Spin-Dependent Wimp Limits from a Bubble Chamber
E. Behnke,1 J. I. Collar,2 P. S. Cooper,3 K. Crum,2 M. Crisler,3 M. Hu,3 I. Levine,1 D. Nakazawa,2 H. Nguyen,3 B. Odom,2 E. Ramberg,3 J. Rasmussen,2 N. Riley,2 A. Sonnenschein,3 M. Szydagis,2 R. Tschirhart3
Science 15 February 2008:Vol. 319. no. 5865, pp. 933 - 936
Why?Why was this experiment done?
Dark matter makes up 70% of the universe.
We don’t know what dark matter is.
It might be WIMP-proton scattering.
Wimp-proton scattering is hard to detect.
…………Do WIMPs even exist??
What to do?What did this experiment do?
Exclude background radiation.
Increase detection time to include WIMPs.
Improve nuclear-recoil specific detection.
Find WIMPs.
Spoiler:
No WIMPs here.
Outline
WIMPs Bubble Chambers Bubble Chamber tweaking
For rateFor background
Data Conclusions
Outline
WIMPs Bubble Chambers Bubble Chamber tweaking
For rateFor background
Data Conclusions
http://serenitythruhaiku.files.wordpress.com/2009/02/wimp.jpg
Weakly-Interacting Massive Particles
•Hypothetical super-symmetric partners
•Not much known (mass, etc)
•Like Heavy, Slow neutrinos.
•Interacts with WNF and Gravity
Axino · Chargino · Gaugino · Gluino · Gravitino · Higgsino · Neutralino · Sfermion
Outline
WIMPs Bubble Chambers Bubble Chamber tweaking
For rateFor background
Data Conclusions
http://maltwood.uvic.ca/physics/Libraries/imagelibrary/29-52low.jpghttp://en.wikipedia.org/wiki/Bubble_chamberhttp://beer.thetazzone.com/images/drinkBeer9.jpg
Outline
WIMPs Bubble Chambers Bubble Chamber tweaking
For rateFor background
Data Conclusions
“deactivate inhomogeneous bubble nucleation centers “Instead of few milliseconds, ‘indefinite’. - Good for WIMP rate of 1/kg*day worst case scenario: < 1/ton*year
Tuned to detect only particles of large stopping power (dE/dx>50keV/um) - slow and big)
Just like WIMPs
A. High (60C)
B. Moderate (30C)- High dE/dx only (222Rn a-decay)
C.WIMP
Outline
WIMPs Bubble Chambers Bubble Chamber tweaking
For rateFor background
Data Conclusions
*****CF3I*****
Outline
WIMPs Bubble Chambers Bubble Chamber tweaking
For rateFor background
Data Conclusions
References Spin-Dependent WIMP Limits from a Bubble Chamber
E. Behnke, J. I. Collar, P. S. Cooper, K. Crum, M. Crisler, M. Hu, I. Levine, D. Nakazawa, H. Nguyen, B. Odom, E. Ramberg, J. Rasmussen, N. Riley, A. Sonnenschein, M. Szydagis, and R. Tschirhart (15 February 2008)Science 319 (5865), 933.
Wikiedia.com G. Jungman, M. Kamionkowski, K. Griest, Phys. Rep. 267, 195 (1996). C. Rubbia, Nucl. Phys. B Proc. Suppl. 36, xvii (1994).