Introduction to Class and Dark Matter Prof. Luke A. Corwin PHYS 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 Matter Evidence for Dark Matter Searching for Dark Matter 3 Reminders L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 2 / 22
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 back for 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 L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 4 / 22
Introduction to Class Mid-term Presentation 20 min. length Select one candidate for dark matter and explain it to the class Your presentation will need to help your fellow students understand the theoretical nature of this candidate and how well (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. L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 5 / 22
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. L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 6 / 22
Introduction to Class Final Project Presentation 20 min. length Select one dark matter detection experiment and explain it to the class. You presentation will need to help your fellow students understand the type of dark matter being sought, the methods used, possible backgrounds, and expected sensitivities or results. You may choose an experiment that has been concluded, is in operation, is under construction, or is planned. We will have the presentations during finals week; exact times will be determined by the class. Choose your experiment before or in class on Feb. 20 Each student will present on a different experiment L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 7 / 22
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 L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 8 / 22
Introduction to Class Independent Study Paper I Students taking the Independent Study Dark Matter course for 1 additional credit are required to write a paper 4-5 pages using L A TEX with header including \documentclass[11pt]{article} \geometry{verbose,letterpaper,lmargin=1in, rmargin=1in,tmargin=1in,bmargin=1in} Due May 1, 2014 L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 9 / 22
Introduction to Class Independent Study Paper II Topic Choices 1 Status and Methods of dark matter searches at particle colliders 2 What theoretical models of dark matter could explain the positive results of DAMA/LIBRA and CoGeNT as well as the 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 know and we will discuss it. L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 10 / 22
Introduction to Dark Matter What do you know about dark matter? L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 11 / 22
Introduction to Dark Matter The Great Misnomer Dark matter is not really dark. If it were, we could detect it absorbing light. It has no electromagnetic interactions, so it is actually transparent, but transparent matter doesn t have quite the same ring to it Some theorists speculate that the effects we see are not actually from matter but from misunderstood gravity. We shall cover this in a later session. In the next few slides, we will briefly review some of the evidence for dark matter and the methods for searching for it. These will all be covered in detail throughout the semester. L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 12 / 22
Introduction to Dark Matter Evidence for Dark Matter Figure : On scales from galaxies to the cosmos, we see more gravity than can be accounted for by visible matter. http://cheezburger.com/2510042880 L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 13 / 22
Introduction to Dark Matter Evidence for Dark Matter Galactic Rotation Curves One of the iconic galactic rotation curves from Mon. Not. Roy. Astron. Soc. 249 (1991) 523.... the dashed curves are for the visible components, the dotted curves for the gas, and the dash-dot curves for the dark halo. L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 14 / 22
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/ L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 15 / 22
Introduction to Dark Matter Evidence for Dark Matter What We Know Something is causing the appearance of more gravity than can be explained with visible matter. Excess matter could also help explain the large-scale structure of the Universe and present abundances of light elements in the Universe. If this something is matter and is in particle form, that particle is nothing we have encountered in the lab or at accelerators. We have bounds on this particle s behavior from stellar behavior and astrophysics. It must have mass and be even more weakly interacting than neutrinos; therefore, the most favored candidates are called Weakly Interactive Massive Particles L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 16 / 22
Introduction to Dark Matter Evidence for Dark Matter What We Don t Know We don t know for certain that dark matter particles exist, as opposed to new physics of gravity. Most physicist are confident, 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 nuclear cross-sections? Is the dark matter particle its own antiparticle? L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 17 / 22
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 small energy deposited by a WIMP on the rare occasion in collides with a nucleus. At Sanford, LUX and the planned LZ experiment use this approach with cryogenic liquid xenon. Indirect Detection If dark matter and anti-dark matter particles exist in sufficient densities and have sufficient annihilation cross-sections, they will produce detectable amounts of annihilation produces (e.g. positrons or neutrinos) that would be indirect evidence of particle dark matter. L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 18 / 22
Introduction to Dark Matter Searching for Dark Matter Direct Detection Example: LUX L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 19 / 22
Introduction to Dark Matter Searching for Dark Matter Direct Detection Example: LUX First Results WIMP nucleon cross section (cm 2 ) 10 44 10 45 10 40 10 42 10 44 10 1 10 2 m (GeV/c 2 10 3 ) WIMP 6 8 10 12 LUX 90% CL (blue) compared with the limits from several previous direct DM searches. The inset (same axis units) also shows the regions claimed as evidence or measurement from other experiments. a a arxiv:1108.3384 L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 20 / 22
Introduction to Dark Matter Searching for Dark Matter Indirect Detection Example: Super-Kamiokande Limit on WIMP-induced upmu (cm -2 s -1 ) 10-12 10-13 10-14 10-15 10-16 Soft channel Expected flux region (E µ > 1 GeV ) AMANDA ICECUBE SK-I SK-I+II+III 10 2 10 3 10 4 WIMP mass(gev/c 2 ) Figure : Upper limit of the flux of ν-induced upward going muons resulting from dark matter particles trapped in the sun annihilating into bb. The shaded region represents a particular dark matter model (Astrophysical J. 742 (2011) 78). L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 21 / 22
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 L. Corwin, PHYS 792 (SDSM&T) Introduction Jan. 14, 2014 (W1-1) 22 / 22