Direct detection of WIMPs: principles18/12/2015

Teresa Marrodan Undagoitia

• Program:

– Introduction

– Characteristics and signatures of dark matter

∗ General properties∗ Spectral shape∗ Annual modulation∗ Directional dependence of the signal

– Cross sections for scattering on nucleons and form factors

– Generic result of a dark matter experiment

• Literature:

– M. W. Goodman and E. Witten, Detectability of certain dark-matter candidates, Phys. Rev.D 31 (1985) 12

– J. D. Lewin and P. F. Smith, Review of mathematics, numerical factors, and corrections fordark matter experiments based on elastic nuclear recoil, Astrop. Phys. 6 (1996) 87

– A.K. Drukier, K. Freese and D. N. Spergel, Detecting cold dark-matter candidates, Phys.Rev. D 33 (1986) 12

– D. N. Spergel, The Motion of the Earth and the Detection of Wimps, Phys. Rev. D37 (1988)1353

– K. Freese et al, Colloquium: Annual modulation of dark matter, Rev. Mod. Phys. 85 (2013)1561, arXiv:1209.3339.

– L. Vietze et al, Nuclear structure aspects of spin-independent WIMP scattering off xenon,Phys. Rev. D 91 (2015) 043520, arXiv:1412.6091

– N. Anand, A. L. Fitzpatrick, and W. Haxton, Weakly interacting massive particle-nucleuselastic scattering response, Phys. Rev. C89 no. 6, (2014) 065501, arXiv:1308.6288

– T. Marrodan Undagoitia and L. Rauch, Dark matter direct-detection experiments, J. Phys.G: 43 (2015) 1, arXiv:1509.08767

• Material for the lecture:

Figure 1: Scheme of the kinematic that give an annual modulation of the dark matter rate.

Figure 2: Effect of annual modulation on the event rate for the standard halo model (SHM), adebris flow and a stream of dark matter. Figure from K. Freeze al. arXiv:1209.3339.

Figure 3: Structure factor SS(u) for 129Xe and 131Xe (black dots) in comparison with the Helmform factor (red) and the Fitzpatrick structure factor. Figures from L. Vietze et al. PRD 91 (2015)043520 and arXiv:1412.609.

Figure 4: Directionality signature: (top) WIMP flux in the case of an isothermal spherical halo,(middle) WIMP-induced recoil distribution and (bottom) a typical simulated measurement: 100WIMP recoils and 100 background events (low angular resolution). Figure from J. Billard et al.2010.

Figure 5: (Left) Event rates as function of nuclear recoil energy for different target materials assum-ing a 100 GeV/c2 WIMP mass and an interaction cross section of 10−45 cm2 (solid lines). (Right)Event rates for argon and tungsten. Dotted line: no form factor correction. Dashed line: for a25 GeV/c2 WIMP mass. Figures from arXiv:1509.08767.

Figure 6: Relative strength of event rates for a 50 GeV/c2 spin-1/2 WIMP in xenon for differentnon-relativistic operators. Figure from Dent et al., PRD 92 (2015) 6, 063515, arXiv:1505.03117.

Figure 7: Sensitivity of direct detection experiments for different detector parameters. Figuresfrom arXiv:1509.08767.