Contents

Idea

In particle physics the term Z’-boson refers to a hypothetical higher-mass cousin of the Z-boson which is predicted by some models that extend the standard model of particle physics, such as grand unified theories (e.g. Sahoo 06).

The existence of the $Z'$ has been proposed as one possible explanation of the apparently observed flavour anomalies (Gauld-Goertz-Haisch 13, D’Ambrosio-Iver-Piccinini-Polosa 19)

References

General

• Paul Langacker, The Physics of Heavy $Z'$ Gauge Bosons, Rev.Mod.Phys.81:1199-1228, 2009 (arXiv:0801.1345)

• The Review of Particle Physics 2017, 59. $Z'$-boson searches (pdf)

• kjende.web.cern.ch/kjende/de/zpath_zprime.htm

• The Z’ Hunter’s Guide

Experimental constraints:

• CMS collaboration, Search for an $L_\mu - L_\tau$ gauge boson using $Z \to 4\mu$ events in proton-proton collisions at $\sqrt{s} = 13TeV$ (arXiv:1808.03684)

As arising in GUTs:

• S. Sahoo, The prediction of mass of $Z'$-boson in an $SO(10)$-based model, Indian J. Phys. 80 (2), 191-194 (2006) (pdf)

In relation to flavour anomalies

As a possible solution to the flavour anomalies:

• Rhorry Gauld, Florian Goertz, Ulrich Haisch, An explicit Z’-boson explanation of the $B \to K^\ast \mu^+ \mu^-$ anomaly, JHEP01(2014)069 (arXiv:1310.1082)

• Richard H. Benavides, Luis Muñoz, William A. Ponce, Oscar Rodríguez, Eduardo Rojas, Minimal $Z^\prime$ models for flavor anomalies (arXiv:1812.05077)

• Giancarlo D’Ambrosio, A. M. Iyer, F. Piccinini, A.D. Polosa, Confronting $B$ anomalies with atomic physics (arXiv:1902.00893)

• P. Ko, Takaaki Nomura, Chaehyun Yu, $b \to s \mu^+ \mu^-$ anomalies and related phenomenology in $U(1)_{B_{3-x_\mu L_\mu - x_\tau L_\tau}}$ flavor gauge models (arXiv:1902.06107)

• Joe Davighi, Connecting neutral current $B$ anomalies with the heaviness of the third family, Contribution to the 2019 QCD session of the 54th Rencontres de Moriond (arXiv:1905.06073)

• Wolfgang Altmannshofer, Joe Davighi, Marco Nardecchia, Gauging the accidental symmetries of the Standard Model, and implications for the flavour anomalies (arXiv:1909.02021)

• Rigo Bause, Gudrun Hiller, Tim Höhne, Daniel F. Litim, Tom Steudtner, B-Anomalies from flavorful $U(1)'$ extensions, safely (arXiv:2109.06201)

  (in view of Higgs field metastability)

• Disha Bhatia, Nishita Desai, Amol Dighe, Frugal $U(1)_X$ models with non-minimal flavor violation for $b \to s \ell \ell$ anomalies and neutrino mixing* (arXiv:2109.07093)

Realization in F-theory of GUT-models with Z'-bosons and/or [leptoquarks]] addressing the flavour anomalies and the (g-2) anomalies:

• Miguel Crispim Romao, Stephen F. King, George K. Leontaris, Non-universal $Z'$ from Fluxed GUTs, Physics Letters B Volume 782, 10 July 2018, Pages 353-361 (arXiv:1710.02349)

• A. Karozas, G. K. Leontaris, I. Tavellaris, N. D. Vlachos, On the LHC signatures of $SU(5) \times U(1)'$ F-theory motivated models (arXiv:2007.05936)

• Ben Allanach, $U(1)_{B_3-L_2}$ Explanation of the Neutral Current $B$−Anomalies (arXiv:2009.02197)

• Andreas Crivellin, Claudio Andreas Manzari, Marcel Alguero, Joaquim Matias, Combined Explanation of the $Z \to b \bar b$ Forward-Backward Asymmetry, the Cabibbo Angle Anomaly, $\tau \to \mu \nu \nu$ and $b \to s \ell^+ \ell^-$ Data (arXiv:2010.14504)

• Marcel Algueró, Andreas Crivellin, Claudio Andrea Manzari, Joaquim Matias, Unified Explanation of the Anomalies in Semi-Leptonic $B$ decays and the $W$ Mass, Physical Review D (2022) [arXiv:2201.08170]