We extend the notion of chord number in the strict large $\textit{N}$ double-scaled Sachdev-Ye-Kitaev (DSSYK) model to the corresponding finite $\textit{N}$ ETH matrix model. The chord number in the strict large $\textit{N}$ DSSYK model is known to correspond to the discrete length of the Einstein-Rosen bridge in the gravity dual, which reduces to the renormalized geodesic length in JT gravity at weak coupling. At finite $\textit{N}$, these chord number states form an over-complete basis of the non-perturbative Hilbert space, as the structure of the inner product gets significantly modified due to the Cayley-Hamilton theorem: There are infinitely many null states. In this paper, by considering “EFT for gravitational observables” or a version of “non-isometric code”, we construct a family of chord number operators at finite $\textit{N}$. While the constructed chord number operator depends on the reference chord number state, it realizes approximate $\textit{q}$-deformed oscillator algebra and reproduces semiclassical bulk geometry around the reference state. As a special case, we will show that when the reference is chosen to be the chord number zero state, the chord number operator precisely matches with the Krylov state complexity, leading to the “ramp-slope-plateau” behavior at late times, implying the formation of “gray hole”.

Japan

Masamichi Miyaji

Soichiro Mori

Kazumi Okuyama

Finite $\textit{N}$ bulk Hilbert space in ETH matrix model for double-scaled SYK. Null states, state-dependence and Krylov state complexity

We consider toroidal asymmetric orbifolds of the heterotic string preserving all 16 supercharges, developing a general formalism to study components of the moduli space characterized by rank reduction of the gauge group. In particular we construct six- and four-dimensional heterotic islands with no massless moduli other than the dilaton. The formalism involves the Leech lattice, its automorphisms and their corresponding invariant and normal, or coinvariant, sublattices.

Argentina

Gerardo Aldazabal

Eduardo Andrés

Venezuela

Germany

Anamaría Font

Italy

Kumar Narain

United Kingdom

Ida Zadeh

Asymmetric orbifolds, rank reduction and heterotic islands

In this work, we propose to investigate the information behavior of quantum systems through accelerated detectors quadratically coupled with a massless scalar field. In addition, we made detailed comparisons with the case of linear coupling. The perturbative method was used to evolve the density matrix that describes the interaction of the detector-field system during a finite time. The systems studied were: accelerated single-qubit, quantum interferometric circuit, and the which-path distinguishability circuit. The results on the probability transition rates show that quadratic coupling amplifies the Unruh effect. This is due to the modification of the interaction structure, allowing the simultaneous absorption of multiple quanta. Our findings showed that the information is degraded more quickly in the case of quadratic coupling, when compared to the linear case. Furthermore, this change is mainly given by the coupling constant and by an additional factor that arises in the case of quadratic coupling. Therefore, these results indicate that the nature of the coupling between the detector and the field plays a fundamental role in the behavior of quantum information in high acceleration regimes.

Brazil

P. Barros

P. Carvalho

H. Costa

On the information behavior from quadratically coupled accelerated detectors

Recent observations of the supermassive black holes $$ M87^{*} $$ and Sgr $$\hbox {A}^{*}$$ by the Event Horizon Telescope (EHT) have sparked intensified interest in studying the optical appearance of black holes (BHs). Inspired by this, we carry out a study on the optical features of Einstein–Euler–Heisenberg-Anti de Sitter/de Sitter (EEH-AdS/dS) BHs, including the trajectories of photons, shadow geometrical shape, energy emission rate, and deflection of light in this spacetime. Since, due to the nonlinear electrodynamics effects, photons propagate along null geodesics in an effective metric rather than the background metric, we first derive the effective metric of the EEH-AdS/dS BH. Then we study the null geodesics of the resulting effective metric and eventually compute the size of the EEH-AdS/dS BH shadow. To validate our results, we confront our results with the extracted information from EHT data of the supermassive BHs $$ M87^{*} $$ and estimate lower bounds for the shadow radius.

