Transcript Slide 1

Precision Measurements, Small Cross-sections,
and Non-Standard Signatures:
Reaching the 1 fb-1 Threshold at the Tevatron
Henry Frisch
University of Chicago
Looking for SUSY at the
Tevatron… Data…
Electron+
CDF Event
2 electrons and a photon: Ht=~350 GeV
Photon
11/26/06
Electron-
`Typical’ lepton+photon+X event (?) No Met- sorry….
Gordy as Pioneer
“Have We Already
Found Ourselves a
Bearino In These
Woods?”
hep-ph/0701999
OUTLINE
1. Luminosity and Reach of the Tevatron and of Gordy*
2. The Triangle of Mtop, MW, and MHiggs
3. New Precision Measurement of MW
4. Precision Measurement of Mtop
5. Brief Summary of Higgs Results/Projections/Opportunities
6. Anomalous Top Production?
7. Anomalous Top Decay?
8. B ->m+m-, Bs mixing, other Precision tests
9. SUSY? –Met+jets
10. SUSY?- stop and H+
11.Photon Signatures (lgX and ggX) and GMSB
12.Lepton Signatures Same-sign dileptons and trileptons
13.High-Pt Z’s, Right-handed Heavy Quarks,…,….
14. Summary- the Tevatron Opportunity at >> 1 fb-1
* A Man’s Reach …. – Robert Browning
Luminosity vs Time
CDF
Run II
Run II So Far
Delivered Lum
D0
(CDF+D0)/2*
Xmas
week
Note patternintegral grows
when you don’t
stop, with
increasing slope
> 40 pb-1/wk/expt
*(Protons are
smaller on this
side (joke))
Where is the Higgs? Mtop vs MW
1s
Assuming
SM (H->bb)
Central Value
Tev/LEP2
Note log scale
Mtop vs MW Status as of Summer 2006 (update below)
Central value prefers a light (too light) Higgs
Puts a High Premium on Measuring Mtop and MW precisely, no matter what
happens at the LHC (really diff. systematics at Tevatron.)
Precision Msremnt* of the Top Mass
CDF Lepton+4jets:
Systematic uncertainties (GeV/c2)
JES residual
0.42
4
Initial state radiation
0.72
2
Jet Energy Scale (JES)
Final state radiation
0.76
1
Set by MW (jj)
Generator
0.19
Background composition and modeling
0.21
Parton distribution functions
0.12
b-JES
0.60
b-tagging
0.31
Monte Carlo statistics
0.04
Lepton pT
0.22
Multiple Interactions
0.05
Total
1.36
Systematics:
Note FSR, ISR,
JES, and b/j JES
dominate- all
measurable with
more data, at
some level…
*like Mrenna
This is very good news!
3
Precision Measuremnt of the Top Mass
TDR
Aspen Conference Annual Values
(Doug Glenzinski Summary Talk)
Jan-05: Mt = +/- 4.3 GeV
Jan-06: Mt = +/- 2.9 GeV
Jan-07: Mt = +/- 2.1 GeV Note we are doing almost 1/root-L even now
Setting JES with MW puts us significantly ahead of the projection based on
Run I in the Technical Design Report (TDR). Systematics are measurable with
more data (at some level- but W and Z are bright standard candles.)
One old feature may be going awaytop mass in dileptons was too low…
Mtop(All Jets)
= 173.4 ± 4.3 GeV/c2
Mtop(Dilepton)
= 167.0 ± 4.3 GeV/c2
Mtop(Lepton+Jets) = 171.3 ± 2.2 GeV/c2
(
Rainer Wallny, Aspen 07)
Dilepton a little low, but
statistically not significantalso D0 number not low now…
7/17/2015
Gordy Fest 1/19/07
Take differences
between the 3 modes:
8
New (Jan. 5, 07) CDF W Mass
From Ashutosh Kotwal’s Jan 5 Wine and Cheese (Fermilab)
Data from Feb. 02-Sept 03
218 pb-1 for e; 191 pb-1 for m
A Systematics Intensive Measurement..
This is a precision spectrometer!
Note: This is a small fraction of data taken to date- this is to
establish the calibrations and techniques (so far) for Run II.
