Limits for ${{\mathit Z}}{}^{′}_{{\mathrm {SM}}}$

INSPIRE   JSON  (beta) PDGID:
S056Z1C
${{\mathit Z}}{}^{′}_{{\mathrm {SM}}}$ is assumed to have couplings with quarks and leptons which are identical to those of ${{\mathit Z}}$, and decays only to known fermions. The most recent preliminary results can be found in the “${{\mathit Z}^{\,'}}$-boson searches” review above.
VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT
$\bf{ > 5150}$ OUR LIMIT
$\text{none 1800 - 2400}$ 95 1
TUMASYAN
2023AF
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}^{\,'}_{SM}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
$> 4400$ 95 2
TUMASYAN
2022AE
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$\bf{> 5150}$ 95 3
SIRUNYAN
2021N
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$\text{none 1133 - 2700}$ 95 4
AAD
2020T
 ATLS ${{\mathit p}}{{\mathit p}}$, ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
$\text{ none 1800 - 2900, 3100 - 3300}$ 95 5
SIRUNYAN
2020AI
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$\text{none 250 - 5100}$ 95 6
AAD
2019L
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$\text{none 600 - 2000}$ 95 7
AABOUD
2018AB
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$
$> 2420$ 95 8
AABOUD
2018G
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$\text{none 200 - 4500}$ 95 9
SIRUNYAN
2018BB
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$\text{none 600 - 2700}$ 95 10
SIRUNYAN
2018BO
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$> 4500$ 95 11
AABOUD
2017AT
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$> 2100$ 95 12
KHACHATRYAN
2017H
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$> 3370$ 95 13
KHACHATRYAN
2017T
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$\text{none 600 - 2100, 2300 - 2600}$ 95 14
KHACHATRYAN
2017W
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$> 3360$ 95 15
AABOUD
2016U
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$>2900$ 95 16
KHACHATRYAN
2015AE
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$\text{none 1200 - 1700}$ 95 17
KHACHATRYAN
2015V
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$> 2900$ 95 18
AAD
2014V
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
• • We do not use the following data for averages, fits, limits, etc. • •
19
BOBOVNIKOV
2018
RVUE ${{\mathit p}}{{\mathit p}}$, ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit W}^{-}}$
$>1900$ 95 20
AABOUD
2016AA
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$>2020$ 95 21
AAD
2015AM
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$> 1400$ 95 22
AAD
2013S
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$> 1470$ 95 23
CHATRCHYAN
2013A
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$> 2590$ 95 24
CHATRCHYAN
2013AF
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$> 2220$ 95 25
AAD
2012CC
 ATLS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$>1400$ 95 26
CHATRCHYAN
2012O
 CMS ${{\mathit p}}{{\mathit p}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$> 1071$ 95 27
AALTONEN
2011I
 CDF ${{\mathit p}}{{\overline{\mathit p}}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$> 1023$ 95 28
ABAZOV
2011A
 D0 ${{\mathit p}}{{\overline{\mathit p}}}$, ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$\text{none 247 - 544}$ 95 29
AALTONEN
2010N
 CDF ${{\mathit Z}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit W}}$
$\text{none 320 - 740}$ 95 30
AALTONEN
2009AC
 CDF ${{\mathit Z}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$> 963$ 95 28
AALTONEN
2009T
 CDF ${{\mathit p}}{{\overline{\mathit p}}}$, ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$> 1403$ 95 31
ERLER
2009
RVUE Electroweak
$> 1305$ 95 32
ABDALLAH
2006C
 DLPH ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$> 399$ 95 33
ACOSTA
2005R
 CDF ${{\overline{\mathit p}}}{{\mathit p}}$: ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$
$\text{none 400 - 640}$ 95
ABAZOV
2004C
 D0 ${{\mathit p}}{{\overline{\mathit p}}}$: ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$>1018$ 95 34
ABBIENDI
2004G
 OPAL ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$>670$ 95 35
ABAZOV
2001B
 D0 ${{\mathit p}}{{\overline{\mathit p}}}$, ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$>1500$ 95 36
CHEUNG
2001B
 RVUE Electroweak
$>710$ 95 37
ABREU
2000S
 DLPH ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$>898$ 95 38
BARATE
2000I
 ALEP ${{\mathit e}^{+}}{{\mathit e}^{-}}$
$>809$ 95 39
ERLER
1999
RVUE Electroweak
$>690$ 95 40
ABE
1997S
 CDF ${{\mathit p}}{{\overline{\mathit p}}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$
$>398$ 95 41
VILAIN
1994B
 CHM2 ${{\mathit \nu}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$ and ${{\overline{\mathit \nu}}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{{\mu}}}}{{\mathit e}}$
$>237$ 90 42
ALITTI
1993
UA2 ${{\mathit p}}{{\overline{\mathit p}}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$\text{none 260 - 600}$ 95 43
RIZZO
1993
RVUE ${{\mathit p}}{{\overline{\mathit p}}}$; ${{\mathit Z}_{{{SM}}}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}$
$>426$ 90 44
ABE
1990F
 VNS ${{\mathit e}^{+}}{{\mathit e}^{-}}$
1  TUMASYAN 2023AF search for resonance decaying to ${{\mathit b}}{{\overline{\mathit b}}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. See their Fig. 4 for limits on $\sigma \cdot{}B$.
2  TUMASYAN 2022AE set limits on ${{\mathit Z}^{\,'}}$ from the measurements of the forward-backward asymmetry in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ and ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ events in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. The quoted limit is for the sequential SM ${{\mathit Z}^{\,'}}$. See their Fig. 6 for limits in mass-coupling plane.
