heavy flavour in alice

F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008 11

Heavy Flavour in ALICEHeavy Flavour in ALICE

Federico AntinoriFederico Antinori(INFN Padova & CERN)(INFN Padova & CERN)

for the ALICE Collaborationfor the ALICE Collaboration


ContentsContents The LHC, Heavy Flavours and ALICE The LHC, Heavy Flavours and ALICE

Expected performance (examples)Expected performance (examples) DD00 K K--++

DD++ K K--+ + ++

B B e + X e + X B B µ + X µ + X B B J/ J/+ X+ X ……

Coming up: proton-protonComing up: proton-proton

ConclusionConclusion


The LHC, Heavy Flavours The LHC, Heavy Flavours and ALICE and ALICE

(or “ALICE in Wonderland”)(or “ALICE in Wonderland”)


LHCLHC

Running conditions: Running conditions:

+ other ions (Sn, Kr, O) & energies (e.g.: pp @ 5.5 TeV)+ other ions (Sn, Kr, O) & energies (e.g.: pp @ 5.5 TeV)

*Lmax (ALICE) = 1031 ** Lint (ALICE) ~ 0.5 nb-1/year

Collision systemCollision system √√ssNNNN(TeV)(TeV) LL0 0 (cm(cm-2-2ss-1-1)) Run time Run time (s/year)(s/year)

geomgeom (b) (b)

pppp 14.014.0 101034 34 ** 101077 0.070.07

PbPbPbPb 5.55.5 10102727 101066 ** ** 7.77.7

pPbpPb 8.88.8 10102929 101066 1.91.9

ArArArAr 6.36.3 10102929 101066 2.72.7


Heavy Flavour @ LHCHeavy Flavour @ LHC cccc and and bbbb rates rates

ALICE PPR (NTLO + shadowing)ALICE PPR (NTLO + shadowing)

115 115 // 4.64.60.65 0.65 // 0.850.856.6 6.6 // 0.20.2Pb-Pb 5.5 TeV (5% Pb-Pb 5.5 TeV (5% cent)cent)

0.160.16 // 0.0070.00711 // 1111.211.2 // 0.50.5 pp 14 TeVpp 14 TeV

shadowingshadowingsystemsystem NN x-sect (mb)NN x-sect (mb) total multiplicitytotal multiplicity

PbPbpp

PbPbpp

cc bbPbPb/pp PbPb/pp

bbRHIC

bbLHC

ccRHIC

ccLHC

100

25

Exploring the low-x region…Exploring the low-x region… Shadowing, saturation, …Shadowing, saturation, …

66

p-A essential!p-A essential!


Probing the medium...Probing the medium...

study medium with probes of known colour charge study medium with probes of known colour charge and massand mass e.g.: energy loss by gluon radiation expected to be:e.g.: energy loss by gluon radiation expected to be: parton-specific: stronger for gluons than quarks parton-specific: stronger for gluons than quarks

(colour charge ratio = 9/4)(colour charge ratio = 9/4) flavour-specific: stronger for lighter than for heavier quarks flavour-specific: stronger for lighter than for heavier quarks

(dead-cone effect)(dead-cone effect) study effect of medium on fragmentation (no extra study effect of medium on fragmentation (no extra

production of c, b at hadronization)production of c, b at hadronization) independent string fragmentation vs recombinationindependent string fragmentation vs recombination e.g.: De.g.: D++

ss/D/D++

+ measurement important for quarkonium physics+ measurement important for quarkonium physics open QQ production natural normalization for quarkonium open QQ production natural normalization for quarkonium

studiesstudies B meson decays non negligible source of non-prompt J/B meson decays non negligible source of non-prompt J/at at

LHCLHC


Large suppression at RHIC!Large suppression at RHIC!

yet, region above 3-4 GeV yet, region above 3-4 GeV expected to be dominated expected to be dominated by beauty...by beauty...