New (Jan. 5, 07) CDF W Mass
From Ashutosh Kotwal’s Jan 5 Wine and Cheese (Fermilab)
Run Ib Problem Now Solved: 2 Calibrations of EM calorimeter:
Zmass ≠ E(cal)/p(track)
Electron and Muon Transverse Mass Fits
New (Jan. 5, 07) CDF W Mass
From Ashutosh Kotwal’s Jan 5 Wine and Cheese (Fermilab)
Note: This is with only 0.2 fb-1
and one experiment!
MW-Mtop Plane with new CDF #’s
MW= 80.398 \pm 0.025 GeV (inc. new CDF 200pb-1)
MTop = 171.4 \pm 2.1 GeV
(ICHEP 06)
=> MH =80+36-26 GeV; MH<153 GeV (95% C.L.)
MH < 189 GeV w. LEPII limit (M. Grunewald, Pvt.Comm.)
Direct Limits on SM Higgs
D0 has updated
high mass region
This is the
factor one
needs to get
the 95% CL
downto the
SM Higgs
Xscn
CDF has updated
low mass region
I’m not willing to prognosticate (other than to bet we don’t see
the SM Higgs)- would rather postnosticate. However, lots of
tools not yet used- we’re learning many techniques, channels,…
New CDF Higgs result:
Tau ID depends on good tracking, photon ID- clean
environment (all good at the Tevatron). Key numbers
are efficiency and jet rejection:
J. Conway- Aspen
New CDF Higgs result:
J. Conway- Aspen
New CDF Higgs result:
Need More Datakeep on running.
Other channels
too…
Have more handlese.g. tau displaced
vertex..
J. Conway- Aspen
New Physics inTop Production?
Note 1 TeV
Note no 500
GeV bump
anymore
Fit ttbar system with known top mass(es) and compare Mtt, pTtt,etatt,X, angular
distributions, etc. with SM expectations. Global fit allows multi-dimensional
comparisons. (Here is only Mtt, for reasons I don’t understand- Dan?)
New Physics inTop Decay?
1. Fit for V-A, V+A, longitudinal: So far no smoking guns
2. Charged Higgs (e,mu+tau+b)
3. Run I odd dilepton distributions
750 pb-1-1
750 pb
Dilepton only
200 pb-1
V+A fits, e.g
?
Single Top Production
Yann Coadou,
Aspen 07
CDF ME
D0
CDF NN
SM
CDF LK
Zack Sullivan, Aspen 07
Situation somewhat confusedExpect 1 and 2 pb in s and t channels,
respectively. Need more data, wits
SUSY? - Same-sign dileptons and trileptons
CDF: SS: 2 of e and/or m: Pt1>20,Pt2> 10; Met > 15
Counting expt agrees, but some extra high Pt SS events on tails. More data!
?
SUSY?
trileptons
Many CDF analyses combined:
DATA and SM! (fergit specific models)
Note: In model
interpretations
limit is very
parameter
dependent, and
for LH plot
there isn’t a
limit on
chargino mass.
Note- in ~1000
pb-1 have only
a few events.
But limits are in
the 1 pb-1
range…
No Slepton mixing
(D0 case)
SUSY? – Missing Et + Jets
CDF: 371 pb-1
Zone A: Met > 75, Ht > 230, Jets > 95, 55, 25
(1 fb-1 in progress) Zone B: Met > 90, Ht > 280, Jets > 120, 70, 25
Zone C: Met > 120, Ht > 330, Jets > 140, 100, 25
SM Bkgd Makeup: Zone B
Data: Zone B HT (sum ET) spectrum
Note how few events are
out here from anything
RESULTS: DATA VS SM EXPECTATIONS
SUSY? – Missing Et + Jets
new (Jan. 5,07) D0 measurement
Cut
D0: 1 fb-1
Cut
Gluino
3-jets
3 (Sub-) Analyses: all with 2j > 35, met> 75 GeV, lepton veto; f12 < 165o
Name
Dijet
3-Jets
Gluino
Jet3, Jet4
----, ----35, ----35, 20
Met
225
150
100
HT
300
400
300
+ dphi(met-jet) cuts
Thanks to D0 for
help with this !
SUSY? – Missing Et + Jets
New Combined (but
useless to all but
MSUGRA experts)
Exclusion MSUGRA
Plot:
m<0; A0=0
Brown is D0 310 pb-1
Yellow is uncertainty
from PDF’s, Q2 scales
in quadrature (?)
CDF: 371 invpb
Tan beta=5
D0: ~1000 invpb
Tan beta =3
(gr-red line is mean limit (?))
