The Physicsof

Generations(Update)

11-Dec-03Don Lincoln

f

Motivation

Under hypothesis of compositeness, deviation from point-like behavior would likely manifest in third generation.

Conclusion: g bb may exhibit desired deviant behavior.

Explore b quark dijet mass as a possible signature.

• Problem– ~100:1 QCD:bb

Solutions tagging2nd VTX tagging Impact parameter

CDF: PRL 82 (1999) 2038

Fact: The multi-generational structure of the quark doublets requires explanation and could herald compositeness.

Fit to CDFqQCD calculation

Strict Cut Summary• Reject multiply analyzed

runs (p13.05.00 & r13.06.01)– 169514 - 170150 (+ others)

• Reject “bad” runs– JET, MET, Muon, CFT, SMT, CAL

• Skim QCD to reduce data set (pt of high pt jet, in order to have < 40% deviation from lower trigger)– Pt(25) > 40 GeV (Guess)

– Pt(45) > 70 GeV

– Pt(65) > 95 GeV

– Pt(95) > 130 GeV

• NP 1mutrk skim– 1 MuonCandidate (medium)

• Nseg ≥ 1

• Nwhits(A) ≥ 2

• Nwhits(B+C) ≥ 3

• Nshits(A) ≥ 1

• Nshits(B+C) ≥ 1

– 1 Track (Pt > 6 GeV)

– |trackcand| < 0.2

• QCD Trigger– JT_25TT_NG, JT_45TT,

JT_65TT, JT_95TT, JT_125TT, JT_8TT, CJT5, min_bias, min_bias_NCU

×2 data reduction

D0JetInfo Building• CalJet (baseline)

– Standard quality cuts

• Trackjet – At least 2 tracks

– Pt(1) > 1.0 GeV

– Pt(others) > 0.5 GeV R < 0.5

• MuonCandidate (tight)– Pt > 4 GeV

– Associated track

– Nseg ≥ 3

– Nwhits(A) ≥ 2

– Nwhits(B+C) ≥ 3

– Nshits(A) ≥ 1

– Nshits(B+C) ≥ 1

• Match to CalJet • TrackJet

– | R | < 0.7– | Z | < 1.5 cm

• 2VTX– Attached to TrackJet– Complex requirements

• Muon– | R | < 0.5– | Z | < 1.5 cm

• MC information– 2VTX

• | R | < 0.5• | Z | < 3 cm

– Parent parton (Leading Order)• | R | < 1.0• | Z | < 100 cm

Ariel S

chwartzm

an based code.

Data Skim Result (All JT Trig) [Entire Skim]

All Data1mutrk skim

My skim TMBTree

P13.05 96,912,122 7,310,036 65,50865,508

43,803

P13.06 255,852,863 22,961,909 136,343 136,343

R13.06 36,728,013 2,675,429 20,014 20,014

Total 389,492,998 32,947,374 221,168

221,251

193,822

100,388

Trigger r13.06.01 p13.05.00 p13.06.01 TotalJT_25TT 0.02298 0.09593 0.6002 0.71911JT_45TT 0.4413 3.651 12.95 17.0423JT_65TT 5.906 14.34 43.15 63.396JT_95TT 6.999 18.35 70.72 96.069JT_125TT 7.001 18.35 70.72 96.071min_bias 7.62E-06 2.04E-05 4.13E-05 6.93E-05min_bias_ncu 0 0 3.12E-05 3.12E-05CJT5 1.91E-04 0.001542 0.001674 0.003407JT_8TT 0 0 0.002476 0.002476

Luminosity [pb-1] (“good” runs)

With bad run removal.

