We conduct a comprehensive investigation into the flavor phenomenology and collider signatures of flavon of ${\mathcal{Z}}_{\mathrm{N}}\times {\mathcal{Z}}_{\mathrm{M}}$ flavor symmetries for the soft symmetry-breaking scenario and a new symmetry-conserving mechanism at the high-luminosity LHC, high-energy LHC, and a 100 TeV hadron collider. The flavor physics of quark and leptonic observables places different bounds on the parameter space of flavons of ${\mathcal{Z}}_{\mathrm{N}}\times {\mathcal{Z}}_{\mathrm{M}}$ flavor symmetries. On the collider side, the decay $t\to ca$ can be probed by the high-luminosity LHC, high-energy LHC, and a 100 TeV hadron collider for the ${\mathcal{Z}}_8\times {\mathcal{Z}}_{22}$ flavor symmetry. The inclusive production signatures can be used to probe the flavon of all the ${\mathcal{Z}}_{\mathrm{N}}\times {\mathcal{Z}}_{\mathrm{M}}$ flavor symmetries for the soft symmetry-breaking scenario for a heavy flavon at a 100 TeV collider. Flavons of all the ${\mathcal{Z}}_{\mathrm{N}}\times {\mathcal{Z}}_{\mathrm{M}}$ flavor symmetries can be probed at high-energy LHC and a 100 TeV collider for a low mass in the case of soft symmetry breaking. The diflavon production is within reach of the high-luminosity LHC, high-energy LHC, and a 100 TeV collider only for a light flavon. The 14 TeV high-luminosity LHC can probe only the ${\mathcal{Z}}_2\times {\mathcal{Z}}_5$ and ${\mathcal{Z}}_8\times {\mathcal{Z}}_{22}$ flavor symmetries for a few specific inclusive signatures. The symmetry-conserving scenario remains beyond the detection capabilities of any collider.

We study the possibility of production of primordial black holes (PBHs) from bubble collisions during a first-order phase transition. While typical colliding bubbles are small and irrelevant for PBH production, we find that those that can produce PBHs must have a macroscopically thick fluid shell and have been born much before the typical nucleation time. Particularly large uncertainties arise from an exponential sensitivity of the nucleation rate on the required duration of bubble growth which depends on the details of the collisions and the evolution of the spacetime metric toward the end of the phase transition. We introduce a few parameters to be obtained from future numerical simulation to represent those unknowns, and estimate the PBH abundance in an Abelian Higgs benchmark model and show that it can be significant. We predict an approximately monochromatic PBH mass spectrum, and find regions in the parameter space where the PBHs can constitute entire dark matter or even overclose the Universe. Our result thus shows that models with a first-order phase transition can be constrained by overabundant PBHs or null results of other PBH searches.

With entropy injection, an early matter-dominated epoch (EMD) impels the axion decay constant $f_a$ toward larger values to produce correct axion dark matter (DM) abundance, thereby unfolding the low-mass axion ($m_a\lesssim {10}^{-5}\mathrm{eV}$) parameter space to be searched for in axion experiments. We implement this proposition in a scenario where $f_a$ and the leptogenesis scale in a seesaw mechanism are equivalent. We show that if, instead, the EMD is provided by evaporating ultralight primordial black holes (PBHs), the scenario becomes strikingly testable with gravitational wave (GW) background alongside the axion searches. In particular, while being consistent with correct axion DM abundance, the scale $f_a\gtrsim {10}^{12}\mathrm{GeV}$, corresponding to the unflavored regime of leptogenesis with hierarchical right-handed neutrinos, can be probed with GW and axion experiments, which is otherwise not testable at neutrino or collider experiments. Additionally, axions produced from PBH evaporation can give rise to dark radiation within reach of future cosmic microwave background experiments.

We investigate the impact of electroweak corrections and effective field theory operators on $W^{+}{W}^{-}$ production at the Large Hadron Collider (LHC). Utilizing the Standard Model effective-field theory (SMEFT) framework, we extend the Standard Model by incorporating higher-dimensional operators to encapsulate potential new physics effects. These operators allow for a model-independent approach to data interpretation, essential for probing beyond the Standard Model physics. We generate pseudodata at the next-to-leading order in quantum chromodynamics and include approximate electroweak corrections. Our analysis focuses on the interplay between these corrections and SMEFT operators at leading order. The inclusion of electroweak corrections is crucial as they can counteract the effects predicted by SMEFT operators, necessitating precise theoretical and experimental handling. By examining $pp\to W^{+}{W}^{-}$ production, a process sensitive to the electroweak symmetry-breaking mechanism, we demonstrate the importance of these corrections in isolating and interpreting new physics signatures. Our results highlight the significant role of electroweak corrections in enhancing the interpretative power of LHC data and in obtaining reliable constraints on new physics interactions.

