dark particle hunters - physics and astronomy at...

LHC:HUNTFOR

DARKMATTER

Teruki Kamon1),2)

1) Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University 2) WCU Collider Physics Research, Kyungpook National University

Colloquium, Korea Institute for Advanced Study (KIAS), KoreaNovember 25, 2010

1

Sean Connery as Marko Ramius

Summary

Teruki Kamon 2

OOUTLINE33

1) Dark Matter and SUSY2) LHC & CMS Detector3) Re-discoveries �� SUSY

PrologueThe LHC started taking data from proton-proton collisions ata center-of-mass energy of 7 TeV on March 30, 2010 andbecame the energy frontier machine to lead to discoveries ofnew particles. The Standard Model (SM) is currently welltested up to ~100 GeV, but is expected to break down in theTeV domain where new physics should occur. This is preciselythe domain that we will study at the LHC.

New Physics at CMS

hhttp://faculty.physics.tamu.edu/kamon/research/Cosmology_at_Colliders/http://faculty.physics.tamu.edu/kamon/research/LHCpheno/

Phys. Lett. B 505 (2001) 161Phys. Lett. B 538 (2002) 121Phys. Lett. B 611 (2005) 223Phys. Lett. B 618 (2005) 182Eur. Phys. J. C46 (2006) 43Phys. Lett. B 639 (2006) 46Phys. Lett. B 649 (2007) 73Phys. Rev. Lett. 100 (2008) 231802Phys. Rev. D 79 (2009) 055002hep-ph/1008.3380, accepted for publication in Phys. Rev. D (2010)

TAMU-KNU Pheno Projects

Today, I focus on theoretical motivation to search for SUSY darkmatter and show a experimental readiness of the CMS detector for2011 run.

We have been working on how to determine cosmologically-consistentcollider signals. Below are the list of papers.

3

4

3

2

11splitting normal matter and dark matter apart

– Another Clear Evidence of Dark Matter –(8/21/06)

Dark Matter(Gravitational Lensing)

Ordinary Matter(NASA’s Chandra XObservatory)

time

Approximately the same size asthe Milky Way

Dark Matter in the Universe

Teruki Kamon 4y y

PPC at the LHC

The UniverseDo we know the content of the universe?

Teruki Kamon 5PPC at the LHC

Wilkinson Microwave Anisotropy Probe (WMAP) : �DM = 23%What is the dark matter? An elementary particle?

CCan it be one of the known particles?LLet’s check out!

It Doesn’t Matter.Right, it doesn’t shake hand with anyone easily. Two dark matter clusters (in blue) are just passing each other. It is a long-lived (stable) object.

It’s a Cold Matter.Yes, it is a “relativistically” slowly moving (“cold”) object.

4

It’s an Invisible Matter.Right, it doesn’t respond to your flash light. This means it is a neutral object.

So, It’s a �� (CDM).

Properties of Cold Dark Matter


Quarks, electron, muon, tau particles, and force carriers cannot be the dark matter, since their interactions are strongerthan what we expect.

Neutrinos can, but they have other problems.

X X XX X X

X X XX X X

XXXX


CDM in The Standard Model?

We need an new idea beyond the Standard Model.

Any guidance?�e.g., Supersymmetry (SUSY)

MENU~SPECIALS~

*Dark Energy Power Drink .. $73- Chef ’s choice

*Dark Matter Sandwich …… $23- Neutral, long-lived

*Atomic Soup ………………. $4- All elements in one

No, Sir. But with neutralino?

MENU

I am hungry. Can you makethe DM sandwich with anyStandard Model particle?

“Dark Matter” Sandwich

Teruki Kamon Probing Supersymmetric Connection with DM 8

Texas-style SUSY Hunting


© S. Kamon

SUSY is :a) Supersymmetrized Standard Model

(“Democratic” solution betweenFermions and Bosons);

b) An elegant solution to solve theproblem associated with the Higgsmass;

Supersymmetry (SUSY)

+

Unification!

c) Beautifully connecting the Standard Modelwith an ultimate unification of thefundamental interactions;

d) Cosmologically consistent with a DarkMatter candidate – stable neutralino.