MC Status

MC Request # Request type # Events Now

5931 bb 100 31000

5932 QCD 100 31000/24461

5933 cc 100 20000

5934 bb 300 40750

5935 QCD 300 26500

5936 cc 300 12500

5937 bb 200 18500

5938 QCD 200 46713

5939 cc 200 41000

?? bb 100 inclusive 0

?? bb 200 inclusive 0

?? bb 300 inclusive 0

Requested 20,000 of each

Big thanks to Drew Meyer of UTA for very helpful MC assistance

MC Production foundered for many months. Statistics only available in the last month

Long Term Goal: Use bb to Search for Exotics

• Dijet bb mass might signal new physics

• Tags:

Pros: Skim based on this, much work done Cons: Poor efficiency, ptrel similar sig/bkd at high Pt, || < 2.0,

avoid ICD for Jet

VTX Pros: Very high efficiency, some work done, 2D Decay Length

Significance tag promising Cons: No skim available, |VTX| < 1.4, avoid ICD for Jet

• First approach: jet + inclusive, |jet| < 0.5

MC Predictions (single jet)Parton N Purity Efficiency N Purity Efficiency N Purity Efficiency

c 1125 1.85124 100 52 7.08447 4.62222 9 4.78723 0.8b 834 1.37239 100 78 10.6267 9.35252 23 12.234 2.75779

light 58811 96.7764 100 604 82.2888 1.02702 156 82.9787 0.265256

Parton N Purity Efficiency N Purity Efficiency N Purity Efficiencyc 1125 1.85124 100 268 5.59265 23.8222 62 4.27881 5.51111b 834 1.37239 100 502 10.4758 60.1918 311 21.4631 37.2902

light 58811 96.7764 100 4022 83.9316 6.83886 1076 74.2581 1.82959

All Pt() > 4.0 GeV Pt() > 4.0 GeV, PtRel > 1 GeV

All "Best" 2VTX Exists Best 2VTX, 2DDLsig > 32

Technique:1. Use QCD MC (Ptmin = 100 GeV)2. Identify “Leading Order” associated parton3. Apply cuts in RECO variables4. Identify efficiency and purity for each type

Note: “light” includes up, down, strange and gluons.

Note: this is for all . Reducing to || < 0.5 will reduce cross section numbers by 1/3, but slightly increase efficiency.

MC Predictions (two jet or double tag)

Parton N Purity Efficiency N Purity Efficiencyc 63.8435 9.95897 5.674972 3.416888 2.456853 0.303723b 302.1628 47.13449 36.23053 115.9725 83.388 13.90559

light 275.0589 42.90654 0.4677 19.68639 14.15515 0.033474

Parton N Purity Efficiency N Purity Efficiencyc 12.38754 12.3083 1.101115 2.865777 6.664155 0.254736b 46.9496 46.64925 5.629449 29.08636 67.63819 3.487573

light 41.30671 41.04246 0.070236 11.05072 25.69765 0.01879

Parton N Purity Efficiency N Purity Efficiencyc 2.403553 15.11504 0.213649 0.003328 4.974592 0.000296b 7.294967 45.87531 0.874696 0.059322 88.67295 0.007113

light 6.203208 39.00965 0.010548 0.00425 6.352454 7.23E-06

Pt) > 4.0 GeV Pt) > 4.0 GeV, PtRel > 1.0Pt) > 4.0 GeV Pt) > 4.0 GeV, PtRel > 1.0

Pt) > 4.0 GeV Pt) > 4.0 GeV2VTX Existence 2D DL Sig > 32

2VTX Existence 2D DL Sig > 322VTX Existence 2D DL Sig > 32

d/dpt “Cross-Section” || < 0.5

Obviously needs rebinningNormalized to luminosity and bin

widthFull luminosity “good runs”Uses standard JESNo efficiency correctionsNo b-enhancing muon cuts

All jets with

Jet kinematics only

JT_25TT_NG

JT_45TT

JT_65TT

JT_95TT

JT_125TT

All jets with

Jet + kinematics

Pt Dependence of Cut Loss ( Data)

Pt Dependence of Cut Loss (QCD Data)

Efficiencies

tBBbbjPVT pffN L)(

T Trigger EffPV Primary Vertex Effj Jet Eff Efffb Frac b (Pt > 4 GeV)

fB Frac B (Pt > 4 GeV)

L Luminositypt Pt bin widthb b cross-sectionB BKD cross-section

tjPVTBBbb p

Nff

L

)(

BBtjPVT

bb fp

Nf

L

b

BBtjPVT

b f

fp

NL

Jet + (Pt > 4 GeV)

b Jet + (Pt > 4 GeV)

b Jet

Correlated

Primary Vertex Cut Event Retention

Respectable fit to a gaussian. Simply count events outside|z| > 50 cm to find loss rate.

