Baryon Number and Lepton Universality Violation in Leptoquark and Diquark Models

Abstract

We perform a systematic study of models involving leptoquarks and diquarks with masses well below the grand unification scale and demonstrate that a large class of them is excluded due to rapid proton decay. After singling out the few phenomenologically viable color triplet and sextet scenarios, we show that there exist only two leptoquark models which do not suffer from tree-level proton decay and which have the potential for explaining the recently discovered anomalies in B meson decays. Both of those models, however, contain dimension five operators contributing to proton decay and require a new symmetry forbidding them to emerge at a higher scale. This has a particularly nice realization for the model with the vector leptoquark $(3,1{)}_{2/3}$, which points to a specific extension of the Standard Model, namely the Pati-Salam unification model, where this leptoquark naturally arises as the new gauge boson. We explore this possibility in light of recent B physics measurements. Finally, we analyze also a vector diquark model, discussing its LHC phenomenology and showing that it has nontrivial predictions for neutron-antineutron oscillation experiments.

10 pages, 3 figures; v2: constraints on the Pati-Salam leptoquark discussed in more detail, brief sketch of a new model presented

References in corpus (21)

• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• B-physics anomalies: a guide to combined explanations
• On the B to D* tau nu Sensitivity to New Physics
• Gauge leptoquark as the origin of B-physics anomalies
• The lifetime of the $B_c^{-}$ meson and the anomalies in $B\to D^{(\ast )}\tau \nu$
• $SU(2)\times U(1)$ gauge invariance and the shape of new physics in rare $B$ decays
• $R(D^{\ast })$, $|V_{cb}|$, and the Heavy Quark Symmetry relations between form factors
• Leptoquark model to explain the $B$-physics anomalies, $R_K$ and $R_D$
• B-decay Anomalies in a Composite Leptoquark Model
• Search for Proton Decay via $p\to e^{+}{\pi }^0$ and $p\to {\mu }^{+}{\pi }^0$ in 0.31 megaton$\cdot$years exposure of the Super-Kamiokande Water Cherenkov Detector
• Lepton universality violation and lepton flavor conservation in $B$-meson decays
• Simplified models with baryon number violation but no proton decay
• Constraint on the branching ratio of B_c \to tau nu from LEP1 and consequences for R(D(*)) anomaly
• Constraints on two-lepton, two quark operators
• Lepton number violation at the LHC with leptoquark and diquark
• Color Sextet Scalars at the CERN Large Hadron Collider
• Neutrino Mass Hierarchy and neutron-anti-neutron Oscillation from Baryogenesis
• Mass limits for scalar and gauge leptoquarks from $K_L^0\to e^{\mp }{\mu }^{\pm },B^0\to e^{\mp }{\tau }^{\pm }$ decays
• Color Sextet Vector Bosons and Same-Sign Top Quark Pairs at the LHC
• The third type of fermion mixing in the lepton and quark interactions with leptoquarks
• SU(5) Unification without Proton Decay