3  SIRUNYAN 2021N search for resonance decaying to ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
4  AAD 2020T search for resonances decaying to ${{\mathit b}}{{\overline{\mathit b}}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. See their Fig. 7(b) for limits on the product of the cross section, acceptance, ${{\mathit b}}$-tagging efficiency, and branching fraction.
5  SIRUNYAN 2020AI search for resonances decaying into dijets in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
6  AAD 2019L search for resonances decaying to ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
7  AABOUD 2018AB search for resonances decaying to ${{\mathit b}}{{\overline{\mathit b}}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
8  AABOUD 2018G search for resonances decaying to ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
9  SIRUNYAN 2018BB search for resonances decaying to ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. See their Fig.5 for limits on the ${{\mathit Z}^{\,'}}$ coupling strengths with light quarks.
10  SIRUNYAN 2018BO search for resonances decaying to dijets in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
11  AABOUD 2017AT search for resonances decaying to ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
12  KHACHATRYAN 2017H search for resonances decaying to ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
13  KHACHATRYAN 2017T search for resonances decaying to ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8, 13 TeV.
14  KHACHATRYAN 2017W search for resonances decaying to dijets in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
15  AABOUD 2016U search for resonances decaying to ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
16  KHACHATRYAN 2015AE search for resonances decaying to ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV.
17  KHACHATRYAN 2015V search for resonances decaying to dijets in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV.
18  AAD 2014V search for resonances decaying to ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV.
19  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. 11 for limits in $\mathit M_{{{\mathit Z}^{\,'}}}−\xi $ plane.
20  AABOUD 2016AA search for resonances decaying to ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV.
21  AAD 2015AM search for resonances decaying to ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV.
22  AAD 2013S search for resonances decaying to ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV.
23  CHATRCHYAN 2013A use ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$=7 TeV.
24  CHATRCHYAN 2013AF search for resonances decaying to ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV and 8 TeV.
25  AAD 2012CC search for resonances decaying to ${{\mathit e}^{+}}{{\mathit e}^{-}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV.
26  CHATRCHYAN 2012O search for resonances decaying to ${{\mathit \tau}^{+}}{{\mathit \tau}^{-}}$ in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV.
27  AALTONEN 2011I search for resonances decaying to ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV.
28  ABAZOV 2011A, AALTONEN 2009T, AALTONEN 2007H, and ABULENCIA 2006L search for resonances decaying to ${{\mathit e}^{+}}{{\mathit e}^{-}}$ in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96$~$TeV.
29  The quoted limit assumes $\mathit g_{{{\mathit W}} {{\mathit W}} {{\mathit Z}^{\,'}}}/\mathit g_{{{\mathit W}} {{\mathit W}} {{\mathit Z}}}$ = ($\mathit M_{{{\mathit W}}}/\mathit M_{{{\mathit Z}^{\,'}}}){}^{2}$. See their Fig.$~$4 for limits in mass-coupling plane.
30  AALTONEN 2009AC search for new particle decaying to dijets.
31  ERLER 2009 give 95$\%$ CL limit on the ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $-0.0026<\theta <$ 0.0006.
32  ABDALLAH 2006C use data $\sqrt {s }$ = $130 - 207$ GeV.
33  ACOSTA 2005R search for resonances decaying to tau lepton pairs in ${{\overline{\mathit p}}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 1.96 TeV.
34  ABBIENDI 2004G give 95$\%$ CL limit on ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $−$0.00422 $<\theta <$0.00091. $\sqrt {s }$ = 91 to 207$~$GeV.
35  ABAZOV 2001B search for resonances in ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ at $\sqrt {\mathit s }$=1.8 TeV. They find $\sigma \cdot{}B({{\mathit Z}^{\,'}}$ $\rightarrow$ ${{\mathit e}}{{\mathit e}})<0.06~$pb for $\mathit M_{{{\mathit Z}^{\,'}}}>500$ GeV.
36  CHEUNG 2001B limit is derived from bounds on contact interactions in a global electroweak analysis.
37  ABREU 2000S uses LEP data at $\sqrt {\mathit s }$=90 to 189 GeV.
38  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 $=0. Bounds in the mass-mixing plane are shown in their Figure$~$18.
39  ERLER 1999 give 90$\%$CL limit on the ${{\mathit Z}}-{{\mathit Z}^{\,'}}$ mixing $-0.0041<\theta <0.0003$. $\rho _{0}$=1 is assumed.
40  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.
41  VILAIN 1994B assume ${\mathit m}_{{{\mathit t}}}$ = 150 GeV.
42  ALITTI 1993 search for resonances in the two-jet invariant mass. The limit assumes B(${{\mathit Z}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}})=0.7$. See their Fig.$~$5 for limits in the ${\mathit m}_{{{\mathit Z}^{\,'}}}−B({{\mathit q}}{{\overline{\mathit q}}}$) plane.
43  RIZZO 1993 analyses CDF limit on possible two-jet resonances.
44  ABE 1990F use data for $\mathit R$, $\mathit R_{{{\mathit \ell}} {{\mathit \ell}}}$, and $\mathit A_{{{\mathit \ell}} {{\mathit \ell}}}$. They fix ${\mathit m}_{{{\mathit W}}}$ = $80.49$ $\pm0.43$ $\pm0.24$ GeV and ${\mathit m}_{{{\mathit Z}}}$ = $91.13$ $\pm0.03$ GeV.
References