Preparations for Early Physics at the...

Preparations for Early Physics

at the LHC

Large Hadron Collider & Planck TelescopeXIV IFT Christmas Workshop: December 17, 2008 Madrid

Joe Incandela

University of California Santa Barbara

Acknowledgements– For slides:

• Davide Boscherini, Jurgen Schukraft, Daniel Froidevaux, Dan Green, Steinar Stapnes, Jörg

Wenninger, Sally Dawson, Ian Hinchliffe, Karl Jacobs, Oliver Buchmuller, Ian Low, Albert De

Roeck, Andy Parker, Roberto Tenchini, Guenther Dissertori, Jorgen D’Hondt,…

– For discussions and special info

• Steve Giddings, Peter Jenni, Henry Frisch, Paris Sphicas, Claudio Campagnari, Chris Quigg,

Nima Arkani-Hamed, Philip Schuster, Natalia Toro, …and many more

– … many others from SPS, Tevatron, LEP, and LHC experiments

Current Situation

– Particle Physics

• Many precise measurements without substantial discrepancies with the Standard Model

– Astrophysics and Cosmology

• Abundant evidence for physics beyond the standard model

– Dark energy and non-baryonic dark matter

– Neutrino oscillations

– Cosmic matter-antimatter asymmetry

– Cosmic density fluctuations consistent with inflation

– There are many good reasons to expect this dilemma to begin to be resolved by experiments at the TeV scale

Joe Incandela UC Santa Barbara

3Ian Low

The Dark Side of SUSY

• Relic Density for non-baryonic dark matter:

– 0.094 < DM h2 < 0.129 (95% CL), h = 0.71 (km/s)/Mpc (Hubble expansion)

– Matter is only ~5% of the energy in the universe and only about 15% as common as dark matter

• Weak scale SUSY with R-Parity conservation is perhaps the best-motivated framework around

– Provides a natural dark matter candidate (neutralino) with about the right relic density


4

5


Or maybe not

• The somewhat surprising absence of SUSY at LEP and the Tevatron has led theorists astray

– Little Higgs (with T Parity)

– Universal extra dimensions (with KK parity)

– Strong dynamics

– Large extra dimensions

– Warped extra dimensions

– Hidden Valleys

– …

• In any case, if you don‟t exactly know what you‟re looking for, a hadron collider is a good tool to be using.


6

Hadron Colliders

– Access high com energies

– A broad range of energies

– Large physics cross-section

Discovery machines …

– but what‟s interesting is rare

– It takes great experiments (and a bit of luck…)


7

Good things come early…and late.• SPS & Tevatron Discoveries

– SPS turn-on led to quick major discoveries

– Not true at the Tevatron

• SPS had a lot of data – Already probed quite a bit higher

than the mean constituent com energy of ~100 GeV

– Tevatron needed to ~match SPS integrated luminosity in order to probe a “new” energy domain

• And then discovered top!

– Early discoveries have been followed by other important results at hadron colliders – but these have generally come late


Precision W&Z masses

Single topDi-bosonsMt ,MW

CDF & D0

LHC will startup in new territory


9

– At 1 TeV constituent com energy

• gg: 1 fb-1 at Tevatron is like 1 nb-1 at LHC

• qq: 1 fb-1 at Tevatron is like 1 pb-1 at LHC

gg luminosity @ LHCqq luminosity @ LHCgg luminosity @ Tevatron

qq luminosity @ Tevatron





ggqq

Ra

tio o

f L

HC

and

Teva

tro

n p

art

on

lum

inosi

ties

ggqq

Ra

tio o

f L

HC

and

Teva

tro

n p

art

on

lum

inosi

ties

C. Campagnari

Parton Luminosity falls steeply

ggqq

LHC

ggqqggqq

LHC

• At the LHC it falls ~ x10 every 600 GeV in multi-TeV region:

– If you have a limit M > 1 TeV for a pair-produced particle, your sensitivity improves by ~ (600/2)=300 GeV = 30% for 10 times more integrated luminosity

• New states always produced near threshold

– If nothing new is found relatively early, you may need to wait a long time


10

Improving sensitivity is tough....

but you can turn evidence into an observation

C. Campagnari

OVERVIEW OF LHC PROGRAM

& STATUS OF EXPERIMENTS

11

The Large Hadron Collider at CERN 12


LHC : 27 km long~100m underground



O.Buchmuller

pp, B-Physics,CP Violation

Heavy ions, ppALICE



O.Buchmuller

General Purpose,pp, heavy ions

CMS+TOTEM

ATLAS



O.Buchmuller

The LHC Accelerator Complex

16


Jörg Wenninger

Peak energy [GeV] Circumference [m]

Linac 0.12 30PSB 1.4 157CPS 26 628 = 4 x PSBSPS 450 6‟911 = 11 x PSLHC 7000 26‟657 = 4 x SPS

LEIR

CPS

SPS

Booster

LINACS

LHC

3

45

6

7

8

12

Ions

protons

Beam 1

Beam 2

TI8

TI2

Energy gain per machine is x10 to x20 because

this is the typical useful range scale of magnets

The LHC injector complex

Limit stored energy 8 power sectors.~1 GJ/sector

Sector = 2.9 km, 154 dipoles + 50 quads

17


Jörg Wenninger

Vast stored energy!

