Editing Weakly interacting massive particle (section)

== Direct detection ==
{{see also|Direct detection of dark matter}}
''Direct detection'' refers to the observation of the effects of a WIMP-nucleus collision as the dark matter passes through a detector in an Earth laboratory. While most WIMP models indicate that a large enough number of WIMPs must be captured in large celestial bodies for indirect detection experiments to succeed, it remains possible that these models are either incorrect or only explain part of the dark matter phenomenon. Thus, even with the multiple experiments dedicated to providing indirect evidence for the existence of cold dark matter, direct detection measurements are also necessary to solidify the theory of WIMPs.

Although most WIMPs encountering the Sun or the Earth are expected to pass through without any effect, it is hoped that a large number of dark matter WIMPs crossing a sufficiently large detector will interact often enough to be seen—at least a few events per year. The general strategy of current attempts to detect WIMPs is to find very sensitive systems that can be scaled to large volumes. This follows the lessons learned from the history of the discovery, and (by now routine) detection, of the neutrino.

[[Image:CDMS parameter space 2004.png |thumb|right|upright=1.6|Fig 1. CDMS parameter space excluded as of 2004. DAMA result is located in green area and is disallowed.]]

=== Experimental techniques ===

'''Cryogenic crystal detectors''' – A technique used by the [[Cryogenic Dark Matter Search]] (CDMS) detector at the [[Soudan Mine]] relies on multiple very cold germanium and silicon crystals. The crystals (each about the size of a hockey puck) are cooled to about 50 [[Kelvin|mK]]. A layer of metal (aluminium and tungsten) at the surfaces is used to detect a WIMP passing through the crystal. This design hopes to detect vibrations in the crystal matrix generated by an atom being "kicked" by a WIMP. The tungsten [[transition edge sensors]] (TES) are held at the critical temperature so they are in the [[superconducting]] state. Large crystal vibrations will generate heat in the metal and are detectable because of a change in [[electrical resistance|resistance]]. [[Cryogenic Rare Event Search with Superconducting Thermometers|CRESST]], [[CoGeNT]], and [[EDELWEISS]] run similar setups.

'''Noble gas scintillators''' – Another way of detecting atoms "knocked about" by a WIMP is to use [[scintillator|scintillating]] material, so that light pulses are generated by the moving atom and detected, often with PMTs. Experiments such as [[DEAP]] at [[SNOLAB]] and [[DarkSide (dark matter experiment)|DarkSide]] at the [[Laboratori Nazionali del Gran Sasso|LNGS]] instrument a very large target mass of liquid argon for sensitive WIMP searches. [[ZEPLIN]], and [[XENON Dark Matter Search Experiment|XENON]] used xenon to exclude WIMPs at higher sensitivity, with the most stringent limits to date provided by the XENON1T detector, utilizing 3.5 tons of liquid xenon.<ref>{{cite journal |arxiv=1705.06655 |last1=Aprile|first1=E|display-authors=etal  |title=First Dark Matter Search Results from the XENON1T Experiment |journal=Physical Review Letters|volume=119|issue=18|pages=181301|year=2017|doi=10.1103/PhysRevLett.119.181301|pmid=29219593|bibcode=2017PhRvL.119r1301A|s2cid=45532100}}</ref> Even larger multi-ton liquid xenon detectors have been approved for construction from the [[XENON]], [[LUX-ZEPLIN]] and [[PandaX]] collaborations.

'''Crystal scintillators''' – Instead of a liquid noble gas, an in principle simpler approach is the use of a scintillating crystal such as NaI(Tl). This approach is taken by [[DAMA/LIBRA]], an experiment that observed an annular modulation of the signal consistent with WIMP detection (see ''{{section link||Recent limits}}''). Several experiments are attempting to replicate those results, including [[ANAIS]], [[Cryogenic_Observatory_for_Signatures_Seen_in_Next-Generation_Underground_Searches|COSINUS]] and [[DM-Ice]], which is codeploying NaI crystals with the [[IceCube Neutrino Observatory|IceCube]] detector at the South Pole. [[Korea Invisible Mass Search|KIMS]] is approaching the same problem using CsI(Tl) as a scintillator.

