Weakly interacting massive particle: Difference between revisions

Revision as of 13:43, 6 December 2023

Revision as of 00:37, 23 December 2023

Line 1:

{{short description|Hypothetical particles that are thought tomay constitute dark matter}}

{{redirect|WIMPs||WIMPS (disambiguation)}}

'''Weakly interacting massive particles''' ('''WIMPs''') are hypothetical particles that are one of the proposed candidates for [[dark matter]].

There exists no formal definition of a WIMP, but broadly, it is a newan [[elementary particle]] which interacts via [[gravity]] and any other force (or forces), potentially not part of the [[Standard Model]] itself, which is as weak as or weaker than the [[weak nuclear force]], but also non-vanishing in its strength. Many WIMP candidates are expected to have been produced thermally in the early Universe, similarly to the particles of the Standard Model<ref>{{cite journal | last = Garrett | first = Katherine | title = Dark matter: A primer | year = 2010 | journal = Advances in Astronomy | volume = 2011 | issue = 968283 | pages = 1–22 | doi = 10.1155/2011/968283| arxiv = 1006.2483 | bibcode = 2011AdAst2011E...8G | doi-access = free }}</ref> according to [[Big Bang]] cosmology, and usually will constitute [[cold dark matter]]. Obtaining the correct abundance of dark matter today via [[thermal production]] requires a self-[[annihilation]] [[Cross section (physics)|cross section]] of <math>\langle \sigma v \rangle \simeq 3 \times 10^{-26} \mathrm{cm}^{3} \;\mathrm{s}^{-1}</math>, which is roughly what is expected for a new particle in the 100&nbsp;[[GeV]] mass range that interacts via the [[electroweak force]].

Obtaining the correct abundance of dark matter today via [[thermal production]] requires a self-[[annihilation]] [[Cross section (physics)|cross section]] of <math>\langle \sigma v \rangle \simeq 3 \times 10^{-26} \mathrm{cm}^{3} \;\mathrm{s}^{-1}</math>, which is roughly what is expected for a new particle in the 100&nbsp;[[GeV]] mass range that interacts via the [[electroweak force]].

Experimental efforts to detect WIMPs include the search for products of WIMP annihilation, including [[gamma ray]]s, [[neutrino]]s and [[cosmic ray]]s in nearby galaxies and galaxy clusters; direct detection experiments designed to measure the collision of WIMPs with [[Atomic nucleus|nuclei]] in the laboratory, as well as attempts to directly produce WIMPs in colliders, such as the LHC[[Large Hadron Collider]] at [[CERN]].

Because [[supersymmetry|supersymmetric]] extensions of the Standard Model of particle physics readily predict a new particle with these properties, this apparent coincidence is known as the "'''WIMP miracle'''", and a stable supersymmetric partner has long been a prime WIMP candidate.<ref>{{cite journal |last1=Jungman |first1=Gerard |last2=Kamionkowski |first2=Marc |last3=Griest |first3=Kim |year=1996 |title=Supersymmetric dark matter |journal=Physics Reports |volume=267 |issue=5–6 |pages=195–373 |s2cid=119067698 |arxiv=hep-ph/9506380 |bibcode=1996PhR...267..195J |doi=10.1016/0370-1573(95)00058-5}}</ref> However, recent null results from [[Dark matter#Direct detection|direct-detection]] experiments along with the failure to produce evidence of supersymmetry in the [[Large Hadron Collider]] (LHC) experiment<ref>{{cite news |url=http://news.discovery.com/space/lhc-discovery-maims-supersymmetry-again-130724.htm |title=LHC discovery maims supersymmetry again |website=Discovery News}}</ref><ref>{{cite arXiv |last=Craig |first=Nathaniel |year=2013 |title=The State of Supersymmetry after Run I of the LHC |class=hep-ph |eprint=1309.0528}}</ref> has cast doubt on the simplest WIMP hypothesis.<ref>{{cite journal |last1=Fox |first1=Patrick J. |last2=Jung |first2=Gabriel |last3=Sorensen |first3=Peter |last4=Weiner |first4=Neal |year=2014 |title=Dark matter in light of LUX |journal=Physical Review D |volume=89 |issue=10 |page=103526 |arxiv=1401.0216 |bibcode=2014PhRvD..89j3526F |doi=10.1103/PhysRevD.89.103526}}</ref>

