We propose a new scotogenic type model based on a global <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>4</mn></msub></math> symmetry involving dark matter candidates. After the symmetry breaking as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>4</mn></msub></math> to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>2</mn></msub></math> via the singlet scalar vacuum expectation value (VEV), the lightest Majorana fermion works as a viable thermal freeze-out dark matter (DM) candidate, and the mass terms for active neutrinos are generated as a finite quantum correction at the one-loop level. A key point of realizing our scotogenic structure is to introduce two types of Majorana fermions (heavy right-handed neutrinos) and inert Higgs doublets with opposite <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>4</mn></msub></math> parities. Since a large VEV for the singlet scalar is not so harmful in an appropriate realization of the Higgs mechanism for the SM gauge symmetry, we can naturally realize a TeV-scale fermionic DM candidate, where constraints via direct detection experiments are less than those for sub-TeV DM. Our scenario involves the Higgs-portal DM interactions, which help the realization of the correct DM relic abundance. Relying on the structure of the model, it is possible to find a natural partner for coannihilation. Our scenario can be investigated via the measurement of the Higgs trilinear self-coupling at the Large Hadron Collider. The simplest way to evade the domain-wall problem, by adding a tiny soft <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>2</mn></msub></math> breaking term, works, keeping a sufficient longevity of the decaying DM lifetime.

India

Noel Jonathan Jobu

Kenji Nishiwaki

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>4</mn></msub></math> scotogenic model with a Higgs portal

In light of the recent measurement of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><mi>γ</mi><mi>γ</mi></math> decay by the KLOE-2 Collaboration, a previous analysis including vector- and scalar-meson exchange contributions using the vector meson dominance and linear sigma model frameworks, respectively, is extended in the present study to incorporate the effects of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>2</mn></msub><mo stretchy="false">(</mo><mn>1320</mn><mo stretchy="false">)</mo></math> tensor meson within a chiral context. Although the individual contribution of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>2</mn></msub></math> is negligible, its destructive interference with the vector-meson resonances is found to be significant, representing approximately 18% of the total signal and substantially affecting the diphoton invariant-mass distribution, especially at low <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>m</mi><mrow><mi>γ</mi><mi>γ</mi></mrow><mn>2</mn></msubsup></math> values. The total decay rate is calculated to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><mi>η</mi><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><mi>γ</mi><mi>γ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>0.154</mn><mo stretchy="false">(</mo><mn>22</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>eV</mi></math>, which corresponds to a branching ratio of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>BR</mi></mrow><mo stretchy="false">(</mo><mi>η</mi><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><mi>γ</mi><mi>γ</mi><mo stretchy="false">)</mo><mo>=</mo><mn>1.17</mn><mo stretchy="false">(</mo><mn>17</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>. This result is approximately <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math> below the reported value of the particle data group, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.55</mn><mo stretchy="false">(</mo><mn>22</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>, while it is in very good agreement with the KLOE-2 measurement, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>0.98</mn><mo stretchy="false">(</mo><mn>1</mn><msub><mn>1</mn><mrow><mi>stat</mi></mrow></msub><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mn>1</mn><msub><mn>4</mn><mrow><mi>syst</mi></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>. In contrast, the total contribution of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>2</mn></msub></math> is found to be negligible in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>η</mi><mo>′</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><mi>γ</mi><mi>γ</mi></math>, as this process is completely dominated by the exchange of an on-shell <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ω</mi></math> vector resonance.

