We discuss the holographic correspondence between 3d “Chern-Simons gravity” and an ensemble of 2d Narain code CFTs. Starting from 3d abelian Chern-Simons theory, we construct an ensemble of boundary CFTs defined by gauging all possible maximal subgroups of the bulk one-form symmetry. Each maximal non-anomalous subgroup is isomorphic to a classical even self-dual error-correcting code over $\textit{ℤ}$ × $\textit{ℤ}$ , providing a way to define a boundary “code CFT.” The average over the ensemble of such theories is holographically dual to Chern-Simons gravity, a bulk theory summed over 3d topologies sharing the same boundary. In the case of prime $\textit{p}$, the sum reduces to that over handlebodies, i.e. becomes the Poincaré series akin to that in semiclassical gravity. As the main result of the paper, we show that the mathematical identity underlying this holographic duality can be understood and rigorously proven using the framework of Howe duality over finite fields. This framework is concerned with the representation theory of two commuting groups forming a dual pair: the symplectic group of modular transformations of the boundary, and an orthogonal group mapping codes to each other. Finally, we reformulate the holographic duality as an identity between different averages over quantum stabilizer states, providing an interpretation in terms of quantum information theory.

United States

Anatoly Dymarsky

France

Switzerland

Johan Henriksson

Canada

Brian McPeak

Holographic duality from Howe duality: Chern-Simons gravity as an ensemble of code CFTs

We present a new mechanism to solve the strong CP problem using N ≥ 2 axions, each dynamically relaxing part of the θ parameter. At high energies M ≫ ΛQCD the SU(3) c  group becomes the diagonal subgroup of an SU(3) N  gauge group, and the non-perturbative effects in each individual SU(3) factor generate a potential for the corresponding axion. The vacuum is naturally aligned to ensure   <math> <mover> <mi>θ</mi> <mo>¯</mo> </mover> <mo>=</mo> <mspace width="0.25em"></mspace> <mn>0</mn> </math>  $$ \overline{\theta} = 0 $$  at low energies, and the masses of these axions can be much larger than for the standard QCD axion. This mechanism avoids the introduction of a discrete Z2 symmetry and associated ‘mirror’ copies of the SM fermions, and also avoids the introduction and stabilization of new light colored states to modify the running of the QCD gauge coupling found in other heavy axion models. This strengthens the motivation for axion-like particles solving the strong CP problem at points beyond the standard QCD axion curve in the (m  a , f  a ) plane.

Prateek Agrawal

Kiel Howe

Factoring the strong CP problem

Motivated by the intimate connection between the strong CP problem and the flavor structure of the Standard Model, we present a flavor model that revives and extends the classic m  u  = 0 solution to the strong CP problem. QCD is embedded into a SU(3)1 × SU(3)2 × SU(3)3 gauge group, with each generation of quarks charged under the respective SU(3). The non-zero value of the up-quark Yukawa coupling (along with the strange quark and bottom-quark Yukawas) is generated by contributions from small instantons at a new scale M ≫ ΛQCD. The Higgsing of SU(3)3 → SU(3) c  allows dimension-5 operators that generate the Standard Model flavor structure and can be completed in a simple renormalizable theory. The smallness of the third generation mixing angles can naturally emerge in this picture, and is connected to the smallness of threshold corrections to   <math> <mover> <mi>θ</mi> <mo>¯</mo> </mover> </math>  $$ \overline{\theta} $$ . Remarkably,   <math> <mover> <mi>θ</mi> <mo>¯</mo> </mover> </math>  $$ \overline{\theta} $$  is essentially fixed by the measured quark masses and mixings, and is estimated to be close to the current experimental bound and well within reach of the next generation of neutron and proton EDM experiments.

A flavorful factoring of the strong CP problem

The oldest and most robust technique to search for new particles is to look for “bumps” in invariant mass spectra over smoothly falling backgrounds. We present a new extension of the bump hunt that naturally benefits from modern machine learning algorithms while remaining model agnostic. This approach is based on the classification without labels (CWoLa) method where the invariant mass is used to create two potentially mixed samples, one with little or no signal and one with a potential resonance. Additional features that are uncorrelated with the invariant mass can be used for training the classifier. Given the lack of new physics signals at the Large Hadron Collider (LHC), such model-agnostic approaches are critical for ensuring full coverage to fully exploit the rich datasets from the LHC experiments. In addition to illustrating how the new method works in simple test cases, we demonstrate the power of the extended bump hunt on a realistic all-hadronic resonance search in a channel that would not be covered with existing techniques.

Jack H. Collins

Benjamin Nachman

Extending the search for new resonances with machine learning

Despite extensive theoretical motivation for physics beyond the standard model (BSM) of particle physics, searches at the Large Hadron Collider have found no significant evidence for BSM physics. Therefore, it is essential to broaden the sensitivity of the search program to include unexpected scenarios. We present a new model-agnostic anomaly detection technique that naturally benefits from modern machine learning algorithms. The only requirement on the signal for this new procedure is that it is localized in at least one known direction in phase space. Any other directions of phase space that are uncorrelated with the localized one can be used to search for unexpected features. This new method is applied to the dijet resonance search to show that it can turn a modest <math><mn>2</mn><mi>σ</mi></math> excess into a <math><mn>7</mn><mi>σ</mi></math> excess for a model with an intermediate BSM particle that is not currently targeted by a dedicated search.