• LHC magnets:• 1 dipole magnet Estored = 7 MJ

• All magnets Estored = 10.4 GJ

• Kinetic energy of 2808 p bunches:• Ebunch = Np x Ep = (1.15 x 1011) x 7 TeV = 129 kJ

• Ebeam = k x Ebunch = 2808 x Ebunch = 362 MJ

Compared to previous accelerators :• A factor 2 in magnetic field

• A factor 7 in beam energy

• A factor 200 in stored energy

Melt 12 tons of Copper!

• 90 kg of TNT • 15 kg of chocolate

18


Jörg Wenninger

LHC Startup - 10 September 200819

LHC Startup - 10 September 2008


20

Beam circulated for 30 minutes within days of start.

Roger Bailey (CMS Week Sep. „08)

First Event in CMS


21

~2x109 protons on collimator 150 m upstream of CMS

Ecal - pink, HB,HE light blue, HO, HF dark blue,Muon DT green

Beam dump at collimators produces many proton collisions upstream that reach 100s and 1000s of TeV in CMS!

Energy Deposits: ECAL vs. HCAL22


23


LHCb 1st Alignment w/ Beam Data

LHCB

Muons originating from the beam stopping in P2 (~300 m away from LHCB)

are used for alignment

VELO

Sensor pitch is R dependent

VELO Alignment with straight muon tracks.Good agreement with test beam data for large

sensor pitch values. Some disagreement at lowervalues - residual mis-alignment?!

Already very little beam data can bevery useful for commissioning!

(e.g. injection test from August 24)

24


Beam-splash event in ATLAS

ATLAS Beam-halo event with magnets on 26


It Works?!

ALICE on the 10th of September28

clean event with 7 tracks from a collision


But it didn‟t last long…

• September 19th

– A resistive zone led to an electrical arc in sector 3-4 (one of 8) while raising the currents on the magnets.

– “the current was being ramped up to 9.3 kA in the main dipole circuit at the nominal rate of 10 A/s, when at a value of 8.7 kA, a resistive zone developed in the electrical bus in the region between dipole C24 and quadrupole Q24”

– This created a rupture in the helium enclosure of the magnets

• Considerable damage

– Several tons of helium were released in the tunnel…


29

LHC incident Sep. 19, 2008• 600 MJ dumped

– 400 into dump resistors

– 200 into Arc (section of LHC)!

• At fault: 1 of 10k brazed joints – Suspect it was not made!

• 100-200 n impedance

“We‟ll never know why… Essential thing is that it never happens again”

• Remedial steps

– Spring-loaded flanges at spare ports in cold sections, replace valves in warm sections

• NB: better p-release would have avoided damage to magnets, cleaning would still require removal, so time lost is comparable

• Detection and monitoring– Post-mortem check of thermometry

shows a warming of 20 mK at the failure point.

• “we didn‟t realize the significance”

– Develop calorimetric method & look elsewhere: heating seen 4 places.

• Consistent with 50-100 n

impedance but is it real? Put nanoVoltmeters across 2-3 splices and find they‟re perfect!

– Something else is causing the heating

• Dipole problem in one case.

• One case ok – has already been tested to high current

• Sector 1-2 has ~100n seen

– Decide in January if need to warm up and remove

• Sector 5/6 anyway has a non-conforming interconnection cryostat


30

Bus-bar splice


31

Q27

32


The plan for 200933

Jan Feb Mar Apr May Jun Jul Aug

Last magnet goes into sector 34

LHC cold

2009

Dec

Removal of damaged magnetsCleaning and repairCold testingReinstallationInterconnectionPressure testingCool down

“We agreed on 5 TeV in the past and I see no reason to re-open it… We won‟t go to 7 TeV”

Lyn Evans CMS week Dec. 8, 2008

ALICE AND LHCB

Current Status

34


35

Formal end of ALICE installation

J. Schukraft


ALICE


36

HMPID – High Momentum Particle Identification detector, ITS – Inner Tracking System, Muon arm–Muon detector, PHOS – Photon Spectrometer, PID – Particle Identification detector, PMD – Photon Multiplicity Detector, TOF – Time of Flight, TPC – Time Projection Chamber, TDR – Transition Radiation Detector