Spain

Rafel Escribano

Sergi Gonzàlez-Solís

Emilio Royo

Assessment of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>2</mn></msub><mo stretchy="false">(</mo><mn>1320</mn><mo stretchy="false">)</mo></math> tensor-meson contribution to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo>/</mo><msup><mi>η</mi><mo>′</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><mi>γ</mi><mi>γ</mi></math> decays

Inspired by the novel idea proposed by Padmanabhan [<a href="http://dx.doi.org/10.1103/PhysRevD.100.045024">Phys. Rev. D 100, 045024 (2019)</a>], we develop a method to uncover the hidden thermal properties of the inertial Feynman propagator in Minkowski spacetime in a causally consistent manner. This, in turn, enables a coherent interpretation based on future-directed propagation. In our approach, the Fourier transform is implemented following the convention used in the analysis of vacuum fluctuations. As a result, future-directed propagation across causal horizons can be consistently interpreted, from the perspective of an observer confined to a causally disconnected region, as the emission of scalar quanta at the past horizon and their absorption at the future horizon. Moreover, we find that the ratio between emission and absorption processes reproduces the characteristic Boltzmann factor of a thermal ensemble. We first apply this analysis to a causal diamond of length <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>α</mi></math>, performing a detailed study of the near-horizon geometry and thereby obtaining the temperature associated with the thermal behavior of the Minkowski vacuum as perceived by an observer with finite lifetime <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>α</mi></math>. For completeness, we also apply the method to the right Rindler wedge, recovering the well-known Unruh temperature, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi><mo>=</mo><mi>a</mi><mo>/</mo><mo stretchy="false">(</mo><mn>2</mn><mi>π</mi><mo stretchy="false">)</mo></math>. Our results demonstrate that thermality can emerge directly from causal structure, independently of acceleration or gravity, with causal diamonds encoding intrinsic thermodynamic behavior in quantum field theory.

United States

Nada Eissa

Carlos R. Ordóñez

Gustavo Valdivia-Mera

Thermal nature of the causal diamond horizon: A hidden property of the inertial propagator

We lay out the phenomenological behavior of event-shape observables evaluated by solving optimal transport problems between collider events and reference geometries — which we name $\textit{manifold distances}$ — to provide guidance regarding their use in future studies. This discussion considers several choices related to the metric used to quantify these distances. We explore the differences between the various options, for the first time using a combination of analytical studies and simulated minimum-bias and multi-jet events. Making judicious choices when defining the metric and reference geometry can improve sensitivity to interesting signal features and reduce sensitivity to non-perturbative effects in QCD. The goal of this article is to provide a ‘field guide’ that can inform how choices made when defining a manifold distance can be tailored for the analysis at-hand.

Cari Cesarotti

Matt LeBlanc

A field guide to event-shape observables using optimal transport

We compute one-loop corrections to the euclidean gravitational path integral of near-extremal (anti-)de Sitter-Kerr black hole in terms of the connection coefficients of the Heun equation describing the black hole linear perturbations in the Teukolsky formalism. We show that different near-extremal limits lead to distinct physical properties of the gravitational configuration, as they get described by distinct limiting differential equations. As a result, the light modes emerging in the limit determine different scaling properties in the temperature of the one-loop determinants. We show that the cold case displays distinctive universal log(T) corrections to the entropy of the system, including the ultracold regime. On the contrary, these do not appear in the limit in which the event horizon superimposes onto the cosmological one. In the Schwarzschild-de Sitter case, a further check is performed by comparison with the Denef-Hartnoll-Sachdev formula.

United Kingdom

Paolo Arnaudo

Italy

Giulio Bonelli

Alessandro Tanzini

One loop corrections to the thermodynamics of near-extremal Kerr-(A)dS black holes from Heun equation

We present a systematic study of baryonic flux tubes in SU(3) Yang-Mills theory in (2+1) dimensions. A recent next-to-leading-order derivation within the Effective String Theory framework has, for the first time, made explicit the corrections proportional to the mass of the baryon junction $\textit{M}$, up to order 1/$\textit{R}$ (where $\textit{R}$ is the length of the confining strings), opening the possibility of its non-perturbative determination. One of the main goals of this paper is, through high precision simulations of the three-point Polyakov loop correlator, to measure for the first time the baryon junction mass. By isolating the predicted 1/$\textit{R}$ term in the open string channel, we obtain the value $$M/\sqrt{\sigma }=0.1355\left(36\right)$$ , similar to the phenomenological value which is used to describe hadrons, although our computation was done in (2 + 1) dimensions. In addition, studying the high temperature behavior of the baryon, we present a new test of the Svetitsky-Yaffe conjecture for the SU(3) theory in three dimensions. Focusing on the high temperature regime, just below the deconfinement transition, we compare our lattice results for Polyakov loop correlators with the quantitative predictions obtained by applying conformal perturbation theory to the three-state Potts model in two dimensions and find excellent agreement.

