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Top Quark and W Boson Mass at CDF. Young-Kee Kim The University of Chicago Forth Workshop on Mass Origin and Supersymmetry Physics March 6-8, 2006 Tsukuba, Japan. x. x. x. x. x. x. x. x. x. x. x. Origin of Mass. There might be something (new particle?!) in the universe - PowerPoint PPT Presentation
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Top Quark and W Boson Mass at CDFTop Quark and W Boson Mass at CDF
Young-Kee Kim
The University of Chicago
Forth Workshop on Mass Origin and Supersymmetry Physics
March 6-8, 2006
Tsukuba, Japan
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 2
Nothing in the universe Something in the universe
Higgs Particles:Higgs Particles:Coupling strength to Higgs
is proportional to mass.
xx
x
xxx
x
xx xxx
x
Photon
Electron
Z,W Boson
Top Quark
There might be something (new particle?!) in the universethat gives mass to particles.
Origin of Mass
The importance of MW and Mtop
Precision Electroweak Measurements
probe the Higgs bosons indirectly
by means of quantum corrections.
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 4
Quantum Corrections
Large quantum corrections to Electroweak observables come from the top quark.
Different quantum corrections to MW and MZ
top
top
top
bottom
W Z
With precision (better than ~1%) MW, MZ, cosW measurements,we can predict top quark mass.
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 5
Mtop: Measurements vs. Prediction
Now
Top Mass Predictionfrom the global fit to EW observables
Limits from direct searches with e+e- and pp
Direct measurementsfrom CDF and D0
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 6
Quantum Corrections
W
W
top
bottom
Higgs
Secondary contributions are from the Higgs.
MW = MW0 + C1 Mtop
2 + C2 ln(MHiggs2)
Mtop (GeV)
MW
(GeV
)
150 175 200
80.5
80.4
80.3
M higgs
= 1
00 G
eV20
0 GeV
300
GeV50
0 GeV
1000
GeV
Inputs:s, em(MZ
2), MZ
For equal weights in 2 fits for MHiggs,
MW = 0.007 Mtop (Mtop = 2 GeV, MW = 14 MeV)
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 7
MW - Mtop - MHiggs
Mtop (GeV)
MW
(GeV
)
150 175 200
80.5
80.4
80.3
Higgs Mass: Will the Tevatron’s prediction agree with what LHC measures?
MHiggs (GeV)
5 D
isco
very
Lum
inos
ity (
fb-1)
hard hard
easy100 200 300 500 800
(LP’05)
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 8
Importance of MW and Mtop in MSSM
Additional quantum corrections from SUSY partners
(Summer 05)
Higher precision MW and Mtop measurements will enable to distinguishbetween the Standard Model, Light SUSY, and Heavy SUSY
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 9
Importance of Mtop in MSSM
Mtop
G. Degrassi, S.. Heinemeyer, W. Hollik, P. Slavich, G. WeigleinEur. Phys. Jour. C28 (2003) 133, hep-ph/0212020
Mtop plays a key role in determining Mh in MSSM.
LEP2 95%CLSM Higgs Limit
Mtop helps constraining MSSM models.
You should go to the masseslearn from them, and
synthesize their experienceinto better, articulated principles and
methods, ….
