Introduction to Class and Dark Matter - SDSM&T
Transcript of Introduction to Class and Dark Matter - SDSM&T
Introduction to Class and Dark Matter
Prof. Luke A. CorwinPHYS 792
South Dakota School of Mines & Technology
Jan. 14, 2014 (W1-1)
L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 1 / 22
Outline
1 Introduction to Class
2 Introduction to Dark MatterEvidence for Dark MatterSearching for Dark Matter
3 Reminders
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Introduction to Class
You’re not Prof. Corwin!
Correct, I am not any of the 3 professors named Corwin(Luke, Edward, or Kelly) at Mines
Prof. Luke Corwin is in Japan on a research-related trip
I have agreed to take over this class for Jan. 14, 16, and 21.
Barring unforeseen problems, Prof. L. Corwin will be backfor Jan. 23 and most or all of the remainder of the semester.
L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 3 / 22
Introduction to Class
Available on the Class Webpage
http://odessa.phy.sdsmt.edu/~lcorwin/PHYS792DM_
Spring2014/ClassWebpage.html
The syllabus
Past lecture notes (and recordings if possible)
All out-of-class homework
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Introduction to Class
Mid-term Presentation
20 min. length
Select one candidate for dark matter and explain it to theclass
Your presentation will need to help your fellow studentsunderstand the theoretical nature of this candidate and howwell (or poorly) it is supported by current experimental data
You may choose any candidate except for WIMPs
Presentations will be during Week 7
Choose your candidate before or in class on Jan. 30.
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Introduction to Class
Dark Matter Candidates
Massive Compact Halo Objects (MaCHOs)
Axions
Particles interacting only via gravity
Sterile neutrinos
superWIMPs
Modified Newtonian Dynamics (MOND)
If you know of another candidate, let Prof. Corwin know.
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Introduction to Class
Final Project Presentation
20 min. length
Select one dark matter detection experiment and explain it tothe class.
You presentation will need to help your fellow studentsunderstand the type of dark matter being sought, themethods used, possible backgrounds, and expectedsensitivities or results.
You may choose an experiment that has been concluded, is inoperation, is under construction, or is planned.
We will have the presentations during finals week; exacttimes will be determined by the class.
Choose your experiment before or in class on Feb. 20
Each student will present on a different experiment
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Introduction to Class
Possible Experiments
Direct Searches
ADMX, ArDM, CDMS, COUPP, Cogent, CRESST, CUORE,DAMA, DAMIC, DarkSide, DEAP/CLEAN, DM-TPC, DM-ice,Drift, Edelweiss, Eureca, IGEX, LIBRA, MIMAC, NAIAD,NEWAGE, ORPHEUS, PandaX, Picasso, ROSEBUD, SIMPLE,TEXONO, UKDMC, XENON, XMASS, WARP, Zeplin
Indirect Searches
AMANDA, AMS, ANTARES, BAIKAL, BESS, CAPRICE, CTA,Fermi, GAPS, HEAT, HESS, IceCube, IMAX, MACRO, Nestor,NINA, Pamela, Super-K
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Introduction to Class
Independent Study Paper I
Students taking the Independent Study Dark Matter coursefor 1 additional credit are required to write a paper
4-5 pages using LATEX with header including
\documentclass[11pt]{article}
\geometry{verbose,letterpaper,lmargin=1in,
rmargin=1in,tmargin=1in,bmargin=1in}
Due May 1, 2014
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Introduction to Class
Independent Study Paper II
Topic Choices
1 Status and Methods of dark matter searches at particlecolliders
2 What theoretical models of dark matter could explain thepositive results of DAMA/LIBRA and CoGeNT as well asthe negative results of LUX, etc?
3 What possibilities exist for WIMP detection beyond the“neutrino floor”?
4 How could WIMPs affect stellar or planetary evolution?
5 If you have a different idea for a topic, please let me knowand we will discuss it.
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Introduction to Dark Matter
What do you know about darkmatter?
