hat’smatter? dark matter - texas a&m...

What’s Matter? Dark Matter!

SMP 2012

Teruki KamonMitchell Institute for Fundamental Physics and Astronomy

Department of Physics and AstronomyTexas A&M University

March 2012 1Dark Matter!

http://faculty.physics.tamu.edu/kamon/research/talk/2012/120331_SMP2012/120331_SMP12_DarkParticleHunters_v2.pdf

Teruki Kamon 2Dark Matter!

Prologue[Science]

Curiosity-driven: Lots of Questions. Priceless ! Fact-based: Interplay between theory and experiment Future investment: today’s new idea can be a future

application

[Today’s Theme] Thinking of the largest scaleby studying the smallestobject…

“What is the mysteriousDark Matter that dominatesthe mass in the Universe?”


Who Wanted “Dark Matter”?

DM

[http://en.wikipedia.org/wiki/Fritz_Zwicky]While examining the Coma Galaxy Cluster (largecluster of galaxies - over 1,000 identified galaxies;mean distance from Earth is 99 Mpc or 321 million ly)in 1933, Zwicky was the first to use the VirialTheorem to infer the existence of unseen matter,what is now called Dark Matter. He was able to inferthe average mass of galaxies within the cluster, andobtained a value about 160 times greater thanexpected from their luminosity, and proposed thatmost of the matter was dark. The same calculationtoday shows a smaller factor, based on greater valuesfor the mass of luminous material; but it is still clearthat the great majority of matter is dark.

I did …


“Dark Matter” Cube

Episode 1: Dark Matter in the Universe (What is Dark Matter?)

Episode 4: Fun examples of Particle Physics

Episode 3: Brief History of “Peaking Signal” Hunters

Episode 2: Where and how the DM can be probed?


Ordinary Matter: Atoms Quarks

10 cm


The proton is complexobject. See Lecture 2by Prof. Gagliardi onFeb 4.

Everything (that we can see) is made of electrons, up quarks anddown quarks.

Elementary Particles

All masses in MeV.ANIMAL MASSES SCALE WITH PARTICLE MASSES

12 elementary particles are known fundamental building blocks of matter.4 fundamental forces govern the transitions between particles. TheStandard Model, a mathematical rule, includes 12 particles and 3 forces.

g γ W G

strong force

electro-magneticforce

weak force

gravity

“Standard Model” Cube


However, the Universe is made of ...3 Contents

Ordinary matter (4%)

Dark Matter (23%)What is the dark matter?An elementary particle?


Very mysterious! SeeLecture 6 by Prof.Macri on Mar. 24.

Today’s focus

Astrophysical Journal 159 (1970) 377

Rotation curve of a typical spiral galaxy:predicted (A) and observed (B). The discrepancybetween the curves is attributed to dark matter.


Dark Matter in Spiral Galaxy

4

3

2

1splitting 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


Learn how todetermine distancesthroughout the wholeuniverse. See Lecture5 by Prof. Krisciunason Mar. 3.

Can it be one of the known particles?Let’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 Cold Dark Matter (CDM).

Properties of Cold Dark Matter


Quiz[Q] Can be the dark matter a Standard Model particle?

[Recap: Dark matter particles](1) Weakly interacting(2) Neutral(3) Heavy … relativistically slowly moving

[A] Quarks, electron, muon, and tau cannot be darkmatter, because they are interacting via strong and/orelectromagnetic forces. Neutrinos are too light.

[Q] What should we do?

[A] Expand the Standard Model framework based on anew symmetry, e.g., Supersymmetry or SUSY (next page)

New particles, including a dark matter candidate


Supersymmetry (SUSY)


Fermions Bosons

A set of new particles, including a dark matter candidate

Spin (& charge) is afundamental propertyand a powerful tool ininformation technology.See Lecture 1 byProf. Sinova on Jan.28.

Connection to Early Universe

We want to understand mysterious dark matter.Teruki Kamon 15Dark Matter!


“Interconnection” between particles and dark matter

Possible Dark Matter Interactions


CMS SuperCDMS AMS-2 GMT

2009 2012 2011 2018?

Geneva, Switzerland North America ISS Chile

Dark matter in pp collisions at the CERN’s

LHC

DM-proton elastic collisions in Ge detector

at SNOLAB

DM annihilation Dark matter & Dark energy, Black hole, Galaxy formation

7 trillion electron-Volts (TeV) 14 TeV

24.5-meter primary mirror

Giant Magellan TelescopeCryogenic Dark Matter SearchLarge Hadron Collider

Interconnection at TAMUAlpha Magnetic Spectrometer


Today’s focus


Conseil Europeen pour la

Recherche Nucleaire ( European Organization for

Nuclear Research)

Large Hadron Collider

LHC : Proton-Proton Collider

27 km ring


27km-long ultra high vacuum tubes with aboutone thousand 14.3m-long dipole magnets and8000 other types of magnets, acceleratingprotons to 99.999999% of speed of

Geneva Airport

Magnets are usedeverywhere and canbe explored at nano-scale. See Lecture 3by Prof. Roshchin onFeb. 11.

of light. You would have toconnect 600,000,000,000 (0.6trillion) 12V batteries l

Application: Proton Therapy

Irradiation of nasopharyngeal carcinoma (acancer originating in the nasopharynx) byphoton(X-ray) therapy (left) and proton therapy(right).


http://en.wikipedia.org/wiki/File:Comparison_of_dose_distributions_between_IMPT_(right)_and_IMRT_(left).jpg�

Pretty Big & Heavy Detector21 m x 15 m x 15 m, 12,500 tons


The CMS is one of two super-fast & super-sensitive detectors, consisting of 15 heavy elements,collecting debris from the collision and converting a visual image for us.

