We investigate the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ϕ</mi><mrow><mn>2</mn><mi>n</mi></mrow></msup></math> deformations of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">O</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math>-symmetric (generalized) free theories with a flat boundary, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi><mo>≥</mo><mn>2</mn></math> is an integer. The generalized free theories refer to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mo>□</mo><mi>k</mi></msup></math> free scalar theories with a higher derivative kinetic term, which is related to the multicritical generalizations of the Lifshitz type. We assume that the (generalized) free theories and the deformed theories have boundary conformal symmetry and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">O</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math> global symmetry. The leading anomalous dimensions of some boundary operators are derived from the bulk multiplet recombination and analyticity constraints. We find that the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ε</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math> expansion in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ϕ</mi><mn>6</mn></msup></math>-tricritical version of the special transition extends to other multicritical cases with larger odd integer <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi></math>, and most of the higher derivative cases involve a noninteger power expansion in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ε</mi></math>. Using the analytic bootstrap, we further verify that the multiplet-recombination results are consistent with boundary crossing symmetry.

China

Yongwei Guo

Wenliang Li

Boundary anomalous dimensions from BCFT: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">O</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math>-symmetric <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ϕ</mi><mrow><mn>2</mn><mi>n</mi></mrow></msup></math> theories with a boundary and higher-derivative generalizations

We investigate the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>O</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></math>-symmetric <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ϕ</mi><mn>6</mn></msup></math> theory in three spacetime dimensions using dimensional regularization and minimal subtraction. The predictions of other methods are scrutinized in a large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> expansion. We show how the tricritical line of fixed point emerges in a strict <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">→</mo><mi>∞</mi></math> limit but argue that it is not a physical manifestation. For the first time in this explicit manner, we compute the effective potential at next-to-leading order in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>/</mo><mi>N</mi></math>-expansion and discuss its stability. The Bardeen-Moshe-Bander phenomenon is also analysed at next-to-leading order, and we demonstrate that it disappears without breaking the scale invariance spontaneously. Our findings indicate that the UV fixed point found by Pisarski persists at large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math>.

Spain

Sandra Kvedaraitė

Germany

Tom Steudtner

Max Uetrecht

Revisiting the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ϕ</mi><mn>6</mn></msup></math> theory in three dimensions at large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math>

Daniel Castillo

Canada

Lotta Jokiniemi

Pablo Soriano

Javier Menéndez

Corrigendum to “Neutrinoless ββ decay nuclear matrix elements complete up to N 2LO in heavy nuclei&#8221; [Physics Letters B 860 (2025) 139181]

We study SU($\textit{N}$) spin systems that mimic the behavior of particles in $\textit{N}$-dimensional de Sitter space for $\textit{N}$ = 2, 3. Their Hamiltonians describe a dynamical system with hyperbolic fixed points, leading to emergent quasinormal modes at the quantum level. These manifest as quasiparticle peaks in the density of states. For a particle in 2-dimensional de Sitter, we find both principal and complementary series densities of states from a PT-symmetric version of the Lipkin-Meshkov-Glick model, having two hyperbolic fixed points in the classical phase space. We then study different spectral and dynamical properties of this class of models, including level spacing statistics, two-point functions, squared commutators, spectral form factor, Krylov operator and state complexity. We find that, even though the early-time properties of these quantities are governed by the saddle points — thereby in some cases mimicking corresponding properties of chaotic systems, a close look at the late-time behavior reveals the integrable nature of the system.

Japan

Sergio Aguilar-Gutierrez

South Korea

Yichao Fu

Kuntal Pal

United States

Klaas Parmentier

Quasinormal modes and complexity in saddle-dominated SU($\textit{N}$) spin systems

In arXiv:2306.17553 a new supersymmetric integrable QFT was constructed from the relativistic limit of the worldsheet theory of AdS × S ×T superstrings with mixed Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz flux. The model is closely reminiscent of one previously considered by Fendley and Intriligator, though it enjoys twice as many supersymmetries. In this paper we study its finite-volume and finite-temperature properties. We formulate the string hypothesis for the Bethe-Yang equations, write down the thermodynamic Bethe ansatz equations, and simplify them in the form of a Y-system. We obtain three decoupled sectors associated with massive, massless-chiral and massless-antichiral particles, for which we compute the UV central charge. We illustrate the similarities and differences between this model and the one of Fendley and Intriligator.

Xavier Kervyn

Italy

Davide Polvara

Alessandro Sfondrini

Thermodynamics of integrable $$ \mathcal{N} $$ = 2 theories, squared

By extending the six-dimensional hybrid formalism for the superstring to include $\textit{d}$ = 6 $$ \mathcal{N} $$ = 1 superspace variables along with unconstrained bosonic ghost fields, we construct a manifestly spacetime supersymmetric vertex operator $\textit{U}$. We demonstrate that the BRST invariance of $\textit{U}$ implies the $\textit{d}$ = 6 $$ \mathcal{N} $$ = 1 SYM equations of motion in superspace. Furthermore, we show that spacetime supersymmetric scattering amplitudes can be computed in a manner analogous to that of the non-minimal pure spinor formalism.

