beauty and charm production · description of the run ii cdf and d0 detectors at the tevatron. run...

Beauty and Charm Productionat the Fermilab Tevatron

Mary Bishai

[email protected]

Fermi National Accelerator lab

Mary Bishai, Fermi National Accelerator lab 1 – p.1/54

b quark discovered - 1977


20 years later.....In 1997, b production cross-sections were still > 2× larger than QCD

predictions. At that time only a small portion of the b hadron inclusive

cross-section, pT > 6.0 GeV/c, had been measured.

σ(pp̄→ bx) for (pT > pminT

) dσ/dy vs yµ (inclusive µ from D0)

Is this a shape or normalization problem? What about charm?


OutlineRecent advances in the theory of heavy quark productioncross-sections in pp̄ collisions.

Description of the Run II CDF and D0 detectors at the Tevatron.

Run II results on beauty and charm hadron productioncross-sections.

Quarkonia production (including diffractive!)

Exotic baryon spectroscopy:

confirmation of Belle’s X(3870) → J/ψππ.

New: Pentaquark searches at the Tevatron


THE THEORY


Heavy Quark Production in pp̄

q

g

g

q

Q

QQ

Q

_

_

_

LO Heavy Quark Production

Q_

Q

g

g

NLO: Gluon splitting

NLO: Flavour excitation

Factorization theorem: factorize physical observable into a

calculable part and a non-calculable but universal piece:

dσ(qq/gg/qg → bX)

dpT (b)︸︷︷︸

NLO/NNLO QCD

⊗ fp,p̄︸︷︷︸

Proton structure

⊗ Db→B︸︷︷︸

fragmentation

=dσ(pp̄→ BX)

dpT (B)︸︷︷︸

observed


Parton Density Functions (PDF)

New PDFs with uncertainties extracted fromfits to the data

The uncertainties from one PDF

fit do not always cover differences

with other fits:

Uncertainties on gluonic function


Evolution of PDFsBy 2004, recalculating the cross-section with updated PDFs increasestheoretical value by almost 2X!


2001: kT Factorization SchemeStandard PDFs are functions of x, the fraction of the momentumcarried by the parton longitudinal to the hadron direction. Partonsalso have a small transverse momentum component:kT factorization : f(x) → f(x, kT ) , σ(x, s) → σ(kT , x, s)

H.Jung, hep-ph/0110034


Fragmentation Functions Db→B

Dmeas(x) =∫Dpert(x′)︸︷︷︸

pQCD/MC

⊗ Dnon−pert(x′)︸︷︷︸

Parameterized/MC

dx′

Peterson parameterization

z =(E+p||)hadron

(E+p)quark


Recent Theory Advances

Next-to-Leading-logresummations (2001): In pQCDcalculations powers ofαs log pT /mQ modify shape offragmentation function:pT >> mQ = Large corrections

Moment analysis (2002): Mellintransformation into momentspace D̃(N) =

∫xN−1D(x)dx

D̃meas(N) = D̃pert(N) × D̃non−pert(N)︸︷︷︸

A product

D(x) Measured

Dnon−pert(x′) Extracted

Non-perturbative functions used must match perturbative assumptions


Comparison with Run I Data - NLLFixed order (FO) QCD NLO cal-culation + Resummation of next-to-leading logs (NLL). Method ofmoments instead of a fragmenta-tion model ⇒ Better agreement with

CDF and D0 Run I data

dσ(pp̄→ B+X)/dpT vs pT (B+) (CDF)

pT (B+) GeV/c

Cacciari, Nason hep-ph/0204025 (Run I)


Theory SummaryAgreement with the Run I b cross-section data for pT > 5.0

GeV/c has greatly improved without the need to invoke exoticsources of excess b quarks. Most of the improvement is due toimproved treatment of experimental inputs.

BUT: Different theoretical approaches: different factorizationschemes, FONLL calculations, new methods to extract thenon-perturbative part of fragmentation function. Which is thecorrect approach?

Total cross-sections do not depend on the fragmentation model!

= powerful experimental test of QCD calculations.

