
Radiator:quark leadalways
prong•Follow
the prongcontaining
Dare
The deepest
levels of thethe
jet treeby measuring D0-meson tagged jets in hadronic
collisions
E=energy of the splitting
at small angles/lower energies
prong at eachdeclustering stepthe splitting energy E•Register
splittingkT atradiator->most sensitive
to mass andand thethe
dead cone
effect(pp 13 TeV)
Outlook: b-jets
each
Cunqueiro, Ploskon,Phys.Rev.Dstep
99 (2019) 7, 074027
radiator

9

Follow a heavy quark through the primary Lund Plane &Define:suppress hadronization effects/non pert. (at small KT)

The Lund plane of heavy-quark jets: exposing a
Ratio of the splitting prediction
angle (θ) distributions
forD0fundamentalofQCD,
the dead conemeson tagged jets and inclusive jets, in bins of E
radiator

PYTHIA 8 q / inclusive
no dead cone limit

PYTHIA 8SHERPA

1.5

charged jets, anti-k T, R =0.4

k T > ΛQCD / 2 , ΛQCD = 200 MeV/c

C/A reclustering|η | < 0.5

0.14
0.08the splitting
0.22
0.14
0.08
E0.22
of
radiator=energy
prong
at eachdeclustering step
5 < E Radiator< 10 GeV
10 < E Radiator < 20 GeV

D0- tagged jets / Inclusive jets

R (θ )

0.37

SHERPA q / inclusive
no dead cone limit

pp s = 13 TeV

1.5

Cunqueiro, Ploskon, Phys.Rev.D 199 (2019) 7, 074027

1
0.5

0.5

0 -meson candidate at each smoreθthan(rad)99% of the cases the prong containing the D
The deepestof theare splittings
with the levels
leading prong.
This jetmeanstreethat following
the D0 -meson candidate or leading
0.22
0.14
0.08
0.05
and therefore
a complementary measurement for an inclusive jet sample
at smallis equivalentangles/lower
energies
20 < E Radiator < 35 GeV
is available,
can be madefollowingleadingeffectprong through the recluster->most tagging
sensitive
to mass
andbythedeadthecone
the inclusive sample is dominated by massless gluon and nearly massless light quark-in
as a reference to highlight the mass effects present in the charm-tagged sample.
lab

D0- tagged jets / Inclusive jets

ALICE Data

Figure 1: A sketch detailing the reconstruction of the showering charm quark, using iteratpresented. The top panels show the initial reclustering procedure with the C/A algorithm,
separated by the smallest angles are brought together first. Once the reclustering is comple
procedure is carried out by unwinding the reclustering history. Each splitting node is number
declustering step in which it is reconstructed. With each splitting, the charm quark energy, ERadi
the gluon is emitted at a smaller angle, qn , with respect to previous emissions. At each splittin
are suppressed in the dead-cone region (shown by a red cone for the last splitting), which increch,leading trackp≥ 2.8 GeV/
c energy decreases throughout the shower.
quark
T,inclusive jet

1.5

Radiation suppressed in the
expected angular region (shaded)

1

0.5

9

Suppression lifted as
4 Extracting thetrue charm
splittings
mass
Q << Eradiator

The selected sample of splittings has contributions from jets tagged with combinato
which
by theapplied topologicaland particle identification selection
1
1.5
2
2.5
31
1.5
2
2.5
31
1.5
2
2.5 are not
3 rejected[nucl-ex]
arXiv:
2106.05713
0invariantln(1/massθ ) of real D mesons, which corresponds to the rest mass, is distributed in a
in the measurement of the momenta of the K⌥ p ± pairs) with a peak at t
at low
for D0 jets as compared to inclusive uncertainties
jets• Suppression
L. Musa (CERN) –of
20themissions
Lomonosov Conference- 22angles
August 2021
16
mass. This allows for the implementation of a statistical 2D side-band subtraction• Smaller effects for higher splitting energy

A Large Ion Collider ExperimentCharm baryon/meson measurements in pp collisions
Λ+c/D0Charm hadronization differs at the LHC
0.8
0.7

arXiv:2011.06078 arXiv:2106.08278
ALICE

0.6

arXiv:2105.05187

arXiv:2105.06335

PYTHIA 8.243, Monash 2013
PYTHIA 8.243, CR-BLC:
Mode 0Mode 2Mode 3
SHM+RQM
Catania
QCM

0.5
0.4
0.3

|y | < 0.5

0.2pp, s = 5 TeV
pp, s = 13 TeV

0.1

BR uncertainty

1e+e– collisions

10
p (GeV/c )T• unique measurements (at low-momenta) of Lc (also Xc and Wc)• cross section (fragmentation fraction) larger than expected (ee and ep)
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

17

A Large Ion Collider ExperimentCharm baryon/meson measurements in pp collisions
Λ+c/D0Charm hadronization differs at the LHC
arXiv:2011.06078 [nucl-ex]