Brazil

Cassiano Daniel

Vertex operators for the superstring with manifest $\textit{d}$ = 6 $$ \mathcal{N} $$ = 1 supersymmetry

We study large $\textit{N}$ phase transitions in $$ \mathcal{N} $$ = 2 theories with gauge group SU($\textit{N}$) and massive hypermultiplets in diverse representations. Using supersymmetric localization we identify cases where phase transitions occur. In particular, we consider deformations of UV superconformal fixed points by giving two different masses to the fundamental hypermultiplets, and show that these theories undergo a third-order phase transition at a critical value of the ’t Hooft coupling. This provides the first example of a phase transition driven by a mass deformation of a $$ \mathcal{N} $$ = 2 superconformal field theory. We also comment on integrated correlators in these theories.

Argentina

Jeremías Aguilera-Damia

Jorge Russo

More on phase transitions in $$ \mathcal{N} $$ = 2 massive gauge theories

Using the Riemann-Hilbert method, the paper systematically investigates the <italic>n</italic>-component generalized Sasa-Satsuma system. By utilizing the Tu scheme, we systematically construct the <italic>n</italic>-component generalized Sasa-Satsuma integrable hierarchy, and obtain the Lax pair of the <italic>n</italic>-component generalized Sasa-Satsuma system. Then we give the spectral analysis of the Lax pair, from which a Riemann-Hilbert problem is formulated. Moreover, by solving the particular Riemann-Hilbert problem with vanishing scattering coefficients, <italic>N</italic>-soliton solutions are obtained for the <italic>n</italic>-component generalized Sasa-Satsuma system. Furthermore, for <math altimg='si1.svg'><mi>n</mi><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>3</mn></math>, we graphically present the structures of the single-soliton and double-soliton solutions by selecting appropriate parameters.

Zhiguo Ren

Jing Yu

Lin Huang

The N-soliton solutions of the <italic>n</italic>-component generalized Sasa-Satsuma system: Riemann-Hilbert method

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mrow><mi>JSNS</mi></mrow><mn>2</mn></msup></math> (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment searching for sterile neutrinos through the observation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>μ</mi></msub><mo stretchy="false">→</mo><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> appearance oscillations, using neutrinos produced by muon decay-at-rest. A key aspect of the experiment involves accurately understanding the neutrino flux and the quantities of pions and muons, which are progenitors of (anti)neutrinos, given that their production rates have yet to be measured. We present the first electron-neutrino flux measurement using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">C</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>12</mn></mrow></mmultiscripts><mo stretchy="false">(</mo><msub><mrow><mi>ν</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo stretchy="false">)</mo></mrow><mrow><mn>12</mn></mrow></msup><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mi mathvariant="normal">g</mi><mo>.</mo><mi mathvariant="normal">s</mi><mo>.</mo></mrow></msub></mrow></math> reaction in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>, yielding a flux of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>6.7</mn><mo>±</mo><mn>1.6</mn><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo><mo>±</mo><mn>1.7</mn><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>9</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><mtext> </mtext><msup><mrow><mi>proton</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> at the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> detector location, located at 24 meters distance from the mercury target. This flux measurement is consistent with predictions from simulations based on hadron models.

T. Dodo

M.K. Cheoun

J.H. Choi

J.Y. Choi

J. Goh

K. Haga

M. Harada

S. Hasegawa

W. Hwang

H.I. Jang

J.S. Jang

K.K. Joo

D.E. Jung

S.K. Kang

Y. Kasugai

T. Kawasaki

E.M. Kim

E.J. Kim

S.Y. Kim

S.B. Kim

H. Kinoshita

T. Konno

D.H. Lee

C. Little

T. Maruyama

E. Marzec

S. Masuda

S. Meigo

D.H. Moon

T. Nakano

M. Niiyama

K. Nishikawa

M.Y. Pac

B.J. Park

H.W. Park

J.B. Park

J.S. Park

R.G. Park

United Kingdom

S.J.M. Peeters

J.W. Ryu

K. Sakai

S. Sakamoto

T. Shima

C.D. Shin

J. Spitz

F. Suekane

Y. Sugaya

K. Suzuya

Y. Yamaguchi

I.S. Yeo

I. Yu

First <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> measurement of the electron neutrino flux using the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mmultiscripts><mrow><mi mathvariant="normal">C</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>12</mn></mrow></mmultiscripts></mrow><mo stretchy="false">(</mo><msub><mrow><mi>ν</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo><mmultiscripts><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mi mathvariant="normal">g</mi><mo>.</mo><mi mathvariant="normal">s</mi><mo>.</mo></mrow></msub></mrow><mprescripts></mprescripts><none></none><mrow><mn>12</mn></mrow></mmultiscripts></mrow></math> reaction

In this work, we revisit the exact computation of the round sphere partition function of 3d <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> circular quiver Chern-Simons theories with mass and Fayet-Iliopoulos (FI) deformations. Utilizing the Fermi gas formalism, we derive the large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> expansion of the partition function and determine the Airy function structure, parametrized by three functions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>A</mi></math>. We propose a novel closed-form expression for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>A</mi></math> that incorporates the effects of FI parameters and satisfies various consistency constraints from quiver reductions. As an application, by using an accidental coincidence of the Fermi gas density matrices we extend our results to the squashed sphere partition function of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> super Yang-Mills theories with an adjoint hypermultiplet and multiple fundamental hypermultiplets. Our findings provide further evidence for the universality of the Airy function structure in supersymmetric gauge theories of multiple M2-branes.

Naotaka Kubo

Tomoki Nosaka

Yi Pang

Exact large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> expansion of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> circular quiver Chern-Simons theories