Iran

Khadije Jafarzade

Zeynab Bazyar

Sara Saghafi

Kourosh Nozari

Optical signatures of Einstein–Euler–Heisenberg AdS/dS black holes in the light of event horizon telescope

We present a method for obtaining an initial-state parton shower model where the (backward) evolution fully consistent with the (forward) evolution of the collinear parton density used. As a proof-of-concept we use parton densities obtained with the parton branching (PB) approach, and modify the default initial-state shower in 8 with this method to be consistent with them. PB is ideally suited for checking the validity of our method since, in addition to producing collinear parton densities, it also produces the corresponding transverse-dependent (TMD) ones, and these can then be directly compared to the transverse momentum distribution obtained from the parton shower. We show that TMD distributions which we in this way obtain from our modified 8 shower using leading order (LO) parton densities and splitting functions are fully consistent with the corresponding leading order TMD densities. At next-to-leading order (NLO) it is not possible to achieve the same consistency using the built-in LO splitting functions in the shower, but we show that by introducing NLO splitting functions using a reweighting procedure, we can achieve consistency also at NLO. The method presented here, which we have named , can be easily extended to any collinear parton densities, as long as the exact conditions for the evolution are known. With the method we obtain an initial-state parton shower which in principle has no free parameters, and is fully consistent with collinear parton densities at LO and NLO.

H. Jung

Sweden

L. Lönnblad

M. Mendizabal

Sara Taheri Monfared

A parton shower consistent with parton densities at LO and NLO:

All charmless <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math> denotes the light pseudoscalar meson and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi></math> denotes the vector meson) decays have not been experimentally observed to date, but some of them might be measured in the near future. The charmless <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> decays with the axial-vector (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>A</mi></math>) resonance states, the tensor (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math>) resonance states, and the excited vector (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>V</mi><mrow><mi>E</mi><mo>,</mo><mi>D</mi></mrow></msub></math>) resonance states are studied based on flavor SU(3) analysis in this work, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>V</mi><mi>E</mi></msub></math> contains <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">{</mo><mi>ρ</mi><mo stretchy="false">(</mo><mn>1450</mn><mo stretchy="false">)</mo><mo>,</mo><msup><mi>K</mi><mo>*</mo></msup><mo stretchy="false">(</mo><mn>1410</mn><mo stretchy="false">)</mo><mo>,</mo><mi>ω</mi><mo stretchy="false">(</mo><mn>1420</mn><mo stretchy="false">)</mo><mo>,</mo><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1680</mn><mo stretchy="false">)</mo><mo stretchy="false">}</mo></math> with quantum numbers <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>n</mi><mrow><mn>2</mn><mi>S</mi><mo>+</mo><mn>1</mn></mrow></msup><msub><mi>L</mi><mi>J</mi></msub><mo>=</mo><msup><mn>2</mn><mn>3</mn></msup><msub><mi>S</mi><mn>1</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>V</mi><mi>D</mi></msub></math> contains <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">{</mo><mi>ρ</mi><mo stretchy="false">(</mo><mn>1700</mn><mo stretchy="false">)</mo><mo>,</mo><msup><mi>K</mi><mo>*</mo></msup><mo stretchy="false">(</mo><mn>1680</mn><mo stretchy="false">)</mo><mo>,</mo><mi>ω</mi><mo stretchy="false">(</mo><mn>1650</mn><mo stretchy="false">)</mo><mo>,</mo><mi>ϕ</mi><mo stretchy="false">(</mo><mn>2170</mn><mo stretchy="false">)</mo><mo stretchy="false">}</mo></math> with quantum numbers <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>n</mi><mrow><mn>2</mn><mi>S</mi><mo>+</mo><mn>1</mn></mrow></msup><msub><mi>L</mi><mi>J</mi></msub><mo>=</mo><msup><mn>1</mn><mn>3</mn></msup><msub><mi>D</mi><mn>1</mn></msub></math>. The hadronic amplitudes of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi><mo>/</mo><mi>T</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> decays are related by the nonperturbative parameters, and the branching ratio predictions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi><mo>/</mo><mi>T</mi><mo>/</mo><msub><mi>V</mi><mrow><mi>E</mi><mo>,</mo><mi>D</mi></mrow></msub><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> are obtained, and then the branching ratios of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi><mo stretchy="false">(</mo><mi>A</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><mo stretchy="false">)</mo><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>T</mi><mo stretchy="false">(</mo><mi>T</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><mo stretchy="false">)</mo><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msub><mi>V</mi><mi>E</mi></msub><mo stretchy="false">(</mo><msub><mi>V</mi><mi>E</mi></msub><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><mo stretchy="false">)</mo><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msub><mi>V</mi><mi>D</mi></msub><mo stretchy="false">(</mo><msub><mi>V</mi><mi>D</mi></msub><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><mo stretchy="false">)</mo><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> are obtained by the narrow width approximation or further considering the width effects. We find that most branching ratios of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> decays and many branching ratios of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi><mo stretchy="false">(</mo><mi>A</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><mo stretchy="false">)</mo><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> decays are on the order of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup><mi>–</mi><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup><mo stretchy="false">)</mo></math>, and all branching ratios with the tensor resonance states and the excited vector resonance states are small. Our results could be tested in the future Belle II and LHCb experiments.