0.8
0.7

ALICE

0.6

arXiv:2105.05187 [nucl-ex]

PYTHIA 8.243, Monash 2013
PYTHIA 8.243, CR-BLC:
Mode 0Mode 2Mode 3
SHM+RQM
Catania
QCM

0.5
0.4
0.3

|y | < 0.5

0.2pp, s = 5 TeV
pp, s = 13 TeV

0.1

BR uncertainty

1e+e– collisions

10
p (GeV/c )T• unique measurements (at low-momenta) of Lc (also Xc and Wc)• cross section (fragmentation fraction) larger than expected (ee and ep)
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

18

A Large Ion Collider Experiment

Strong interaction between hadrons (1)Stronginteraction
between hadrons(1)
Stronginteraction
betweenhadrons

Correlation
function
sensitivetopotential
Correlation
functionsensitive
sensitive
to interaction
interaction
potential
Correlation function
to interaction
potential

talk I. Altsybeev

1. Fix source geometry
1. Fix source geometry
2. Measure correlation fct. C(k**)
2. Measure correlation fct. C(k )→ study the strong interaction→ study the strong interaction

talk
talkBhawani
BhawaniSingh
Singh
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

EPS-HEP
2021 || Highlights
Highlights fromfromthetheALICE
ALICEexperimentexperiment| K.
| K.Reygers
Reygers
EPS-HEP 2021

3535

19

A Large Ion Collider Experiment

Strong interaction between hadrons
ALICE measurements on topic
Phys. Rev. C 99 (2019) 024001

p-p, p-L, L-L (pp)Phys. Lett. B 797 (2019) 134822

L-L (p-Pb)

3URWRQK\SHURQLQWHUDFWL“Unveiling the strong interaction among stable and unstable”
Nature 588 (2020) 232-238

Ë$QHZ-

Phys. Rev. Lett. 123 (2019) 112002

p-X (p-Pb)

Phys. Rev. Lett. 124 (2020) 092301

p-K (pp)Phys. Letters B 805 (2020) 135419

p-S (pp)Phys. Lett. B 811 (2020) 135849

source size in pp

Nature 588 (2020) 232-238

p-W (pp)

arXiv:2104.04427

NL – NS (pp)arXiv: 2105.05578

p-f (pp)

arXiv:2105.05683

K-p (Pb-Pb)

arXiv:2105.05190

p-/p, p-/L, L-/L (pp)Proton-hyperon (p-Y) strong interaction poorly known䌏(YLGHQ䌏'DWDVKSȄU sIPSȍU sIP

$/,&(SDWGLVWD
Ɣ &RQVH[LVWH
Ɣ 5HFHQFDQE

precise measurement of strong interaction for p-X- and p-Wo direct comparison to lattice QCD
o p-X- important for the EoS of neutron stars (which containhyperon-rich matter)
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

20

A Large Ion Collider Experiment

Upgrade activities for Run 3 and Run 4
ALICE version 2.0

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

21

A Large Ion Collider Experiment

ALICE Detector Version 2.0 (Upgrades for Run 3+)- From LoI to last TDR: 2013 – 2015 ✓- Construction: 2016 – 2019 ✓- Installation: 2020 – 2021 ✓- Global commissioning: ongoing
DEC 2012

NOV 2013

DEC 2013

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

SEP 2013

MAR 2014

MAY 2015

NOV 2015
22

A Large Ion Collider Experiment

ALICE Detector Version 2.0 (Upgrades for Run 3+)
Runs 1 and 2: 1 nb-1 of Pb-Pb collisions

talk T. Karavicheva

91Interaction rate ~8 kHz

98readout rate ≈ 1 kHz

511

LS2 upgrade• New TPC R/O planes• New silicon tracker (ITS & MFT)
• New Fast Interaction Trigger (FIT)• New Online/Offline system (O2)
• Upgrade readout of all other detectors> Improve tracking
resolution at low pT

9
7

10

2
3

4

5

6

x50 statistics increase
for most observables

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

10

10

10
11

1

ITS | Inner Tracking System

2

TPC | Time Projection Chamber

3

TRD | Transition Radiation Detector

4

TOF | Time Of Flight5

EMCal | Electromagnetic Calorimeter

6

PHOS / CPV | Photon Spectrometer

7

HMPID | High Momentum Particle

8

MFT| Muon Forward Tracker

9

FIT | Fast Interaction Trigger

10

Muon Spectrometer

11

ZDC | Zero Degree Calorimeter

Identification Detector

Run 3+Run 4: 13 nb-1 of Pb-Pb collisions
readout rate ≈ 50 kHz (Pb-Pb), ≈ 1 MHz (pp)online reconstruction : all events to storage!
23

A Large Ion Collider Experiment

TPC Upgrade for continuous readout

2 TPC

continuous
readout (ano gating grid)
ratesGoal:
withTPCGEMs(replacing
MWPCs)