Michele Caselle

Nicodemo Magnoli

Dario Panfalone

Lorenzo Verzichelli

The mass of the baryon junction: a lattice computation in 2 + 1 dimensions

Applying the light-cone sum rules approach, the next-to-leading-order corrections to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi></math> form factors are calculated with the twist-two and twist-three <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>-meson light-cone distribution amplitudes (LCDAs) at leading power in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo>/</mo><msub><mi>m</mi><mi>b</mi></msub></math>. At one-loop level, the vacuum-to-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>-meson correlation functions defined with interpolating currents for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math>-wave axial-vector meson are factorized into short-distance coefficients and the distribution amplitudes of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> meson, among which the hard coefficients for A0-type currents and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi></math>-dependent jet functions entering correlation functions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Π</mi><mrow><mi>μ</mi><mo>,</mo><mo stretchy="false">∥</mo></mrow><mrow><mo stretchy="false">(</mo><mi>T</mi><mo>+</mo><mover accent="true"><mi>T</mi><mo stretchy="false">˜</mo></mover><mo stretchy="false">)</mo></mrow></msubsup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Π</mi><mrow><mi>δ</mi><mi>μ</mi><mo>,</mo><mo>⊥</mo></mrow><mrow><mo stretchy="false">(</mo><mi>V</mi><mo>−</mo><mi>A</mi><mo stretchy="false">)</mo></mrow></msubsup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Π</mi><mrow><mi>δ</mi><mi>μ</mi><mo>,</mo><mo>⊥</mo></mrow><mrow><mo stretchy="false">(</mo><mi>T</mi><mo>+</mo><mover accent="true"><mi>T</mi><mo stretchy="false">˜</mo></mover><mo stretchy="false">)</mo></mrow></msubsup></math> are identical to the corresponding ones of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>V</mi></math> in soft-collinear effective theory (SCET). In addition, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Π</mi><mrow><mi>μ</mi><mo>,</mo><mo stretchy="false">∥</mo></mrow><mrow><mo stretchy="false">(</mo><mi>V</mi><mo>−</mo><mi>A</mi><mo stretchy="false">)</mo></mrow></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Π</mi><mrow><mi>μ</mi><mo>,</mo><mo stretchy="false">∥</mo></mrow><mrow><mo stretchy="false">(</mo><mi>T</mi><mo>+</mo><mover accent="true"><mi>T</mi><mo stretchy="false">˜</mo></mover><mo stretchy="false">)</mo></mrow></msubsup></math> coincide with the results of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>π</mi><mo>,</mo><mi>K</mi></math> under the limit <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>q</mi></msub><mo stretchy="false">→</mo><mn>0</mn></math> up to one-loop accuracy. Then the subleading-power corrections to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi></math> form factors are computed with the higher-twist <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>-meson LCDAs at tree level up to the twist-six accuracy. Furthermore, we predict the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>q</mi><mn>2</mn></msup></math> dependence of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi></math> form factors via the Bourrely-Caprini-Lellouch <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>z</mi></math>-series expanding parametrization to compute several physical observables including branching ratios of semileptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi><mo>ℓ</mo><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mo>ℓ</mo></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi><msub><mi>ν</mi><mo>ℓ</mo></msub><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mo>ℓ</mo></msub></math> processes, transverse asymmetries, forward-backward asymmetries, and lepton-flavor universality observables employing the given mixing angles <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>θ</mi><mi>K</mi></msub><mo>=</mo><mo>−</mo><mn>3</mn><mn>4</mn><mi>°</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>θ</mi></mrow><mrow><msub><mrow><mn>1</mn></mrow><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></msub></mrow></msub><mo>=</mo><mn>2</mn><mn>8</mn><mi>°</mi></mrow></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>θ</mi><msub><mn>3</mn><msub><mi>P</mi><mn>1</mn></msub></msub></msub><mo>=</mo><mn>2</mn><mn>3</mn><mi>°</mi></math>. We also compare our theory calculations with the results from other methods.

