${{\mathit Z}}_{\mathit LR}$ is the extra neutral boson in left-right symmetric models. ${{\mathit g}_{{{L}}}}$ = ${{\mathit g}_{{{R}}}}$ is assumed unless noted. Values in parentheses assume stronger constraint on the Higgs sector, usually motivated by specific left-right symmetric models (see the Note on the ${{\mathit W}^{\,'}}$). Values in brackets are from cosmological and astrophysical considerations and assume a light right-handed neutrino. Direct search bounds assume decays to Standard Model fermions only, unless noted.

VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT $\bf{> 1162}$ 95 1 DEL-AGUILA 2010 RVUE Electroweak $\bf{>630}$ 95 2 ABE 1997 S CDF ${{\mathit p}}{{\overline{\mathit p}}}$; ${{\mathit Z}}{}^{'}_{\mathit LR}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ • • We do not use the following data for averages, fits, limits, etc. • • 3 TUMASYAN 2023 BE CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{LR}}}^{\,'}}$ $\rightarrow$ ${{\mathit N}}{{\overline{\mathit N}}}$ , ${{\mathit N}}$ $\rightarrow$ ${{\mathit \ell}}{{\mathit q}}{{\overline{\mathit q}}^{\,'}}$ 4 BOBOVNIKOV 2018 RVUE ${{\mathit p}}{{\mathit p}}$, ${{\mathit Z}_{{{LR}}}^{\,'}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$ $> 998$ 95 5 ERLER 2009 RVUE Electroweak $> 600$ 95 SCHAEL 2007 A ALEP ${{\mathit e}^{+}}{{\mathit e}^{-}}$ $> 455$ 95 6 ABDALLAH 2006 C DLPH ${{\mathit e}^{+}}{{\mathit e}^{-}}$ $>518$ 95 7 ABBIENDI 2004 G OPAL ${{\mathit e}^{+}}{{\mathit e}^{-}}$ $>860$ 95 8 CHEUNG 2001 B RVUE Electroweak $>380$ 95 9 ABREU 2000 S DLPH ${{\mathit e}^{+}}{{\mathit e}^{-}}$ $>436$ 95 10 BARATE 2000 I ALEP Repl. by SCHAEL 2007A $>550$ 95 11 CHAY 2000 RVUE Electroweak 12 ERLER 2000 RVUE ${}^{}\mathrm {Cs}$ 13 CASALBUONI 1999 RVUE ${}^{}\mathrm {Cs}$ $\text{(>1205)}$ 90 14 CZAKON 1999 RVUE Electroweak $>564$ 95 15 ERLER 1999 RVUE Electroweak $\text{(>1673)}$ 95 16 ERLER 1999 RVUE Electroweak $\text{(>1700)}$ 68 17 BARENBOIM 1998 RVUE Electroweak $>244$ 95 18 CONRAD 1998 RVUE ${{\mathit \nu}_{{{\mu}}}}{{\mathit N}}$ scattering $>253$ 95 19 VILAIN 1994 B CHM2 ${{\mathit \nu}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$ and ${{\overline{\mathit \nu}}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{{\mu}}}}{{\mathit e}}$ $\text{none 200 - 600}$ 95 20 RIZZO 1993 RVUE ${{\mathit p}}{{\overline{\mathit p}}}$; ${{\mathit Z}}_{\mathit LR}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$ $\text{[> 2000]}$ WALKER 1991 COSM Nucleosynthesis; light ${{\mathit \nu}_{{{R}}}}$ $\text{none 200 - 500}$ 21 GRIFOLS 1990 ASTR SN 1987A; light ${{\mathit \nu}_{{{R}}}}$ $\text{none 350 - 2400}$ 22 BARBIERI 1989 B ASTR SN 1987A; light ${{\mathit \nu}_{{{R}}}}$ 1  DEL-AGUILA 2010 give 95$\%$ CL limit on the ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $-0.0012<\theta <$ 0.0004. 2  ABE 1997S find $\sigma\mathrm {({{\mathit Z}^{\,'}})}{\times }B({{\mathit e}^{+}}{{\mathit e}^{-}},{{\mathit \mu}^{+}}{{\mathit \mu}^{-}})<40~$fb for ${\mathit m}_{{{\mathit Z}^{\,'}}}>600$ GeV at $\sqrt {\mathit s }$= 1.8 TeV. 3  TUMASYAN 2023BE search for pair production of heavy Majorana neutrinos via the decay of a ${{\mathit Z}^{\,'}}$ boson in a final state with ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ and at least two jets. For cases with ${\mathit m}_{{{\mathit N}}}$ = ${{\mathit M}}_{{{\mathit Z}^{\,'}}}$/4, their 95$\%$ CL limits are ${{\mathit M}}_{{{\mathit Z}^{\,'}}}$ $>$ 3.59 TeV ($>$ 4.10 TeV) in the dielectron (dimuon) channel. See their Fig. 5 for limits on $\sigma \cdot{}B$. 