'''Bubble chambers''' – The [[PICASSO]] (Project In Canada to Search for Supersymmetric Objects) experiment is a direct dark matter search experiment that is located at [[SNOLAB]] in Canada. It uses bubble detectors with [[Freon]] as the active mass. PICASSO is predominantly sensitive to spin-dependent interactions of WIMPs with the fluorine atoms in the Freon. COUPP, a similar experiment using trifluoroiodomethane(CF<sub>3</sub>I), published limits for mass above 20&nbsp;GeV/''c''<sup>2</sup> in 2011.<ref>{{cite journal |last1=Behnke |first1=E. |last2=Behnke |first2=J. |last3=Brice |first3=S. J. |last4=Broemmelsiek |first4=D. |last5=Collar |first5=J. I. |last6=Cooper |first6=P. S. |last7=Crisler |first7=M. |last8=Dahl |first8=C. E. |last9=Fustin |first9=D. |last10=Hall |first10=J. |last11=Hinnefeld |first11=J. H. |last12=Hu |first12=M. |last13=Levine |first13=I. |last14=Ramberg |first14=E. |last15=Shepherd |first15=T. |last16=Sonnenschein |first16=A. |last17=Szydagis |first17=M. |title=Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter Bubble Chamber |journal=Physical Review Letters |date=10 January 2011 |volume=106 |issue=2 |doi=10.1103/PhysRevLett.106.021303 |arxiv=1008.3518 |bibcode=2011PhRvL.106b1303B |pmid=21405218 |page=021303|s2cid=20188890 }}</ref> The two experiments merged into PICO collaboration in 2012.

A bubble detector is a radiation sensitive device that uses small droplets of superheated liquid that are suspended in a gel matrix.<ref>{{cite web |url=http://www.bubbletech.ca/radiation_detectors_files/bubble_detectors.html |title=Bubble Technology Industries |access-date=2010-03-16 |archive-date=2008-03-20 |archive-url=https://web.archive.org/web/20080320061130/http://www.bubbletech.ca/radiation_detectors_files/bubble_detectors.html |url-status=dead }}</ref> It uses the principle of a [[bubble chamber]] but, since only the small droplets can undergo a [[phase transition]] at a time, the detector can stay active for much longer periods.{{clarify |reason=this would make more sense if it read 'only a small number of droplets' |date=March 2015}} When enough energy is deposited in a droplet by ionizing radiation, the superheated droplet becomes a gas bubble. The bubble development is accompanied by an acoustic shock wave that is picked up by piezo-electric sensors. The main advantage of the bubble detector technique is that the detector is almost insensitive to background radiation. The detector sensitivity can be adjusted by changing the temperature, typically operated between 15&nbsp;°C and 55&nbsp;°C. There is another similar experiment using this technique in Europe called SIMPLE.

PICASSO reports results (November 2009) for spin-dependent WIMP interactions on <sup>19</sup>F, for masses of 24 Gev new stringent limits have been obtained on the spin-dependent cross section of 13.9 pb (90% CL). The obtained limits restrict recent interpretations of the DAMA/LIBRA annual modulation effect in terms of spin dependent interactions.<ref>{{cite journal |author=PICASSO Collaboration |title=Dark Matter Spin-Dependent Limits for WIMP Interactions on <sup>19</sup>F by PICASSO |journal=Physics Letters B |date=2009 |doi=10.1016/j.physletb.2009.11.019 |bibcode=2009PhLB..682..185A |volume=682 |issue=2 |pages=185–192 |arxiv=0907.0307|s2cid=15163629 }}</ref>

PICO is an expansion of the concept planned in 2015.<ref>{{cite journal |title=Overview of non-liquid noble direct detection dark matter experiments |date=28 October 2014 |journal=Physics of the Dark Universe |doi=10.1016/j.dark.2014.10.005 |arxiv=1410.4960 |bibcode=2014PDU.....4...92C |volume=4 |pages=92–97|last1=Cooley |first1=J. |s2cid=118724305 }}</ref>

'''Other types of detectors''' – [[Time projection chamber]]s (TPCs) filled with low pressure gases are being studied for WIMP detection. The [[Directional Recoil Identification From Tracks]] (DRIFT) collaboration is attempting to utilize the predicted directionality of the WIMP signal. DRIFT uses a [[carbon disulfide]] target, that allows WIMP recoils to travel several millimetres, leaving a track of charged particles. This charged track is drifted to an [[MWPC]] readout plane that allows it to be reconstructed in three dimensions and determine the origin direction. DMTPC is a similar experiment with CF<sub>4</sub> gas.

