Fresh look at the LHC limits on scalar leptoquarks

Abstract

The scalar-leptoquark (sLQ) parameter space is well explored experimentally. The direct pair production searches at the LHC have excluded light sLQs almost model agnostically, and the high-$p_{\mathrm{T}}$ dilepton tail data have put strong bounds on the leptoquark-quark-lepton Yukawa couplings for a wide range of sLQ masses. However, these do not show the complete picture. Previously, Mandal \emph{et al.} [Single productions of colored particles at the LHC: An example with scalar leptoquarks, \href{https://doi.org/10.1007/JHEP07(2015)028}{J. High Energy Phys. 07 (2015) 028}] showed how the dilepton-dijet data from the pair production searches could give strong limits on these couplings. This was possible by including the single-production contribution to the dilepton-dijet signal. In this paper, we take a fresh look at the LHC limits on all sLQs by following the same principle and combine all significant contributions -- from pair and single productions, $t$-channel sLQ exchange and its interference with the Standard Model background -- to the $\mu \mu jj$ final state and recast the limits. We notice that the sLQ exchange and its interference with the background processes play significant roles in the limits. The $\mu \mu jj$-recast limits are comparable to or, in some cases, significantly better than the currently known limits (from high-$p_{\mathrm{T}}$ dilepton data and direct searches), i.e., the LHC data rules out more parameter space than what is considered in the current literature. For the first time, we also show how including the QED processes can noticeably improve the sLQ mass exclusion limits from the QCD-only limits.

arXiv comment13 pages, 7 figures and 4 tables. The models are available at https://github.com/rsrchtsm/LQ_Models. Same as the journal version

References in corpus (51)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• The anti-k_t jet clustering algorithm
• FastJet user manual
• DELPHES 3, A modular framework for fast simulation of a generic collider experiment
• FeynRules 2.0 - A complete toolbox for tree-level phenomenology
• UFO - The Universal FeynRules Output
• Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
• R-parity violating supersymmetry
• Physics of leptoquarks in precision experiments and at particle colliders
• Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm
• High-$p_T$ dilepton tails and flavour physics
• Measurement of the anomalous precession frequency of the muon in the Fermilab Muon g-2 experiment
• Search for resonant and nonresonant new phenomena in high-mass dilepton final states at $\sqrt{s}=$ 13 TeV
• The Leptoquark Hunter's Guide: Pair Production
• Pair production of scalar leptoquarks at the LHC
• The Leptoquark Hunter's Guide: Large Coupling
• Cornering Scalar Leptoquarks at LHC
• Search for pairs of scalar leptoquarks decaying into quarks and electrons or muons in $\sqrt{s}=13$ TeV pp collisions with the ATLAS detector
• Pair Production of Scalar Leptoquarks at the LHC to NLO Parton Shower Accuracy
• Drell-Yan Tails Beyond the Standard Model
• $R_{D^{(\ast )}}$ motivated ${\mathcal{S}}_1$ leptoquark scenarios: Impact of interference on the exclusion limits from LHC data
• Hunting leptoquarks in monolepton searches
• Lepton-quark collisions at the Large Hadron Collider
• Precision predictions for scalar leptoquark pair-production at hadron colliders
• Charm Physics Confronts High-$p_T$ Lepton Tails
• Single Productions of Colored Particles at the LHC: An Example with Scalar Leptoquarks
• Addressing the ${\mathbf{R}}_{D^{(\ast )}}$ anomalies with an ${\mathbf{S}}_1$ leptoquark from $\mathbf{SO}(10)$ grand unification
• Combined Constraints on First Generation Leptoquarks
• Anticipating Non-Resonant New Physics in Dilepton Angular Spectra at the LHC
• Hunting scalar leptoquarks with boosted tops and light leptons
• Enhancing Scalar Productions with Leptoquarks at the LHC
• Inclusive nonresonant multilepton probes of new phenomena at $\sqrt{s}=$ 13 TeV
• Combined explanation of $W$-mass, muon $g-2$, $R_{K^{(\ast )}}$ and $R_{D^{(\ast )}}$ anomalies in a singlet-triplet scalar leptoquark model
• Revisiting scalar leptoquark at the LHC
• Precise limits on the charge-$2/3$ $U_1$ vector leptoquark
• Complete Lagrangian and Set of Feynman Rules for Scalar Leptoquarks
• Indirect and monojet constraints on scalar leptoquarks
• Distinguishing signatures of scalar leptoquarks at hadron and muon colliders
• Improving third-generation leptoquark searches with combined signals and boosted top
• Probing Color Octet Electrons at the LHC
• Phenomenology of Scalar Leptoquarks at the LHC in Explaining the Radiative Neutrino Mass, Muon $g-2$ and Lepton Flavour Violating Observables
• Scalar leptoquark pair production at the LHC: precision predictions in the era of flavour anomalies
• Probing Compositeness with the CMS $eejj$ & $eej$ Data
• Leptoquark-assisted Singlet-mediated Di-Higgs Production at the LHC
• On Drell-Yan production of scalar leptoquarks coupling to heavy-quark flavours
• Scalar leptoquarks at the LHC and flavour anomalies: a comparison of pair-production modes at NLO-QCD
• Addendum to: Combined Constraints on First Generation Leptoquarks
• Precise probing and discrimination of third-generation scalar leptoquarks
• Asymmetric Leptoquark Pair Production at LHC
• Non-resonant Leptoquark with multigeneration couplings to $\mu \mu jj$ and $\mu \nu jj$ at LHC
• Revisiting the Scalar Leptoquark ($S_1$) Model with the Updated Leptonic Constraints

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