arXiv subjects

Ricardo C. Silva

Publications and source records attributed to Ricardo C. Silva.

3 recordsLinked to original sources

arXiv2026

Updated Bounds on the Minimal Left-Right Symmetric Model from LHC Dilepton Resonance Searches

The Left-Right model is a popular extension of the Standard Model that features three new neutral gauge bosons, $W^{\pm}_R$ and $Z_R$. Collider searches for a Left-Right symmetry are often concentrated on the charged right-handed current, but in this work, we take advantage of the dilepton data at the LHC with center-of-mass energy of 13 TeV and 139 fb$^{-1}$ of integrated luminosity to place lower mass bounds in the $Z_R$ mass based on the $p\,p \rightarrow Z_{R} \rightarrow \ell^{+} \, \ell^{-}$ process. We vary the $SU(2)_R$ gauge coupling from $g_{R}=0.4$ to $g_{R}=1.0$, and impose $M_{Z_R}>4.9$ TeV and $M_{Z_{R}}>6.1$ TeV, respectively. Lastly, we put our findings into perspective with $W_R$ searches at the LHC and show that our limits cover an unexplored region of parameter space, where the right-handed neutrino is heavier than the $W_R$ boson.

hep-ph↗

arXiv2025

Can the FCC-hh prove the B-L gauge symmetry?

We present a phenomenological study of the discovery potential at the FCC-hh for a new heavy neutral vector boson, Z', predicted by the $U(1)_{B-L}$ gauge symmetry. Focusing on the parameter space currently not excluded by Large Hadron Collider data, we analyze the dilepton production channel $p p \rightarrow Z^{\prime} \rightarrow l^{+} l^{-}$ ($l^{\pm} = e^{\pm}, μ^{\pm}$) at a center-of-mass energy of $\sqrt{s} = 100$ TeV. Full Monte Carlo simulations was performed for different ($M_{Z'}$, $g_{B-L}$) BSM scenarios and relevant Standard Model backgrounds (including irreducible Drell-Yan, diboson, single top-quark and top-quark pair productions) identifying optimal kinematic and angular selection cuts to guide future searches for this type resonance. We estimate the FCC-hh reach for an integrated luminosity of $\mathcal{L}_{int}$ = 3~$ab^{-1}$. Our results demonstrate that the FCC-hh can exclude Z' masses up to $\sim 40$ TeV with 95\% C.L. for couplings of $g_{B-L} \sim 1$, and up to $\sim 15$ TeV for $g_{B-L} \sim 0.1$. We find the kinematic and angular cuts that optimize the signal over background ratio and achieve a $5σ$ signal up to Z' masses of $\sim 30$ TeV. These findings highlight the FCC-hh potential to uncover new physics signals in the high-mass regime.

hep-ph↗

arXiv2024

LHC and HL-LHC Bounds on Visible and Invisible Decays in the $B-L$ Model

In this work, we use publicly available data from ATLAS collaboration collected at LHC run 2 at a center-of-mass energy of $\sqrt{s}=13$TeV with an integrated luminosity of $139 fb^{-1}$ to derive lower mass limits on the $Z^\prime$ gauge boson associated with the B-L gauge symmetry. Using dilepton data we find that $M_{Z^\prime} > 4$TeV ($6$TeV) for $g_{BL}=0.1$ ($g_{BL}=0.5$) in the absence of invisible decays. Once invisible decays are turned on these limits are substantially relaxed. Assuming an invisible branching ratio of $BR_{inv}=0.9$, the LHC bound is loosened up to $M_{Z^\prime}> 4.8$TeV for $g_{BL}=0.5$. This analysis confirms that the LHC now imposes stricter constraints than the longstanding bounds established by LEP. We also estimate the projected HL-LHC bounds that will operate with at $\sqrt{s}=14$TeV and a planned integrated luminosity of $\mathcal{L}=3 ab^{-1}$ that will probe $Z^\prime$ masses up to $7.5$TeV.

hep-ph↗