Alignment with Cosmics

~50k cosmic for alignment collected since end of May (~0.1 Hz), using Pixel trigger


Silicon Pixel Detector (SPD):

~10M channels

Silicon Drift Detector (SDD):

~133k channels

Silicon Strip Detector (SSD):

~2.6M channels

ITS Event

display

Distribution of clusters in the 6 layers

37

TPC Performance


38

• Preliminary results from cosmics

– dE/dx resolution (goal: ~ 5.5%)

< 6%

– pt resolution (goal: ~ 5% @ 10 GeV)

~ 10% @ 10 GeV w/o calibration

ParticleIdentification

Momentum Resolution(uncalibrated)

Looking Forward to Physics • Configuration 2008

– complete: ITS, TPC, TOF, HMPID, muons, PMD, V0, T0, ZDC, Acorde,..

– partially complete: TRD (25%), EMCAL (0%), PHOS(20%)

• Complete ALICE: TRD (2009), DAQ/HLT(2009), PHOS (2010), EMCAL (2011)

• Physics of the first „year‟…

– „day 1‟ physics in 2009 with pp: global event properties (0.9/10 TeV)

• requiring only subset of detectors, few 10,000 events

– „ early pp physics‟ 2009: detailed studies of pp

• First heavy ion run will be „at the end of the first long pp run‟– Is the quark gluon plasma an ideal fluid?


39

LHCb


40Pascal Perret

LHCb is ready for data taking

• All sub-detectors >95% channels are working

With the first fb-1 LHCb will already be doing core physics:

Bs , Bs J/, B K*, cosg etc.

41


ATLAS AND CMS

Current Status

42

|η|<2.5 : Tracker

[GeV] 01.0p105p/ T

5

T

|η|<4.9 : EM Calorimeter

|η|<4.9 : HAD Calorimeter

|η|<2.7 : Muon spectrometer

07.0p/ T

[GeV] /%10E/ E

[GeV] 03.0/%50E/ E

(1TeV muons)

ATLAS and CMS


43

See D. Froidevaux & P. Sphicas An. Re. Nucl. Part. Sci 56 (375) 2006

|η|<2.6 : Tracker

|η|<4.9 : EM Calorimeter

|η|<4.9 : Had Calorimeter

|η|<2.6 : Muon spectrometer

005.0p105.1p/ T

5

T

E/%52E/

05.0/%100E/ E

10.0p/ T (1TeV muons)

ATLAS CMS

Mass [tons] 7000 12500

Diameter 22 m 15 m

Length 46 m 22 m

Solenoid 2 T 4 T

44

45 m

24 m

LHC and ATLAS, Motivation and Status

7000 Tons

ATLAS Detector


Davide Boscherini

ATLAS TOROIDS

45


Running with cosmics46


Davide Boscherini

Cosmic event in ATLAS


47Davide Boscherini

Cosmic in ATLAS Pixels and Strips48


ID alignment performed in steps with increasing DoF

globalO(100) tracks

sub-detectorO(10k) tracks

single elementsO(1M) tracks

sub-sub-detectorO(50k) tracks

Inner detector alignment with cosmics


49Davide Boscherini

Alignmenthit resolution = 174m(already comparable to 130m design)

TRT event displaycosmic event in the barrel TRTwith magnetic field on

Cosmics in the Transition Radiation Tracker


50Davide Boscherini

MUON BARREL

CALORIMETERS

Pixels

Silicon Microstrips

210 m2 of silicon sensors

9.6M channels

ECAL

76k scintillating PbWO4 crystals

Cathode Strip Chambers (CSC)

Resistive Plate Chambers (RPC)

Drift TubeChambers (DT)

Resistive PlateChambers (RPC)

4T Solenoid

IRON YOKE

TRACKER

MUONENDCAPS

HCAL

Scintillator/brasssandwich

Total weight 12500 tOverall diameter 15 mOverall length 21.6 m

51


CMS Central Detector


52

CMS Endcap Preshower (ES)


53

ES „ready for installation‟ by beg-Jan 09. Installation foreseen in mid-Feb and mid-Mar

CRAFT • CMS Cosmic Run At ~Four Tesla

– Ran 4 weeks continuously and 19 days with B=3.8T

• 370M cosmic events collected in total

• 290M with B=3.8T and with strip tracker and DT in readout

• 194M with all detectors


54

CRAFT Global Muon with pixel hits55

I. Osborne


Pixel Occupancy Maps56


CMS Tracker Alignment

Silicon Microstrips

(~4M tracks)

Pixels

55K tracks

57

Pixels:200-350 hits/module Joe Incandela UC Santa Barbara

% modules with>30 hits:Strips:

Inner Barrel 96% Inner Disks 98% Outer Barrel 98%End Caps 94%

Pixels: Barrel 89% Forward 4%

Inner Barrel26m

47m

(was 112m)

Outer Barrel27m

CRAFT PT Spectrum


58

Tracking: 7 M tracks, 500 K with P> 100 GeV

CMS Preliminary

PREPARATIONS FOR PHYSICS

CMS & ATLAS

59

SM at 10-14 TeV– Low initial luminosity

• Study Min Bias, dN/dh etc

– Constrain Underlying Event , PDFs

• Jets

– Optimize algorithms for resolution & scale

– Study lepton fakes, b tagging, photons

• Then more complex final states

– Also calibrate with known objects

• Study “candles” for leptons and photons

– o,, initially to understand detector,

tracking, leptons & other objects

– Extend to W or Z leptons

– Compare to MC V+Jets

– Extend into tt core region and then

– Deal with tails…

QCD Jets

60


• A new window on NatureParts of SM we have not seen.

• Somewhat familiar but with

more jets than we‟re used to !

• Inclusive charged hadron production (at 14 TeV*)

– “first-paper” analysis…

Charged Hadrons

J. Incandela (UCSB): Oxford University Seminar; March 22, 2008

Efficiency vs. pT for , K and p to very low pT

pT Spectra ofhadrons in various h intervals

*Recently repeated at 900 Gev and 10 TeV

Discovery of the SM at 10-14 TeVJ/ ϒ Z

ttqq′b b

62


Life at low x in a pp collider

• LHC ≠ Tevatron

– Small p momentum fractions x

are involved in many key

searches:

• large phase space for gluon

emission

– Consider tt:

• For a jet threshold of ~15 GeV,

essentially all tt events will

have 1 or more additional jets

– Consider V+jets

• Ratio of LHC to Tevatron

production cross sections for

W/Z + n jets becomes huge as

n increases

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

0 2 4 6

W+jets

Z+jets

63


M.L.Mangano

tt at 10-14 TeV• We‟ll have to deal with tt

– The additional jets complicate

reconstruction/isolation of top.

• Top is not like W or Z

“Top is not a candle, it‟s more like

a candelabra” – Ken Bloom (U. Nebraska)

– Once we understand the control

regions:(W/Z + n jets for low n, and

QCD fakes), we can begin to tackle

the core regions of tt.

– But the devil is in „da‟ tails

• If a new physics signal overlaps the

tails of top, it will be difficult to

untangle …

QCD Jets

64


Early Searches for New Physics

• Follow the data

– Higgs and Dark Matter seem to be for real

– Good chance we can make both at the LHC

• Higgs

– Rocío Vilar will cover this

• so I can skip it

• Dark Matter

– We don‟t know what it is

– Can think of early SUSY searches as effectively looking for Dark Matter, whatever it may be

• The topologies, methods, backgrounds relevant to SUSY apply to broad class of Dark Matter theories


65

“SUSY search”

• Missing Energy:

– from LSP

• Multi-Jet:

– from cascade decay (gaugino)

• Multi-Leptons:

– from decay of charginos/neutralios


66

R-Parity-Conserving SUSY example

O. Buchmuller

“SUSY search”

• Missing Energy:

– Nwimp - end of the cascade

• Multi-Jet:

– from decay of the N‟s (possibly via heavy SM particles like top, W/Z)

• Multi-Leptons:

– from decay of the N‟s


67

Extra dimensions, Little Higgs, Technicolor, etcO. Buchmuller

Jets + ETmiss - Inclusive Search

ETmiss=360 GeV

ETjet1=330 GeV

ETjet2=140 GeV

ETjet3= 60 GeV

Run IIV. Shary CALOR04

no cleaning

after cleaning

The simplest topology and the greatest potential

Analysis Strategy:• Be brave

• Fight background and noise• Use data control samples• Estimate background from data

M(g ̃) ≈ M(q̃) ≈ 500 GeV

1fb-1

ETmiss

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Z to invisible

68


Idea:Search for squark-squark production with squark decay directly to quark + LSP Exp. signature: 2 jets + missing ET

Important analysis properties:• <2/3

• T = ETj2/MTj1,j2 > 0.55 (inspired by arXiv0806.1049)

T > 0.55LM1: 430Z: 60t,Z,W: 20QCD: 0

1fb-1

LSPLSP

jetjet jet

jet

Analysis only relies onkinematics of the dijet system:• no direct calorimetric missing Energy dependence • idea can be extended to genericn-jet system

SUSY search with dijet events 69


O. Buchmuller

Data Driven Background Estimations

An illustrative example: Z+jets Irreducible background for Jets+MET search

Z

MET

Z

W

g

Zll+jets Wl+jets g+jets

larger statistics but not so clean, SM and signal contamination

large statistics, clean for high Ebut not clean for Eg<100 GeV,

70


very clean but low statistics: factor 6 suppressed wrt. to Z

Define control samples and understand their strength and weaknesses:

Theory correction applied

All cuts

Subset of cuts

Predicting Z→Å 100 pb-1


71

g + jets: 124 events

– Backgrounds estimated from data

• QCD, electrons

– Dynamics is different from Z production.

