Electroweak (EW) amplitudes in the gauge-Goldstone five-component formalism have a distinctive property: gauge symmetry is imprinted in the amplitudes, manifested as the massive Ward identity (MWI) $ k^M{\cal{M}}_M=0 $ . In this study, we used the HELAS package to numerically study gauge symmetry in EW amplitudes. First, we directly tested gauge symmetry by examining the MWI of amplitudes. Second, we modified the couplings within a vertex and among vertices to check if and how the MWI changes. Third, we tested gauge symmetry by considering the couplings modified by operators from the standard model effective field theory (SMEFT). Similar to the standard model, there are relations between different couplings that are protected by gauge symmetry. We observed that, if we modify the couplings to deviate from the relations, the MWI is violated. In contrast, the MWI is restored when the relations between couplings reduce to those in the SMEFT.

China

Wang-Fa Li

Junmou Chen

Qian-Jiu Wang

Zhao-Huan Yu

Numerical study on the gauge symmetry of electroweak amplitudes * Junmou Chen is supported by National Natural Science Foundation of China (12205118), Wang-Fa Li, Qian-Jiu Wang, and Zhao-Huan Yu are supported by the Guangzhou Science and Technology Planning Project (2024A04J4026)

Large-scale organic liquid scintillator detectors are highly efficient in the detection of MeV-scale electron antineutrinos. These signal events can be detected through inverse beta decay on protons, which produce a positron accompanied by a neutron. A noteworthy background for antineutrinos coming from nuclear power reactors and from the depths of the Earth (geoneutrinos) is generated by ( $$\alpha ,\,n$$ ) reactions. In organic liquid scintillator detectors, $$\alpha $$ particles emitted from intrinsic contaminants such as $$^{238}$$ U, $$^{232}$$ Th, and $$^{210}$$ Pb/ $$^{210}$$ Po, can be captured on $$^{13}$$ C nuclei, followed by the emission of a MeV-scale neutron. Three distinct interaction mechanisms can produce prompt energy depositions preceding the delayed neutron capture, leading to a pair of events correlated in space and time within the detector. Thus, ( $$\alpha ,\,n$$ ) reactions represent an indistinguishable background in liquid scintillator-based antineutrino detectors, where their expected rate and energy spectrum are typically evaluated via Monte Carlo simulations. This work presents results from the open-source SaG4n software, used to calculate the expected energy depositions from the neutron and any associated de-excitation products. Also simulated is a detailed detector response to these interactions, using a dedicated Geant4-based simulation software from the JUNO experiment. An expected measurable $$^{13}$$ C $$(\alpha ,\,n)^{16}$$ O event rate and reconstructed prompt energy spectrum with associated uncertainties, are presented in the context of JUNO, however, the methods and results are applicable and relevant to other organic liquid scintillator neutrino detectors.

