DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June...
-
date post
21-Dec-2015 -
Category
Documents
-
view
215 -
download
1
Transcript of DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June...
![Page 1: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/1.jpg)
DARK MATTER
Jonathan FengUniversity of California, Irvine
University of Colorado, Boulder21 June 2011
Credit: John K
orm
endy
![Page 2: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/2.jpg)
21 June 11 Feng 2
PHYSICS: TRADITIONAL VIEW
small largeParticlePhysics
NuclearPhysics
AtomicPhysics
CondensedMatter Physics
Biophysics
Astrophysics
Cosmology
![Page 3: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/3.jpg)
21 June 11 Feng 3
Particle Physics
CondensedMatter Physics
Biophysics
Astrophysics
Cosmology
Nuclear Physics
Atomic Physics
PHYSICS: UPDATED VIEW
![Page 4: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/4.jpg)
21 June 11 Feng 4
![Page 5: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/5.jpg)
21 June 11 Feng 5
THE LARGE FRONTIER
clusters ofgalaxies
1012
meters
solar system galaxy
1017
meters1023
meters> 1026
meters
universe
![Page 6: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/6.jpg)
21 June 11 Feng 6
EVIDENCE FOR DARK MATTER:CLUSTERS OF GALAXIES
In the 1930’s Fritz Zwicky observed the Coma cluster and found that the galaxies were moving too fast to be
contained by the visible matter
![Page 7: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/7.jpg)
21 June 11 Feng 7
EVIDENCE FOR DARK MATTER:INDIVIDUAL GALAXIES
In the 1970’s Vera Rubin and collaborators and Albert Bosma found that stars in galaxies were rotating too fast
to be contained by the visible matter
![Page 8: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/8.jpg)
THE STANDARD MODEL OF COSMOLOGY
• Atoms make up only 4% of the Universe
• The rest of the matter is dark matter, which does not shine or reflect light– Not atoms– Cold– Stable
• Also, 73% of the Universe isn’t even matter
21 June 11 Feng 8
![Page 9: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/9.jpg)
21 June 11 Feng 9
THE SMALL FRONTIER
electron
1010 meters(thickness of human
hair ~ 10-5 m)
up quarkdown quark
atom
nucleus protonneutron
1014
meters1015
meters< 108
meters
![Page 10: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/10.jpg)
• Strong
• Weak
4 FORCES OF NATURE
• Gravity
• Electromagnetism
21 June 11 Feng 10
![Page 11: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/11.jpg)
21 June 11 Feng 11
STANDARD MODEL OF PARTICLE PHYSICS
Atoms
![Page 12: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/12.jpg)
21 June 11 Feng 12
Known DM properties
WHICH PARTICLE IS DARK MATTER?
• Not atoms
The extraordinarily successful standard models of cosmology and particle physics are inconsistent
• Cold
• Stable
![Page 13: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/13.jpg)
• In 1821 Alexis Bouvard found anomalies in the path of Uranus and suggested they could be caused by unseen matter
• In 1845-46 Urbain Le Verrier determined where this matter should be. With this guidance, Johann Galle discovered the unseen matter at the Berlin Observatory in 1846
21 June 11 Feng 13
• Le Verrier wanted to call it Le Verrier, but this matter is now known as Neptune, the farthest known planet (1846-1930, 1979-1999, 2006-present)
WHAT SHOULD WE DO?
![Page 14: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/14.jpg)
• Strong
• Weak
WHICH FORCES DOES DARK MATTER FEEL?
• Gravity
• Electromagnetism
21 June 11 Feng 14
?
![Page 15: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/15.jpg)
OPTION 1: WIMPS
• Dark matter feels the weak force
• DM = WIMPs: weakly-interacting massive particles
• Why WIMPs? Looking under the lamp post
21 June 11 Feng 15
![Page 16: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/16.jpg)
THE WIMP MIRACLE
• But there’s more to it than that
• Many theories predict WIMPs that are around 100 times heavier than the proton
Feng 16
DM DM
q q
time
• Such particles are present just after the Big Bang, but then annihilate in pairs. Assuming they annihilate through the weak force, calculations show that they should be ~ 10% of the Universe now. This is what is required to be dark matter!
21 June 11
![Page 17: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/17.jpg)
WIMP DETECTION
• If WIMPs annihilated in the early Universe, they should also be doing that now
• We can look for rare forms of matter and anti-matter created in these collisions
Feng 17
DM DM
q qtim
e21 June 11
![Page 18: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/18.jpg)
ICECUBE IN ANTARCTICA
Looking for neutrinos produced by WIMP annihilation in the Sun
Feng 18Feng 1821 June 11
![Page 19: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/19.jpg)
ALPHA MAGNETIC SPECTROMETER
Carried by Space Shuttle to the International Space Station
Feng 19Feng 1921 June 11
![Page 20: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/20.jpg)
Feng 20
WIMP PRODUCTION
• If WIMPs annihilated in the early Universe, we should also be able to run time backwards
• We can collide two normal particles at high velocities to create dark matter, which we detect as missing energy
Feng 20
DM DM
q qtim
e21 June 11
![Page 21: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/21.jpg)
Feng 21
LARGE HADRON COLLIDER
Colliding protons at 99.999999% the speed of light
Feng 2121 June 11
![Page 22: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/22.jpg)
Feng 22
Billion collisions per second; dark matter is a needle in the haystack
21 June 11
CMS
![Page 23: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/23.jpg)
WIMP RECOILS• If WIMPs annihilated in the early Universe, we should also be
able to run time sideways
• We can watch for normal matter recoiling from a WIMP collision. At any given time, there is roughly 1 WIMP per coffee cup, but their interactions are weak and recoils are rare
Feng 23
DM DM
q q
time21 June 11
![Page 24: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/24.jpg)
CRYOGENIC DARK MATTER SEARCH
Colliding protons at 99.999999% the speed of lightOperating at milli-Kelvin temperatures in a mine in Minnesota
Feng 2421 June 11
![Page 25: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/25.jpg)
Collision rate should change as the Earth goes around the Sun: annual modulation (1986)
21 June 11 Feng 25
DAMA/LIBRA signal with period ≈ 1 year, maximum ≈ June 2
DAMA/LIBRA IN ITALYD
AM
A/L
IBR
A (2
01
0)
![Page 26: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/26.jpg)
OPTION 2: SUPERWIMPS
• Dark matter does not feel the weak force
• DM = SuperWIMPs: superweakly-interacting massive particles
• Seemingly a lost cause
Feng 2621 June 11
![Page 27: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/27.jpg)
GRAVITINOS
Feng 27
• An example: gravitinos proposed by Pagels and Primack in 1982
• Gravitinos feel only gravity
• But they may be created by decaying particles that have dramatic implications for the LHC
Long-lived progenitor(charge and mass)
q(charge)
SuperWIMP(mass)
21 June 11
![Page 28: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/28.jpg)
GRAVITINOS AT THE LHC
D. A
kerib
Feng 2821 June 11
![Page 29: DARK MATTER Jonathan Feng University of California, Irvine University of Colorado, Boulder 21 June 2011 Credit: John Kormendy.](https://reader030.fdocuments.net/reader030/viewer/2022032521/56649d5a5503460f94a3a370/html5/thumbnails/29.jpg)
SUMMARY
• We now have two extraordinarily successful theories of the large and small, but they don’t match
• A quarter of the Universe is dark matter, but we don’t know what it is
• We have some ideas, though, and many interesting search experiments underway
Feng 2921 June 11