Charm quark mass and production cross-sections are close to b-quark

but fragmentation is very different - test theory predictions


THE EXPERIMENTS


The Tevatron TodayIn 1985, Tevatron collider begins operating @

√s = 1.6 TeV

Run I of the Tevatron collected collider data at√s = 1.8 TeV

from 1992-1995. ∼ 109 pb −1 of data was collected by the 2collider detectors with Ltypical = 1.6 × 1031cm−2s−1

Run II : Summer 2001 - present. 4X more data already!


CDF Run II - OverviewSignals: J/ψ → µµ, D → Kπ, displaced b vertices

z

End WallHadronCal.

End PlugHadron

Calorimeter

Solenoid Coil

End P

lug C

alo

rim

ete

r

CentralOuter

Tracker

TOF

SVX-II Intermediate Silicon Layers

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Central Hadron Calorimeter

Central Muon (CMU)

(COT)

(CHA)

(PHA)

(WHA)EM Calorimeter (CEM)E

M C

alor

imet

er (

PE

M)

R=150 cm

R=1.4 cm

η=0.6 η=1.0

η=2.0

η = −1/2 ln tan θ/2

Central Muon detector: Prop.chambers outside centralcalor. ∼ 5π interactionlengths.

96 layer COT:σ(pt)/pt = 0.002pt

Silicon vertex detector: 8Layers of 3-D Silicon up to|η| = 2, 700,000 readoutchannels, σ(d0) ∼ 30µm


D0 Run II - OverviewNew forward muon system with |η| < 2 and good shielding

16 layer Fiber Trackers in 2T

4 layer Silicon, σ(d0) = 54µm at 1 GeV/c


RUN II MEASUREMENTS OF THE J/ψ AND b-HADRONINCLUSIVE CROSS-SECTIONS

−

s,d

_ J/ψb c

cW


J/ψ → µµ signals

Et = 5.75 GeV

Event : 21462 Run : 127369 EventType : DATA | Unpresc: 43,49,21,53,23,55 Presc: 49 Myron mode: 0

J/

µ

µ

ψ−>µµ

2), GeV/c-µ +µMass (3.0 3.5

2E

vent

s pe

r 10

MeV

/c

0

500

1000

1500

2000

2500

2x10

2 0.03 MeV/c±: Events: 1.2M, Width: 22.6 ΨJ/

CDF Run II Preliminary, 120 inv. pb, June 2003

3.5 3.6 3.7 3.8 3.932000

34000

36000

38000

40000

42000

2 0.5 MeV/c±(2s): Events: 38k, Width: 22.1 Ψ


L1 Muon triggers (CDF)Tracks are reconstructed in theCOT by the Level 1 Trigger eX-tra Fast Tracker (XFT). A match ismade to hits in the Muon Cham-bers. (Offline ε = 0.986 ± 0.010)

-1, (GeV/c)TInverse Muon P

0.2 0.4 0.6

CM

U T

rigge

r E

ffici

ency

0.80

0.82

0.84

0.86

0.88

0.90

0.92

0.94

0.96

0.98

1.00CDF Run II Preliminary

L1 muon trigger efficiency .vs. 1/pT

TRIGGERED TOWER

EXTRAPOLATED TOWER

wedgeCalorimeter15 degree

L1 XFT TRK

lower pt reach:

pt(µ) > 1.5(|η| < 0.6).

pt(µ) > 2.0(0.6 < |η| < 1.0)

Can now reach pt(J/ψ) = 0 GeV/c.


Counting J/ψs (pT = 0 to 20 GeV/c)0 < pT (J/ψ) < 0.25GeV/c

CDF Run II Preliminary 0<Pt(µµ)<0.25 GeV/c

2.85 2.95 3.05 3.15 3.25 3.35M(µµ) GeV/c2

0

20

40

60

80

Even

ts/5 M

eV/c2

358±26 EventsLuminosity = 14.8 pb-1

5 < pT (J/ψ) < 5.5GeV/cCDF Run II Preliminary 5.0<Pt(µµ)<5.5 GeV/c

2.85 2.95 3.05 3.15 3.25 3.35M(µµ) GeV/c2

0

500

1000

1500

2000

Even

ts/5 M

eV/c2

18,200±200 EventsLuminosity = 39.7 pb-1

12 < pT (J/ψ) < 14GeV/cCDF Run II Preliminary 12.0<Pt(µµ)<14.0 GeV/c

2.85 2.95 3.05 3.15 3.25 3.35M(µµ) GeV/c2

0

25

50

75

100

Even

ts/5 M

eV/c2

1551±60 EventsLuminosity = 39.7 pb-1

Transverse momentumresolution:δ(pT )/pT = 0.003pT

A detector simulation is usedto model the expected shapeof the J/ψ signal.