Primary Vertex Cut Event Retention

Error bars RMSPt

Z(P

V)

+50

-50

100

300

700 PV = 0.935 ± 0.050

Independent of Pt

Effect of Jet QCAlgorithm same as QCD analysis:

Find ratio (QC applied)/(QC not applied)Correction = ½ differenceError = ½ difference

J = 0.99 ± 0.01

Pt Dependence of log(2D DL Sig)

3.65

2.75

2.5

Essentially Pt independent in MC

Effect of Jet Pt on log(2D DL sig)

Pt Dependence of log(2D DL Sig)Essentially Pt independent in Data (Pt > 100)

Effect of Including -only Jets in log(2D DL sig)

Effect of existence on log(2D DL sig)

Compare templates of log(2D DL sig)

Compare templates of log(2D DL sig)

Fractions of b using Templates

For jets with both a good 2VTX and a muon, use log(2D dl sig)and fit for b fraction.

Result: 15 2 and 22.6 2%MC: 24.4 1.5%

w/o 2VTX requirement:

MC: 10.5 0.4%

Fit to smoothed templates

4 gaussian

3 gaussian 2 gaussian

Bump in c template probablyUnphysical. Under investigation.

For jets with a good 2VTX use log(2D dl sig) and fit for b fraction. No muon requirement.

Result: 16.7 1.2%MC: 26.2 0.8% Note: doesn’t have the same selection of

events as data. (Even though no muon requirement, was a muon skim.)

Fit to Smoothed Templates

Fraction of b-generated Events with Pt > 4.0 GeV

Generate bb MCCalculate fraction of b (Pt > 4 GeV)Plot vs. Jet + RECO PtFitSys. Error. From adding parameter error.

Frac = 0.045 + 0.000081 Pt

Fraction of QCD-generated Events with Pt > 4.0 GeV

Generate QCD MCCalculate fraction of QCD (Pt > 4 GeV)Plot vs. Jet + RECO PtFitSys. Error. From adding parameter error.

Frac = 1.0E-5 + 3.1E-6 Pt

tBBbbjPVT pffN L)(

EfficiencyDetail Value

T Trigger Eff 1.000PV Primary Vertex Eff 0.935 ± 0.005 Eff

j Jet Eff 0.99 ± 0.01fB Frac B (Pt > 4 GeV) Pt dependentfb Frac b (Pt > 4 GeV) Pt dependent

Efficiency/Fraction Summary

RECO Efficiencymatch tracksystem geometry

Geometry

system hole |A Layer| < 1.1 4.25 < < 5.15 %7.85

2

9.02geometry

MC # RECO # MC Eff %

b100 2708 3907 69.3

c100 853 1174 72.6

b300 6561 9831 66.7

c300 1098 1483 74.0

Thoughts:

system shouldn’t care if it’s in a jet? (High Pt punch through?)

track should care if it’s in a jet. Low tracking efficiency in jet

match should care if it’s in a jet. Lots of potential fakes.

Not much information from ID group on this topic. (But tracking eff ~ 82% gives total eff of 85.782 ~ 70.2%.

Heavy Flavor JES

Heavy Flavor JES

Still To Do• Double check efficiencies• Double check fractions of b/c/light• Smearing Resolution Unsmearing• Rebin (How to deal with highest pt events?)

• Bottom Line– Most required knowledge is grossly available

d/dm“Cross-Section” || < 0.5

Obviously needs rebinningNormalized to luminosity and bin

widthFull luminosity “good runs”Uses standard JESNo efficiency correctionsNo b-enhancing muon cuts

At least one jet with

Jet kinematics only

Both jets with

Jet kinematics only

At least one jet with

Jet + kinematics

JT_25TT_NG

JT_45TT

JT_65TT

JT_95TT

JT_125TT