Solution: Replace MWPC with 4-GEMs
Continuous readout at 50 kHz
Pb-Pb
interaction ratepossible100
m2 single-mask
foils GEM
production
due to GEMs
Fully installed in August 2020

Read Out Chambera GEM provides ion backflow suppression to < 1%a 524 000 pads readout continuously a 3.4 TByte/sec

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

EPS-HEP 2021 | Highlights from the ALICE experiment | K. Reygers

924

A Large Ion Collider Experiment

New Inner Tracking System and Muon Froward Tracker
Inner Tracking System upgrade (ITS2)
ITS2
MFT

• Closer to the IP: first layer at ≈22 mm• Smaller pixels: 28 x 29 µm2• Lower material budget: 0.35% X0

a improved pointing resolution (x 3)a Improved tracking efficieny at low pT

CERNCOURIER
July/August 2021 cerncourier.com

PIXEL
PERFECT
Exploring the Hubble tension

Reporting on international high-energy physics

Based on MAPS technology (ALPIDE)•

10 m2 active silicon area•

12.5 G-pixels•

50 𝝁𝒎 thin sensor•

Spatial resolution ~5µm•

Max particle rate ~ 100 MHz /cm2

New Muon Forward Tracker (MFT)• New forward vertex detector upstream muon
absorbera improved muon pointing resolution

A CERN for climate change
Medical technologies

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

25

A Large Ion Collider Experiment

The (new) Fast Interaction Trigger (FIT)

FT0-C

TOP
BOT

FT0-A + FV0

Fast Interaction Trigger• Minimum Bias and centrality selection• Rejection of beam/gas events
Collision time for Time-Of-Flight particle ID
Multiplicity à Centrality and Event Plane
L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

Based on quartz Cherenkov radiators
Modified Planacon MCP-PMTs
Excellent time resolution:• < 50 ps for single channels @ 1 MIP• 7 ps achieved with higher amplitudes
or multi-channel average26

A Large Ion Collider Experiment

Perspectives: upgrades forRun
4, ALICE
ALICE
upgradesin LS33& forLS4 Run 5
LS2

Run 3

Commissioning
Physics run

2020

2021

2022

A
L
I
C 2023
E

ITS3

LS3
2024

Introduction
2025

2026

Run 4
2027

2028

2029

LS4
2030

2031

Run 5
2032

ALICE 3: new dedicated heavy-ion experiment at the LHC, replacing ALICE
starting of Run 5: access to novel measurements of electromagnetic and
FoCal
ITS3
ALICE 3
hadronic probesof the QGP at very low momenta

FoCal

ALICE 3

Ø Discussed at the heavy-ion town meeting(CERN, Oct 2018)
Ø Expression of Interest submitted as input
to the European Particle Physics Strategy
Update (Granada, May 2019)

In thispresentation
Selectedmaterialfromthe preliminary
talks Filip>>>
Krizek,Gian Michele
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FoCal:
forward
EM calowith Si readout
ITS3: wafer-scale, ultra-thin, bent
MAPS

ufalinodiscussions on the ALICE 3 physics goals and scientific
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LoI ALICE-PUBLIC-2019-005

LoI: CERN-LHCC-2019-018

2 /17

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

Antonio Uras

Physics Prospects for ALICE in Run 5 and Beyond27

A Large Ion Collider Experiment

ALICE 3: a new dedicated heavy-ion detector for Run 5+ (> 2030)

periment
at the LHC,ofreplacing
ALICE
Novel measurements
electromagnetic
and hadronic probes of the QGP at very low momenta
asurementsof electromagnetic
a mechanismof hadron formation inandthe QGP, QGP transport properties, QGP electrical conductivity, QGP
ow momenta
radiation and access to the pre-hydrodynamization phase, Chiral Symmetry restoration, …
Expression of Interest arXiv:1902.01211
Also submitted as input to the European Strategy
for Particle Physics Update (Granada, May 2019)

Timeline- Conceptual studies ongoing 2019-2021- Public workshop in October 2021
- Submit a LoI to the LHCC by 2021
- Construction and installation by LS4LS2m the preliminary2020
cientific

Run 3

LS3

Run 4

LS4

Run 5

Commissioning2023
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L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

2025

2026

2027

2028

2029

2030

2031

2032
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A Large Ion Collider Experiment

Conclusions
A wealth of results based on full Run 2 samples offer:• Detailed insights into QGP workings and properties• plus a broader and rich QCD programme:-

pQCD, hadron structure, formation of hadrons and nuclei

Underway and coming up:• Major upgrade for Run 3 on track (ALICE v. 2.0)
• In preparation: ITS3, FoCal for Run 4 (ALICE v. 2.1)
• Plans for next generation dedicated HI experiment for Run 5+ (ALICE v. 3.0)

L. Musa (CERN) – 20th Lomonosov Conference - 22 August 2021

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