Muon triggers (D0)Large rapidity coverage up

to |η| < 2.0

Offline reco eff:loose ε = 0.905 ± 0.0033

medium ε = 0.8 ± 0.0045


J/ψ Cross-sections - Run IIdσ(pp̄→J/ψX)dpT (J/ψ) = Number of J/ψ

luminosity×acceptance×efficiency×∆pT

σ(pp̄→ J/ψX, |y| < 0.6) vs pT (J/ψ)

CDF Run II Preliminary

0 4 8 12 16pT(J/ψ) GeV/c

10-1

1

101

102

dσ/d

p T(|y

|<0.

6) .

Br(

J/ψ

→µµ

) nb

/(G

eV/c

)

Data with stat. uncertainties

Systematic uncertainties

σ(pp̄→ J/ψX, pT > 5, 8GeV/c) vs y(J/ψ)

RapidityψJ/0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Cro

ss S

ecti

on

, n

b

1

10

102

Cross Section per 1.2 unit of rapidityψJ/

CDF RunI results17.4 +/- 2.8 nb

2.7 +/- 0.4 nb

Dzero Run2 PRELIMINARY)>5GeV/cψ pT(J/)>8GeV/cψ pT(J/

Cross Section per 1.2 unit of rapidityψJ/

(Run II 18.7+/−2.0 nb)(Run II 3.1+/−0.4 nb)

σ(pp→ J/ψX, | y(J/ψ) |< 0.6) = 4.08 ± 0.02(stat)+0.60−0.48(syst) µb


Separate Hb → J/ψX from TotalThe J/ψ inclusive cross-section includes contributions from

Direct production of J/ψ

Indirect production from decays of excited charmoniumstates such as ψ(2S) → J/ψπ+π−

Decays of b-hadrons such as B → J/ψX

p p

b−hadron direction

J/ψ vertex

µ+

µ−

b−hadron decay vertex

Primary vertex

b-hadrons have long life-times, J/ψ from Hb → J/ψX

will be displaced.


Extracting the b-fraction

A maximum likelihood fit tothe flight path of the J/ψ inthe r − φ plane, Lxy is usedto extract the b-fraction.

template

Parameterizedbackground

CDF Run II Preliminary 5.0 < pT(J/ψ) < 5.5 GeV/c

-2000 -1000 0 1000 2000 3000

1

101

102

103

104

Lxy(J/ψ)/pT(J/ψ).M(J/ψ) µm

Eve

nts/

50µm

Total Fit

Total J/ψ Contribution

b→J/ψ X Contribution

Background

Prompt J/is a double Gaussian

ψ

= resolution function

shape from MCb−>J/ Xψ

1.25 < pT < 1.5 GeV/c, fb = 9.7%

CDF Run II Preliminary 1.25 < pT(J/ψ) < 1.5 GeV/c

-2000 -1000 0 1000 2000 3000

1

101

102

103

104


Even

ts/50

µm

Total Fit



Background

10 < pT < 12 GeV/c, fb = 28%

CDF Run II Preliminary 10 < pT(J/ψ) < 12 GeV/c

-2000 -1000 0 1000 2000 3000

1

101

102

103

104


Even

ts/50

µm

Total Fit



Background


b-Production cross-sectionσ(pp̄→ B+X) vs (pT (B+))

1997

σ(pp̄→ bx) versus (pT (Hb))


0 5 10 15 20 25

pT(Hb) GeV/c

1

101

102

103

104

dσ/d

p T(H

b) n

b/(G

eV/c

)|y|<1.0

Run II Inclusive b→J/ψ X, σ(|y|<1.0)=29 ± 6 µb

Run Ib Exclusive B+ corrected for fb=0.4

Run Ia Exclusive B+ corrected for fb=0.4

FONLL CTEQ6M, mb=4.75, µ=µ0, σ=27.5+11 -8.2 µb

FONLL uncertainty from PDF(10%), mass, factorization

2003Data: σ = 29 ± 6µb, FONLL: σ = 27.5µb (CTEQ6M, mb = 4.75, µ = µ0)


High pT b-Jet Production (D0)b-jets include much of the quark fragmentation remnants ⇒ jetcross-sections have small dependence on fragmentation.