• QFT correction to reproduce Z spectrum

– Correction depends on the event selection

• Out-of-box agreement is already good

W + jets: 24 events W– Backgrounds estimated from data

• QCD, tt, Z

– Well known correspondence to Z+jets

uncorrected

Control Region :

Meff < 100 GeV

Inclusive MET + Jets + 1 lepton

Meff > 100 GeV

ATLAS

1 fb-1

• Add lepton clean trigger– Important during early running!

• Typical Characteristics:– Single Isolated lepton

• Low pT ~ 20-30 GeV

– 3 or 4 jets:• Hard leading (& NL) Jets

– Large MET• Typically > 100 GeV

– Cuts on (jets, MET) – Large Meff

• Main remaining backgrounds– ttbar, W/Z+n-Jets Signal Region :

Meff > 100 GeV

72


First Kinematic Measurements…With a bit of luck we might see this

Jets + MET+ 2 Leptons (SFOS )

• Estimate same flavour top and di-boson bkg

directly from e data

• Relatively precise extraction of Mllmax in the first

few hundred pb-1

Meemax=1.07stat0.36sys GeV for 1/fb (CMS)

Mmax=0.75stat0.18sys GeV for 1/fb (CMS)

M(l+l-) GeV





73


Inclusive MET + Jets + 2 leptons

2 OS SF Leptons

2 SS SF Leptons

L = 1 fb-1

L = 1 fb-1

74


What we see may be difficult to interpret


75

• Minimal Universal Extra Dimensions– 1 Extra compact dimension: R– Everything propagates in Bulk– KK tower of “SM-like” states

• evenly separated • nearly degenerate

• Signatures like low mass SUSY!– Many Jets– Large MET (KK parity stable LKP)

– Leptons• With OS dilepton mass edges

– High cross-section• Early Physics Potential

• Current constraints:– R-1 > 600 Gev (for mH >115 GeV)

CMSPreliminary

CMS AN 2006/008

Datta, Matchev, KongPhys.Rev. D72 (2005) 096006q

l (near)

l (far)

Di-lepton Resonances (Example Z‟)

Main background: Drell-Yan:

<1 event for M>1.5 TeV

in 1fb-1





MZ‟=1.5 TeV

~80 Events in 1fb-1

Very early discovery potential with clean signatures!

has always been the subject of (clean) searches …



Z‟e+e- Discovery Potential

76


Early LHC Discovery Potential

Model Mass reach Luminosity (fb-1) Early Systematic Challenges

Contact Interaction < 2.8 TeV 0.01 Jet Eff., Energy Scale

Z’

ALRM

SSM

LRM

E6, SO(10)

M ~ 1 TeV

M ~ 1 TeV

M ~ 1 TeV

M ~ 1 TeV

0.01

0.02

0.03

0.03 – 0.1

Alignment

Excited Quark M ~0.7 – 3.6 TeV 0.1 Jet Energy Scale

Axigluon or Colouron M ~0.7 – 3.5 TeV 0.1 Jet Energy Scale

E6 diquarks M ~0.7 – 4.0 TeV 0.1 Jet Energy Scale

Technirho M ~0.7 – 2.4 TeV 0.1 Jet Energy Scale

ADD Virtual GKK MD~ 4.3 - 3 TeV, n = 3-6

MD~ 5 - 4 TeV, n = 3-6

0.1

1

Alignment

ADD Direct GKK MD~ 1.5-1.0 TeV, n = 3-6 0.1 MET, Jet/photon Scale

SUSY

Jet+MET+0 lepton

Jet+MET+1 lepton

Jet+MET+2 leptons

M ~1.5 – 1.8 TeV

M ~0.5 TeV

M ~0.5 TeV

M ~0.5 TeV

1

0.01

0.1

0.1

MET, Jet Energy Scale, Multi-

Jet backgrounds, Standard

Model backgrounds

mUED M ~0.3 TeV

M ~ 0.6 TeV

0.01

1

ibid

TeV-1 (ZKK(1)) Mz1 < 5 TeV 1

RS1

di-jets

di-muons

MG1~0.7- 0.8 TeV, c=0.1

MG1~0.8- 2.3 TeV, c=0.01-0.1

0.1

1

Jet Energy Scale

Alignment

Early LHC Runs: 0.1 to 1 fb-1

77


Summary

• We‟ll run in 2009 (10 TeV?) and all experiments are ready

– In 2009 we will commission everything: machine, detector, and physics analysis

• We‟ll discover the Standard Model at 10 TeV and start to refine our understanding of the “LHC environment”

• We may discover a candidate for Dark Matter early

– Low energy SUSY ?

