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Quark Density $-$ Matter Searches

QUARKS/ NUCLEON

CHG ${\mathrm {(\mathit e/3)}}$

MASS ${\mathrm {(GeV)}}$

MATERIAL/METHOD

EVTS

DOCUMENT ID

$ \text{<1.17E-22} $

silicone oil drops

0

$ \text{<4.71E-22} $

silicone oil drops

1

$ \text{<4.7E-21} $

$\pm1$,2

silicone oil drops

0

$ \text{<8.E-22} $

$+2$

${}^{}\mathrm {Si}$/infrared photoionization

0

$ \text{<5.E-27} $

$\pm1$,2

sea water/levitation

0

$ \text{<4.E-20} $

$\pm1$,2

meteorites/mag. levitation

0

$ \text{<1.E-19} $

$\pm1$,2

various/spectrometer

0

$ \text{<5.E-22} $

$\pm1$,2

${}^{}\mathrm {W}$/levitation

0

$ \text{<3.E-20} $

$+1$,2

org liq/droplet tower

0

$ \text{<6.E-20} $

$-1$,2

org liq/droplet tower

0

$ \text{<3.E-21} $

$\pm1$

${}^{}\mathrm {Hg}$ drops-untreated

0

$ \text{<3.E-22} $

$\pm1$,2

levitated niobium

0

$ \text{<2.E-26} $

$\pm1$,2

${}^{4}\mathrm {He}$/levitation

0

$ \text{<2.E-20} $

>+-1

$0.2-$250

niobium+tungs/ion

0

$ \text{<1.E-21} $

$\pm1$

levitated niobium

0

$ $

$+1$,2

<100

niobium/mass spec

0

$ \text{<5.E-22} $

levitated steel

0

$ \text{<9.E-20} $

$\pm{}<$13

water/oil drop

0

$ \text{<2.E-21} $

$>\vert \pm1/2\vert $

levitated steel

0

$ \text{<1.E-19} $

$\pm1$,2

photo ion spec

0

$ \text{<2.E-20} $

mercury/oil drop

0

$ \text{1.E-20} $

$+1$

levitated niobium

4

$ \text{1.E-20} $

$-1$

levitated niobium

4

$ \text{<1.E-21} $

levitated steel

0

$ \text{<6.E-16} $

helium/mass spec

0

$ \text{1.E-20} $

$+1$

levitated niobium

2

$ \text{<4.E-28} $

earth+/ion beam

0

$ \text{<5.E-15} $

$+1$

tungs./mass spec

0

$ \text{<5.E-16} $

$+3$

<1.7

hydrogen/mass spec

0

$ \text{<1.E-21} $

$\pm2$,4

water/ion beam

0

$ \text{<6.E-15} $

$>$1/2

levitated tungsten

0

$ \text{<1.E-22} $

metals/mass spec

0

$ \text{<5.E-15} $

levitated tungsten ox

0

$ \text{<3.E-21} $

levitated iron

0

$ \text{2.E-21} $

$-1$

levitated niobium

1

$ \text{4.E-21} $

$+1$

levitated niobium

2

$ \text{<1.E-13} $

$+3$

<7.7

hydrogen/mass spec

0

$ \text{<5.E-27} $

water+/ion beam

0

$ \text{<1.E-21} $

lunar+/ion spec

0

$ \text{<1.E-15} $

$+1$

<60

oxygen+/ion spec

0

$ \text{<5.E-19} $

levitated graphite

0

$ \text{<5.E-23} $

water+/atom beam

0

$ \text{<1.E-17} $

$\pm1$,2

levitated graphite

0

$ \text{<1.E-17} $

water+/uv spec

0

$ \text{<3.E-19} $

$\pm1$

levitated iron

0

$ \text{<1.E-10} $

sun/uv spec

0

$ \text{<1.E-17} $

$+1$,2

meteorites+/ion beam

0

$ \text{<1.E-16} $

$\pm1$

levitated graphite

0

$ \text{<1.E-22} $

argon/electrometer

0

$ $

$-2$

levitated oil

0

¹	95$\%$ CL limit for fractional charge particles with 0.18$\mathit e{}\leq{}\vert Q_{residual}\vert {}\leq{}0.82\mathit e$ in total of 70.1 mg of silicone oil.

²	95$\%$ CL limit for particles with fractional charge $\vert Q_{residual}\vert >$0.16e in total of 17.4~mg of silicone oil.

³	Also set limits for $\mathit Q$ = $\pm{}\mathit e$/6.

⁴	Note that in PHILLIPS 1988 these authors report a subtle magnetic effect which could account for the apparent fractional charges.

⁵	Limit inferred by JONES 1977B.

Except where otherwise noted, content of the 2024 Review of Particle Physics is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license. The publication of the Review of Particle Physics is supported by US DOE, MEXT (Japan), INFN (Italy) and CERN. Individual collaborators receive support for their PDG activities from their respective institutes or funding agencies. © 2024. See LBNL disclaimers.