(GeV/c)µ RelTP

0 0.5 1 1.5 2 2.5 3 3.5

Entri

es/0.

1 GeV

0

100

200

300

400

500

600

700DØ Run 2 Preliminary

Data

Background template

Signal template

Fitted templates

jetTE

20 30 40 50 60 70 80 90 100

% b

-jets

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

b fractionUncertainty

DØ Run 2 Preliminary

(GeV)jetTE

20 30 40 50 60 70 80 90 100

(nb/

GeV)

jet TdE

σd

10-3

10-2

10-1 Data

R<0.3δPythia, CTEQ4M,

DØ Run 2 Preliminary


CHARM MESONCROSS-SECTIONS


L2 Silicon Vertex Trigger (CDF)

-600 -400 -200 0 200 400 6000

2000

4000

6000

8000

10000

12000

14000

16000

18000

m)µ (0SVT d

mµtrac

ks per

10

25≤ SVT2χ 2 GeV/c; ≥tP

mµ = 47 dσ

mµtrac

ks per

10

Track Pt (GeV/c)

SVT e

ff. (%

)

new SVT patterns

old SVT patterns

0

0.2

0.4

0.6

0.8

1

0 1 2 3 4 5 6 7 8 9 10

Eff. vs track pt

SVX |d0| (cm)

SVT t

rackin

g effic

iency

new SVT patterns

old SVT patterns

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14

SVT Eff. vs track d0


Charm Production in Run II

]2) [GeV/c+π-m(K1.8 1.85 1.9

2E

ntr

ies

pe

r 2

Me

V/c

0

1000

2000

3000

+π-K→0D (a)

]2) [GeV/c+π-)-m(K+π+π-m(K0.14 0.15 0.16

2E

ntr

ies

pe

r 0

.3 M

eV

/c

0

200

400

600

800 ,+π0D→+D*+π-K→0D

(b)

]2) [GeV/c+π+π-m(K1.7 1.8 1.9 2

2E

ntr

ies

pe

r 2

Me

V/c

0

1000

2000

+π+π-K→+D (c)

]2) [GeV/c+π-K+m(K1.8 1.9 2 2.1

2E

ntr

ies

pe

r 5

Me

V/c

0

100

200

300+πφ→s

+D+πφ→+D

(d)

Analysis uses 5.8pb −1 ofearly 2002 data.

Challenges: SVT notfully efficient at the time.Efficiency is a complexfunction of pT , z, cot(θ)

and time.


Direct Charm Production Run IIUse impact parameter of reconstructed charm mesons FD(d0) todistinguish directly produced charm from B → DX , FB(d0)

Impact Parameter [cm]S0K

-0.04 -0.02 0 0.02 0.04

mµEv

ent N

um./

10

1

10

102

103

104

+π-π→S0K

CDF RunII Preliminary

From Ks → ππ data we findFD(d0) = Gaussian + exptails. From B → DX MC :FB(d0) = a double exponen-tial.