The DAMIC (DArk Matter In CCDs) and SENSEI (Sub Electron Noise Skipper CCD Experimental Instrument) collaborations employ the use of scientific [[Charge-coupled device|Charge Coupled Devices]] (CCDs) to detect light Dark Matter. The CCDs act as both the detector target and the readout instrumentation. WIMP interactions with the bulk of the CCD can induce the creation of electron-hole pairs, which are then collected and readout by the CCDs. In order to decrease the noise and achieve detection of single electrons, the experiments make use of a type of CCD known as the Skipper CCD, which allows for averaging over repeated measurements of the same collected charge.<ref>{{cite journal|last1=DAMIC Collaboration|last2=Aguilar-Arevalo|first2=A.|last3=Amidei|first3=D.|last4=Baxter|first4=D.|last5=Cancelo|first5=G.|last6=Cervantes Vergara|first6=B. A.|last7=Chavarria|first7=A. E.|last8=Darragh-Ford|first8=E.|last9=de Mello Neto|first9=J. R. T.|last10=D’Olivo|first10=J. C.|last11=Estrada|first11=J.|date=2019-10-31|title=Constraints on Light Dark Matter Particles Interacting with Electrons from DAMIC at SNOLAB|url=https://link.aps.org/doi/10.1103/PhysRevLett.123.181802|journal=Physical Review Letters|volume=123|issue=18|pages=181802|doi=10.1103/PhysRevLett.123.181802|pmid=31763884|arxiv=1907.12628|bibcode=2019PhRvL.123r1802A|s2cid=198985735}}</ref><ref>{{cite journal|last1=Abramoff|first1=Orr|last2=Barak|first2=Liron|last3=Bloch|first3=Itay M.|last4=Chaplinsky|first4=Luke|last5=Crisler|first5=Michael|last6=Dawa|last7=Drlica-Wagner|first7=Alex|last8=Essig|first8=Rouven|last9=Estrada|first9=Juan|last10=Etzion|first10=Erez|last11=Fernandez|first11=Guillermo|date=2019-04-24|title=SENSEI: Direct-Detection Constraints on Sub-GeV Dark Matter from a Shallow Underground Run Using a Prototype Skipper-CCD|journal=Physical Review Letters|volume=122|issue=16|pages=161801|doi=10.1103/PhysRevLett.122.161801|pmid=31075006|issn=0031-9007|arxiv=1901.10478|bibcode=2019PhRvL.122p1801A|s2cid=119219165}}</ref>

=== Recent limits ===

[[File:Direct Detection Constraints.png |frame|Figure 2: Plot showing the parameter space of dark matter particle mass and interaction cross section with nucleons. The LUX and SuperCDMS limits exclude the parameter space above the labelled curves. The CoGeNT and CRESST-II regions indicate regions which were previously thought to correspond to dark matter signals, but which were later explained with mundane sources. The DAMA and CDMS-Si data remain unexplained, and these regions indicate the preferred parameter space if these anomalies are due to dark matter.]]

There are currently no confirmed detections of dark matter from direct detection experiments, with the strongest exclusion limits coming from the [[Large Underground Xenon experiment|LUX]] and [[Cryogenic Dark Matter Search|SuperCDMS]] experiments, as shown in figure 2.
With 370 kilograms of xenon LUX is more sensitive than XENON or CDMS.<ref>
{{cite web |url=https://www.science.org/content/article/new-experiment-torpedoes-lightweight-dark-matter-particles |title=New Experiment Torpedoes Lightweight Dark Matter Particles |date=30 October 2013 |access-date=6 May 2014}}
</ref> First results from October 2013 report that no signals were seen, appearing to refute results obtained from less sensitive instruments.<ref>
{{cite web |url=http://newscenter.lbl.gov/news-releases/2013/10/30/lux-first-results/ |title=First Results from LUX, the World's Most Sensitive Dark Matter Detector |publisher=Berkeley Lab News Center |date=30 October 2013 |access-date=6 May 2014}}
</ref> and this was confirmed after the final data run ended in May 2016.<ref>[https://www.science.org/content/article/dark-matter-search-comes-empty Dark matter search comes up empty. July 2016]</ref>