France

Thomas Adam

Germany

Kai Adamowicz

Pakistan

Shakeel Ahmad

Rizwan Ahmed

Italy

Sebastiano Aiello

Fengpeng An

United Kingdom

Costas Andreopoulos

Giuseppe Andronico

Russia

Nikolay Anfimov

Vito Antonelli

Tatiana Antoshkina

João Athayde Marcondes de André

Didier Auguste

Weidong Bai

Nikita Balashov

Andrea Barresi

Davide Basilico

Eric Baussan

Marco Beretta

Antonio Bergnoli

Nikita Bessonov

Daniel Bick

Lukas Bieger

Svetlana Biktemerova

Thilo Birkenfeld

Simon Blyth

Anastasia Bolshakova

Mathieu Bongrand

Matteo Borghesi

Dominique Breton

Augusto Brigatti

Riccardo Brugnera

Riccardo Bruno

Marcel Büchner

Antonio Budano

Jose Busto

Anatael Cabrera

Barbara Caccianiga

Hao Cai

Xiao Cai

Yanke Cai

Zhiyan Cai

Stéphane Callier

Steven Calvez

United Arab Emirates

Antonio Cammi

Chuanya Cao

Guofu Cao

Jun Cao

Yaoqi Cao

Rossella Caruso

Cédric Cerna

Vanessa Cerrone

Jinfan Chang

Taiwan

Yun Chang

Thailand

Auttakit Chatrabhuti

Chao Chen

Guoming Chen

Jiahui Chen

Jian Chen

Jing Chen

Junyou Chen

Pingping Chen

Shaomin Chen

Shiqiang Chen

Xin Chen

Yiming Chen

Yixue Chen

Yu Chen

Ze Chen

Zhangming Chen

Zhiyuan Chen

Jie Cheng

Yaping Cheng

Yu Cheng

Alexander Chepurnov

Alexey Chetverikov

Davide Chiesa

Brazil

Pietro Chimenti

Po-Lin Chou

Ziliang Chu

Artem Chukanov

Gérard Claverie

Catia Clementi

Belgium

Barbara Clerbaux

Claudio Coletta

Selma Conforti Di Lorenzo

Simon Csakli

Chenyang Cui

United States

Olivia Dalager

Christophe Taille

Zhi Deng

Ziyan Deng

Xiaoyu Ding

Xuefeng Ding

Yayun Ding

Bayu Dirgantara

Carsten Dittrich

Sergey Dmitrievsky

David Doerflinger

Dmitry Dolzhikov

Simulation of the background from $$^{13}$$ C $$(\alpha ,\,n)^{16}$$ O reaction in the JUNO scintillator

We study the fortuity phenomenon in supersymmetric Sachdev-Ye-Kitaev (SYK) models. For generic choices of couplings, all the BPS states in the $$ \mathcal{N} $$ = 2 SUSY SYK model are fortuitous. The SYK models reveal an intimate connection between fortuity and the Schwarzian description of supersymmetric black holes, reflected in a sharp feature of $\textit{R}$-charge concentration — microscopically, all the fortuitous states are concentrated in particular charge sectors. We propose that both $\textit{R}$-charge concentration and the random matrix behavior near the BPS states are key properties of a generic $\textit{q}$-local supercharge and formulate these as a supercharge chaos conjecture. We expect supercharge chaos to hold universally for supercharges in holographic CFTs near their fortuitous states, potentially providing a microscopic interpretation for the charge constraints of supersymmetric black holes.

Chi-Ming Chang

Bik Sia

Zhenbin Yang

Fortuity in SYK models

We explore the decay of bound neutrons in the JUNO liquid scintillator detector into invisible particles (e.g., $$n\rightarrow 3 \nu $$ or $$nn \rightarrow 2 \nu $$ ), which do not produce an observable signal. The invisible decay includes two decay modes: $$ n \rightarrow { inv} $$ and $$ nn \rightarrow { inv} $$ . The invisible decays of -shell neutrons in $$^{12}\textrm{C}$$ will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino $${\bar{\nu }}_e$$ , natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are $$\tau /B( n \rightarrow { inv} ) > 5.0 \times 10^{31} \, \textrm{years}$$ and $$\tau /B( nn \rightarrow { inv} ) > 1.4 \times 10^{32} \, \textrm{years}$$ .

Chile

Angel Abusleme

Qi An

João André

Wander Baldini

Marco Bellato

Iwan Blake

Agustin Campeny

Zelin Chen

Zikang Chen

Yen-Ting Chin

Marta Molla

Selma Lorenzo

Alberto Coppi

Daniele Corti

Flavio Corso

Jaydeep Datta

JUNO sensitivity to invisible decay modes of neutrons

This paper presents an energy resolution study of the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of the liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The results of this study reveal an energy resolution of 2.95% at 1 MeV. Furthermore, this study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection. Moreover, it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.

JINR

João Pedro Athayde Marcondes de André

David Blum

Clément Bordereau

YuChin Cheng

Marta Colomer Molla

Flavio Dal Corso

Christophe De La Taille

Prediction of energy resolution in the JUNO experiment  

The fundamental heterotic string has a tower of BPS states whose supersymmetric index has an exponential growth in the charges. We construct the saddle-point of the gravitational path integral corresponding to this index. The saddle-point configuration is a supersymmetric rotating non-extremal Euclidean black hole. This configuration is singular in the two-derivative theory. We show that the addition of higher-derivative terms in four-dimensional   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 2 supergravity resolves the singularity. In doing so, we extend the recently-developed “new attractor mechanism” to include the effect of higher-derivative terms. Remarkably, the one-loop, four-derivative F-term contribution to the prepotential leads to a precise match of the gravitational and microscopic index. We also comment, using the effective theory near the horizon, on the possibility of a string-size near-extremal black hole. Our results clarify the meaning of different descriptions of this system in the literature. The thermal state transitions to a winding condensate and a gas of strings without ever reaching a small black hole, while the index is captured by the rotating Euclidean black hole solution and is constant and thus smoothly connected to the microscopic ensemble.