01�~

Neutral

Lightest

SUSY

Particle typeTeruki Kamon 10

ggPPC at the LHC

LHC

annihilation

combination

Probing Early Universe

11

I am traveling a lot …

1

2

3

0Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University

12

WWORLD PHYSICS AGENCY

High Energy Physics Special Agent

TERUKI KAMON

WPA Code: XXXX XXXX XXXX 0007(Dark Matter Hunter)

Code Name: SUSY

Affiliations: TAMU, KNUOccupation: Professor

Current Status: ACTIVE, TravelingCountry: Europe, Japan, Korea, USA

DOB: unknownLocation: unknown

I always have to carry on Japanese passport, USresidency card, Texas A&M faculty ID card, Texas statedrivers license card, and Korean residency card.

© S. Kamon

My Daughter’s Image of Dad …

13

27 km ring

Large Hadron Collider (LHC)

14

� Accelerator to provide 7-TeV(*) proton beams from aH bottle;

� Big (27 km circumference);� Cool (1.9K using 60 tons of

Liquid Helium);� Hot (synchrotron radiation,

in media);� Enormous and very sophisticated magnetic system;� Powerful (14 TeV(*) collisions, Total magnetic energy

stored is that of Aerobus A380 flying at 700 km/h).

The LHC is :


(*) 3.5 TeV/beam in 2010

Powerful to Create Massive Objects


14 TeV Proton-Proton Collisions

Proton Collisions 1 billion (109) Hz

Bunch Crossing 40 million (106) Hz

7.5 m (25 ns)

One “discovery” event in 10,000,000,000,000

14,000 x mass of proton (14 TeV) = Collision EnergyProtons fly at 99.999999% of speed of light

2808 = Bunches/Beam100 billion (1011) = Protons/Bunch

Parton Collisions

New Particles 1 Hz to 10 micro (10-5) Hz(Higgs, SUSY, ....)

Discovery Path at the LHC


Cosm

olo

gica

lly

Con

sist

ent

Sig

nals

1 0 trillion collisions

Discoveries with “Missing ET”Standard Model’s CV

1973 B.S. �� Neutral current@ CERN SPS (400 GeV p)

1983 M.S. – “W/Z discovery”@ CERN SppS (540 GeV )

1995 Ph.D. – “Top discovery”@ Fermilab Tevatron (1.8 TeV )

20?? Evidence of SUSY-like new physics in the jets + MET final stateat the LHC

pp

pp

W � e�

t � W b

Missing ET (MET) - inferring neutrinos


MET - inferring new physics (if the dark matter is like a heavy neutrino.)

Cosmology � LHC = [Exciting Motivation]�[Right Place&Timing]

��

�e

b

b ��

eb

b�

�

�slash

det��0��

pectedvisible

ppppp��

��

[Ref.] Missing ET


slashp

Experimentally, we measure a momentumimbalance in transverse plane and call it “missingtransverse energy” ( or ).TEmiss

TE

The CMS (21 m x 15 m x 15 m, 12,500 tonnes) is one of two super-fast & super-sensitive detectors,consisting of 15 heavy elements, collecting debris from the collision and converting a visualimage for us. “Particle” Telescope at CERN vs. Hubble Space Telescope in outer space

Compact Muon Solenoid

Hubble Space Telescope

Teruki Kamon 20

22008.09.10: First LHC Beam

21

CMS

ALICE

ATLAS

LHCbp

p

ALICEAAAAAAAAAAAAAAAAAAAAAALLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLIIIIIIIIIIIIIIIIIIIIIIIIIIIIICCCCCCCCCCCCCCCCCCCCCCCCCCCCCCEEEEEEEEEEEEEEEEEEE