Historically there have been four anomalous sets of data from different direct detection experiments, two of which have now been explained with backgrounds ([[CoGeNT]] and CRESST-II), and two which remain unexplained ([[DAMA/LIBRA]] and [[Cryogenic Dark Matter Search|CDMS-Si]]).<ref>{{cite journal |title=Largest-ever dark-matter experiment poised to test popular theory |url=http://www.nature.com/news/largest-ever-dark-matter-experiment-poised-to-test-popular-theory-1.18772 |journal=Nature |access-date=15 January 2017|doi=10.1038/nature.2015.18772 |year=2015 |last1=Cartlidge |first1=Edwin |s2cid=182831370 |url-access=subscription }}</ref><ref>{{cite journal |last1=Davis |first1=Jonathan H. |date=2015 |title=The Past and Future of Light Dark Matter Direct Detection |journal=International Journal of Modern Physics A |volume=30 |issue=15 |page=1530038 |arxiv=1506.03924 |bibcode=2015IJMPA..3030038D |doi=10.1142/S0217751X15300380 |s2cid=119269304}}</ref> In February 2010, researchers at CDMS announced that they had observed two events that may have been caused by WIMP-nucleus collisions.<ref name="strib">{{cite web |url=http://www.startribune.com/local/79624932.html?page=1&c=y |title=Key to the universe found on the Iron Range? |website=[[Star Tribune]] |access-date=December 18, 2009}}</ref><ref>
{{cite web
 |url    = http://cdms.berkeley.edu/0912.3592v1.pdf
 |title    = Results from the Final Exposure of the CDMS II Experiment
 |author    = CDMS Collaboration
 |access-date    = 2009-12-21
 |archive-date    = 2009-12-29
 |archive-url    = https://web.archive.org/web/20091229234000/http://cdms.berkeley.edu/0912.3592v1.pdf
 |url-status    = dead
}}. See also a non-technical summary:
{{cite web
 |url          = http://cdms.berkeley.edu/results_summary.pdf
 |title        = Latest Results in the Search for Dark Matter
 |author       = CDMS Collaboration
 |url-status   = dead
 |archive-url  = https://web.archive.org/web/20100618221140/http://cdms.berkeley.edu/results_summary.pdf
 |archive-date = 2010-06-18
}}</ref><ref>{{cite journal |author=The CDMS II Collaboration |date=2010 |title=Dark Matter Search Results from the CDMS II Experiment |journal=Science |volume=327 |issue=5973 |pages=1619–1621 |arxiv=0912.3592 |bibcode=2010Sci...327.1619C |doi=10.1126/science.1186112 |pmid=20150446 |s2cid=2517711}}</ref>

[[CoGeNT]], a smaller detector using a single germanium puck, designed to sense WIMPs with smaller masses, reported hundreds of detection events in 56 days.<ref name="NN-2010-02-26">{{cite journal |author=Hand |first=Eric |date=2010-02-26 |title=A CoGeNT result in the hunt for dark matter |url=http://www.nature.com/news/2010/100226/full/news.2010.97.html |journal=Nature |publisher=Nature News |doi=10.1038/news.2010.97|url-access=subscription }}</ref><ref>{{cite journal |title=Results from a Search for Light-Mass Dark Matter with a P-type Point Contact Germanium Detector |author=C. E. Aalseth |collaboration=CoGeNT collaboration |doi=10.1103/PhysRevLett.106.131301 |date=2011 |journal=Physical Review Letters |volume=106 |issue=13 |arxiv=1002.4703 |bibcode=2011PhRvL.106m1301A |pmid=21517370 |page=131301|s2cid=24822628 }}</ref> They observed an annual modulation in the event rate that could indicate light dark matter.<ref name="Dacey2011">{{cite web |last1=Dacey |first1=James |date=June 2011 |title=CoGeNT findings support dark-matter halo theory |url=http://physicsworld.com/cws/article/news/2011/jun/15/cogent-findings-support-dark-matter-halo-theory |access-date=5 May 2015 |publisher=physicsworld}}</ref> However a dark matter origin for the CoGeNT events has been refuted by more recent analyses, in favour of an explanation in terms of a background from surface events.<ref>{{cite journal |last1=Davis |first1=Jonathan H. |last2=McCabe |first2=Christopher |last3=Boehm |first3=Celine |title=Quantifying the evidence for Dark Matter in CoGeNT data |journal=Journal of Cosmology and Astroparticle Physics |date=2014 |volume=1408 |issue=8 |page=014 |doi=10.1088/1475-7516/2014/08/014 |arxiv = 1405.0495 |bibcode = 2014JCAP...08..014D |s2cid=54532870 }}</ref>