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Introduction to Dark Matter
The Great Misnomer
“Dark” matter is not really dark. If it were, we could detectit absorbing light. It has no electromagnetic interactions, soit is actually transparent, but “transparent matter” doesn’thave quite the same ring to it
Some theorists speculate that the effects we see are notactually from matter but from misunderstood gravity. Weshall cover this in a later session.
In the next few slides, we will briefly review some of theevidence for dark matter and the methods for searching for it.These will all be covered in detail throughout the semester.
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Introduction to Dark Matter Evidence for Dark Matter
Figure : On scales from galaxies to the cosmos, we see more gravitythan can be accounted for by visible matter.http://cheezburger.com/2510042880
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Introduction to Dark Matter Evidence for Dark Matter
Galactic Rotation Curves
One of the iconicgalactic rotationcurves from Mon.Not. Roy. Astron.Soc. 249 (1991)523. “. . . thedashed curves arefor the visiblecomponents, thedotted curves forthe gas, and thedash-dot curves forthe dark halo.”
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Introduction to Dark Matter Evidence for Dark Matter
Figure : The “Bullet Cluster”: Hot gas detected in X-rays (pink),visible matter (white and orange), and gravitational lensing (blue)indicate most of the matter in these clusters is “dark”.http://chandra.harvard.edu/photo/2006/1e0657/
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Introduction to Dark Matter Evidence for Dark Matter
What We Know
Something is causing the appearance of more gravity thancan be explained with visible matter.
Excess matter could also help explain the large-scalestructure of the Universe and present abundances of lightelements in the Universe.
If this “something” is matter and is in particle form, thatparticle is nothing we have encountered in the lab or ataccelerators.
We have bounds on this particle’s behavior from stellarbehavior and astrophysics.
It must have mass and be even more weakly interacting thanneutrinos; therefore, the most favored candidates are calledWeakly Interactive Massive Particles
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Introduction to Dark Matter Evidence for Dark Matter
What We Don’t Know
We don’t know for certain that dark matter particles exist, asopposed to new physics of gravity. Most physicist areconfident, but it would be better to actually find the particles
Are dark matter particles WIMPs?
Does more than one dark matter particle exist?
What is it’s mass?
What are its spin-independent and spin-dependent nuclearcross-sections?
Is the dark matter particle its own antiparticle?
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Introduction to Dark Matter Searching for Dark Matter
How We Find Out: Two Search Methods
Direct Detection
Cryogenic liquid or solid detectors are used to search for the smallenergy deposited by a WIMP on the rare occasion in collides witha nucleus. At Sanford, LUX and the planned LZ experiment usethis approach with cryogenic liquid xenon.
Indirect Detection
If dark matter and anti-dark matter particles exist in sufficientdensities and have sufficient annihilation cross-sections, they willproduce detectable amounts of annihilation produces (e.g.positrons or neutrinos) that would be indirect evidence of particledark matter.
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Introduction to Dark Matter Searching for Dark Matter
Direct Detection Example: LUX
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Introduction to Dark Matter Searching for Dark Matter
Direct Detection Example: LUX First Results
mWIMP (GeV/c2)
WIM
P−nu
cleo
n cr
oss
sect
ion
(cm
2 )
101 102 103
10−45
10−44
6 8 10 12
10−44
10−42
10−40
LUX 90% CL(blue) comparedwith the limitsfrom severalprevious direct DMsearches. The inset(same axis units)also shows theregions claimed asevidence ormeasurement fromother experiments.a
aarXiv:1108.3384
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Introduction to Dark Matter Searching for Dark Matter
Indirect Detection Example: Super-Kamiokande
10-16
10-15
10-14
10-13
10-12
102
103
104
WIMP mass(GeV/c2)
Lim
it o
n W
IMP
-in
du
ce
d u
pm
u (
cm
-2 s
-1)
Expected flux region
(Eµ > 1 GeV )
SK-I
AMANDA
ICECUBE
SK-I+II+III
Soft channel
Figure : Upper limit of the flux of ν-induced upward going muonsresulting from dark matter particles trapped in the sun annihilatinginto bb. The shaded region represents a particular dark matter model(Astrophysical J. 742 (2011) 78).
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