Impact Parameter [cm]0D-0.04 -0.02 0 0.02 0.04

mµ

En

trie

s p

er

10

1

10

102

103

-1CDF Run II Preliminary 5.8pb

5.5GeV/c≥Tp

+π-K→0D 3.5%±0.4±=86.6Df

0 D→B

Impact Parameter [cm]0D-0.04 -0.02 0 0.02 0.04

mµ

En

trie

s p

er

10

1

10

102

103


6GeV/c≥Tp

+π0D→+D*+π-K→0D

3.9%±1.1±=88.1Df

+ D*→B

Impact Parameter [cm]s+D

-0.04 -0.02 0 0.02 0.04m

µE

ntr

ies

pe

r 2

0

10-1

1

10

102


8GeV/c≥Tp

+πφ→s+D

+K-

K→φ2.1%±3.8±=77.3Df

s+ D→B


Charm cross-sectionsD0 Meson Differential Cross-section

M. Cacciari, P. Nason. hep-ph/0306212.

D Meson Cross-sections Data/Theory

σ(pp→ D0X, | y |< 1.0, pT > 5.5 GeV/c) = 13.3 ± 0.2(stat) ± 1.5(syst) µb

σ(pp→ D+X, | y |< 1.0, pT > 6.0 GeV/c) = 4.3 ± 0.1(stat) ± 0.7(syst) µb

σ(pp→ D∗+X, | y |< 1.0, pT > 6.0 GeV/c) = 5.2 ± 0.1(stat) ± 0.8(syst) µb

σ(pp→ DsX, | y |< 1.0, pT > 8.0 GeV/c) = 0.75 ± 0.05(stat) ± 0.22(syst) µb


Charm .vs. Beauty (FONLL)

) [GeV/c]0(DTp5 10 15 20

Data

/The

ory

0

0.5

1

1.5

2

2.5

) [GeV/c]0(DTp5 10 15 20

Data

/The

ory

0

0.5

1

1.5

2

2.5

CDF Run II preliminary Data/Theory Cross Section0D

Charm and Beauty meson crossection predictions are consistent


QUARKONIA PRODUCTION

Quarkonia = discovery. J/ψ signal at Brookhaven in 1974


Prompt Quarkonia ProductionQuarkonia bound states are non-relativistic. NRQCD LO perturbative expansion is

O(α3sv

0) as in the color singlet model (CSM) + higher order O(α3sv

4).

Fragmentation processes ∝ color octet matrix element dominate. CO matrix

elements extracted from fits to data - agree well with Run I data at high pt.CDF Run II Preliminary

0 4 8 12 1610-2

10-1

1

101

102

dσ/d

p T(J/

ψ) .

Br(J

/ψ→

µµ) n

b/(G

eV/c

)

pT(J/ψ) GeV/c

(includes correlated uncertainties)

Data with stat. uncertainties

Systematic uncertainties

Prompt J/ψ production (Run I) Prompt J/ψ production (Run II)


Bottomonium productionAt lower pt NRQCD non-fragmentation diagrams from other octet matrix elements

are important, soft gluon effects cause rates to diverge.

pT (GeV)

B d

σ/dp

Tdy

(pb/

GeV

)

Υ(1S)

10-1

1

10

10 2

0 5 10 15 20 25 30

Υ(1S) production (CDF Run I) Υ(1S) production (D0 Run II)

No new theoretical predictions for low pT quarkonium at pp̄ yet.

BUT: resummation of color octet matrix elements by summer 2004 ?.


Charmonium Polarization MysteryBUT Inclusion of color octet in NRQCD leads to a prediction of increasing

transverse polarization of charmonium at high pt.

Method: Fit the production angle,cos θ∗, distribution to MC distribu-tion which is a mixture of trans-verse and longitudinal polariza-tions. Use lifetime fit method toseparate prompt and b→ J/ψX

dN/d cos θ∗ ∝ (1 + α cos2 θ∗)

CDF Run I

Run II :Need more precise measurements

N.B. Accurate measurements needed to reduce systematic uncertainty on detector accep-

tance Mary Bishai, Fermi National Accelerator lab 37 – p.37/54

Diffractive production of χcAt LHC SM Higgs boson could be produced by exclusiveproduction with NOTHING else in the interaction (σ ∼ 40 fb ?):

p+ p→ p+H + p

To test prediction, search for a similar process at the Tevatron:p+ p̄→ p+ χ0

c + p̄→ p+ J/ψγ + p̄

χb−loop:c−loop:

t−loop: Hb

χc


Exclusive χc candidate 1

Et = 1.96 GeV

Event : 119697 Run : 155318 EventType : DATA | Unpresc: 23,56 Presc: 56

Missing Et

Et= 0.6 phi=4.1

List of Tracks

Id pt phi eta

Cdf Tracks: first 5

11 -1.6 2.5 -0.5

12 1.5 -0.6 -0.6

To select track type

SelectCdfTrack(Id)

Svt Tracks: first 5

0 -5.2 2.5

1 1.5 0.0


SelectSvtTrack(Id)

η

-6

-4

-2

0

2

4

6

φ

0100

200

300

TE

0

1

2

3

0500010000200003000050000

01

2 3

4 5 6 7

89

10 11

12 13 14 15 16 17

West East

Channel ID : ADC :0500010000200003000050000

01

2 3

4 5 6 7

89

10 11

12 13 14 15 16 17

West East

Channel ID : ADC :