Annual modulation is one of the predicted signatures of a WIMP signal,<ref>{{cite journal|last1=Drukier|first1=Andrzej K.|last2=Freese|first2=Katherine|last3=Spergel|first3=David N.|title=Detecting cold dark-matter candidates|journal=Physical Review D|date=15 June 1986|volume=33|issue=12|pages=3495–3508|doi=10.1103/PhysRevD.33.3495|pmid=9956575|bibcode=1986PhRvD..33.3495D}}</ref><ref name="Freese1988">{{cite journal |author=Freese |first1=K. |last2=Frieman |first2=J. |last3=Gould |first3=A. |year=1988 |title=Signal Modulation in Cold Dark Matter Detection |journal=Physical Review D |volume=37 |issue=12 |pages=3388–3405 |bibcode=1988PhRvD..37.3388F |doi=10.1103/PhysRevD.37.3388 |osti=1448427 |pmid=9958634 |s2cid=2610174}}</ref> and on this basis the DAMA collaboration has claimed a positive detection. Other groups, however, have not confirmed this result. The CDMS data made public in May 2004 exclude the entire DAMA signal region given certain standard assumptions about the properties of the WIMPs and the dark matter halo, and this has been followed by many other experiments (see Figure 2).

The [[Korea Invisible Mass Search#COSINE|COSINE-100]] collaboration (a merging of KIMS and DM-Ice groups) published their results on replicating the DAMA/LIBRA signal in December 2018 in journal Nature; their conclusion was that "this result rules out WIMP–nucleon interactions as the cause of the annual modulation observed by the DAMA collaboration".<ref>{{cite journal | doi=10.1038/s41586-018-0739-1|pmid = 30518890| title=An experiment to search for dark-matter interactions using sodium iodide detectors| journal=Nature| volume=564| issue=7734| pages=83–86| year=2018| author1=COSINE-100 Collaboration| bibcode=2018Natur.564...83C|arxiv = 1906.01791|s2cid = 54459495}}</ref> In 2021 new results from COSINE-100 and [[ANAIS-112]] both failed to replicate the DAMA/LIBRA signal<ref>{{cite journal |last1=Amaré |first1=J. |last2=Cebrián |first2=S. |last3=Cintas |first3=D. |last4=Coarasa |first4=I. |last5=García |first5=E. |last6=Martínez |first6=M. |last7=Oliván |first7=M. A. |last8=Ortigoza |first8=Y. |last9=de Solórzano |first9=A. Ortiz |last10=Puimedón |first10=J. |last11=Salinas |first11=A. |date=2021-05-27 |title=Annual modulation results from three-year exposure of ANAIS-112 |url=https://link.aps.org/doi/10.1103/PhysRevD.103.102005 |journal=Physical Review D |language=en |volume=103 |issue=10 |pages=102005 |arxiv=2103.01175 |bibcode=2021PhRvD.103j2005A |doi=10.1103/PhysRevD.103.102005 |issn=2470-0010 |s2cid=232092298}}</ref><ref>{{cite journal |last1=Adhikari |first1=Govinda |last2=de Souza |first2=Estella B. |last3=Carlin |first3=Nelson |last4=Choi |first4=Jae Jin |last5=Choi |first5=Seonho |last6=Djamal |first6=Mitra |last7=Ezeribe |first7=Anthony C. |last8=França |first8=Luis E. |last9=Ha |first9=Chang Hyon |last10=Hahn |first10=In Sik |last11=Jeon |first11=Eunju |date=2021-11-12 |title=Strong constraints from COSINE-100 on the DAMA dark matter results using the same sodium iodide target |journal=Science Advances |language=en |volume=7 |issue=46 |pages=eabk2699 |bibcode=2021SciA....7.2699A |doi=10.1126/sciadv.abk2699 |issn=2375-2548 |pmc=8580298 |pmid=34757778|arxiv=2104.03537 }}</ref><ref>{{cite web |title=Is the end in sight for famous dark matter claim? |url=https://www.science.org/content/article/end-sight-famous-dark-matter-claim |access-date=2021-12-29 |website=www.science.org |language=en}}</ref> and in August 2022 COSINE-100 applied an analysis method similar to one used by DAMA/LIBRA and found a similar annual modulation suggesting the signal could be just a statistical artifact<ref>{{cite journal |last1=Adhikari |first1=G. |last2=Carlin |first2=N. |last3=Choi |first3=J. J. |last4=Choi |first4=S. |last5=Ezeribe |first5=A. C. |last6=Franca |first6=L. E. |last7=Ha |first7=C. |last8=Hahn |first8=I. S. |last9=Hollick |first9=S. J. |last10=Jeon |first10=E. J. |last11=Jo |first11=J. H. |last12=Joo |first12=H. W. |last13=Kang |first13=W. G. |last14=Kauer |first14=M. |last15=Kim |first15=B. H. |date=2023 |title=An induced annual modulation signature in COSINE-100 data by DAMA/LIBRA's analysis method |journal=Scientific Reports |volume=13 |issue=1 |page=4676 |doi=10.1038/s41598-023-31688-4 |pmid=36949218 |pmc=10033922 |arxiv=2208.05158 |bibcode=2023NatSR..13.4676A }}</ref><ref>{{cite journal |last=Castelvecchi |first=Davide |date=2022-08-16 |title=Notorious dark-matter signal could be due to analysis error |url=https://www.nature.com/articles/d41586-022-02222-9 |journal=Nature |language=en |doi=10.1038/d41586-022-02222-9|pmid=35974221 |s2cid=251624302 |url-access=subscription }}</ref> supporting a hypothesis first put forward in 2020.<ref>{{cite journal |author=Buttazzo |first=D. |display-authors=etal |year=2020 |title=Annual modulations from secular variations: relaxing DAMA? |journal=Journal of High Energy Physics |volume=2020 |issue=4 |page=137 |arxiv=2002.00459 |bibcode=2020JHEP...04..137B |doi=10.1007/JHEP04(2020)137 |s2cid=211010848}}</ref>