==Theoretical framework and properties==

WIMP-like particles are predicted by [[R-parity]]-conserving [[supersymmetry]], a popular type of extension to the [[Standard Model]] of particle physics, although none of the large number of new particles in supersymmetry have been observed.<ref>{{cite book |last1=Klapdor-Kleingrothaus |first1=H. V. |title=Beyond the Desert |publisher=IOP |year=1998 |editor1=Klapdor-Kleingrothaus |editor-first=V. |volume=1997 |page=485 |chapter=Double beta decay and dark matter search -– window to new physics now, and in future (GENIUS) |titlebibcode=Beyond the Desert |editor1=Klapdor-Kleingrothaus, V1998hep.ex....2007K |editor2=Paes, H. |publisher=IOP |volume=1997 |page=485 |bibcode editor-first2= 1998hepH.ex....2007K |arxiv=hep-ex/9802007}}</ref> WIMP-like particles are also predicted by [[universal extra dimension]] and [[little Higgs]] theories.

{{More citations needed section |date=January 2011}}

WIMP-like particles are predicted by [[R-parity]]-conserving [[supersymmetry]], a popular type of extension to the [[Standard Model]] of particle physics, although none of the large number of new particles in supersymmetry have been observed.<ref>{{cite book |last1=Klapdor-Kleingrothaus |first1=H.V. |year=1998 |chapter=Double beta decay and dark matter search - window to new physics now, and in future (GENIUS) |title=Beyond the Desert |editor1=Klapdor-Kleingrothaus, V. |editor2=Paes, H. |publisher=IOP |volume=1997 |page=485 |bibcode = 1998hep.ex....2007K |arxiv=hep-ex/9802007}}</ref>

WIMP-like particles are also predicted by [[universal extra dimension]] and [[little Higgs]] theories.

{| class="wikitable"

|-

Line 37 ⟶ 33:

*Large mass compared to standard particles (WIMPs with sub-[[Electron volt|GeV]] masses may be considered to be [[light dark matter]]).

Because of their lack of electromagnetic interaction with normal matter, WIMPs would be invisible through normal electromagnetic observations. Because of their large mass, they would be relatively slow moving and therefore "cold".<ref>{{cite journal |arxiv=0707.0472 |last1=Zacek |first1=Viktor |title=Dark Matter |year=2007 |doi=10.1142/9789812776105_0007 |journal=Fundamental Interactions|pages=170–206 |isbn=978-981-277-609-9 |s2cid=16734425 }}</ref> Their relatively low velocities would be insufficient to overcome the mutual gravitational attraction, and as a result, WIMPs would tend to clump together.<ref name="Griest">{{Cite journal |arxiv=hep-ph/9303253 |last1=Griest |first1=Kim |title=The Search for the Dark Matter: WIMPs and MACHOs |journal=Annals of the New York Academy of Sciences |volume=688 |pages=390–407 |year=1993 |doi=10.1111/j.1749-6632.1993.tb43912.x|pmid=26469437 |bibcode=1993NYASA.688..390G |s2cid=8955141 }}</ref> WIMPs are considered one of the main candidates for [[cold dark matter]], the others being [[massive compact halo objects]] (MACHOs) and [[axions]]. These names were deliberately chosen for contrast, with MACHOs named later than WIMPs.<ref>{{cite journal |doi=10.1086/169575 |last=Griest |first=Kim |title=Galactic Microlensing as a Method of Detecting Massive Compact Halo Objects |journal=The Astrophysical Journal |date=1991 |volume=366 |pages=412–421 |bibcode=1991ApJ...366..412G}}</ref> In contrast to MACHOs, there are no known stable particles within the [[Standard Model]] of particle physics that have all the properties of WIMPs. The particles that have little interaction with normal matter, such as [[neutrino]]s, are all very light, and hence would be fast moving, or "hot".