E (G

eV)

00.020.040.060.08

E (G

eV)

00.05

0.10.15

E (G

eV)

00.005

0.010.015

0.02

E (G

eV)

0

0.05

0.1


Exclusive χc candidate 2

Et = 1.67 GeV

Event : 149270 Run : 156365 EventType : DATA | Unpresc: 23,56 Presc: 56

Missing Et

Et= 1.1 phi=1.0

List of Tracks

Id pt phi eta

Cdf Tracks: first 5

7 1.6 2.9 -0.6

8 -1.5 -0.4 -0.5


SelectCdfTrack(Id)

η

-6

-4

-2

0

2

4

6

φ

0100

200

300

TE

0

1

2

3

0500010000200003000050000

01

2 3

4 5 6 7

89

10 11

12 13 14 15 16 17

West East

Channel ID : ADC :0500010000200003000050000

01

2 3

4 5 6 7

89

10 11

12 13 14 15 16 17

West East

Channel ID : ADC :

E (G

eV)

00.05

0.10.15

E (G

eV)

00.05

0.10.15

E (G

eV)

00.020.040.060.08

E (G

eV)

0

0.05

0.1


Analysis of exclusive events

Di-muon mass (GeV) Exclusive2.8 3 3.2 3.4 3.6 3.8 4

Eve

nts/

bin

02468

1012141618202224

Di-muon mass (GeV) Exclusive+cosmic veto2.8 3 3.2 3.4 3.6 3.8 4

Eve

nts/

bin

0

2

4

6

8

10

Di-muon mass (GeV) Exclusive(1 EM)2.8 3 3.2 3.4 3.6 3.8 4

Eve

nts/

bin

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Di-muon mass (GeV) Exclusive(1 EM)+cosmic veto2.8 3 3.2 3.4 3.6 3.8 4

Eve

nts/

bin

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Di-muon + photon invariant mass (GeV)2.8 3 3.2 3.4 3.6 3.8 4

Eve

nts/

bin

0

0.5

1

1.5

2

2.5

3

3.5

4

Di-muon + photon invariant mass (GeV)2.8 3 3.2 3.4 3.6 3.8 4

Eve

nts/

bin

0

0.5

1

1.5

2

2.5

3

3.5

4

data

FakeEvt

CDF Run 2 Preliminary

Exclusive χc candidates

Need to understand backgrounds!. IF all 10 events are signalthen: σ(pp̄→ pp̄µµγ, |y| < 0.6) = 49 ± 18(stat) ± 39(syst) pb

Prediction: σ =∼ 200 pb hep-ph/0011393


EXOTIC SPECTROSCOPY


Belle observes X(3870) → J/ψππ

At LP 2003, the Belle collab-oration announced the ob-servation of a new state de-caying into J/ψππ from anal-ysis of B decays.

3820 3860 3900

M(π+π-J/ψ) (MeV/c2)

0

15

30

Events

/5 M

eV

/c2

3630 3670 3710

M(π+π-J/ψ) (MeV/c2)

0

100

200

300

M = 3872.0 ± 0.6 ± 0.5 MeV

Belle signal favors large ππ

mass

0.40 0.60 0.80

M(π+π-) (GeV/c2)

0

2.5

5

Events

/0.0

05 G

eV

/c2

0.40 0.60 0.80

M(π+π-) (GeV/c2)

0

10

20

30


X(3870) → J/ψππ observed in pp̄

CDF Run II

all candidates

)2

Mass (GeV/c-π+πψJ/3.65 3.70 3.75 3.80 3.85 3.90 3.95 4.00

2C

an

did

ate

s/

5 M

eV

/c

0

1000

2000

3000

4000

5000

6000

3.80 3.85 3.90 3.951700

1800

1900

2000

2100

2200

-1220 pbCDF II

CDF Run II

m(ππ) > 500 MeV

)2 Mass (GeV/c-π+πψJ/3.65 3.70 3.75 3.80 3.85 3.90 3.95 4.00

2C

an

did

ate

s/

5 M

eV

/c

0

500

1000

1500

2000

2500

3000

3.80 3.85 3.90 3.95

900

1000

1100

1200

1300

1400

-1220 pbCDF II

D0 Run II

∆[M(J/ψ) −M(J/ψππ)]

)2 (GeV/c-µ+µ - M-π+π-µ+µM0.6 0.7 0.8 0.9 1

2C

an

did

ate

s / 1

0 M

eV

/c

0

100

200

300

400

500

|y| < 1

1< |y| < 2

DØ

M(CDF) = 3871.3 ± 0.7 ± 0.4 MeV

Yield : 730 ± 90 (CDF) 522 ± 100 (D0).