=== Future of direct detection ===
[[File:WIMPsLZexperiment2023.png|frame|Upper limits for WIMP-nucleon elastic cross sections from selected experiments as reported by the LZ experiment in July 2023.]]

The 2020s should see the emergence of several multi-tonne mass direct detection experiments, which will probe WIMP-nucleus cross sections orders of magnitude smaller than the current state-of-the-art sensitivity. Examples of such next-generation experiments are LUX-ZEPLIN (LZ) and XENONnT, which are multi-tonne liquid xenon experiments, followed by DARWIN, another proposed liquid xenon direct detection experiment of 50–100 tonnes.<ref>{{cite arXiv |eprint=1110.0103|last1= Malling|first1= D. C.|title= After LUX: The LZ Program |display-authors= etal |class= astro-ph.IM|year= 2011}}</ref><ref>{{cite journal |last1=Baudis |first1=Laura |title=DARWIN: dark matter WIMP search with noble liquids |journal=J. Phys. Conf. Ser. |date=2012 |volume=375 |issue=1 |page=012028 |doi=10.1088/1742-6596/375/1/012028 |arxiv=1201.2402|bibcode=2012JPhCS.375a2028B |s2cid=30885844 }}</ref>

Such multi-tonne experiments will also face a new background in the form of neutrinos, which will limit their ability to probe the WIMP parameter space beyond a certain point, known as the neutrino floor. However, although its name may imply a hard limit, the neutrino floor represents the region of parameter space beyond which experimental sensitivity can only improve at best as the square root of exposure (the product of detector mass and running time).<ref>{{cite journal |last1=Billard |first1=J. |last2=Strigari |first2=L. |last3=Figueroa-Feliciano |first3=E. |date=2014 |title=Implication of neutrino backgrounds on the reach of next generation dark matter direct detection experiments |journal=Physical Review D |volume=89 |issue=2 |page=023524 |arxiv=1307.5458 |bibcode=2014PhRvD..89b3524B |doi=10.1103/PhysRevD.89.023524 |s2cid=16208132}}</ref><ref>{{cite journal |last1=Davis |first1=Jonathan H. |title=Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor |journal=Journal of Cosmology and Astroparticle Physics |date=2015 |volume=1503 |issue=3 |page=012 |doi=10.1088/1475-7516/2015/03/012 |arxiv=1412.1475|bibcode = 2015JCAP...03..012D |s2cid=118596203 }}</ref> For WIMP masses below 10&nbsp;GeV/''c''<sup>2</sup> the dominant source of neutrino background is from the [[Solar neutrino|Sun]], while for higher masses the background contains contributions from [[Neutrino#Atmospheric|atmospheric neutrino]]s and the [[diffuse supernova neutrino background]].