We analyze the static potentials induced by vacuum domains for various representations in SU(4) Yang-Mills theory within the framework of the domain structure model. By studying the interactions within the vacuum domains, we can uncover fundamental properties of the static potentials. It appears that attractions within the vacuum domains strongly adhere to Casimir scaling at intermediate distances. Conversely, the repulsions within the vacuum domains may decompose them into center vortices with the lowest magnitude of center vortex fluxes, thereby exhibiting $N$-ality at asymptotic distances.

Simulating nonequilibirum dynamics of a quantum many-body system is one of the promising applications of quantum computing. We simulate the time evolution of one-dimensional ${\mathbf{Z}}_2$ lattice gauge theory on IBM’s superconducting 156-qubit device, ibm_fez. We consider the Floquet circuit made of the Trotter decomposition of Hamiltonian evolution and focus on its dynamics toward thermalization. Quantum simulation with the help of error mitigation is successful in running the Floquet circuit made of 38 and 116 qubits up to 10 Trotter steps in the best case. This is enough to reach the early stage of prethermalization. Our work would be a benchmark for the potential power of quantum computing for high-energy physics problems.

We calculate the correlation functions for the ${\overline{K}}^{0}p,{\pi }^{+}{\mathrm{\Sigma }}^0,{\pi }^0{\mathrm{\Sigma }}^{+},{\pi }^{+}\mathrm{\Lambda }$, and $\eta {\mathrm{\Sigma }}^{+}$ states, which in the chiral unitary approach predict an excited ${\mathrm{\Sigma }}^{*}(1/2^{-})$ state at the $\overline{K}N$ threshold, recently observed by the Belle Collaboration. Once this is done, we tackle the inverse problem of seeing how much information one can obtain from these correlation functions. With the resampling method, one can determine the scattering parameters of all the channels with relative precision, by means of the analysis in a general framework, and find a clear cusplike structure corresponding to the ${\mathrm{\Sigma }}^{*}(1/2^{-})$ in the different amplitudes at the $\overline{K}N$ threshold.

The phenomenology of hadronic states at high energy is well described in the framework of quantum chromodynamics. By the other hand, that is the description of the low-energy regime, e.g., mesoniclike states, requires the introduction of effective degrees of freedom, a condition resulting from confinement. As an alternative to lattice gauge calculations, and own to the similarities with other quantum many-body systems, we have adopted a nonperturbative scheme where quarks are treated as quasiparticles. These quasiquarks interact between them, allowing mesonlike states to be described as collective superposition of quasiquark pairs. The results of the calculations, performed in the context of the random phase approximation method, show that this scheme is a suitable one to describe meson states up to energies of the order of couple of GeV.

Our study focuses on the weak decay of $D_s^{+}\to p\overline{n}$, which is the only possible two-body baryonic decay in the $D$ meson system. An analysis using perturbative quantum chromodynamics (pQCD) is challenging in this decay due to the small amount of energy released. In particular, naive factorization, suppressed by the light quark masses, results in a minor contribution to this channel. In the framework of final state interactions, the hidden strangeness in the intermediate state naturally avoids this chiral suppression from light quark masses. The branching fraction is predicted to be $\mathcal{B}(D_s^{+}\to p\overline{n})=(1.43\pm 0.10)\times {10}^{-3}$, in agreement with the experimental value of $(1.22\pm 0.11)\times {10}^{-3}$. We also analyze the decays of $B$ mesons into two charmed baryons involving annihilation-type topological diagrams. In these decays, we conduct a joint analysis of naive factorization and final state interactions. Using the experimental upper bound of $\mathcal{B}(B_s^0\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-})<8\times {10}^{-5}$, we set a constraint on the coupling constant $g_{D^{+}{\mathrm{\Lambda }}_c^{+}n}<7.5$. Final state interactions lead to a prediction of the decay parameter $\gamma (B_s^0\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-})>0.8$, whereas pQCD predicts it to be negative. We propose future measurements of $B^0\to {\mathrm{\Xi }}_c^{+}{\overline{\mathrm{\Xi }}}_c^{-}$, predicting a significant $SU(3{)}_F$ breaking effect with $\frac{\mathcal{B}(B^0\to {\mathrm{\Xi }}_c^{+}{\overline{\mathrm{\Xi }}}_c^{-})}{\mathcal{B}(B_s^0\to {\mathrm{\Lambda }}_c^{+}{\overline{\mathrm{\Lambda }}}_c^{-})}=1.4\%$, contrary to the naive estimate of 5.3%. We strongly recommend future measurements.