ATLAS

14:22 pm

CMS

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCMMMMMMMMMMMMMMMMMMMMMMMMMMSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS

19:20 pmCMS

LHCb

17:59 pmLHCb

LHC is Back!(Nov. 23, 2009)

Teruki Kamon 2222222222222222222

2.36 TeV … 12/06/20097 TeV … 3/30/20108 TeV in 2011-12?

2009.11.23: 900 GGeV

Charged Particle Multiplicity

Teruki Kamon 23

M=1.116 GeV/c2

��=3.1 MeV/c2M=497.7 MeV/c2

�=7.6 MeV/c2

LHC is back!&

We are ready!!

�� 0

�� p� KK�� 0sK

JHEP 02 (2010) 041

Re--Discoveries 2009

7:467:467:15 7:50

9:11 10:08

12:4612:33 12:48

12:58

10:13

7:465 7:462010.03.30: 7 TeV

24Teruki Kamon

Sunghyun Chang

BBeam1(c.w.)Beam2(c.c.w.)

3329 GeV3500 GeV

22010 Run (Mar 30 ~ Oct 29)

Teruki Kamon 25

SSUSY Searches at CMS

Teruki Kamon 26

It is critical to understand the SM production (e.g., W, Z,top), since they are often dominant backgrounds for newparticle searches. I will go through selected topics on theSM analyses and new particle searches:

1) Dilepton resonances; W and Z bosons2) Top quark--------------------------------------------------------------------------------------3) We have to understand jets – see an example in “Search

for new quark-like or gluon-like particle: X �� jj”4) We have to understand MET.5) Remark on “particle physics and cosmology”

280 nb-1

1.1 pb-1

22010.08.09: First 1 pb--11

(~80 x 109 ppp collisions)

1977 � � �+�–

1974 J� � �+�–

LHC is powerful enough to re-discover those particles in ~4 months.

Teruki Kamon 27

1983 Z� �+�–

WW and Z bosons

Teruki Kamon 28

��

��

�

�

WW and Z in � CChannel

� Simultaneous fits tobackgrounds and signalcontributions.

� QCD background shapesobtained using data.

� Electroweak backgroundshapes and signal fromMC.

1.1 pb-1

Teruki Kamon 29

)4.2(GeV 20][

)1.2(GeV 9][

��

��

�

�

T

T

pZ

pW

WW and Z in e Channel

� W: 75% efficiency� Z: 90% efficiency� QCD background shapes

from data� Electroweak background

and signal shapes from MC

Teruki Kamon 30

1.1 pb-1

)5.2566.1

,442.10(GeV 20]&[

��

��

�

�

�TpZW

22.9 pb-1

Teruki Kamon 31

ATLAS arXiv:1010.2130 0.32 pb-1 2250 W’s, 179 Z/�*’s ��/� ~ 5%

CMS Soon 2.9 pb-1

W and Z: Results

Teruki Kamon 32

WW and Z: toward Results with 35 pb--11

TTop� Precise SM measurements� Great tool to calibrate detector (e.g., jet energy scale, b-

tagging efficiency)� Top is one of dominant BGs in many new physics

scenarios (e.g., SUSY).� A window to new physics …

Teruki Kamon 33

TTop DDilepton:: Event Display

VVery clean candidate sitting in a region where we expect very littlebackground!

Teruki Kamon 34

μμ +bb + MET Candidate Event

z [cm]

y[c

m]

b1

b2

b2 b1

j

j

��

��

��

TE

• FFull selection applied: Z-boson Veto, |M(��)-M(Z)| > 15 GeV• MET>30 (20) GeV in ee, ��, (e� ) ; N(jets)��T > 30 GeV)

Top DDilepton: Results

3.1 pb-1

Teruki Kamon 35

11 tt candidates (3e�, 3ee, 5��) over a negligible backgroundtttt_

arXiv:1010.5994, submitted to PLB

w/o N(jets)��

• TTesting with KINematic (KIN) method and Matrix-element Weighting Technique (MWT)

Top DDilepton: Results3.1 pb-1

Teruki Kamon 36

Consistent with top pair-production (Mtop = 172.5 GeV) � Massmeasurement with ~40 pb-1 in lepton+jets+MET.