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• On the single leptoquark solutions to the $B$-physics anomalies
• Constraints on Lepton Universality Violation from Rare $B$ Decays
• High-pT Signatures in Vector-Leptoquark Models
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• $B$ Flavour Anomalies: 2021 Theoretical Status Report
• A Model of Muon Anomalies
• Combined explanations of $(g-2{)}_{\mu }$, $R_{D^{(\ast )}}$, $R_{K^{(\ast )}}$ anomalies in a two-loop radiative neutrino mass model
• Searching for Leptoquarks at Future Muon Colliders
• Inclusive Nucleon Decay Searches as a Frontier of Baryon Number Violation
• Vector Leptoquarks Beyond Tree Level
• Effective Theory Approach to New Physics with Flavour: General Framework and a Leptoquark Example
• GUT Physics in the era of the LHC
• Muonic Force Behind Flavor Anomalies
• Leptoquarks and Matter Unification: Flavor Anomalies and the Muon $g-2$
• Investigation of Effects of New Physics in ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ Decay
• Confronting the vector leptoquark hypothesis with new low- and high-energy data
• Impact of ${\Lambda }_b\to {\Lambda }_c\tau \nu$ measurement on New Physics in $b\to cl\nu$ transitions
• Neutron Stars with Baryon Number Violation, Probing Dark Sectors
• Unified SU(4) theory for the $R_{D^{(\ast )}}$ and $R_{K^{(\ast )}}$ anomalies
• Exploiting dijet resonance searches for flavor physics
• Probing the $R_{K^{(\ast )}}$ Anomaly at a Muon Collider
• Phenomenology of $b\to c\tau \bar{\nu }$ decays in a scalar leptoquark model
• Classifying Standard Model Extensions Effectively with Precision Observables
• Scalar Leptoquarks, Baryon Number Violation and Pati-Salam Symmetry
• An EFT approach to baryon number violation: lower limits on the new physics scale and correlations between nucleon decay modes
• Twin Pati-Salam theory of flavour with a TeV scale vector leptoquark
• Phenomenology of Scalar Leptoquarks at the LHC in Explaining the Radiative Neutrino Mass, Muon $g-2$ and Lepton Flavour Violating Observables
• Vector Leptoquarks Beyond Tree Level II: $\mathcal{O}({\alpha }_s)$ Corrections and Radial Modes
• Flavorful leptoquarks at the LHC and beyond: Spin 1
• LHC Constraints on Scalar Diquarks
• Collider Signatures of Coannihilating Dark Matter in Light of the B-Physics Anomalies
• Origin of Yukawa couplings for Higgs and leptoquarks
• Composite Higgs and leptoquarks from a simple group
• Marriage between neutrino mass and flavor anomalies
• Drell-Yan production in third-generation gauge vector leptoquark models at NLO+PS in QCD
• Pursuit of paired dijet resonances in the Run 2 dataset with ATLAS
• Quark masses, CKM angles and Lepton Flavour Universality violation
• All possible first signals of gauge leptoquark in quark-lepton unification and beyond
• Leptoquarks, axions and the unification of B, L, and Peccei-Quinn symmetries
• A comprehensive study of vector leptoquark with $U(1{)}_{B_3-L_2}$ on the $B$-meson and Muon g-2 anomalies
• Vector leptoquark contributions to lepton dipole moments
• Probing New Physics in light of recent developments in $b\to c\ell \nu$ transitions
• Chiral gauge leptoquark mass limits and branching ratios of $K_L^0,B^0,B_s\to l_i^{+}{l}_j^{-}$ decays with account of the general fermion mixing in leptoquark currents
• Baryonic and Leptonic GeV Dark Matter
• Singlet vector leptoquark model facing recent LHCb and BABAR measurements
• Prospects for discovering new physics in charm sector through low-energy scattering processes $e^{-}p\to e^{-}({\mu }^{-}){\Lambda }_c$
• Correlating $0\nu \beta \beta$ decays and flavor observables in leptoquark models
• Dimension-5 baryon-number violation in low-scale Pati-Salam
• Searching for new physics from SMEFT and leptoquarks at the P2 experiment
• Searching and identifying leptoquarks through low-energy polarized scattering processes $e^{-}p\to e^{-}{\Lambda }_c$
• TeV-scale vector leptoquark from Pati-Salam unification with vectorlike families
• Invisible neutron decay and light BSM particles
• Perturbative unitarity constraints on generic Yukawa interactions
• Flavour anomalies meet flavour symmetry
• Rare decay $t\to c\gamma \gamma$ via scalar leptoquark doublets
• The $B$ Anomalies, the $U_1$ Leptoquark and Dark Matter
• Potential Blind Directions at TeraZ
• Constraining Scalar Doublet and Triplet Leptoquarks with Vacuum Stability and Perturbativity
• Flavor Anomalies and Quark-Lepton Unification
• Comment on "Neutron lifetime and dark decay of the neutron and hydrogen''
• Renormalization-group-improved constraints on dimension-7 baryon-number-violating operators
• Leptoquarks with Exactly Stable Protons