==As dark matter==

Line 47 ⟶ 43:

==Indirect detection==

{{see also|Indirect detection of dark matter}}

Because WIMPs may only interact through gravitational and weak forces, they would be extremely difficult to detect. However, there are many experiments underway to attempt to detect WIMPs both directly and indirectly. ''Indirect detection'' refers to the observation of annihilation or decay products of WIMPs far away from Earth. Indirect detection efforts typically focus on locations where WIMP dark matter is thought to accumulate the most: in the centers of galaxies and galaxy clusters, as well as in the smaller [[Satellite galaxy|satellite galaxies]] of the Milky Way. These are particularly useful since they tend to contain very little baryonic matter, reducing the expected background from standard astrophysical processes. Typical indirect searches look for excess [[gamma rays]], which are predicted both as final-state products of annihilation, or are produced as charged particles interact with ambient radiation via [[inverse Compton scattering]]. The spectrum and intensity of a gamma ray signal depends on the annihilation products, and must be computed on a model-by-model basis. Experiments that have placed bounds on WIMP annihilation, via the non-observation of an annihilation signal, include the [[Fermi Gamma-ray Space Telescope|Fermi]]-LAT gamma ray telescope<ref>{{cite journal |doi=10.1103/PhysRevD.89.042001 |title=Dark matter constraints from observations of 25 Milky Way satellite galaxies with the Fermi Large Area Telescope |date=2014 |collaboration=The Fermi-LAT Collaboration |journal=Physical Review D |volume=89 |issue=4 |pages=042001 |arxiv=1310.0828 |last1=Ackermann |first1=M. |display-authors=etal |bibcode=2014PhRvD..89d2001A |s2cid=46664722 }}</ref> and the VERITAS ground-based gamma ray observatory.<ref>{{cite journal |last1=Grube |first1=Jeffrey |title=VERITAS Limits on Dark Matter Annihilation from Dwarf Galaxies |pages=689–692 |author2=VERITAS Collaboration |year=2012 |doi=10.1063/1.4772353 |journal=AIP Conference Proceedings|volume=1505 |bibcode=2012AIPC.1505..689G |arxiv = 1210.4961 |s2cid=118510709 }}</ref> Although the annihilation of WIMPs into Standard Model particles also predicts the production of high-energy neutrinos, their interaction rate is thought to be too low to reliably detect a dark matter signal at present. Future observations from the [[IceCube]] observatory in Antarctica may be able to differentiate WIMP-produced neutrinos from standard astrophysical neutrinos; however, by 2014, only 37 cosmological neutrinos had been observed,<ref>{{cite journal |doi=10.1103/PhysRevLett.113.101101 |pmid=25238345 |title=Observation of High-Energy Astrophysical Neutrinos in Three Years of IceCube Data |date=2014 |collaboration=IceCube Collaboration

Because WIMPs may only interact through gravitational and weak forces, they are extremely difficult to detect. However, there are many experiments underway to attempt to detect WIMPs both directly and indirectly. ''Indirect detection'' refers to the observation of annihilation or decay products of WIMPs far away from Earth.

Indirect detection efforts typically focus on locations where WIMP dark matter is thought to accumulate the most: in the centers of galaxies and galaxy clusters, as well as in the smaller [[Satellite galaxy|satellite galaxies]] of the Milky Way. These are particularly useful since they tend to contain very little baryonic matter, reducing the expected background from standard astrophysical processes. Typical indirect searches look for excess [[gamma rays]], which are predicted both as final-state products of annihilation, or are produced as charged particles interact with ambient radiation via [[inverse Compton scattering]]. The spectrum and intensity of a gamma ray signal depends on the annihilation products, and must be computed on a model-by-model basis. Experiments that have placed bounds on WIMP annihilation, via the non-observation of an annihilation signal, include the [[Fermi Gamma-ray Space Telescope|Fermi]]-LAT gamma ray telescope<ref>{{cite journal |doi=10.1103/PhysRevD.89.042001 |title=Dark matter constraints from observations of 25 Milky Way satellite galaxies with the Fermi Large Area Telescope |date=2014 |collaboration=The Fermi-LAT Collaboration |journal=Physical Review D |volume=89 |issue=4 |pages=042001 |arxiv=1310.0828 |last1=Ackermann |first1=M. |display-authors=etal |bibcode=2014PhRvD..89d2001A |s2cid=46664722 }}</ref> and the VERITAS ground-based gamma ray observatory.<ref>{{cite journal |last1=Grube |first1=Jeffrey |title=VERITAS Limits on Dark Matter Annihilation from Dwarf Galaxies |pages=689–692 |author2=VERITAS Collaboration |year=2012 |doi=10.1063/1.4772353 |journal=AIP Conference Proceedings|volume=1505 |bibcode=2012AIPC.1505..689G |arxiv = 1210.4961 |s2cid=118510709 }}</ref> Although the annihilation of WIMPs into Standard Model particles also predicts the production of high-energy neutrinos, their interaction rate is too low to reliably detect a dark matter signal at present. Future observations from the [[IceCube]] observatory in Antarctica may be able to differentiate WIMP-produced neutrinos from standard astrophysical neutrinos; however, by 2014, only 37 cosmological neutrinos had been observed,<ref>{{cite journal |doi=10.1103/PhysRevLett.113.101101 |pmid=25238345 |title=Observation of High-Energy Astrophysical Neutrinos in Three Years of IceCube Data |date=2014 |collaboration=IceCube Collaboration

