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Beauty and Charm Productionat the Fermilab Tevatron
Mary Bishai
Fermi National Accelerator lab
Mary Bishai, Fermi National Accelerator lab 1 – p.1/54
b quark discovered - 1977
Mary Bishai, Fermi National Accelerator lab 2 – p.2/54
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?
Mary Bishai, Fermi National Accelerator lab 3 – p.3/54
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
Mary Bishai, Fermi National Accelerator lab 4 – p.4/54
THE THEORY
Mary Bishai, Fermi National Accelerator lab 5 – p.5/54
Heavy Quark Production in pp̄
q
g
g
q
Q
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
Mary Bishai, Fermi National Accelerator lab 6 – p.6/54
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
Mary Bishai, Fermi National Accelerator lab 7 – p.7/54
Evolution of PDFsBy 2004, recalculating the cross-section with updated PDFs increasestheoretical value by almost 2X!
Mary Bishai, Fermi National Accelerator lab 8 – p.8/54
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
Mary Bishai, Fermi National Accelerator lab 9 – p.9/54
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
Mary Bishai, Fermi National Accelerator lab 10 – p.10/54
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
Mary Bishai, Fermi National Accelerator lab 11 – p.11/54
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)
Mary Bishai, Fermi National Accelerator lab 12 – p.12/54
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
Mary Bishai, Fermi National Accelerator lab 13 – p.13/54
THE EXPERIMENTS
Mary Bishai, Fermi National Accelerator lab 14 – p.14/54
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!
Mary Bishai, Fermi National Accelerator lab 15 – p.15/54
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
Mary Bishai, Fermi National Accelerator lab 16 – p.16/54
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
Mary Bishai, Fermi National Accelerator lab 17 – p.17/54
RUN II MEASUREMENTS OF THE J/ψ AND b-HADRONINCLUSIVE CROSS-SECTIONS
−
s,d
_ J/ψb c
cW
Mary Bishai, Fermi National Accelerator lab 18 – p.18/54
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
Mary Bishai, Fermi National Accelerator lab 19 – p.19/54
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.
Mary Bishai, Fermi National Accelerator lab 20 – p.20/54
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.
Mary Bishai, Fermi National Accelerator lab 21 – p.21/54
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
Mary Bishai, Fermi National Accelerator lab 22 – p.22/54
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
Mary Bishai, Fermi National Accelerator lab 23 – p.23/54
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.
Mary Bishai, Fermi National Accelerator lab 24 – p.24/54
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
Lxy(J/ψ)/pT(J/ψ).M(J/ψ) µm
Even
ts/50
µm
Total Fit
Total J/ψ Contribution
b→J/ψ X Contribution
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
Lxy(J/ψ)/pT(J/ψ).M(J/ψ) µm
Even
ts/50
µm
Total Fit
Total J/ψ Contribution
b→J/ψ X Contribution
Background
Mary Bishai, Fermi National Accelerator lab 25 – p.25/54
b-Production cross-sectionσ(pp̄→ B+X) vs (pT (B+))
1997
σ(pp̄→ bx) versus (pT (Hb))
CDF Run II Preliminary
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)
Mary Bishai, Fermi National Accelerator lab 26 – p.26/54
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
Mary Bishai, Fermi National Accelerator lab 27 – p.27/54
CHARM MESONCROSS-SECTIONS
Mary Bishai, Fermi National Accelerator lab 28 – p.28/54
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
Mary Bishai, Fermi National Accelerator lab 29 – p.29/54
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.
Mary Bishai, Fermi National Accelerator lab 30 – p.30/54
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
-1CDF Run II Preliminary 5.8pb
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
-1CDF Run II Preliminary 5.8pb
8GeV/c≥Tp
+πφ→s+D
+K-
K→φ2.1%±3.8±=77.3Df
s+ D→B
Mary Bishai, Fermi National Accelerator lab 31 – p.31/54
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
Mary Bishai, Fermi National Accelerator lab 32 – p.32/54
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
Mary Bishai, Fermi National Accelerator lab 33 – p.33/54
QUARKONIA PRODUCTION
Quarkonia = discovery. J/ψ signal at Brookhaven in 1974
Mary Bishai, Fermi National Accelerator lab 34 – p.34/54
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)
Mary Bishai, Fermi National Accelerator lab 35 – p.35/54
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 ?.
Mary Bishai, Fermi National Accelerator lab 36 – p.36/54
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
Mary Bishai, Fermi National Accelerator lab 38 – p.38/54
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
To select track type
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
Mary Bishai, Fermi National Accelerator lab 39 – p.39/54
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
To select track type
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
Mary Bishai, Fermi National Accelerator lab 40 – p.40/54
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
Mary Bishai, Fermi National Accelerator lab 41 – p.41/54
EXOTIC SPECTROSCOPY
Mary Bishai, Fermi National Accelerator lab 42 – p.42/54
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
Mary Bishai, Fermi National Accelerator lab 43 – p.43/54
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).
Mary Bishai, Fermi National Accelerator lab 44 – p.44/54
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?
Mary Bishai, Fermi National Accelerator lab 45 – p.45/54
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.
Mary Bishai, Fermi National Accelerator lab 46 – p.46/54
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.
Mary Bishai, Fermi National Accelerator lab 47 – p.47/54
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
Mary Bishai, Fermi National Accelerator lab 48 – p.48/54
BACKUP
Mary Bishai, Fermi National Accelerator lab 49 – p.49/54
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
Mary Bishai, Fermi National Accelerator lab 50 – p.50/54
Detector Acceptance (CDF)A detector simulation is used to estimate acceptance:
CDF Run II Preliminary
0 4 8 12 16Pt(J/ψ) GeV/c
10-2
10-1
J/ψ
Acc
epta
nce
Transverse momentum
CDF Run II Preliminary
-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
Mary Bishai, Fermi National Accelerator lab 51 – p.51/54
dσ(pp̄→ HbX)/dpT (J/ψ)
Fraction of J/ψs from Hb
CDF Run II Preliminary
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)
Mary Bishai, Fermi National Accelerator lab 52 – p.52/54
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
Mary Bishai, Fermi National Accelerator lab 53 – p.53/54
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
Mary Bishai, Fermi National Accelerator lab 54 – p.54/54