Sameer Murthy

Gustavo Turiaci

Gravitational index of the heterotic string

The gravitational path integral can be used to compute the number of black hole states for a given energy window, or the free energy in a thermal ensemble. In this article we explain how to use the gravitational path integral to compute the separate number of bosonic and fermionic black hole microstates. We do this by comparing the partition function with and without the insertion of (−1)F. In particular we introduce a universal rotating black hole that contributes to the partition function in the presence of (−1)F. We study this problem for black holes in asymptotically flat space and in AdS, putting constraints on the high energy spectrum of holographic CFTs (not necessarily supersymmetric). Finally, we analyze wormhole contributions to related quantities.

Spin-statistics for black hole microstates

In this paper we revisit the double cone wormhole introduced by Saad, Shenker and Stanford (SSS), which was shown to reproduce the ramp in the spectral form factor. As a first approximation we can say that this solution computes Tr[e  −iKT ], a trace of the “evolution” operator that generates Schwarzschild time translations on the two sided wormhole geometry. This point of view leads to a simple way to compute the normalization factor of the wormhole. When we have bulk matter fields, SSS suggested using a modified evolution  $$\widetilde{K}$$  which involves a slightly complex geometry, so that we are really computing  $${\text{Tr}}\left[{e}^{-i\widetilde{K}T}\right]$$ . We argue that, for general black holes, the spectrum of  $$\widetilde{K}$$  is given by quasinormal mode frequencies. We explain that this reproduces various features that were previously predicted from the spectral form factor on hydrodynamics grounds. We also give a general algebraic construction of the modified boost in terms of operators constructed from half sided modular inclusions. For the special case of JT gravity, we work out the backreaction of matter on the geometry of the double cone and find that it deforms the geometry in an undesirable direction. We finally give some comments on the possible physical interpretation of  $$\widetilde{K}$$ .

Victor Ivo

Juan Maldacena

Comments on the double cone wormhole

It has long been conjectured that the large $\textit{N}$ deconfinement phase transition of $$ \mathcal{N} $$ = 4 SU($\textit{N}$) super-Yang-Mills corresponds via AdS/CFT to the Hawking-Page transition in which black holes dominate the thermal ensemble, and quantitative evidence of this has come through the recent matching of the superconformal index of $$ \frac{1}{16} $$ -BPS states to the supersymmetric black hole entropy. We introduce the half-BPS Gukov-Witten surface defect as a probe of the superconformal index, which also serves as an order parameter for the deconfinement transition. This can be studied directly in field theory as a modification of the usual unitary matrix model or in the dual description as a D3-brane probe in the background of a (complex) supersymmetric black hole. Using a saddle point approximation, we determine our defect index in the large $\textit{N}$ limit as a simple function of the chemical potentials and show independently that it is reproduced by the renormalized action of the brane in the black hole background. Along the way, we also comment on the Cardy limit and the thermodynamics of the D3-brane in the generalized ensemble. The defect index sharply distinguishes between the confining and the deconfining phases of the gauge theory and thus is a supersymmetric non-perturbative order parameter for these large $\textit{N}$ phase transitions which deserves further investigation. Finally, our work provides an example where the properties of a black hole coupled to an external system can be analyzed precisely.

Matthew Heydeman

Yifan Wang

Mengyang Zhang

Probing supersymmetric black holes with surface defects

We consider the scattering of high energy and ultra relativistic spherically symmetric shells in asymptotically AdS D  spacetimes. We analyze an exclusive amplitude where a single spherically symmetric shell goes in and a single one comes out, such that the two have different global symmetry charges of the effective gravity theory. We study a simple wormhole configuration that computes the square of the amplitude and analyze its properties.

Ibrahima Bah

Estimating global charge violating amplitudes from wormholes