Jack Collins

Anomaly Detection for Resonant New Physics with Machine Learning

We investigate induced electroweak symmetry breaking (EWSB) in models in which the Higgs is a pseudo-Nambu-Goldstone boson (pNGB). In pNGB Higgs models, Higgs properties and precision electroweak measurements imply a hierarchy between the EWSB and global symmetry-breaking scales, v H ≪ f H . When the pNGB potential is generated radiatively, this hierarchy requires fine-tuning to a degree of at least ∼  v h 2 / f H 2 . We show that if Higgs EWSB is induced by a tadpole arising from an auxiliary sector at scale f Σ ≪ v H , this tuning is significantly ameliorated or can even be removed. We present explicit examples both in Composite Higgs models based on SO(5) / SO(4) and in Twin Higgs models. For the Twin case, the result is a fully natural model with f H ∼ 1 TeV and the lightest colored top partners at 2 TeV. These models also have an appealing mechanism to generate the scales of the auxiliary sector and Higgs EWSB directly from the scale f H , with a natural hierarchy f Σ ≪ v H ≪ f H ∼ TeV. The framework predicts modified Higgs coupling as well as new Higgs and vector states at LHC13.

Roni Harnik

John Kearney

Tadpole-induced electroweak symmetry breaking and pNGB Higgs models

Natural supersymmetric theories of the weak scale are under growing pressure given present LHC constraints, raising the question of whether untuned supersymmetric (SUSY) solutions to the hierarchy problem are possible. In this paper, we explore a class of 5-dimensional natural SUSY theories in which SUSY is broken by the Scherk-Schwarz mechanism. We pedagogically explain how Scherk-Schwarz elegantly solves the traditional problems of 4-dimensional SUSY theories (based on the MSSM and its many variants) that usually result in an unsettling level of fine-tuning. The minimal Scherk-Schwarz set up possesses novel phenomenology, which we briefly outline. We show that achieving the observed physical Higgs mass motivates extra structure that does not significantly affect the level of tuning (always better than ~ 10%) and we explore three qualitatively different extensions: the addition of extra matter that couples to the Higgs, an extra U(1)' gauge group under which the Higgs is charged and an NMSSM-like solution to the Higgs mass problem.

United Kingdom

Isabel García

John March-Russell

Natural Scherk-Schwarz theories of the weak scale

In supersymmetric (SUSY) theories with extra dimensions the visible energy in sparticle decays can be significantly reduced and its energy distribution broadened, thus significantly weakening the present collider limits on SUSY. The mechanism applies when the lightest supersymmetric particle (LSP) is a bulk state — e.g. a bulk modulino, axino, or gravitino — the size of the extra dimensions ≳ 10 −14 cm, and for a broad variety of visible sparticle spectra. In such cases the lightest ordinary supersymmetric particle (LOSP), necessarily a brane-localised state, decays to the Kaluza-Klein (KK) discretuum of the LSP. This dynamically realises the compression mechanism for hiding SUSY as decays into the more numerous heavier KK LSP states are favored. We find LHC limits on right-handed slepton LOSPs evaporate, while LHC limits on stop LOSPs weaken to ∼ 350 ÷ 410 GeV compared to ∼ 700 GeV for a stop decaying to a massless LSP. Similarly, for the searches we consider, present limits on direct production of degenerate first and second generation squarks drop to ∼ 450 GeV compared to ∼ 800 GeV for a squark decaying to a massless LSP. Auto-concealment typically works for a fundamental gravitational scale of M * ∼ 10 ÷ 100 TeV, a scale sufficiently high that traditional searches for signatures of extra dimensions are mostly avoided. If superpartners are discovered, their prompt, displaced, or stopped decays can also provide new search opportunities for extra dimensions with the potential to reach M * ∼ 10 9 GeV. This mechanism applies more generally than just SUSY theories, pertaining to any theory where there is a discrete quantum number shared by both brane and bulk sectors.

Savas Dimopoulos

James Scoville

Auto-concealment of supersymmetry in extra dimensions

Results are presented for a variety of SUSY Simplified Models at the 14 TeV LHC as well as a 33 and 100 TeV proton collider. Our focus is on models whose signals are driven by colored production. We present projections of the upper limit and discovery reach in the gluino-neutralino (for both light and heavy flavor decays), squark-neutralino, and gluino-squark Simplified Model planes. Depending on the model a jets + $ E_T^{\mathrm{miss}} $ , mono-jet, or same-sign di-lepton search is applied. The impact of pileup is explored. This study utilizes the Snowmass backgrounds and combined detector. Assuming 3000 fb −1 of integrated luminosity, a gluino that decays to light flavor quarks can be discovered below 2.3 TeV at the 14 TeV LHC and below 11 TeV at a 100 TeV machine.

Timothy Cohen

Tobias Golling

Mike Hance

Anna Henrichs

Joshua Loyal

Sanjay Padhi

Jay G. Wacker

SUSY simplified models at 14, 33, and 100 TeV proton colliders

We show that naturalness of the weak scale can be comfortably reconciled with both LHC null results and observed Higgs properties provided the double protection of supersymmetry and the twin Higgs mechanism. This double protection radically alters conventional signs of naturalness at the LHC while respecting gauge coupling unification and precision electroweak limits. We find the measured Higgs mass, couplings, and percent-level naturalness of the weak scale are compatible with stops at ~ 3.5 TeV and higgsinos at ~ 1 TeV. The primary signs of naturalness in this scenario include modifications of Higgs couplings, a modest invisible Higgs width, resonant Higgs pair production, and an invisibly-decaying heavy Higgs.