We investigate neutron–antineutron oscillations of ultracold neutrons in a storage bottle represented by a 1D potential. The experimental sensitivity is determined by the annihilation rate of antineutrons. Its dependence on the antineutron reflectivity and the relative phase shift between the neutron and the antineutron wavefunctions by a reflection from the wall is derived. Optimization of the antineutron pseudopotential was found crucial to maximize the sensitivity of the experiment. Furthermore, methods are discussed for determining the antineutron pseudopotential, which has only been studied indirectly thus far.

Japan

Hiroyuki Fujioka

Takashi Higuchi

Impact of a Reflecting Material on the Search for Neutron–Antineutron Oscillations using Ultracold Neutrons

A proposed future ultra-high-energy collider such as the Future Circular Collider is expected to produce intense and collimated neutrino beams from weak hadron decays. In this study, we estimate the production yields of such neutrinos from proton–proton collisions at a center-of-mass energy of 100 TeV and an integrated luminosity of 1 ab <inline-formula><tex-math id='TM0001' notation='LaTeX'>$^{-1}$</tex-math></inline-formula>. Based on a hypothetical detector positioned either 0.5&#160;km or 2&#160;km downstream from the interaction point along the beamline, we derive the expected rates of charged current neutrino scattering events and their extension to neutrino energies of up to 50&#160;TeV. We, for the first time, also evaluate the feasibility of observing the experimentally unverified direct production of <inline-formula><tex-math id='TM0002' notation='LaTeX'>$W^{\pm }$</tex-math></inline-formula> bosons from neutrino&#8211;nucleus interactions.

South Korea

E Won

B R Ko

Forward Neutrino Production and Event Rates at the Future Circular Collider for Hadron Collisions

We consider the bosonic theory for a single M5-brane on the plane-wave background and derive a family of Bogomol’nyi–Prasad–Sommerfield (BPS) solutions with nonzero components of the angular momentum. By explicit construction of a BPS solution, we find the solution describes an ellipsoidal five-brane rotating without changing its shape. The methodology developed in this paper is expected to provide a strategy for obtaining the BPS solutions that correspond to a BPS sector in the dual gauge theory, such as the Berenstein–Maldacena–Nastase (BMN) matrix model.

Yuhma Asano

Goro Ishiki

Yuto Yoshida

Classical BPS M5-Brane on the Plane-Wave Background

In lattice gauge theory with compact gauge field variables, an introduction of the gauge field topology requires the assumption that lattice field configurations are sufficiently smooth. This assumption is referred to as the admissibility condition. However, the admissibility condition always ensures the Bianchi identity, and thus prohibits the existence of magnetic objects such as the ’t Hooft line. Recently, in 2D compact scalar field theory, a method was proposed to define magnetic objects without violating the admissibility condition by introducing holes into the lattice. In this paper, we extend this “excision method” to 4D Maxwell theory and propose a new definition of the ’t Hooft line on the lattice. Using this definition, we first demonstrate a lattice counterpart of the Witten effect which endows the ’t Hooft line with electric charge and makes it a dyon. Furthermore, we show that by interpreting the ’t Hooft line as a boundary of the lattice system, the statistics of the dyon can be directly read off. We also explain how the dyonic operator which satisfies the Dirac quantization condition becomes a genuine loop operator even at finite lattice spacings.

Soma Onoda

’t Hooft Line in 4D <italic>U</italic>&#160;(1) Lattice Gauge Theory and a Microscopic Description of Dyon&#8217;s Statistics

We investigate the phase structure of a 2D lattice CP(1) model with a <inline-formula><tex-math id='TM0002' notation='LaTeX'>$\theta$</tex-math></inline-formula> term. In particular, we aim to identify a critical region expected to exist along a <inline-formula><tex-math id='TM0003' notation='LaTeX'>$\theta =\pi$</tex-math></inline-formula> line. To explore the phase structure nonperturbatively and avoid the sign problem, we employ the tensor renormalization group method. We make two improvements compared to previous tensor network studies. The first improvement involves refining the initial tensor. Specifically, we construct it using a quadrature method, which achieves higher accuracy compared to the conventional approach. The second improvement consists of analyzing the phase structure using the information on the conformal field theory, namely the central charge and the scaling dimensions, which can be accessed relatively easily via the tensor renormalization group method. Thanks to these improvements, we identify both the onset of the critical region, <inline-formula><tex-math id='TM0004' notation='LaTeX'>$\beta _{\rm c}=0.5952(8)$</tex-math></inline-formula>, and its universality class as the SU(2) <inline-formula><tex-math id='TM0005' notation='LaTeX'>${}_{k=1}$</tex-math></inline-formula> Wess&#8211;Zumino&#8211;Witten model.