China

Yi Qiao

Jin-Huan Sheng

Yuan-Guo Xu

Ru-Min Wang

Flavor SU(3) analysis of the charmless semileptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> decays

The black hole information paradox has been an important problem in quantum gravity. In the study of evaporating black hole, it has been proposed that the holographic map between the semiclassical effective description in bulk and the fundamental description in boundary cannot be isometric. In this work, we would like to study the reflected entropy in an evaporating black hole model through a nonisometric holographic map. We assume that the evaporating is slow enough that it makes sense to ascribe a slowly varying temperature to the Hawking radiation. We then introduce a two-sided black hole model to canonically purify the semiclassical state. The holographic map to the fundamental description is nonisometric and defined by a Haar random unitary matrix. We show that the entropy of radiation in the model computed in the fundamental description matches the result read from the quantum extremal surface formula and agrees with the Page curve. Furthermore, through a nonisometric holographic map, we study the reflected entropies between different regions, including the one between the black holes on different sides, the one between the radiations distributed symmetrically but disconnectedly, and the one between the black hole and the radiation on a single side. Our results are consistent with the existing ones based on the effective descriptions.

Bin Chen

Zhi-jun Yin

Reflected entropy in an evaporating black hole through a nonisometric map

This work investigates the discovery potential for singly produced vectorlike quarks (VLQs) <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Q</mi><mo>=</mo><mo>+</mo><mn>2</mn><mo>/</mo><mn>3</mn><mi>e</mi></math>) and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Q</mi><mo>=</mo><mo>−</mo><mn>4</mn><mo>/</mo><mn>3</mn><mi>e</mi></math>) decaying to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi><mi>b</mi></math> at future <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi><mi>p</mi></math> colliders with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>5.29</mn></math>, 6.48, and 9.16 TeV, analyzing both leptonic and hadronic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math> decay channels through detailed detector simulations. The hadronic channel demonstrates superior sensitivity, enabling <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math> discovery up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>=</mo><mn>3750</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>Y</mi></msub><mo>=</mo><mn>4100</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>) at 9.16 TeV with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>100</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, while exclusion limits reach <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>=</mo><mn>4500</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>g</mi><mo>*</mo></msup><mo>≥</mo><mn>0.06</mn></math>) and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>Y</mi></msub><mo>=</mo><mn>4800</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>Y</mi></msub><mo>≥</mo><mn>0.04</mn></math>)—significantly beyond LHC capabilities. At 5.29 TeV, discovery regions cover <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>g</mi><mo>*</mo></msup><mo>∈</mo><mo stretchy="false">[</mo><mn>0.15</mn><mo>,</mo><mn>0.5</mn><mo stretchy="false">]</mo></math> for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>∈</mo><mo stretchy="false">[</mo><mn>1500</mn><mo>,</mo><mn>2520</mn><mo stretchy="false">]</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>Y</mi></msub><mo>∈</mo><mo stretchy="false">[</mo><mn>0.12</mn><mo>,</mo><mn>0.5</mn><mo stretchy="false">]</mo></math> for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>Y</mi></msub><mo>∈</mo><mo stretchy="false">[</mo><mn>1700</mn><mo>,</mo><mn>2700</mn><mo