What is it?

� � � � � � � � � � � � � � � � � � � � � � � ��

� �� ! � " #$ # % #& '( ) * +, - �� . / 0 021 3 321 3 &

� 4� � � ! ! 5 6$ 7 8 9: '( ) * ; '( ) * / < '= >? * 0 < ' ?@ ( @ * 0 <1 3 < A <1

� �B � � � ! CD ' ( ?E F * G D '( ( H@ * I � - �JK � . I & - �B . /D L M 0 D ' ?N ?@ * 0 1 D ' ? FE O *

� 4B � � � PQ ' ( N F@ * < RQ '( E H@ * < $ RQ '( H( @ * < S & Q '( T * S , Q '( T * / <Q '( N E @ *

� 4B � � � � P D '( ? O@ * RD '( ? = F * $ RD '( N ?@ * S & D '( T * S , D '( T * /D U M

� 4B � � � � PV '( E ?@ * RV '( ? H@ * $ R %V '( F ? F * S & V '( T * S , V '( T * / <V '( N E @ * 0 <V ' ?N O@ *

� �W � � ! � "V ' ( O H@ * + � - �XY Z . + � - �K [ � . /V '( H H@ *

� 4W � � ! ! 5 '( H@ @ * 6 ' ( O F@ * : 'E H H@ * / < '( O= @ * \

� 4W � � ! ! /V '( = ?@ *

� 4W 4 J ! ! 5] '( O >@ * 6 ] '( O H@ * $ 7 ] ' ( = F@ * / <] '( H= @ *

� 4^_ Y � � P` ' ?@ N @ * R` ' ?@ F@ * a_ -� � � � . / <` ' ?@ N F *

� �� ! � " ' ( E @ @ * # '( ? > F * $ # '( N N @ * #& ' ? ) * b - �Y X � .

� 4� � � ! ! 5 '( N F@ * 6 ' ( N ?@ * $ 7 ' ( O= @ * : ' ? ) * ; ' ? ) * / < '( N ( @ * \

� 4B � � � � c � - � [ � � . a � - �d Z � . RV ' ?@ ( @ * S , V ' ? T * b <� - �dK � .

J �� ! � " ' ( = @ @ * + - � [X � . b - �K J � .

J/ψ π π+ −

c c

??

L = 2

PDG Quark Model:

BUT: 3D2 expected around 3810 MeV/c2

Is this a DD∗ molecule? Can CDF/D0 determine production mech-

anism? If mostly prompt, looks like a quarkonium rate.Is the ππ a ρ?


Pentaquarks at the Tevatron?

Evidence for Θ(1540) (CLAS)Ξ(1860) (NA49) M(D∗p̄) = 3099 (H1).

)2) (GeV/cS0m(pK

1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8

2En

tries p

er 2 Me

V/c

0

50

100

150

200

250

300 jet20 data

CDF Run II preliminary

]2[GeV/c1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2

2N

/ 10

MeV

/c

0

500

1000

1500CDF Run II Preliminary

)πΞM( ]2[GeV/c1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2

2N

/ 10

MeV

/c

0

500

1000

1500

+π-Ξ-π-Ξ

-1L~220pb track found in SVXΞ(1860)’Ξ’

]2[GeV/c3.0 3.1 3.2 3.3

2N

/ 2

MeV

/c

0

200

400

600

800CDF Run II Preliminary

)p*+M(D

-1L=240pb

No evidence for “pentaquark” states at CDF with larger statistics.


SummaryStudies of heavy quark production are precision tests of NLO pQCD.

NEW: Run II measurements of heavy flavor production at theTevatron:

Quarkonia: New measurements of the inclusive J/ψcross-sections down to pT = 0 GeV/c (CDF) and |y| < 2.0

(D0). New Υ cross-sections (D0). Diffractive production ofexclusive µµγ candidates observed (CDF).