What would it take to get both D0 and CDF to agree on some common points, e.g.
same tan beta?
eeggmet Event Followup and
Signature-Based Searches
Rather than look for a specific model, test the SM predictions in
inclusive but interesting channels- gauge bosons+X, 3rd generation +X
Signature-based Searches – eeggmet
Event Followup (lg+X,gg+X)
One event from CDF in Run I fot me (and
Gordy, remarkably enough) excited- 2 high-Pt
electrons, 2 high-Pt photons, large missing Et,
and nothing else. Lovely clean signature- and
very hard to do in the SM (WWgg).
2 Run I analyses looked for `cousins’ in 86 pb-1
- spread a wide net: 2 photons+X (X=anything;
Toback) and photon+lepton+X (Berryhill). In gl+X found a 2.7s excess over SM. From PRL:
``CDF Run I PRL: ..an interesting result, but …
not a compelling observation of new physics.
We look forward to more data…”
SUSY? – eeggmet Event Followup
Andrei Loginov repeated the lgmet analysis- same cuts (no
optimization- kept it truly a priori.
Run II: 929 pb-1 at 1.96 TeV vs Run I: 86 pb-1 at 1.8 TeV
Conclude that eeggmet event, l+g+met `excess’, Run II Wgg event all were
Nature playing with us- a posteriori searches show nothing with more data…
Signature-based Searches – eeggmet
Event Followup
929 pb-1
929 pb-1
Distributions look good too- small numbers of events on tail, but QCD
bkgds there too. Sad- but led to systematic search strategies- and
emphasis on SM prediction faithfulness- and not over yet.
(Andrei Loginov PhD Thesis, ITEP, Moscow
Signature-Based High Pt Z+X Searches
Look at a central Z +X, for Pt > 0, 60, 120 GeV, and at distributions…
(idea being new heavy things- e.g. QR a la Bj, Rosner, and/or Carlos…)
Sasha Paramonov, UC
Signature-Based High Pt Z+X Searches
PTZ>0
PTZ>120
PTZ> 60
PTZ>0
PTZ> 60
PTZ>120
HT for PTZ>0, PTZ> 60, and PTZ>120 GeV Z’s:
ee (Left) and mm (right)
Signature-Based High Pt Z+X Searches
PTZ>0
PTZ> 60
PTZ>60
PTZ>120
Njets for PTZ>0, PTZ> 60, and PTZ>120 GeV Z’s vs
Pythia (Tune AW)- this is the control for
Met+Jets at the LHC (excise leptons – replace
with neutrinos).
High Precision B-physics; Mixing, Bs->mm
Note: 1 psec = 300 microns. SVT is critical.
High Precision B-physics; Mixing, Bs->mm
Pure Experimentalist’s reaction- pretty!
High Precision B-physics; Bs->mm
Copious Source of B’s;
Mass Resolution and Trigger
Result: World's best limits
BR( Bs → μμ ) < 1.0x10-7 @95% CL
BR( Bd → μμ ) < 3.0x10-8 @95% CL
BR( Bs → μμ ) < 8.0x10-8 @90% CL
BR( Bd → μμ ) < 2.3x10-8 @90% CL
This is with 780 pb-1; have more, and
have improved analysis sensitivitynew # very soon. Getting to have
teeth (imagine 10X data+>Accept.).
One of a number of rare-decay mode searches; Bs->mmX; also new
states with B quarks, …. (whole industry).
Conclusion (but not yet an ending)
1. Tevatron running well and producing lots of beautiful rich data
2. Experiments running pretty well and producing lots of hands-on
and minds-on opportunities (lots of room for new ideas, analyses,
and hardware upgrades (great for students!)
3. Precision measurements- MW, Mtop, Bs Mixing, B states- MW
and Mtop systematics statisics-limited
4. Can make a strong argument that pbar-p at 2 TeV tis the best
place to look for light SUSY, light Higgs,…; as met at EWK
scale, (MW/2, Mtop/4) doesn’t scale with mass, root-s, and
tau’s (maybe b’s) are better due to lower mass in detector, and
SVT and L1 tracking triggers,
5. All of which implies keep the Tevatron running until we know that
we don’t need it.
6. Gordy has played a big role in the thinking of the whole fieldHappy Birthday Gordy!
Happy Birthday Gordy!
Backup- D0 btagging
Backup- lum on tape