China

Fang-Zhou Di

Yu-Hao Liu

Next-to-leading-order QCD calculations of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>A</mi></math> form factors with higher-twist corrections

We consider a recently discovered mathematical correspondence between the spectra of a naively discretized lattice fermion and that of a periodically driven (i.e., Floquet) quantum system and enhance it into an infrared equivalence between the two systems. The equivalence can be framed as a duality relation, allowing us to simulate a two-flavor discrete-time fermion theory on the lattice side, where the two flavors arise from time discretization, using a single-flavor fermion theory on the Floquet side. Our demonstration establishes an equivalence between (i) the fermion content, (ii) the correlation functions, and consequently (iii) observables of the two theories in the infrared, going substantially beyond the previously discovered spectral equivalence. We also show how interactions may be incorporated into this enhanced infrared equivalence.

Raúl A. Briceño

William Gyory

Thomas Iadecola

Srimoyee Sen

Simulating lattice fermion doubling with a Floquet drive

Some relevant aspects of a new form of generalized entropic cosmology, recently introduced by Nojiri, Odintsov and Faraoni, are considered. The setup is a logarithmic equation of state for a viscous dark fluid coupled with dark matter, in the ordinary Friedmann–Lemaître–Robertson–Walker flat universe. The influence of thermal effects, caused by Hawking radiation, near the singularity, are carefully investigated. In particular, their role on the formation and specific type of the Big Rip expected to occur within a finite time. It is shown that a scenario arises, where a qualitative change towards the good direction, in the type of the singularity formed, does occur. On top of that, another very interesting scenario is obtained, where the singularity vanishes completely.

E. Elizalde

Russia

A. Yurov

A. Timoshkin

Singularity softening and avoidance by the action of thermal radiation in a generalized entropic cosmology

We study an alternative $$U(1)_{B-L}$$ model with singlet chiral fermions which can act as WIMP and FIMP type DM, which is anomaly-free by constructions in contrast to the well studied $$B-L$$ extension where three right handed neutrinos are needed for gauge anomaly cancellation. Fermion dark matter masses are generated after the $$U(1)_{B-L}$$ is broken spontaneously, so the Yukawa couplings for WIMP and FIMP components can be distinguished by the hierarchical values of the vacuum expectation values of the singlet scalar fields. Moreover, the $$U(1)_{B-L}$$ gauge boson receives a TeV-scale mass for a tiny extra gauge coupling, so it goes out of equilibrium from the rest of the model content in the early Universe. Both the $$U(1)_{B-L}$$ gauge boson and FIMP component are produced from the decays of the bath particles, and the former can decay into FIMP DM and/or WIMP DM before BBN. The WIMP component can reside in the resonance region of the Higgs bosons or dominantly annihilate into a pair of singlet-like scalars. Thus, there is a flexibility to choose a small mixing between the visible and dark sectors, thereby evading all the current direct and indirect detection bounds. Furthermore, we show that WIMP and FIMP components can coexist in suitable fractions, depending on the choice of model parameters, allowing for additional protection for WIMP DM against various experimental bounds. Finally, we identify the dimension-6 and dimension-7 operators for Majorana neutrino masses in our model, being consistent with the $$U(1)_{B-L}$$ gauge symmetry, and provide a possibility of extending the model with additional singlet fermions for neutrino masses.

South Korea

Sarif Khan

Hyun Lee

WIMP-FIMP option and neutrino masses via a novel anomaly-free $$B-L$$ symmetry