The Japan Proton Accelerator Research Complex (J-PARC) currently delivers a 1 MW, 3 GeV proton beam to the Materials and Life Science Experimental Facility (MLF). Power is expected to increase to 1.3 MW, driven by the needs of Hyper-Kamiokande. As a result, the MLF presently provides the highest neutron yield of any spallation source, while potentially holding the best current and foreseeable conditions for Coherent Elastic Neutrino-Nucleus Scattering (CE$\textit{ν}$NS) experimentation. We explore this potential, using as examples detector technologies presently funded for construction and under development. We quantify their sensitivity to a rich variety of particle physics scenarios, finding that very-high-statistics CE$\textit{ν}$NS measurements with significant sensitivity to relevant scenarios are feasible at this facility within the next few years.

United States

Spain

J. Collar

Ivan Esteban

J. Gomez-Cadenas

M. Gonzalez–Garcia

L.C. Ji

L. Larizgoitia

C. Lewis

F. Monrabal

China

João Pinheiro.

A. Simón

S. Yoon

Coherent elastic neutrino-nucleus scattering at the Japan Proton Accelerator Research Complex

The flat space limit of bulk scalar fields in anti–de Sitter (AdS) is discussed within a Lorentzian canonical quantization setup. We construct their Lorentzian wave functions and use time dependent perturbation theory to compute amplitudes. These can be computed once the wave functions of the incoming and outgoing states, relevant to set up an scattering problem, have been determined. To get the flat limit we need states tailored so that the flat S-matrix arises naturally. This limit is provided by the algebraic action of the Ìnönü-Wigner contraction on the wave functions we construct. We develop the embedding formalism to describe the bulk AdS scalar primary wave functions as holomorphic functions. Flat space massive particle states are built out of the AdS primary together with AdS boosted wave functions. We compute their inner products and show that these become orthogonal in the flat limit, resulting in the correct continuous spectrum for a standard unitary representation of the Lorentz group. In this same limit the original AdS descendants become null states. We also argue how the flat space S-matrix emerges from standard perturbation theory in the interaction picture. To obtain flat space massless particles requires to consider a double scaled limit in which the boost rapidity is scaled to infinity keeping the average particle energy in the flat space limit fixed. We comment on how this limit generates interesting massless state wave functions with nontrivial shape profiles that remember the dimension of the AdS operator. We discuss some of the puzzles attached to these.

David Berenstein

United Kingdom

Joan Simón

Aspects of the bulk flat space limit in AdS/CFT

Spread complexity uses the distribution of support of a time-evolving state in the Krylov basis to quantify dispersal across accessible dimensions of a Hilbert space. Here, we describe how variations in initial conditions, the Hamiltonian, and the dimension of the Hilbert space affect spread complexity and Krylov basis structure. We introduce $\textit{Koherence}$, the entropy of coherence between perturbed and unperturbed Krylov bases, which can, e.g., quantify dynamical amplification of differences in initial conditions in chaos. To illustrate, we show that dynamics on SL(2, $\textit{ℝ}$), SU(2), and Heisenberg-Weyl group manifolds, often used as paradigmatic settings for contrasting chaotic and integrable (semi-)classical behavior, display distinctively different responses to variations of the initial state or Hamiltonian. We then describe a lattice model that displays linear growth of spread complexity, saturating for bounded lattices and continuing forever in a thermodynamic limit. The latter example illustrates a breakdown of continuum/classical effective descriptions of complexity growth in bounded quantum systems.

Belgium

Vijay Balasubramanian

Japan

Poland

Sweden

Pawel Caputa

Variations on a theme of Krylov

We study a class of infinite-distance loci, referred to as K-points, in one-parameter complex-structure moduli spaces of type IIB string theory compactified on Calabi-Yau manifolds. We show that around K-points the effective four-dimensional supergravity exhibits certain unusual properties. The two most prominent being that the leading order dependence of the prepotential on the gauge couplings is non-perturbative and that the leading gauge kinetic terms in the action vanish when evaluated on an anti self-dual graviphoton background. These properties are shared with the conifold locus in moduli space, rather than the large complex-structure locus. The conifold locus is well-known to arise from integrating out a charged BPS state, and so the similarities suggest that the K-point also arises from integrating out a BPS state. We develop such an interpretation, finding that it corresponds to a BPS state which is extremely light, whose mass in Planck units is doubly-exponentially small in the distance to the K-point. The state behaves as if it had complex charges, or as if it couples to the self-dual and anti self-dual parts of the graviphoton differently. Assuming such an integrating-out scenario is indeed the correct physics for the K-point, we discuss the implications for our understanding of infinite distances in moduli space and for the Swampland Distance Conjecture.