Measurement of the central b-hadron cross-sections over allpT (CDF) and b-jet cross-sections at

√

(s) = 1960 GeV (D0)

D+,0,∗, Ds cross-sections published (CDF).

Exotic Spectroscopy: X(3870) confirmed at pp̄ (CDF/D0).CDF observes no pentaquark candidates.


Lots of theory advances:New PDF fits to proton structure data and betterunderstanding of uncertainties.New factorization schemes: kT

Resummation of NLL for factorization schemeswhere quarks are massive - now valid for all pT

New and improved treatments of heavy quarkfragmentation

Total inclusive b-hadron cross-sections are in agreement

with theoretical predictions within uncertainties.Charm cross-sections in reasonable agreement with theoryand consistent with beauty meson results.Mysteries: Quarkonia production/polarization, X(3870), Θ


BACKUP


CDF Data Flow

L2 Trigger

�Detector

�L3 Farm

MassStorage

L1 Accept

Level 2:Asynchronous 2 stage pipeline~40µs latency300 Hz Accept Rate

L1+L2 rejection: 20,000:1

2.5 MHz Crossing rate396 ns Bunch Spacing

L1 Trigger

Level1:2.5 MHz Synchronous pipeline5544ns latency<50 kHz Accept rate

L2 Accept

L1 StoragePipeline:42 Clock Cycles Deep

L2 Buffers: 4 Events

DAQ Buffers

PJW 2/2/97

Dataflow of CDF "Deadtimeless" Trigger and DAQ

L1 latency: Pipeline depth = L1processing time ∼ 5µsecs.The SVXII detector is readout on

L1 Accept.

L2 processing time: The SiliconVertex Trigger is in L2 ⇒readout of the Silicon takes place

in ∼ 15µsecs + ∼ 15µsecs SVT

processing time

Data logging rate: sustainedrate of 18MB/s (150-200KB/event)

250 pb −1 ⇒ 480TB on tape


Detector Acceptance (CDF)A detector simulation is used to estimate acceptance:


0 4 8 12 16Pt(J/ψ) GeV/c

10-2

10-1

J/ψ

Acc

epta

nce

Transverse momentum


-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6J/ψ Rapidity

0.000

0.025

0.050

0.075

0.100

J/ψ

Acc

epta

nce

(1<P

t<20

GeV

/c)

Rapidity


dσ(pp̄→ HbX)/dpT (J/ψ)

Fraction of J/ψs from Hb


0 5 10 15 200.00

0.10

0.20

0.30

0.40

0.50

0.60

pT(J/ψ) GeV/c

Fra

ctio

n of

J/ψ

from

b

Run II (stat. uncertainties only)

Run I (stat. uncertainties only)

dσ(pp̄→ HbX,Hb → J/ψX)/dpT (J/ψ)

Theory: M.Cacciari, S. Frixione, M.L.

Mangano, P. Nason. G. Ridolfi (Dec, 2003)


Algorithm to extract dσ/dpT (Hb)

Count the observed numberof b-hadrons in a givenpT (Hb) bin

N bi =

N∑

j=1

wijNJ/ψj

wij is the fraction of b eventsin the ith pT (Hb) from the jth

pT (J/ψ) bin obtained fromMC.

Examples of b-hadron Transverse Momentum Distributions

0 10 20 30

pT(Hb) GeV/c

0.000

0.020

0.040

0.060

0.080

Frac

tion

of b

-had

rons

in 0

.2 G

eV/c

1.25<pT(J/ψ)<1.5 GeV/c

5.0<pT(J/ψ)<5.5 GeV/c

12.0<pT(J/ψ)<14.0 GeV/c

Correct the observed number of b-hadrons for the kinematicacceptance


Iterating...

After a dσ/dpT (Hb) spectrum is

obtained, the MC weights wij are

recomputed using the new

spectrum and the algorithm

repeated.

A χ2 test is performed on theinput and output spectra untilno difference is seen.

χ2 per iteration

0 10 20 30 40 50

iteration

0

2.5

5

7.5

10

χ2/2

00 D

.O.F

.

Data

MC


beauty and charm production · description of the run ii cdf and d0 detectors at the tevatron. run...

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