stretchy="false">]</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, with exclusions extending to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>T</mi></msub><mo>=</mo><mn>2750</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>Y</mi></msub><mo>=</mo><mn>3020</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. These results, obtained within a simplified two-parameter framework (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mrow><mi>T</mi><mo>/</mo><mi>Y</mi></mrow></msub></math> and electroweak couplings <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>g</mi><mo>*</mo></msup></math>), establish <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi><mi>p</mi></math> colliders as uniquely powerful tools for probing high-mass VLQ states, particularly in the boosted jet regime.

Jin-Zhong Han

Yao-Bei Liu

Stefano Moretti

Searching for single production of vectorlike quarks decaying into <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi><mi>b</mi></math> at a future muon-proton collider

Left-right symmetric models which employ a generalized seesaw mechanism to generate quark and charged lepton masses are known to solve the strong <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> problem via parity symmetry, without the need for the axion. These models lead to naturally light Dirac neutrinos with their masses arising through radiative corrections. In this work, we show how baryogenesis via Dirac leptogenesis can be implemented in this framework. A pair of left-right symmetric scalar doublets <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mrow><mi>L</mi><mo>,</mo><mi>R</mi></mrow></msub></math> carrying (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi><mo>−</mo><mi>L</mi></mrow></math>) charge of 3 is introduced for this purpose, which preserves the parity solution to the strong <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> problem. Small neutrino masses are generated through one-loop diagrams mediated by these scalars. The decay of vectorlike leptons (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>E</mi><mi>i</mi></msub></math>) involved in the seesaw mechanism to generate charged lepton masses, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>E</mi></mrow><mrow><mi>i</mi></mrow></msub><mo stretchy="false">→</mo><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mi>j</mi><mi>R</mi></mrow></msub><msubsup><mrow><mi>ϕ</mi></mrow><mrow><mi>R</mi></mrow><mrow><mo>−</mo></mrow></msubsup></mrow></math>, creates a right-handed neutrino (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>R</mi></msub></math>) asymmetry, while preserving total lepton number. The compensating lepton asymmetry is converted to baryon asymmetry via electroweak sphalerons. We show that for a large range of model parameters successful baryogenesis can be realized, with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>W</mi></mrow><mrow><mi>R</mi></mrow><mrow><mo>±</mo></mrow></msubsup></mrow></math> gauge boson mass of order <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mn>11</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>.

United States

K.S. Babu

Ajay Kaladharan

Dirac leptogenesis in left-right symmetric models

The IceCube Upgrade will provide unprecedented sensitivity to dark matter particles annihilating in the core of the Sun. For dark matter candidates with spin-dependent couplings to nuclei and that annihilate significantly to tau leptons or neutrinos, we find that the IceCube Upgrade will be capable of testing parameter space that is beyond the reach of existing direct detection experiments. After calculating the sensitivity of the IceCube Upgrade to dark matter annihilation in the Sun, we explore dark matter models that could be tested by this experiment, identifying two classes of scenarios as promising targets for such searches.

Dan Hooper

Fabrizio Vassallo

Searching for dark matter annihilation in the Sun with the IceCube Upgrade