Hayato Aizawa

Shinji Takeda

Yusuke Yoshimura

Phase Structure Analysis of a 2D Lattice CP(1) Model with a <italic>&#952;</italic> Term using the Tensor Renormalization Group Method

We study a 6D U(1) <inline-formula><tex-math id='TM0001' notation='LaTeX'>$_\chi$</tex-math></inline-formula> gauge theory compactified on a magnetized torus, where the zero mode of the extra-dimensional gauge field (a Wilson-line scalar field) plays the role of a pseudo-Nambu&#8211;Goldstone (pNG) dark matter (DM) candidate. The pNG DM is naturally included by construction without introducing an additional scalar field. We show that the leading spin-independent DM-nucleus amplitude is suppressed by momentum transfer in our model, as expected from the pNG DM model. This suppression allows the model to evade the current severe direct detection bounds while achieving the observed thermal relic abundance in well-defined regions of parameter space.

Kento Akamatsu

Takuya Hirose

Nobuhito Maru

Akio Nago

Pseudo-Nambu–Goldstone Dark Matter in Flux Compactification

We consider quantum electrodynamics with chiral four-Fermi interactions in the functional renormalization group approach. In gauge theories, the functional flow equation for the effective action is accompanied by the quantum master equation that governs the underlying gauge symmetry. Beyond perturbation theory, fully gauge-consistent solutions are very difficult to obtain. In the present work, by including the lowest-order correction to the photon two-point function, we construct a RG-improved one-loop formula that gives rise to dressed nonperturbative photon propagators in the flow equation as well as the quantum master equation. We show that the one-particle irreducible effective action with the new formula satisfies both equations within our truncations. We also discuss the phase structure in terms of the gauge and four-Fermi couplings based on a numerical solution of the system.

Yoshio Echigo

Yuji Igarashi

Katsumi Itoh

Germany

Jan M Pawlowski

Yu Takahashi

Functional Renormalization Group Flows and Gauge Consistency in Quantum Electrodynamics

We explore spacetimes with multiple energy injections in asymptotically flat two-dimensional black hole and analyze the entanglement entropy in such spacetimes. This work is an extension of the setup of the single-injection case, by F. F. Gautason, L. Schneiderbauer, W. Sybesma and L. Thorlacius, to include multiple energy injections. We derive a solution of the model, by J. G. Russo, L. Susskind and L. Thorlacius, for a general number <italic>n</italic> of total injections, and discuss the entropy only for the case <inline-formula><tex-math id='TM0002' notation='LaTeX'>$n=2$</tex-math></inline-formula>. The essential point of this work is in the delay of the island. This delay makes the intermediate state necessary, where the island&#8217;s endpoint lies between the 1st and the 2nd injections while the observer is located after the 2nd injection. The intermediate state makes the entanglement entropy evolve continuously across the 2nd injection time.

Yuuta Saito

Page curves and island's delays in asymptotically flat 2d spacetimes with injections

In field theory, one can consider a variety of states. Within the framework of factorization algebras, one typically works with the natural augmentation state <inline-formula><tex-math id='TM0001' notation='LaTeX'>$\langle -\rangle _{\rm aug}$</tex-math></inline-formula>. In physics, however, other states arise naturally, such as the compactification state <inline-formula><tex-math id='TM0002' notation='LaTeX'>$\langle -\rangle _{\rm cptf}$</tex-math></inline-formula> or the Schwartz state <inline-formula><tex-math id='TM0003' notation='LaTeX'>$\langle -\rangle _{\rm Sch}$</tex-math></inline-formula>, defined by imposing Schwartz boundary conditions. At first sight, the relation among these three states is not obvious. This paper gives a definition of the compactification state in factorization algebras and provides a method for handling infrared divergences in the massless theory. We then prove that the three states are equivalent in both the massive and massless cases.

Masashi Kawahira

Tomohiro Shigemura

States and IR Divergences in Factorization Algebras

The Left-Right Symmetric Model (LRSM) in this work is extended with a sterile fermion per generation, the lightest of which is considered to be a suitable dark matter candidate for the study and analysis of its associated properties. The model has been realized using <inline-formula><tex-math id='TM0003' notation='LaTeX'>$A_{4}$</tex-math></inline-formula> modular symmetry, the advantage being the nonrequirement of the use of extra fields, hence keeping the model minimal. Because of the extension of the LRSM with the sterile fermion, the neutrino mass in this work will be generated by the double seesaw mechanism as described thoroughly within the paper. And for phenomenological studies, we have considered neutrinoless double beta decay, the details of which have been discussed thoroughly within the work.