Halo-independent direct detection analyses without mass assumptions

Journal Article · Tue Oct 06 00:00:00 EDT 2015 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2015/10/012· OSTI ID:1212755

Anderson, Adam J. ^[1]; Fox, Patrick J. ^[2]; Kahn, Yonatan ^[1]; McCullough, Matthew ^[3]

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1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
3. European Organization for Nuclear Research (CERN), Geneva (Switzerland)

Results from direct detection experiments are typically interpreted by employing an assumption about the dark matter velocity distribution, with results presented in the m_χ – σ_n plane. Recently methods which are independent of the DM halo velocity distribution have been developed which present results in the v_min – g^~ plane, but these in turn require an assumption on the dark matter mass. Here we present an extension of these halo-independent methods for dark matter direct detection which does not require a fiducial choice of the dark matter mass. With a change of variables from v_min to nuclear recoil momentum (p_R), the full halo-independent content of an experimental result for any dark matter mass can be condensed into a single plot as a function of a new halo integral variable, which we call tilde h(p_R). The entire family of conventional halo-independent tilde g^~(v_min) plots for all DM masses are directly found from the single tilde h^~(p_R) plot through a simple rescaling of axes. By considering results in tildeh^~(p_R) space, one can determine if two experiments are inconsistent for all masses and all physically possible halos, or for what range of dark matter masses the results are inconsistent for all halos, without the necessity of multiple tilde g^~(v_min) plots for different DM masses. As a result, we conduct a sample analysis comparing the CDMS II Si events to the null results from LUX, XENON10, and SuperCDMS using our method and discuss how the results can be strengthened by imposing the physically reasonable requirement of a finite halo escape velocity.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: AC02-07CH11359; SC00012567; AC05-06OR23100
• OSTI ID: 1212755
• Alternate ID(s): OSTI ID: 1254825
• Report Number(s): FERMILAB-PUB-15-096-T; CERN-PH-TH-2015-073; MIT-CTP-4661; arXiv eprint number arXiv:1504.03333
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2015, Issue 10; ISSN 1475-7516
• Publisher: Institute of Physics (IOP)
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
dark matter theory
dark matter detectors
dark matter experiements
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
dark matter experiments