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GAUGE AND HIGGS BOSONS

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${{\mathit Z}}$

$J$ = $1$

See related reviews:

${{\mathit Z}}$ Boson
Anomalous ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ , ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ , and ${{\mathit Z}}{{\mathit Z}}{{\mathit V}}$ Couplings
Anomalous ${{\mathit W}}/{{\mathit Z}}$ Quartic Couplings (QGCs)

▾ Collapse all sections

${{\mathit Z}}$ MASS

$91.1876 \pm0.0021$ GeV

${{\mathit Z}}$ WIDTH

$2.4952 \pm0.0023$ GeV

▸	AVERAGE PARTICLE MULTIPLICITIES IN HADRONIC ${{\mathit Z}}$ DECAY

${{\mathit Z}}$ HADRONIC POLE CROSS SECTION

$41.541 \pm0.037$ nb

▸	${{\mathit Z}}$ VECTOR COUPLINGS

▸	${{\mathit Z}}$ AXIAL-VECTOR COUPLINGS

▸	${{\mathit Z}}$ COUPLINGS TO NEUTRAL LEPTONS

▸	${{\mathit Z}}$ ASYMMETRY PARAMETERS

▸	TRANSVERSE SPIN CORRELATIONS IN ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$

▸	FORWARD-BACKWARD ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit f}}{{\overline{\mathit f}}}$ CHARGE ASYMMETRIES

CHARGE ASYMMETRY IN ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$

CHARGE ASYMMETRY IN ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$

▸	ANOMALOUS ${{\mathit Z}}{{\mathit Z}}{{\mathit \gamma}}$ , ${{\mathit Z}}{{\mathit \gamma}}{{\mathit \gamma}}$ , AND ${{\mathit Z}}{{\mathit Z}}{{\mathit V}}$ COUPLINGS

ANOMALOUS ${{\mathit W}}/{{\mathit Z}}$ QUARTIC COUPLINGS

$\mathit a_{0}/\Lambda {}^{2}$, $\mathit a_{{{\mathit c}}}/\Lambda {}^{2}$

${{\mathit Z}}$ Decay Modes

${{\mathit e}^{+}}{{\mathit e}^{-}}$

$(3.3632 \pm{0.0042 )\%}$

${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

$(3.3662 \pm{0.0066 )\%}$

${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$

$(3.3696 \pm{0.0083 )\%}$

${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$

$(3.3658 \pm{0.0023 )\%}$

${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$

$(4.55\pm{0.17})\times 10^{-6}$

$(20.000 \pm{0.055 )\%}$

$(69.911 \pm{0.056 )\%}$

(${\mathit {\mathit u}}$ ${\mathit {\overline{\mathit u}}}$ + ${\mathit {\mathit c}}$ ${\mathit {\overline{\mathit c}}}$)/2

$(11.6\pm{0.6})\%$

(${\mathit {\mathit d}}$ ${\mathit {\overline{\mathit d}}}$ + ${\mathit {\mathit s}}$ ${\mathit {\overline{\mathit s}}}$ + ${\mathit {\mathit b}}$ ${\mathit {\overline{\mathit b}}}$)/3