Israel

Jarod Hattab

Eran Palti

Joan Quirant

On the K-point in moduli space

The formalism of Dashen, Ma and Bernstein (DMB) expresses the thermal partition function of a system in terms of the S-matrix operator, roughly $\textit{Z}$($\textit{β}$) ∝ ∫$\textit{dEe}$ Tr ln $\textit{S}$($\textit{E}$), where $\textit{S}$ denotes the full scattering operator on the asymptotic Fock space — i.e. including all multi-particle sectors — defined via the Lippmann-Schwinger equation. Recently we have employed this formalism to compute the free energy of flux tubes (essentially a two-dimensional theory of derivatively coupled scalars) and the two-loop $\textit{O}$($\textit{α}$ ) QCD thermal free energy.

Slovenia

Pietro Baratella

Italy

Joan Miró

Thermodynamics from the S-matrix reloaded: emergent thermal mass

We demonstrate a precise relation between the rate of complexity of quantum states excited by local operators in two-dimensional conformal field theories and the radial momentum of particles in three-dimensional anti–de Sitter spacetimes. Similar relations have been anticipated based on qualitative models for operator growth. Here, we make this correspondence sharp with two key ingredients: the precise definition of quantum complexity given by the spread complexity of states, and the match of its growth rate to the bulk momentum measured in the proper radial distance coordinate.

Bowen Chen

Ross W. McDonald

Benjamin Strittmatter

Spread complexity rate as proper momentum

We develop a procedure to analytically calculate higher-order contributions to the high-temperature real-time static potential in QCD. It is based on the introduction of a semihard external scale, which lies between the hard scale (the temperature) and the soft scale (the screening mass), and the method of integration by regions. We calculate the leading and next-to-leading corrections in the region where bound states transit from narrow resonances to wide ones. The calculation involves both loop diagrams calculated in the hard thermal loop (HTL) effective theory and power corrections to the HTL Lagrangian calculated in QCD. We also calculate the thermal corrections to the heavy quarkonium spectrum, and estimate the dissociation temperatures. We compare our results with recent lattice data and discuss their usefulness to guide lattice inputs in inverse problems.

Canada

Margaret E. Carrington

Cristina Manuel

Joan Soto

Real-time QCD static potential at high temperature

If neutrinoless double beta decay is discovered, the next natural step would be understanding the lepton number violating physics responsible for it. Several alternatives exist beyond the exchange of light neutrinos. Some of these mechanisms can be distinguished by measuring phase-space observables, namely the opening angle cos $\textit{θ}$ among the two decay electrons, and the electron energy spectra, $\textit{T}$ and $\textit{T}$ . In this work, we study the statistical accuracy and precision in measuring these kinematic observables in a future xenon gas detector with the added capability to precisely locate the decay vertex. For realistic detector conditions (a gas pressure of 10 bar and spatial resolution of 4 mm), we find that the average $$ \overline{\cos\ \theta } $$ and $$ \overline{T_1} $$ values can be reconstructed with a precision of 0.19 and 110 keV, respectively, assuming that only 10 neutrinoless double beta decay events are detected.

M. Martínez-Vara

K. Mistry

F. Pompa

B. Jones

J. Martín-Albo

M. Sorel

C. Adams

H. Almazán

V. Álvarez

B. Aparicio

A. Aranburu

L. Arazi

I. Arnquist

F. Auria-Luna

S. Ayet

Portugal

C. Azevedo

K. Bailey

F. Ballester

M. Barrio-Torregrosa

A. Bayo

J. Benlloch-Rodríguez

F. Borges

A. Brodolin

N. Byrnes

S. Cárcel

A. Castillo

E. Church

L. Cid

C. Conde

T. Contreras

F. Cossío

R. Coupe

E. Dey

G. Díaz

C. Echevarria

M. Elorza

J. Escada

R. Esteve

R. Felkai

L. Fernandes

P. Ferrario

A. Ferreira

F. Foss

Z. Freixa

J. García-Barrena

J. Gómez-Cadenas

J. Grocott

R. Guenette

J. Hauptman

C. Henriques

J. Hernando Morata

P. Herrero-Gómez

V. Herrero

C. Hervés Carrete

Y. Ifergan

F. Kellerer

A. Larumbe

P. Lebrun

F. Lopez

N. López-March

R. Madigan

R. Mano

A. Marques

G. Martínez-Lema

R. Miller

J. Molina-Canteras

C. Monteiro

F. Mora

K. Navarro

P. Novella

A. Nuñez

D. Nygren

E. Oblak

J. Palacio

B. Palmeiro

A. Para

I. Parmaksiz

A. Pazos

J. Pelegrin

M. Pérez Maneiro

M. Querol

J. Renner

I. Rivilla

C. Rogero

L. Rogers

B. Romeo

C. Romo-Luque

V. San Nacienciano

F. Santos

J. Santos

M. Seemann

I. Shomroni

P. Silva

S. Soleti

J. Soto-Oton

J. Teixeira

S. Teruel-Pardo

Reconstructing neutrinoless double beta decay event kinematics in a xenon gas detector with vertex tagging