TTop DDilepton:: Results33.1 pb-1

Teruki Kamon 37

ATLAS ? ? ?

CMS 1010.5994 ((PLB) 3.1 pb-1 ��/� ~ 15%

Top Lepton+Jets: Event Display

Event passes all cuts:� 1 high-momentum electron� significant MET ��GeV� 4 high-pT jets, � two of which with good/clear b-tags

mT(W) ��2

m(jj) � 102 GeV/c2

m(jjj) � 208, 232 GeV/c2

(for the two 3-jet combinations) Teruki Kamon 38

e + jj + bb + MET Candidate Event

b1

b1

b2

b2

j1

j2

TE

j1

e

e

TTop Lepton + jjj ++ bbb ++ MET: Results

NN(jets) � 33:� Observed: 30 e /� candidates

� PPredicted background: N(BG,MC) = 5.3

� Predicted signal: N(tt,MC) = 15

Requiring at least 1 jet b-tagged � secondary vertex tagger with �� high efficiency with ~1% fake rate

Teruki Kamon 39

0.84 pb-1

tt MC_

Seeing tt events at a rate roughly consistent with NLO cross section,considering experimental (jet energy scale, b-tagging) and theoretical(scale, PDF, …) uncertainties

_

Aggressively preparing the paper! With ~35 pb-1

DDijet mass differential cross section - sensitive to the coupling of anynew massive object (narrow resonance) to quarks and gluons.

X �� jjPRL 105 (2010) 211801 or arXiv:1010.0203

Teruki Kamon 40

2.9 pb-1

[Selection] |�1,2| < 2.5 and |��12| < 1.3

XX �� jjjModel CMS

(2.9 pb-1)CDF

(1.13 fb-1)

String 0.50 - 2.50 1.4

q* 0.50 - 1.58 0.26 - 0.87

Axigluon /Coloron 0.50-1.171.47-1.52

0.26 - 1.25

Scalar E6 Diquark 0.50-0.580.97-1.081.45-1.60

0.29 - 0.63

Randall-Sundrum(RS) Graviton (G)

--- ---

W’ --- 0.28 - 0.84

Z’ --- 0.32 - 0.74

Teruki Kamon 41

2.9 pb-1

ATLAS PRL 105 (2010) 1161801;arXiv:1008.2461

0.315 pb-1 q* : 0.30 - 1.26 TeV

ATLAS-CONF-2010-093

3.1 pb-1 q* : 0.50 - 1.53 TeV

MORE DATA

SSUSY Reference AnalysesRRA11 .. Jets .. �TRA2 .. Jets + METRA3 .. Photon + jets + METRA4 .. Lepton + jets + METRA5 .. OS Dilepton + jets +METRA6 .. LS Dilepton + jets + METRA7 .. Trilepton

Teruki Kamon 42

EExample: RA1RRA1 .. �T = ET2/MT(jj)

Teruki Kamon 43

Aggressively preparing the paper with ~35 pb-1

SUS-10-001

No QCD!New Physics, here

Just using jet topology,avoiding from a directuse of MET.

We want to understandMET …

((Absolute) MET Scale

[[Goal] Improve a linearity of MET (�5% �3% with 35 pb-1). The MET scale isinsensitive to NPV (JME-10-005). We also need to study with � + 3jet events forSUSY-like topology.

for events with photon pT > 20 GeV)(/ T �qu||

Type II CaloMET TC MET PF MET

1.05

0.95

0.988�0.007 0.990�0.005 0.995�0.004

JME-10-005 (0.2 pb-1)

Da

ta/M

C

111

)(T �q

3 different algorithms …

44

JJME-10-004

0.5 events PF MET [GeV]

Illustrating CMS’ Amusement� ~20 x 106 MB events @ 70 mb,

corresponding to �LMBdt ~0.3 nb-1

� �(W�e�, ��, ��) ~ 30 nb

� NEWK = 30 nb x 0.3 nb-1 = 9 events� ~0.5 events per 1-GeV bin in the

figure, assuming a flat distributionbetween 25 and 45 GeV.