[Xin Dong@QM05]

n.p. electrons ~ as suppressed as n.p. electrons ~ as suppressed as expected for c only (no b)expected for c only (no b)

scaled to

M. Cacciari et al., hep-ph/0502203

[J.Bielcik @QM05] disentangling c/b is a mustdisentangling c/b is a must

full reconstruction of D vertices!full reconstruction of D vertices!

non phot. el.


By the way: the factor 9/4? By the way: the factor 9/4?

energy loss should be energy loss should be proportional to: proportional to: CCRR = 4/3 for q, = 3 for g = 4/3 for q, = 3 for g

at RHIC, at 6-8 GeV pat RHIC, at 6-8 GeV pTT: : x ~ 10 x ~ 10-1-1

large quark contribution large quark contribution also for light flavours?also for light flavours?

at LHC, at same pat LHC, at same pTT: : x ~ a few 10 x ~ a few 10-4-4

quark contribution quark contribution negligiblenegligible

10ALICE Set-upALICE Set-up

HMPID

Muon Arm

TRD

PHOS

PMD

ITS

TOF

TPC

Size: 16 x 26 meters

Weight: 10,000 tons


longitudinal coverage:

|| < 1 (tracking), ||<2 (multiplicity)

Inner Tracking System (ITS)Inner Tracking System (ITS)

1212

ITS and TPCITS and TPC


Silicon Pixel Detector (SPD)Silicon Pixel Detector (SPD)

PIXEL CELL

z: 425 m

r: 50 m

Two layers:r = 4 cmr = 7 cm

9.8 M


Expected resolution Expected resolution on track impact parameter on track impact parameter

track impact parameter (dtrack impact parameter (d00))


Expected performanceExpected performance(examples)(examples)


DD00 K K--++

expected ALICE expected ALICE performance performance S/B ≈ 10 %S/B ≈ 10 % S/S/(S+B) ≈ 40 (S+B) ≈ 40

(1 month Pb-Pb running)(1 month Pb-Pb running)

statistical.

systematic.

ppTT - differential - differential


DD++ K K--++++

Performance comparable to that for DPerformance comparable to that for D00 KK--++

Pb-Pb significance ~ 30(1 month)

p-p


Beauty to electronsBeauty to electrons Expected ALICE performance (1 month Pb-Pb)Expected ALICE performance (1 month Pb-Pb)

ee±± identification from TRD and dE/dx in TPC identification from TRD and dE/dx in TPC impact parameter from ITSimpact parameter from ITS

pt > 2 GeV/c , 200 < |d0| < 600 m80% purity

8 104 e from Bpt > 2 GeV/c , 200 < |d0| < 600 m

80% purity

8 104 e from B

S/(S+B)S/(S+B) S per 10S per 1077 central Pb-Pb events central Pb-Pb events


Electrons (from b) pElectrons (from b) ptt spectrum spectrum

Error compositionstat error

stat syst error

11% from overall normalization not included


tDpp

tDAA

collt

DAA dpdN

dpdN

NpR

/

/1)(

tepp

teAA

collt

eAA dpdN

dpdN

NpR

/

/1)(

Expected performance on D, B Expected performance on D, B RRAAAA

mb = 4.8 GeV

D0 K B e + X

1 year at nominal luminosity(107 central Pb-Pb events, 109 pp events)

should help clarify the heavy flavour quenching story!should help clarify the heavy flavour quenching story!

mass dependencecolour charge dependence

)()()( D from eB from e/ tAAtAAtDB pRpRpR )()()(/ t

hAAt

DAAthD pRpRpR


Beauty to single muonsBeauty to single muons

expected in the muon armexpected in the muon arm

very high statistics and heavy flavour purity expectedvery high statistics and heavy flavour purity expected


Beauty to dimuonsBeauty to dimuons Two main sources:Two main sources:

B µ+ + D + Xµ- + X

B B µ- + XX + µ+

“BDSAME” “BBDIFF”

consistency check!consistency check!


low mass

high mass

2424

B B J/ J/ + X + X

More “exclusive” than B More “exclusive” than B e/µ + X e/µ + X better handle on B momentum distributionbetter handle on B momentum distribution