In December 2021, results from [[PandaX]] have found no signal in their data, with a lowest excluded cross section of {{val|3.8|e=-47|ul=cm2}} at 40&nbsp;GeV with 90% confidence level.<ref name="Meng et al-2021">{{cite journal|last1=Meng|first1=Yue|last2=Wang|first2=Zhou|last3=Tao|first3=Yi|last4=Abdukerim|first4=Abdusalam|last5=Bo|first5=Zihao|last6=Chen|first6=Wei|last7=Chen|first7=Xun|last8=Chen|first8=Yunhua|last9=Cheng|first9=Chen|last10=Cheng|first10=Yunshan|last11=Cui|first11=Xiangyi|date=2021-12-23|title=Dark Matter Search Results from the PandaX-4T Commissioning Run|url=https://link.aps.org/doi/10.1103/PhysRevLett.127.261802|journal=Physical Review Letters|language=en|volume=127|issue=26|pages=261802|doi=10.1103/PhysRevLett.127.261802|pmid=35029500| arxiv=2107.13438 | bibcode=2021PhRvL.127z1802M |s2cid=236469421|issn=0031-9007}}</ref><ref name="Stephens-2021">{{cite journal|last=Stephens|first=Marric|date=2021-12-23|title=Tightening the Net on Two Kinds of Dark Matter|url=https://physics.aps.org/articles/v14/s164|journal=Physics|language=en|volume=14| doi=10.1103/Physics.14.s164 | bibcode=2021PhyOJ..14.s164S | s2cid=247277808 |doi-access=free}}</ref> 

In July 2023 the [[XENON#XENONnT|XENONnT]] and [[LZ experiment]] published the first results of their searches for WIMPs,<ref>{{cite journal |last=Day |first=Charles |date=2023-07-28 |title=The Search for WIMPs Continues |url=https://physics.aps.org/articles/v16/s106 |journal=Physics |volume=16 |pages=s106 |doi=10.1103/Physics.16.s106 |bibcode=2023PhyOJ..16.s106D |s2cid=260751963 |language=en |doi-access=free }}</ref> the first excluding cross sections above {{val|2.58|e=-47|u=cm2}} at 28&nbsp;GeV with 90% confidence level<ref>{{cite journal |last1=XENON Collaboration |last2=Aprile |first2=E. |last3=Abe |first3=K. |last4=Agostini |first4=F. |last5=Ahmed Maouloud |first5=S. |last6=Althueser |first6=L. |last7=Andrieu |first7=B. |last8=Angelino |first8=E. |last9=Angevaare |first9=J. R. |last10=Antochi |first10=V. C. |last11=Antón Martin |first11=D. |last12=Arneodo |first12=F. |last13=Baudis |first13=L. |last14=Baxter |first14=A. L. |last15=Bazyk |first15=M. |date=2023-07-28 |title=First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment |url=https://link.aps.org/doi/10.1103/PhysRevLett.131.041003 |journal=Physical Review Letters |volume=131 |issue=4 |pages=041003 |doi=10.1103/PhysRevLett.131.041003|pmid=37566859 |arxiv=2303.14729 |bibcode=2023PhRvL.131d1003A |s2cid=257767449 }}</ref> and the second excluding cross sections above {{val|9.2|e=-48|u=cm2}} at 36&nbsp;GeV with 90% confidence level.<ref>{{cite journal |last1=LUX-ZEPLIN Collaboration |last2=Aalbers |first2=J. |last3=Akerib |first3=D. S. |last4=Akerlof |first4=C. W. |last5=Al Musalhi |first5=A. K. |last6=Alder |first6=F. |last7=Alqahtani |first7=A. |last8=Alsum |first8=S. K. |last9=Amarasinghe |first9=C. S. |last10=Ames |first10=A. |last11=Anderson |first11=T. J. |last12=Angelides |first12=N. |last13=Araújo |first13=H. M. |last14=Armstrong |first14=J. E. |last15=Arthurs |first15=M. |date=2023-07-28 |title=First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment |url=https://link.aps.org/doi/10.1103/PhysRevLett.131.041002 |journal=Physical Review Letters |volume=131 |issue=4 |pages=041002 |doi=10.1103/PhysRevLett.131.041002|pmid=37566836 |arxiv=2207.03764 |bibcode=2023PhRvL.131d1002A |s2cid=250343331 }}</ref>