We study the Abelian Higgs model with multiple scalar fields, but without mass terms. Solving the model nonperturbatively order-by-order in the number of scalar fields, we find that radiative corrections generate masses for the scalar and gauge boson, without spontaneous symmetry breaking. The mass scales are set by the $\mathrm{\Lambda }$-parameter of the electroweak running coupling, thereby naturally avoiding the hierarchy problem. No part of our calculation employs a weak-coupling expansion, and we find that the perturbative vacuum is metastable, and hence must decay to the stable nonperturbative vacuum of the theory, which we identify. Although the field content of our Lagrangian is standard, our results predict the existence of two heavy scalar resonances in addition to the Higgs. We believe that these predicted resonances will ultimately allow experimentalists to discriminate between our method and standard solutions of the Higgs model.

Using $(2712.4\pm 14.3)\times {10}^6$ $\psi (3686)$ events collected with the BESIII detector operating at the BEPCII collider, we search for the hadronic transition $h_c\to {\pi }^{+}{\pi }^{-}J/\psi$ via $\psi (3686)\to {\pi }^0{h}_c$. No significant signal is observed. We set the most stringent upper limits to date on the branching fractions $\mathcal{B}(\psi (3686)\to {\pi }^0{h}_c)\times \mathcal{B}(h_c\to {\pi }^{+}{\pi }^{-}J/\psi )$ and $\mathcal{B}(h_c\to {\pi }^{+}{\pi }^{-}J/\psi )$ at the 90% confidence level, which are determined to be $6.7\times {10}^{-7}$ and $9.4\times {10}^{-4}$, respectively.

By analyzing $(27.12\pm 0.14)\times {10}^8$ $\psi (3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decays ${\chi }_{cJ}\to p\overline{p}{K}_S^0{K}^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.$ $(J=0,1,2)$ are observed for the first time with statistical significances greater than $10\sigma$. The branching fractions of these decays are determined to be $\mathcal{B}({\chi }_{c0}\to p\overline{p}{K}_S^0{K}^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.)=(2.61\pm 0.27\pm 0.32)\times {10}^{-5}$, $\mathcal{B}({\chi }_{c1}\to p\overline{p}{K}_S^0{K}^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.)=(4.16\pm 0.24\pm 0.46)\times {10}^{-5}$, and $\mathcal{B}({\chi }_{c2}\to p\overline{p}{K}_S^0{K}^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.)=(5.63\pm 0.28\pm 0.46)\times {10}^{-5}$, respectively. The processes ${\chi }_{c1,2}\to \overline{p}\mathrm{\Lambda }(1520)K_S^0{\pi }^{+}+\mathrm{c}.\mathrm{c}.$ are also observed, with statistical significances of $5.7\sigma$ and $7.0\sigma$, respectively. Evidence for ${\chi }_{c0}\to \overline{p}\mathrm{\Lambda }(1520)K_S^0{\pi }^{+}+\mathrm{c}.\mathrm{c}.$ is found with statistical significances of $3.3\sigma$. The corresponding branching fractions are determined to be $\mathcal{B}({\chi }_{c0}\to \overline{p}\mathrm{\Lambda }(1520)K_S^0{\pi }^{+}+\mathrm{c}.\mathrm{c}.)=(1.61_{-0.64}^{+0.68}\pm 0.23)\times {10}^{-5}$, $\mathcal{B}({\chi }_{c1}\to \overline{p}\mathrm{\Lambda }(1520)K_S^0{\pi }^{+}+\mathrm{c}.\mathrm{c}.)=({4.06}_{-0.76}^{+0.80}\pm 0.52)\times {10}^{-5}$, and $\mathcal{B}({\chi }_{c2}\to \overline{p}\mathrm{\Lambda }(1520)K_S^0{\pi }^{+}+\mathrm{c}.\mathrm{c}.)=(4.09_{-0.84}^{+0.87}\pm 0.42)\times {10}^{-5}$. Here, the first uncertainties are statistical and the second ones are systematic.

We construct a celestial conformal field theory on the horizon corresponding to a nonperturbative eikonal scattering amplitude involving two massless scalars mediated by soft gravitons in the near-horizon region of a large eternal Schwarzschild black hole. From the known two-dimensional near-horizon scattering amplitude computed within the effective field theory framework, we first construct a four-dimensional amplitude involving two external s-wave legs in a flat spacetime frame around the bifurcation sphere strictly in a small angle approximation limit by resumming over the spherical harmonics. While the kinematics of external particles in this frame at leading order are analogous to a Minkowski spacetime, the eikonal amplitude differs from those about flat spacetime due to the near-horizon scattering potential. We derive a celestial correlator following a Mellin transform that provides an all loop order result, with a universal leading UV soft scaling behavior of the conformally invariant cross-ratio, and an IR pole for the scaling dimension at each loop order. We argue these properties manifest soft graviton exchanges in the near-horizon region and, consequently, the soft UV behavior of the amplitude.