- Mao
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 11
Tevatron Performance (Run II)
Peak luminosity record: 1.8 1032 cm-2 s-1
Integrated luminosity– weekly record: 27 pb-1 / week / expt – total delivered: 1.5 fb-1 / expt, total recorded: 1.3 fb-1 / expt
Doubling time: 1 year Future: ~2 fb-1 by 2006, ~4 fb-1 by 2007, ~8 fb-1 by 2009
2002 2003 2004 2005 2002 2003 2004 2005
Peak Luminosity Int. Lum. (delivered) / Experiment
shutdown
LP’05
Today
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 12
Tevatron Detectors
CDF
DZero
Excellent Detectors - tracking, b-tagging, calorimeter, muon
CDF Strength: momentum resolution and particle ID(K,)DZero Strength: muon coverage and energy resolution
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 13
Tevatron MW and Mtop Status in Lepton-Photon 2005
Run I
W Mass Top MassTevatron Run I (~110 pb-1) Tevatron Run I (~110 pb-1) + Run II (320-350 pb-1)
W Mass Measurements
q
q g
W, Z
q
e, e, e,
W Z
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 15
Lepton Momentum and Energy Scale
• Understand passive material well:• Flatness of J/ +- mass over a large pT range• E/p tail - data vs. simulation
•MJ/ = 0.05 MeVMB = 0.2 MeV
p / p = - (0.03 ± 0.01)%
+- mass (GeV) near Upsilon
p / p = - (0.10 ± 0.01)%
pp_
1 / pT(GeV-1)
J/+- mass vs 1/pT
E / p of W electrons
DataMC
p(tracking)
E(EM cal)
beampipe, silicon
e
e
CDF Preliminary
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 16
Run II MW StatusRun II W e Run II W
Uncert.Source e II (Ib) II(Ib)
Statistics 45 (65) 50(100)
e/ p Scale 70 (80) 30 (87)
Recoil Energy 50 (37) 50 (35)
Backgrounds 20 (5) 20 (25)
Prod. & Decay 30 (30) 30 (30)
Total 105(110) 85(140)
Run II 200 pb-1 (Run Ib 90 pb-1) Integrated Luminosity [fb-1]
MW [M
eV]
CDF Run II
W Transverse Mass [GeV/c2] W Transverse Mass [GeV/c2]
DataMC
Top Mass Measurements
q
q g
t
tq
W+
b
b
W-
g
all jets: 44%
e+jets:15%
+jets: 15%
: 21%
ee,e,: 5%
e/+jets is most powerful Large Br, 1 - better than dilepton Sig / Bgrnd - better than all jetsB tagging Secondary vertex, Jet Prob., Soft e/
b
b
q
q
e+ ,
g
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 18
Mtop Analysis Method: Template Select jet-parton assignment that gives the best 2
for M(2 jets) = MW and M(top) = M(anti-top) Reconstruct top mass
– tt-bar MC “templates” with different Mtop values
– background “templates”– data
Perform maximum likelihood fit to extract measured mass.
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 19
Mtop Analysis Method: Matrix Element
Originally proposed in 1988 by Kuni Kondo– J. Phys. Soc. 57, 4126
For each event,– All jet-parton assignments are
considered and weighted by comparing that to the leading order Matrix element calculation.
– A probability distribution is produced.
Each curve is a probability functionfrom one Monte Carlo event.
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 20
Jet Energy Determination
Jet energy resolution
– 84%/√ET
– Statistical uncertainty
Jet energy scale– ~3% for jets from top decay– Dominant systematic
uncertainty
New technique in Run II– In-situ calibration
using W 2 jets mass
in lepton+jets channel
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 21
Mtop in lepton+jets: Template (680 pb-1)
Tsukuba group(Shinhong Kim, Taka Maruyama, Tomonobu Tomura, Koji Sato)
has been playing key roles!!