– 2009/2010 the year(s) of “SUSY” ?

• If it is not low energy (high production rate) it could be difficult and long.

• There are many other things that may appear

– Many new physics models; Black hole, Extra Dimensions,Little Higgs, Split Susy, New Bosons, Technicolour, etc …

• Exciting times…. And…


78


79

Cosmics in CMS


80

http://iguana.web.cern.ch/iguana/docs/pictures1/2008/CRAFT-run66748.gif

MORE INFORMATION

81

50 Best Inventions of 2008Top 10 Scientific Discoveries1. Large Hadron Collider

http://www.time.com/time/specials/2008/top10/article/0,30583,1855948_1863947,00.html

ATLASPrel.

Gauge Mediated Breaking of SUSY• SUSY broken at lower scale by Gauge Bosons

– Couple to “messengers” from hidden sector at some high energy scale Fo

– Gravitino becomes LSP

– Neutralino can be NLSP

• Distinctive Signature

– Large MET

– Large Meff

– High ET photon

• NLSP Lifetime large ct Non-pointing

• Prompt NLSP decays Pointing

• Depends on SUSY breaking scale!

• Interesting Phenomenology

– From Eg , L, ct

– Can derive mNLSP and thus SUSY Breaking Scale

• Early Discover Potential

– N = 1 ; tan = 1 ; sgn[] = +1 ;

Mm = 280 GeV ; = 140 Gev

– O(1) fb-1

ATLAS

CMS Prel.100 pseudo experiments of 10 fb-1

83


Object-ID/efficiency: data-driven methods

• Tag and Probe (T&P):

– identify object in an unbiased way in order to study efficiencies.

• One object (tag) has strict ID criteria imposed on it. Second object (probe) has looser ID criteria. Additional property that links it to the Tag object to ensure a pure sample.

• Zee events: one tight electron (tag); the other can be a probe, provided the invariant mass of the pair is ≈MZ

T&PZee

Zee

Efficiency from T&P: 94.36±0.24 Efficiency from MC truth: 94.63±0.24} (for 10 pb-1)

84


Drell-Yan above the Z peak

+- channelCMS

10% at 1 TeV

Drell-Yan

production

Systematic uncertainties


Efficiencies from data

Z’

High mass dimuons:

Tracking: alignment and propagation muons tracker important

As noted yesterday: Mass resolution (and so discovery potential)

not too strongly affected by tracker alignment scenario

Z‟, graviton resonances, large extra dimensions…

86


Track Momentum resolution: 10-1000 pb-1

pT resolution integrated over h

Z peak visible with first rough alignments

87


New Physics Search with Di-jets

1fb-1



Contact Interaction



Exited Quarks

10pb-1

100pb-1QuickTime™ and a

TIFF (Uncompressed) decompressorare needed to see this picture.

X

q, q, g

q, q, g

q, q, g

q, q, gContact Interaction

q

q q

q

Dijet Resonance

mainly t - channel

QCD

s - channel

88


New Physics Search with Di-jets

1fb-1



Contact Interaction



Exited Quarks

10pb-1

100pb-1QuickTime™ and a

TIFF (Uncompressed) decompressorare needed to see this picture.

Small systematic due to use of ratio: Di-jet Ratio = N(|h|<0.7) / N(0.7<|h|<1.3) Significant

discovery potential:e.g. up to ~10 TeV

in 2009/2010



89


Dijet xsec ratio and new Physics90


SUSY Searches @ LHC

LHC: gluino and squark production dominate(strong couplings)

Large production rates at “low mass”

Huge number of theoretical models Very complex analysis; MSSM >100 parameter

To reduce complexity we have to choose some

“reasonable”, “typical” models; use a theory of dynamical

SUSY breaking

mSUGRA (main model)

GMSB (studied in less detail)

AMSB (studied in less detail)

Use models to study different SUSY signatures in the

detector.

Msp(GeV) (pb) Evts/yr

500 100 106-10

7

1000 1 104-10

5

2000 0.01 102-10

3

For low masses the LHC becomes a realSUSY factory

Clear signatures oflarge missing energy,hard jets and many

leptons!(assume R-Parity)

Could be very spectacular!