|journal=Physical Review Letters |volume=113 |issue=10 |pages=101101 |arxiv=1405.5303 |bibcode=2014PhRvL.113j1101A |last1=Aartsen |first1=M. G. |s2cid=220469354 |display-authors=etal}}</ref> making such a distinction impossible.

Another type of indirect WIMP signal could come from the Sun. Halo WIMPs may, as they pass through the Sun, interact with solar protons, helium nuclei as well as heavier elements. If a WIMP loses enough energy in such an interaction to fall below the local [[escape velocity]], it would theoretically not have enough energy to escape the gravitational pull of the Sun and would remain gravitationally bound.<ref name="Griest" /> As more and more WIMPs thermalize inside the Sun, they would begin to [[annihilation|annihilate]] with each other, theoretically forming a variety of particles, including high-energy [[neutrino]]s.<ref>{{cite journal |doi=10.1103/PhysRevD.74.115007 |title=Indirect detection of light neutralino dark matter in the next-to-minimal supersymmetric standard model |date=2006 |last1=Ferrer |first1=F. |last2=Krauss |first2=L. M. |last3=Profumo |first3=S. |journal=Physical Review D |volume=74 |issue=11 |pages=115007 |arxiv=hep-ph/0609257 |bibcode=2006PhRvD..74k5007F |s2cid=119351935 }}</ref> These neutrinos may then travel to the Earth to be detected in one of the many neutrino telescopes, such as the [[Super-Kamiokande]] detector in Japan. The number of neutrino events detected per day at these detectors depends on the properties of the WIMP, as well as on the mass of the [[Higgs boson]]. Similar experiments are underway to attempt to detect neutrinos from WIMP annihilations within the Earth<ref>{{cite journal |doi=10.1016/0370-2693(86)90349-7|title=Can scalar neutrinos or massive Dirac neutrinos be the missing mass?|journal=Physics Letters B|volume=167|issue=3|pages=295–300|year=1986|last1=Freese|first1=Katherine|bibcode=1986PhLB..167..295F}}</ref> and from within the galactic center.<ref>{{cite journal |doi=10.1142/S0217732305017391 |title=Dark Matter Dynamics and Indirect Detection |date=2005 |last1=Merritt |first1=D. |last2=Bertone |first2=G. |author-link=David Merritt |journal=Modern Physics Letters A |volume=20 |issue=14 |pages=1021–1036 |arxiv=astro-ph/0504422 |bibcode=2005MPLA...20.1021B |s2cid=119405319 }}</ref><ref>{{Cite journal |arxiv=astro-ph/0612786 |last1=Fornengo |first1=Nicolao |author-link=Nicolao Fornengo |title=Status and perspectives of indirect and direct dark matter searches |journal=Advances in Space Research |volume=41 |issue=12 |pages=2010–2018 |year=2008 |doi=10.1016/j.asr.2007.02.067|bibcode=2008AdSpR..41.2010F |s2cid=202740 }}</ref>

==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.

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 up 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 |350px upright=1.6|Fig 1. CDMS parameter space excluded as of 2004. DAMA result is located in green area and is disallowed.]]

===Experimental techniques===

Line 80 ⟶ 74:

'''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 CF₄ 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===

Line 115 ⟶ 109:

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=K. Freese |author2=J. Frieman |author3=A. Gould |title=Signal Modulation in Cold Dark Matter Detection |journal=Physical Review D |year=1988 |doi=10.1103/PhysRevD.37.3388 |pmid=9958634 |volume=37 |issue=12 |pages=3388–3405|bibcode = 1988PhRvD..37.3388F |osti=1448427 |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 Fig 2, right).

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 }}</ref> supporting a hypothesis first put forward on 2020.<ref>{{cite journal |author=D. Buttazzo |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>

===The future of direct detection===