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


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.



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


http://odessa.phy.sdsmt.edu/~lcorwin/PHYS792DM_Spring2014/ClassWebpage.html

http://odessa.phy.sdsmt.edu/~lcorwin/PHYS792DM_Spring2014/ClassWebpage.html


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.



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.



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



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



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



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.


Introduction to Dark Matter

What do you know about darkmatter?


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.


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


http://cheezburger.com/2510042880


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.”



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/


http://chandra.harvard.edu/photo/2006/1e0657/


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



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?


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.



Direct Detection Example: LUX



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



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).


Reminders

Reminders

First Homework Due Jan. 21

Choose your topic for mid-term presentation before Jan. 30

Choose your topic for final presentation on or before Feb. 20


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