Constraints on the malaphoric model from di-lepton resonance searches at the LHC

Ben Allanach

doi:10.1140/epjc/s10052-025-14007-1

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2025) 85: 297
https://doi.org/10.1140/epjc/s10052-025-14007-1

Regular Article - Theoretical Physics

Constraints on the malaphoric $B_{3} - L_{2}$ model from di-lepton resonance searches at the LHC

Ben Allanach^a

DAMTP, University of Cambridge, Wilberforce Road, CB3 0WA, Cambridge, UK

^a ben.allanach.work@gmail.com

Received: 18 December 2024
Accepted: 24 February 2025
Published online: 14 March 2025

Abstract

We confront the malaphoric $B_{3} - L_{2}$ $$B_3-L_2$$ model with bounds coming from a search for resonances in the di-lepton channels at the 13 TeV LHC. In contrast to the original $B_{3} - L_{2}$ model, the $Z^{'}$ $Z^\prime$ of the malaphoric $B_{3} - L_{2}$ model has sizeable couplings to the lighter two families; these originate from order unity kinetic mixing with the hypercharge gauge boson and ameliorate the fit to lepton flavour universality measurements in B-meson decays. The $Z^{'}$ $Z^\prime$ coupling to the first two families of quark means that the resulting constraints from resonant di-lepton searches are stronger. Nevertheless, we find that for $M_{Z^{'}} > 2.8$ $M_{Z^\prime }>2.8$ TeV there remains a non-negligible region of allowed parameter space where the model significantly improves upon several Standard Model predictions for observables involving the $b \to s l^{+} l^{-}$ $b \rightarrow s l^+ l^-$ transition. We estimate that the 3000 fb $^{- 1}$ $^{-1}$ HL-LHC will extend this sensitivity to $M_{Z^{'}} = 4.2$ $M_{Z^\prime }= 4.2$ TeV.

This work was partially supported by STFC HEP Consolidated grants ST/T000694/1 and ST/X000664/1.

© Crown 2025

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