4  BOBOVNIKOV 2018 use the ATLAS limits on $\sigma ({{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit Z}^{\,'}})\cdot{}B({{\mathit Z}^{\,'}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$) to constrain the ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing parameter $\xi $. See their Fig. 10 for limits in $\mathit M_{{{\mathit Z}^{\,'}}}−\xi $ plane. 5  ERLER 2009 give 95$\%$ CL limit on the ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $-0.0013<\theta <$ 0.0006. 6  ABDALLAH 2006C give 95$\%$ CL limit $\vert \theta \vert <$ 0.0028. See their Fig. 14 for limit contours in the mass-mixing plane. 7  ABBIENDI 2004G give 95$\%$ CL limit on ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $−$0.00098 $<\theta <$ 0.00190. See their Fig. 20 for the limit contour in the mass-mixing plane. $\sqrt {s }$ = 91 to 207$~$GeV. 8  CHEUNG 2001B limit is derived from bounds on contact interactions in a global electroweak analysis. 9  ABREU 2000S give 95$\%$ CL limit on ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $\vert \theta \vert <0.0018$. See their Fig.$~$6 for the limit contour in the mass-mixing plane. $\sqrt {\mathit s }$=90 to 189 GeV. 10  BARATE 2000I search for deviations in cross section and asymmetries in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ fermions at $\sqrt {\mathit s }$=90 to 183 GeV. Assume $\theta $=0. Bounds in the mass-mixing plane are shown in their Figure$~$18. 11  CHAY 2000 also find $-0.0003<\theta <0.0019$. For ${{\mathit g}_{{{R}}}}$ free, ${\mathit m}_{{{\mathit Z}^{\,'}}}>430$ GeV. 12  ERLER 2000 discuss the possibility that a discrepancy between the observed and predicted values of ${{\mathit Q}_{{{W}}}}({}^{}\mathrm {Cs}$) is due to the exchange of ${{\mathit Z}^{\,'}}$. The data are better described in a certain class of the ${{\mathit Z}^{\,'}}$ models including ${{\mathit Z}}_{\mathit LR}$ and ${{\mathit Z}_{{{\chi}}}}$. 13  CASALBUONI 1999 discuss the discrepancy between the observed and predicted values of ${{\mathit Q}_{{{W}}}}({}^{}\mathrm {Cs}$). It is shown that the data are better described in a class of models including the ${{\mathit Z}}_{\mathit LR}$ model. 14  CZAKON 1999 perform a simultaneous fit to charged and neutral sectors. Assumes manifest left-right symmetric model. Finds $\vert \theta \vert <0.0042$. 15  ERLER 1999 give 90$\%$ CL limit on the ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $-0.0009<\theta <0.0017$. 16  ERLER 1999 assumes 2 Higgs doublets, transforming as 10 of SO(10), embedded in $\mathit E_{6}$. 17  BARENBOIM 1998 also gives 68$\%$ CL limits on the ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $-0.0005<\theta <0.0033$. Assumes Higgs sector of minimal left-right model. 18  CONRAD 1998 limit is from measurements at CCFR, assuming no ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing. 19  VILAIN 1994B assume ${\mathit m}_{{{\mathit t}}}$ = 150 GeV and $\theta $=0. See Fig.$~$2 for limit contours in the mass-mixing plane. 20  RIZZO 1993 analyses CDF limit on possible two-jet resonances. 21  GRIFOLS 1990 limit holds for ${\mathit m}_{{{\mathit \nu}_{{{R}}}}}{ {}\lesssim{} }~$1 MeV. A specific Higgs sector is assumed. See also GRIFOLS 1990D, RIZZO 1991. 22  BARBIERI 1989B limit holds for ${\mathit m}_{{{\mathit \nu}_{{{R}}}}}{}\leq{}$10 MeV. Bounds depend on assumed supernova core temperature.

References