91


Signature based analyses

• A Variety of inclusive analyses @ a specific benchmark points then extended to the m1/2-mo

plane using FAMOS (CMS fast detector simulation)

– MET + jets @ LM1: MET>200

– Muons + MET + jets @ LM1: MET>130

– Same sign di-muons @ LM1: MET>200

– Opposite sign dileptons @ LM1:MET>200

– Di-taus @ LM2 : decays 95% to tt: MET>150

– Inclusive analysis with Higgs @LM5:MET>200

– Inclusive Zo @LM4:MET>230

– Inclusive top @ LM1: Top plus leptons: MET>150

02

~ ~

92


CMSSM:

Phys. Lett. B, 657/1-3 (2007)Preferred region @ 95%CL:

Discoverable with just 6 pb-1

Excludable with less than 1 fb-1!

Expected CMSSM Discovery Reach

• As a function of integrated luminosity

• For different discovery channels (1 fb-1) SN-ATLAS-2002-020

CMS Preliminary

Expected Tevatron Reach

ATLAS Similar

CMSSM:

without systematics

1 fb-1

ATLASPreliminary

93


SUSY Discovery Potential -

CMSSM

Discover Potential for “muli-jet, multi-lepton and missing energy search”is described in the CMSSM.

Both ATLAS and CMS have very similar performance (as expected).

94


Preferred CMSSM Parameter

Space

“CMSSM fit clearly favors low-mass SUSY -Evidence that a signal might show up very early?!”

“LHC Weather Forecast”

Simultaneous fit of CMSSM parameters m0, m1/2, A0, tan

(>0) to more than 30 colliderand cosmology data (e.g. MW,

Mtop, g-2, BR(BXg), relic density)

JHEP 0809:117,2008OB, R.Cavanaugh, A.De Roeck,

J.R.Ellis, H.~Flaecher, S.~Heinemeyer,

G.Isidor, K.A.Olive, P.Paradisi,

F.J.Ronga, G.Weiglein

95


SUSY signals (cascades)

0

2

g~

q~

q q

0

2

0hM(bb)

Can be

discovery

channel

for the

Higgs

1 fb-1

miss

TE0

1 miss

TE0

1

h

b

0

2b

96


LM1: MET and 3 jets

• Cleanup instrumental bkds, halo, cosmics, etc.

– E.g. require

• primary vertex

• Total EM fraction Fem>0.175

– Fem = ET weighted EM fraction in |h|<3

• Event charged fraction Fch>0.1

– Fch = PT of charged tracks associated to jets over calorimeter jet ET in |h|<1.7

97


• Add 1 Same Flavor Lepton– Even cleaner– Little to no QCD

• Typical Selection Strategy– Several, high pT Jets– Large MET– Strong lepton isolation cuts

• Main backgrounds– tt– Double boson

• 2 OS SF : W+W-, WZ, ZZ• 2 SS SF : W+W+, W-W-

~unique to LHC

– Double partons not yet studied• W “+” W, W “+” Z, Z “+” Z

Inclusive MET + Jets + 2 leptons

p

p

W

,Zg

d

u

u

u

u

d

W

d

d

W W

98


A Glimpse at the LHC Physics ProgramHiggs!

Supersymmetry?

Extra Dimensions??

Black Holes???

Precision Electroweak!

Quark Gluon Plasma?

CKM triangle!

Physics at a new energy frontier!

MtopMW

99


Collimator settings at 7 TeV• Up to now collimators were not needed for machine operation

– Used to reduce backgrounds in experiments

• LHC: essential for machine operation (above few % of nominal intensity)– A series of collimators and absorbers remove much of the halo and the hadronic showers that they induce.

– More than 100 collimators jaws required for nominal LHC beam

1 mm

Opening ~3-5 mm

RF contacts for guiding

image currents

Beam spot

Must be aligned to better than 100 m to be as efficient as needed (> 99.9%).

100


Jörg Wenninger

Collimation Picture Gallery\IMG_3385.JPG

First Beam on September 10101


102


Lyn Evans

Post mortem calorimetry in S3-4 and S1-2

0

10

20

30

40

50

60

70

80

1.85

1.87

1.89

1.91

1.93

1.95

1.97

1.99

18:00 19:00 20:00 21:00 22:00

Val

ve o

pe

nin

g [%

], c

urr

en

t [k

A],

CC

flo

w [

g/s

]

Co

ld-m

ass

tem

pe

ratu

e [

K]