“Particle” Telescope at CERN vs. Hubble Space Telescope in outer space

E = mc2

Proton and (anti)proton collision can produce the Standard Modelparticles like heavy top quarks (~180 times heavier than a proton!) aswell as dark matter particles.

Physics Magic in Collisions

Fast Ping-pong balls Slow Steel BallsTeruki Kamon 23Dark Matter!

Possible?

Yes ! Possible to create heavier new particles in the“elementary particle” world.

New particle will be seen as a Peaking Signal …


Proton

Higgs

New Particles

Electron

Mass of SystemWhen a top quark is created, followed by a break-up(“decay”; t W + b; W e ν), its signal is detected at aspecific amount of energy (e.g., “mass” of the “e”, “ν” and“b” system).


Complete the decaydiagram.

t W+ + bW+ e+ ν

Heavy

What is “Peaking” Signal?When a new particle (e.g., top quark) is created, followedby a break-up (“decay”; t W + b; W e ν), its signal isdetected at a specific amount of energy (“mass”). We plotthe frequency of total energy of “e”, “ν” and “b”.


freq

uenc

y

Energy


t W+ + bW+ e+ ν

Heavy

What is “Peaking” Signal?When a new particle (e.g., top quark) is created, followedby a break-up (“decay”; t W + b; W e ν), its signal isdetected at a specific amount of energy (“mass”). We plotthe frequency of total energy of “e”, “ν” and “b”.


freq

uenc

y

Energy

No particular structure

“Background”

“Signal”

Normal -like distribution


t W+ + bW+ e+ ν

Heavy

Heaviest quark, discovered

Peaking Signal (I)


April 3, 1995

1995 … CDF and D0 collaborations co-discovered the top quark.

More Peaking Signals (II)

(~80 x 109 pp collisions)

1977 ϒ → µ+µ–

1974 J/ψ → µ+µ–

1983 Z→ µ+µ–

LHC is powerful enough tore-discover those particlesin 4 months.

Aug. 9, 2010

We expect an evidence of dark matter to appear as “Peaking Signal”in complex final states.


Where will the spin-0 Higgs Bosons be discovered ?How about the dark matter particles ?

Spin-1/2 Fermions

quark, c, τ c, νµ

b, top, ντ

gluon

W, Z

World “Discovery” Map

Spin-1 Bosons


m(νµ) ≠ 0

14 TeV Proton-Proton Collisions

Proton Collisions ??? Hz

Bunch Crossing ??? Hz

7.5 m (25 ns)

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

??? = Bunches/Beam??? = Protons/Bunch

Parton Collisions

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

Discovery Path at the LHC


We want to see many “discovery” events.

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 trillion collisions (10,000,000,000,000)

14 TeV (~14,000 x proton mass) = 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


Why do we need so many collisions?

Fabrication of nano-meter devices is thekey for moderntelecommuication toread massive datasuper fast. SeeLecture 4 by Prof.Belyanin on Feb. 25.

1 Terabit/s Readout

Statistical Significance


How do you know the probability ofseeing “1”?

What do you do to report itaccurately?

We need many trials !!!

If the nature were a complex die system, how can we probe?

?

Supposed that you have a black box of a “die” system(you don’t know the number of dices and its shape), butyou know the total number.

Quiz: How Many Giraffes?

One !

Shot #1


Two!!

Shot #2 Shot #3 Shot #4


We need more than one snap-shot!!!

No! It is two!!Still, one! Yes, definitely!!!

Experimental Method

We analyze “debris” after eachproton-proton collision using super-fast and super-sensitive detectorand extract evidence (“peakingsignal”) of new and rare phenomena.

Hubble Space Telescope


Big Bang, Back to the Future


13.8 Billion Years Ago


CERN Courier (July/August 2009)

1976 … A bold idea of proton-antiproton collider by Cline, McIntyre and Rubbia1983 … Discovery of W and Z1984 … Nobel prize to Carlo Rubbia and Simon van der Meer

1983


Tim Berners-Lee “We’ve learned Earth’slanguages though theWWW.”

World Wide Web (WWW)

1989

Twenty-three years ago an event at CERNchanged the world forever. Tim Berners-Leehanded a document to his supervisor MikeSendall entitled “Information Management : aProposal”. “Vague, but exciting” is how Mikedescribed it, and he approved it to go forward.The following year, the World Wide Web wasborn.


“Faster” internet! SeeLecture 4 by Prof.Belyanin on Feb 25.

1995

43 candidates from 3.4x1012 collisions


Discovery of Top

1985.10.13: First pp Collisions−

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


2007-2008

2010 …

2.5 x 1012 CollisionsTeruki Kamon 44Dark Matter!

2010.03.30: First 7000-GeV pp Collisions

2011 …

350 x 1012 CollisionsTeruki Kamon 45Dark Matter!

2012 …

>1000 x 1012 CollisionsTeruki Kamon 46Dark Matter!

Interconnection between Particle Physics and Cosmology

PPC 2011 at CERN, June 14-18PPC 2012 in KoreaPPC 2013 in TAMU??

“PPC”

PPC Cube


20**


Discovery of Dark Matter?

DM

p

Epilogue

Explained by known particles.

New particle?Expected to be discovered at the LHC.

Still huge puzzle



Congratulations for finishing 7th lecture!

Particle-Physics in Movie


Particle-Physics in Movie [2]


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