A classification of soft supersymmetry breaking deformation of general four dimensional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> superconformal field theory (SCFT) is provided. Given the large class of newly discovered <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> SCFTs and their known properties such as the central charges and full information of BPS operators, it is possible to get a huge number of new <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>1</mn></math> SCFTs and nonsupersymmetric CFTs. Many properties of these new <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>1</mn></math> SCFTs such as central charges, chiral spectrum and a duality can be derived from known information of parent <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> SCFT.

China

Dan Xie

Soft supersymmetry breaking of 4D <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> SCFT

We study the possibility of light Dirac neutrino portal dark matter (DM) in an effective field theory setup. Dirac nature of light neutrino automatically includes its right chiral part <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>R</mi></msub></math> which, in our setup, also acts like a portal between DM and the standard model (SM) particles. Considering a Dirac fermion singlet DM stabilized by an unbroken <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>2</mn></msub></math> symmetry, we write down all possible dimension-6 effective operators involving DM-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>R</mi></msub></math> as well as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>R</mi></msub></math>-SM which conserve <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>2</mn></msub></math>, global lepton number and SM gauge symmetries. DM thermalization also ensures the thermalization of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>R</mi></msub></math>, leading to enhanced effective relativistic degrees of freedom <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>eff</mi></msub></math>, within reach of future cosmic microwave background (CMB) experiments. We study the complementarity among DM and CMB related observations for different Lorentz structures of effective operators. We also propose a UV complete gauged B-L symmetric model with Dirac neutrino portal dark matter.

India

United States

Debasish Borah

South Korea

Satyabrata Mahapatra

Japan

Dibyendu Nanda

Sujit Kumar Sahoo

Narendra Sahu

Effective theory of light Dirac neutrino portal dark matter with observable <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><msub><mi>N</mi><mrow><mi>eff</mi></mrow></msub></math>

We investigate the transition between weak and strong coupling in thermal <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> supersymmetric Yang-Mills theory as a function of ’t Hooft coupling <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi></math> for several quantities of phenomenological interest for which next-to-leading order calculations are available in both regimes. We use Padé approximants to interpolate between the weak and strong coupling expansions and determine the location and width of the transition between the asymptotic regimes.

Berndt Müller

Transition from weak to strong coupling in thermal gauge theories: Lessons from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> SYM theory

Spain

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 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.

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>.

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>

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.

Sergio Aguilar-Gutierrez

Yichao Fu

Kuntal Pal

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