$(15.6\pm{0.4})\%$

${\mathit {\mathit c}}$ ${\mathit {\overline{\mathit c}}}$

$(12.03\pm{0.21})\%$

${\mathit {\mathit b}}$ ${\mathit {\overline{\mathit b}}}$

$(15.12\pm{0.05})\%$

${{\mathit b}}{{\overline{\mathit b}}}{{\mathit b}}{{\overline{\mathit b}}}$

$(3.6\pm{1.3})\times 10^{-4}$

${{\mathit g}}{{\mathit g}}{{\mathit g}}$

${{\mathit \pi}^{0}}{{\mathit \gamma}}$

$<2.01\times 10^{-5}$

${{\mathit \eta}}{{\mathit \gamma}}$

$<5.1\times 10^{-5}$

${{\mathit \rho}^{0}}{{\mathit \gamma}}$

$<2.5\times 10^{-5}$

${{\mathit \omega}}{{\mathit \gamma}}$

$<6.5\times 10^{-4}$

${{\mathit \eta}^{\,'}{(958)}}{{\mathit \gamma}}$

$<4.2\times 10^{-5}$

${{\mathit \phi}}{{\mathit \gamma}}$

$<9\times 10^{-7}$

${{\mathit \gamma}}{{\mathit \gamma}}$

$<1.46\times 10^{-5}$

${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$

$<1.52\times 10^{-5}$

${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \gamma}}$

$<2.2\times 10^{-6}$

${{\mathit \pi}^{\pm}}{{\mathit W}^{\mp}}$

$<7\times 10^{-5}$

${{\mathit \rho}^{\pm}}{{\mathit W}^{\mp}}$

$<8.3\times 10^{-5}$

${{\mathit J / \psi}{(1S)}}$ X

$(3.51^{+0.23}_{-0.25})\times 10^{-3}$

${{\mathit J / \psi}{(1S)}}{{\mathit \gamma}}$

$<1.4\times 10^{-6}$

${{\mathit \psi}{(2S)}}$ X

$(1.60\pm{0.29})\times 10^{-3}$

${{\mathit \psi}{(2S)}}{{\mathit \gamma}}$

$<4.5\times 10^{-6}$

${{\mathit J / \psi}{(1S)}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$

${{\mathit J / \psi}{(1S)}}{{\mathit J / \psi}{(1S)}}$

$<2.2\times 10^{-6}$

${{\mathit \chi}_{{c1}}{(1P)}}$ X

$(2.9\pm{0.7})\times 10^{-3}$

${{\mathit \chi}_{{c2}}{(1P)}}$ X

$<3.2\times 10^{-3}$

${{\mathit \Upsilon}{(1S)}}$ X +${{\mathit \Upsilon}{(2S)}}$ X +${{\mathit \Upsilon}{(3S)}}$ X

$(1.0\pm{0.5})\times 10^{-4}$

${{\mathit \Upsilon}{(1S)}}$ X

$<4.4\times 10^{-5}$

${{\mathit \Upsilon}{(1S)}}{{\mathit \gamma}}$

$<2.8\times 10^{-6}$

${{\mathit \Upsilon}{(2S)}}$ X

$<1.39\times 10^{-4}$

${{\mathit \Upsilon}{(2S)}}{{\mathit \gamma}}$

$<1.7\times 10^{-6}$

${{\mathit \Upsilon}{(3S)}}$ X

$<9.4\times 10^{-5}$

${{\mathit \Upsilon}{(3S)}}{{\mathit \gamma}}$

$<4.8\times 10^{-6}$

${{\mathit \Upsilon}{(1,2,3S)}}{{\mathit \Upsilon}{(1,2,3S)}}$

$<1.5\times 10^{-6}$

( ${{\mathit D}^{0}}$ /${{\overline{\mathit D}}^{0}}$) X

$(20.7\pm{2.0})\%$

${{\mathit D}^{\pm}}$ X

$(12.2\pm{1.7})\%$

${{\mathit D}^{*}{(2010)}^{\pm}}$ X

$(11.4\pm{1.3})\%$

${{\mathit D}_{{s1}}{(2536)}^{\pm}}$ X

$(3.6\pm{0.8})\times 10^{-3}$

${{\mathit D}_{{sJ}}{(2573)}^{\pm}}$ X

$(5.8\pm{2.2})\times 10^{-3}$

${{\mathit D}^{*'}{(2629)}^{\pm}}$ X

${{\mathit B}}$ X

${{\mathit B}^{*}}$ X

${{\mathit B}^{+}}$ X

$(6.08\pm{0.13})\%$

${{\mathit B}_{{s}}^{0}}$ X

$(1.59\pm{0.13})\%$

${{\mathit B}_{{c}}^{+}}$ X

${{\mathit \Lambda}_{{c}}^{+}}$ X

$(1.54\pm{0.33})\%$

${{\mathit \Xi}_{{c}}^{0}}$ X

${{\mathit \Xi}_{{b}}}$ X

${{\mathit b}}$ -baryon X

$(1.38\pm{0.22})\%$

anomalous ${{\mathit \gamma}}$ + hadrons

$<3.2\times 10^{-3}$

${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \gamma}}$

$<5.2\times 10^{-4}$

${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}}$

$<5.6\times 10^{-4}$

${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}{{\mathit \gamma}}$

$<7.3\times 10^{-4}$

${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\mathit \gamma}}{{\mathit \gamma}}$

$<6.8\times 10^{-6}$

${{\mathit q}}{{\overline{\mathit q}}}{{\mathit \gamma}}{{\mathit \gamma}}$

$<5.5\times 10^{-6}$

${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit \gamma}}{{\mathit \gamma}}$

$<3.1\times 10^{-6}$

${{\mathit e}^{\pm}}{{\mathit \mu}^{\mp}}$

$<7.5\times 10^{-7}$

${{\mathit e}^{\pm}}{{\mathit \tau}^{\mp}}$

$<5.0\times 10^{-6}$

${{\mathit \mu}^{\pm}}{{\mathit \tau}^{\mp}}$

$<6.5\times 10^{-6}$

${{\mathit p}}{{\mathit e}}$

$<1.8\times 10^{-6}$

${{\mathit p}}{{\mathit \mu}}$

$<1.8\times 10^{-6}$

FOOTNOTES

Except where otherwise noted, content of the 2022 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. © 2022. See LBNL disclaimers.