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 22
Mtop in lepton+jets and dilepton Channels
Mtop (template) = 173.4 ± 2.5 (stat. + jet E) ± 1.3 (syst.) GeVMtop (matrix element) = 174.1 ± 2.5 (stat. + jet E) ± 1.4 (syst.) GeV
Template Matrix Element
Mtop (matrix element) = 164.5 ± 4.5 (stat.) ± 3.1 (jet E. + syst.) GeV
Lepton+jets
Dilepton
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 23
Mtop Uncertainty (Run II)
Source of Uncertainty lepton+jets Template
(680 pb-1)
lepton+jets
Matrix Element
(680 pb-1)
dilepton
Matrix Element
(750 pb-1)
Statistics / Jet Energy Scale 2.5 2.5 4.5 / 2.6
Residual / Bgrnd Jet E Scale 0.8 0.42
Monte Carlo Statistics 0.3 0.04
Monte Carlo Generators 0.2 0.19 0.5
Initial State Gluon Radiation 0.5 0.72 0.5
Final State Gluon Radiation 0.2 0.76 0.5
Parton Distribution Functions 0.3 0.12 0.6
b-tagging 0.1 0.31
b jet Energy Scale 0.6 0.60
Background Modeling 0.5 0.21 1.1
Total 2.8 2.9 5.5
CDF Run II Preliminary
CDF Combined: MtopCDF = 172.0 ± 1.6 ± 2.2 GeV = 172.0 ± 2.7 GeV
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 24
Mtop in l+jets using Decay Length Technique
B hadron decay length
b-jet boost
Mtop
Difficult– Measure slope of exponential
But systematics dominated by tracking effects– Small correlation with
traditional measurements Statistics limited now
– Can make significant contribution at LHC
Mtop (Lxy) = 183.9 +15.7-13.9 (stat.) ± 5.6 (syst.) GeV
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 25
Other CDF Mtop results (318 - 360 pb-1 data through Aug. 04)
Three template-style analyses in dilepton channel– Combined result (340 - 360 pb-1)
170.1 ± 6.0(stat.) ± 4.1(syst.) GeV
Dynamical Likelihood method (Matrix Element)– Lepton+jets (318 pb-1)
173.2 +2.6-2.4(stat.) ± 3.2(syst.) GeV
(Kohei Yorita’s Ph.D. Thesis)
– Dilepton (340 pb-1)
166.6 +7.3-6.7(stat.) ± 3.2(syst.) GeV
(Ryo Tsuchiya’s Ph.D. Thesis)
63 events joint likelihood
All consistent with more recent measurements reported here.
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 26
Tevatron Top Mass Results
Summer 2005
Dilepton: CDF-II Mtop
ME = 164.5 ± 5.5 GeV
Lepton+Jets: CDF-II Mtop
Temp = 174.1 ± 2.8 GeV CDF-II Mtop
ME = 173.4 ± 2.9 GeV
CDF Combined: Mtop
CDF = 172.0 ± 1.6 ± 2.2 GeV = 172.0 ± 2.7 GeV
New since Summer 2005
Updated CDF + DØ combined result is coming!
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 27
Electroweak Projections
MW [MeV] MTop [GeV] MHiggs / Mhiggs [%]
Luminosity / Experiment [fb-1] Luminosity / Experiment [fb-1] Luminosity / Experiment [fb-1]
10-1 1 1010-2 10-1 1 10
CDF Run II
CDF Run II
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 28
Comments on Projections (e.g. Mtop)
Run I Measured110 pb-1
Run II (2fb-1)Projections
in 1996318 pb-1
680 pb-1
Run IIMeasured
CDF Top Mass Uncertainties
Run II (8fb-1)ProjectionsIn 2005
Mtop = MtopRun I / √ LumRun II / LumRun
Int. Lum [pb-1]
We have been doing much better than we predicted. Data makes us smarter!
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 29
MW, Mtop and Mhiggs in Tevatron/LHC/ILC
Conclusions
W Mass: 1st Run II meas. - coming soon (by this summer) - better than Run I
Top Mass: Mtop
CDF = 172.0 ± 2.7 GeV/c2 (680 pb-1) CDF surpassed 2 fb-1 Run II goal of 3 GeV/c2
Significant improvements in analysis techniques– Matrix element method, in situ jet energy calibration
Tevatron measurements in the LHC era: By LHC turn-on, we expect Mtop~2 GeV, MW~30 MeV.
By the end of this decade, Mtop~1.5 GeV, MW~20 MeV
– Comparable to LHC measurements Most likely be the best for quite some time. Higgs mass:
– Will Tevatron’s prediction agree with LHC’s direct measurement?
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 31
BACKUP
4th Workshop on Mass Origin & Supersymmetry: Mar 6-8, 2006, Tsukuba Young-Kee Kim, Univ. of Chicago 32
MW Luminosity Effects
Effects of higher instantaneous luminosity on uncertainty
W Transverse Mass
e, LeptonTransverse Momentum
Transverse Momentum