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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.

References:

PR D66 012002

Large Bulk Matter Search for Fractional Charge Particles

PRL 84 2576

Search for Free Fractional Electric Charge Elementary Particles

PR D53 6017

An Improved Search for Elementary Particles with Fractional Electric Charge

PRL 70 1053

Search for Fractional-Charge Impurities in Silicon Using Infrared Photoionization and Field Ionization

ZPHY C55 549

A Search for Fractional Electric Charge in Sea Water

ZPHY C43 349

Search for Fractional Electric Charge in Meteorite Samples

PR D36 37

Search for Fractionally Charged Particles

PL B197 447

Searches for Fractional Electric Charge in Tungsten

PR D36 1983

Search for Fractional Charges using Droplet Jet Techniques

PL 167B 481

A Search for Fractional Charges in Native Mercury

PL B181 407

Searches for Fractional Electric Charge on Niobium Samples Exposed to Liquid Helium

PL B171 129

A Search for Fractional Charge Changes on Levitated Niobium Spheres

PRL 54 1472

Search for Fractional Charges in Niobium and Tungsten

PL 153B 188

A Search for Fractional Electric Charge on Levitated Niobium Spheres

PR D29 791

Cryogenic Search for Fractionally Charged Particles

PL 137B 439

The Electric Neutrality of Matter: a Summary

PRL 51 731

Search for Fractional Charges in Water

PRL 50 1640

Search for Fractional Charges

PRL 50 1234

Spectroscopic Search for Fractional Charge in Ultrapure Semiconductors

PRL 47 1651

Results of a Search for Fractional Charges on Mercury Drops

PRL 46 967

Observation of Fractional Charge of (1/3)e on Matter

PL 94B 433

Confirmation of the Electric Neutrality of Matter at the Milligram Level

PL 94B 427

New Results in the Search of Quarks in Matter by the Magnetic Levitation Electrometer

PRL 43 1288

Search for Fractionally Charged Ions in Helium Gas

PRL 42 142

Further Evidence for Fractional Charge on Matter

PRL 42 1019

Erratum: LARUE 1979 Further Evidence for Fractional Charge on Matter

JETP 49 953

Search for Fractionally Charged Particles in Large Samples of Matter

PRL 40 216

A Search for Fractionally Charged Tungsten Ions

PL 72B 484

A Search for Integrally Charged Quarks

RA 25 75

Search for Quarks in Sea-Water and Fresh Water

PR D17 1466

Search for Fractional Charge in Tungsten

PR D17 2241

Search for +1/3e Fractional Charges in ${}^{}\mathrm {Nb}$, ${{\mathit W}}$, and ${}^{}\mathrm {Fe}$ Metal

PRL 39 369

A Search for Fractional Charge on Tungsten Particles

PRL 38 1255

The Electric Neutrality of Matter

PRL 38 1011

Evidence for the Existence of Fractional Charge on Matter

SCI 196 521

Quarks with Unit Charge: a Search for Anomalous Hydrogen

JETP 45 857

Search for Fractionally Charged Particles in Sea Water, Ocean Sediment Deposits and Volcano Lava

PR D14 716

Search for Fractionally Charged Particles in Lunar Soil

NP B20 217

A Quark Search in Ordinary Matter using Simultaneous Measurement of Mass and Charge

NIM 79 95

The Magnetic Levitation Electrometer and Its Use in the Search for Fractionally Charged Particles

PR 188 2092

Search for Fractionally Charged Particles

JETP 27 51

:none.:

PR 176 1635

Search for Stable Fractionally Charged Particles

PR 164 1599

Search for an Electron Proton Charge Inequality by Charge Measurements on an Isolated Macroscopic Body

PRL 17 1196

Detection of Quarks in the Ultraviolet Solar Spectrum

PRL 17 60

Experimental Search for Stable, Fractionally Charged Particles

PL 23 609

Preliminary Results in the Search for Fractionally Charged Particles by the Magnetic Levitation Electrometer

NAT 184 B92

A Comparison of the Charges of the Electron, Proton and Neutron

Phil Mag 19 209

A New Modification of the Gloud Method of Determining the Elementary Electrical Charge and the most Probable Value of that Charge

Except where otherwise noted, content of the 2023 Review of Particle Physics is licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license. The publication of the Review of Particle Physics is supported by US DOE, MEXT (Japan), INFN (Italy), JPS and CERN. Individual collaborators receive support for their PDG activities from their respective institutes or funding agencies. © 2023. See LBNL disclaimers.