MET from W ��(scaled)( )

With ~35 pb-1, we are seeing more rare noses. Further improvementsare being made.

In CDF and D0, we haven’t seen the MET distribution closer to a level ofElectroweak physics.

45

EExample: RA2 Prospects

46

Warning!

Even

ts/5

0 G

eV/1

00 p

b-1 103

102

10

1

10-1

[GeV])(4

�� i

i,TTeff EEM

q~GeV 600SUSY

Background

ts/5

00 eV

GV

00 p

b/1

bbVV

-1 1

1

1

�E

tt/5

00V

G

�An Excess – Not Good Enough


“2011”


1) An inclusive search in Jets + MET using mT2

2) If we see an excess, we could estimate a mass of thedark matter particle assuming this is SUSY.

QCDtt

��Z

arXiv:0907.2713v1Alan J. Barr and Claire Gwenlan

1) Bs�� 2) Inclusive mT23) MET + jets + X

123

CDMS II

Rouzbeh Allahverdi, Bhaskar Dutta, Yudi SantosoarXiv:0912.4329

WCU Projects


Excluded by1) Rare B decay b � s�2) No CDM candidate3) Muon magnetic moment

abc

LLHC 2011

• Beam back around 21st February• 2 weeks re-commissioning with

beam (at least)• 4 day technical stop every 6

weeks• Count 1 day to recover from TS

(optimistic)• 2 days machine development

every 2 weeks or so• 4 days ions set-up• 4 weeks ion run • End of run – 12th December

~200 days proton physicsLHC status

Roger Bailey’s talk at LHCC(Nov 12, 2010)

50

•

• 4 TeV (*)• 936 bunches (75 ns)• 3 micron emittance• 1.2 x 1011 protons/bunch• �* = 2.5 m, nominal crossing

angle

2011: “Reasonable” & “Ultimate” Numbers

Peak luminosity 6.4 x 1032

Integrated per day 11 pb-1

200 days 2.2 fb-1

Stored energy 72 MJ

12/11/10

Usual warnings apply – see problems,problems above

Peak luminosity 2.2 x 1033

Integrated per day 38 pb-1

200 days 7.6 fb-1

Stored energy 134 MJ

• 4 TeV• 1400 bunches (50 ns)• 2.5 micron emittance• 1.5 x 1011 protons/bunch• �* = 2.0 m, nominal crossing

angle

LHC status51

(*) to be discussed at Chamonix)

EExample of Impact on LHC Physics

Teruki Kamon 52

88 TeV

7 TeV7 TeV

Consistent with SUSY

https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsHIGStandardModelProjections

Tevatron to LHC

http://faculty.physsics.tamu.edu/kamon/research/refColliders/LHC/httttp: aacultyty.phy//fafa

Teruki Kamon 53

remarkremarkr

refColliders/LHC/

PPC at the LHC

CBS comedy “Big Bang Theory”(Season 1 Episode 15)

54

SummaryRRemark: PPCInterconnection between Particle Physics and Cosmology

PPC 2011 at CERN, June 14-18PPC 2012 at ???

Teruki Kamon 55

CSI: Supersymmetry

at the LHCCollider Scene Investigation

SSummary

Teruki Kamon 56

LHC – keep going!

FFYI: ZZ Candidate

57

Nov. 8, 2010Pb-Pb collision2.76 TeV/nucleon pair(RHIC x 14)

FFYI: Heavy Ion Collision

58

Nov. 14, 2010

FFYI: Z in Heavy Ion Collision

59

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