PreliminaryPreliminary pppp study: pseudoproper decay time study: pseudoproper decay time

(à la CDF)(à la CDF))/(

)/( /

Jp

MJLx

T

Jxy

CDF (data) ALICE

(prelim. simulation)

pT>0

F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

Many more under study…Many more under study…


...

jets tagged-flavour heavy

v

prong-5 B

DD

pK

KD

KK,D

2

0*

c

0

*s


Coming up: ppComing up: pp


Example: DExample: D00 in pp in pp DD00 K K--++

1 year run 1 year run ~ 10 ~ 1099 events events ~ 20 shifts, 10 hrs each ~ 20 shifts, 10 hrs each a few 10 a few 1077 events events

reach out to 12 GeV or soreach out to 12 GeV or so


Example: B Example: B e + X in pp e + X in pp

LHC CooldownLHC Cooldown


ALICE Status1/5 PHOS, 4/18 TRD, 18/18 TOFHMPID0/6 EMCAL

Detector Status Today & for First Beam


ALICE StatusALICE Status

Startup configuration:Startup configuration: complete: ITS, TPC, TOF, HMPID, muon arm, trigger detectors complete: ITS, TPC, TOF, HMPID, muon arm, trigger detectors

(V0, T0, ZDC, Acorde)(V0, T0, ZDC, Acorde) partially complete: PHOS (1/5), TRD (4/18), PMD (6/48), partially complete: PHOS (1/5), TRD (4/18), PMD (6/48),

DAQ/HLT (20-30%)DAQ/HLT (20-30%)

Timeline:Timeline: Global commissioning/cosmic runs I and II in Dec 2007 & Feb Global commissioning/cosmic runs I and II in Dec 2007 & Feb

20082008 Cosmic run III under wayCosmic run III under way LHC will close end July LHC will close end July first injection expected shortly after first injection expected shortly after commissioning run in 2008commissioning run in 2008 ““long run” in 2009long run” in 2009 followed by first Pb-Pb run (√s = 5.5 TeV, L = 5·10followed by first Pb-Pb run (√s = 5.5 TeV, L = 5·102525 cm cm-2-2ss-1-1))

Taking data!Taking data!


ALICE sees particles!ALICE sees particles!

TPCTPC


ITSITS

TPC + ITSTPC + ITS

ITS alignment with cosmicsITS alignment with cosmics

21982198 sensitive modules X sensitive modules X 66 d.o.f. each d.o.f. each = = 1318813188 alignment parametersalignment parameters to be to be determined!determined!


ITS Alignment 06/05/2008ITS Alignment 06/05/2008Adam Jacholkowski 3535

SPD alignment QA plots SPD alignment QA plots (first sample of 940, 4P tracks)(first sample of 940, 4P tracks)

ITS Alignment 06/05/2008ITS Alignment 06/05/2008Adam Jacholkowski 3636

AliMillepede re-alignmentAliMillepede re-alignment(first test)(first test)

First particles from LHC!First particles from LHC!

TI2 injection test (15/6): muons from beam dumpTI2 injection test (15/6): muons from beam dump


First particles from LHC!First particles from LHC!

Seen from an SPD half-sector:Seen from an SPD half-sector:


inner layerinner layer

outer layerouter layer

transversal tracks!transversal tracks!


ConclusionConclusion

With heavy flavours, Nature kindly provides us with a With heavy flavours, Nature kindly provides us with a beautiful tool to study the properties of the strongly beautiful tool to study the properties of the strongly interacting medium produced in ultra-relativistic interacting medium produced in ultra-relativistic nucleus-nucleus collisionsnucleus-nucleus collisions

At LHC At LHC very high ratesvery high rates very extended pvery extended pT T rangerange well developed jetswell developed jets

ALICE is very well equipped for this physicsALICE is very well equipped for this physics

The FUN is just starting!The FUN is just starting!

heavy flavour in alice

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