LBALA_24R3_TT821.POSST




LBALB_24R3_TT821.POSST


LBBLA_24R3_TT821.POSST




LBBLD_25R3_TT821.POSST


LQASB_23R3_TT821.POSST

LQOAA_25R3_TT821.POSST

LQOBA_24R3_TT821.POSST


QRLAA_25R3_CV910.POSST

QRLAB_23R3_CV910.POSST

QURCA_4_FT201.POSST

RPTE.UA43.RB.A34:I_MEAS

0

10

20

30

40

50

60

1.85

1.87

1.89

1.91

1.93

1.95

1.97

1.99

2.01

2.03

2.05

17:00 18:00 19:00 20:00 21:00

Val

ve o

pe

nin

g [%

], c

urr

en

t [k

A]

Co

ld m

ass

tem

pe

ratu

re [

K]

LBARA_16R1_TT821.POSST




LBARB_16R1_TT821.POSST


LBBRA_16R1_TT821.POSST




LBBRD_17R1_TT821.POSST


LQATH_16R1_TT821.POSST


LQATK_17R1_TT821.POSST

LQATO_15R1_TT821.POSST

QRLAA_17R1_CV910AO.POSST

QRLAB_15R1_CV910AO.POSST


Post-mortem analysis of the powering at

7 kA of the sub-sector 23R3 (15/09/2008)

Analysis of the powering at 9.3 kA of

the sub-sector 15R1 (01/09/2008)

First sign of abnormal dissipation in S3-4 and S1-2:

Can we implement calorimetric measurement to detect and to

estimate some abnormal resistive heating ?

103

Lyn Evans

Conclusion (I)

104

Calorimetric measurement on sectors 1-2, 6-7 & 7-8 has identified four problematic cases on MB circuit:

– 15R1: local resistance of ~ 90 n confirmed also by electrical

measurement (in B16R1).

– 31R6: local resistance of ~ 50 n confirmed also by electrical

measurement (in B32R6).

– 19R1: not continuous heat dissipation of ~ 7 kJ in Q21R1 two

minutes after the 7-kA plateau start. Origin identify: Helium

refilling during the current plateau.

– 31R1: local resistance of ~ 50 nW calculated at 7 kA but with a

correlation at lower current not very good.

no electrical confirmation

additional test not possible (S-1-2 under emptying)

correlation with the two other cases (supplier, # series...) ?

analysis of SM18 electrical tests ?

Conclusions (III)

• The repowering and investigations performed in sectors 1-2, 6-7 and 7-8 were very successful

• There is no excessive splice resistance in the dipole bus-bars in suspicious cryo-cell 15-16 of sector 1-2

•

– Perfect (nominal) splice resistances of 0.35 nΩ were measured

• An excessive resistance inside dipoles B16.R1, B32.R6 was detected

– The electrical resistance, estimated by two independent methods, is of the order of 100 and 47 nΩ

105


Lyn Evans

Post mortem calorimetry in S3-4 and S1-2

0

10

20

30

40

50

60

70

80

1.85

1.87

1.89

1.91

1.93

1.95

1.97

1.99

18:00 19:00 20:00 21:00 22:00

Val

ve o

pe

nin

g [%

], c

urr

en

t [k

A],

CC

flo

w [

g/s

]

Co

ld-m

ass

tem

pe

ratu

e [

K]













LQASB_23R3_TT821.POSST

LQOAA_25R3_TT821.POSST



QRLAA_25R3_CV910.POSST

QRLAB_23R3_CV910.POSST

QURCA_4_FT201.POSST


0

10

20

30

40

50

60

1.85

1.87

1.89

1.91

1.93

1.95

1.97

1.99

2.01

2.03

2.05

17:00 18:00 19:00 20:00 21:00

Val

ve o

pe

nin

g [%

], c

urr

en

t [k

A]

Co

ld m

ass

tem

pe

ratu

re [

K]















LQATK_17R1_TT821.POSST

LQATO_15R1_TT821.POSST

QRLAA_17R1_CV910AO.POSST

QRLAB_15R1_CV910AO.POSST


Post-mortem analysis of the powering at

7 kA of the sub-sector 23R3 (15/09/2008)

Analysis of the powering at 9.3 kA of

the sub-sector 15R1 (01/09/2008)

First sign of abnormal dissipation in S3-4 and S1-2:

Can we implement calorimetric measurement to detect and to

estimate some abnormal resistive heating ?

106

LHC Experimental Challenge

• LHC requires a new generation of detectors

– 109 pp interactions/sec

– Can record for only ~102 out of 4x107 crossings/sec

– Level-1 trigger decision takes ~2-3 s

electronics need to store data locally (pipelining)

– Large Particle Multiplicity

Up to 20 superposed collisions each bunch crossing

1000‟s of tracks stream into the detector every 25 ns

– Need fine spatial granularity and time resolution for low occupancy

large number of channels (~ 100 M)

– Must handle high radiation levels

radiation hard (tolerant) detectors and electronics

107


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