Perturbative quantum gravity starts from prescribing a background metric. That background metric is then used in order to carry out two separate steps: 1. One splits the nonperturbative metric into background and deviation from it (graviton) and expands the action in terms of the graviton which results in an infinite series of unknown radius of convergence. 2. One constructs a Fock representation for the graviton and performs perturbative graviton quantum field theory on the fixed background as dictated by the perturbative action. The result is a nonrenormalizable theory without predictive power. It is therefore widely believed that a nonperturbative approach is mandatory in order to construct a fundamental, not only effective, predictive quantum field theory of the gravitational interaction. Since perturbation theory is by definition background dependent, the notions of background dependence (BD) and perturbation theory (PT) are often considered as symbiotic, as if they imply each other. In the present work, we point out that there is no such symbiosis; these two notions are in fact logically independent. In particular, one can use BD structures while not using PT at all. Specifically, we construct BD Fock representations (step 2 above) for the full, nonperturbative metric rather than the graviton (not step 1 above) and therefore never perform a perturbative expansion. Despite the fact that the gravitational Lagrangian is a nonpolynomial, not even analytic, function of the metric, we show that, e.g., the Hamiltonian constraint with any density weight can be defined as a quadratic form with dense form domain in such a representation.

The canonical quantization of general relativity including matter on a spacetime manifold in the globally hyperbolic setting involves, in particular, the representation theory of the spatial diffeomorphism group (SDG) and/or its Lie algebra (SDA) of the underlying spatial submanifold. There are well-known Fock representations of the SDA in one spatial dimension and non-Fock representations of the SDG in all dimensions. The latter are not strongly continuous and do not descend to representations of the SDA. In this work, we report some partial results on nonanomalous representations of the SDA for both geometry and matter: (1) Background-independent Fock representations of the SDA by operators exist in all dimensions. (2) Infinitely many unitary equivalence classes of background-dependent Fock representations of the SDA by operators exist in one dimension but these do not extend to higher dimensions. (3) Infinitely many unitary equivalence classes of background-dependent Fock representations of the SDA of volume preserving diffeomorphisms by operators exist in all dimensions. (4) Infinitely many unitary equivalence classes of background-dependent Fock representations of the SDA by quadratic forms exist in all dimensions. Except for 1 these representations do not descend from an invariant state of the Weyl algebra and 4 points to a new strategy for solving the quantum constraints.

Vielbeins are necessary when coupling general relativity (GR) to fermionic matter. This enhances the gauge group of GR to include local Lorentz transformations. In view of a reduced phase space formulation of quantum gravity, in this work we completely gauge fix that Lorentz gauge symmetry by using a so-called triangular gauge. Having solved the Gauss constraints already classically opens access to new Hilbert space representations that are free of the complications that otherwise arise due to a non-Abelian gauge symmetry. In that sense, a connection formulation as being pursued in loop quantum gravity is no longer the only practicable option and other less dimension-dependent representations, e.g., based on triads and even metrics suggest themselves. These formulations make it easier to identify states representing nondegenerate quantum geometries and thus to investigate the hypersurface deformation algebra which implicitly assumes nondegeneracy.

It has recently been shown that extended cosmological epochs can exist during which the abundances associated with different energy components remain constant despite cosmological expansion. Indeed, this “stasis” behavior has been found to arise generically in many beyond-the-Standard-Model theories containing large towers of states, and even serves as a cosmological attractor. However, all previous studies of stasis took place within nonthermal environments, or more specifically within environments in which thermal effects played no essential role in realizing or sustaining the stasis. In this paper, we demonstrate that stasis can emerge and serve as an attractor even within thermal environments, with thermal effects playing a critical role in the stasis dynamics. Moreover, within such environments, we find that no towers of states are needed—a single state experiencing two-body annihilations will suffice. This work thus extends the stasis phenomenon into the thermal domain and demonstrates that thermal effects can also generally give rise to an extended stasis epoch, even when only a single matter species is involved.

It has recently been realized that many theories of physics beyond the Standard Model (BSM) give rise to cosmological histories exhibiting extended epochs of cosmological stasis. During such epochs, the abundances of different energy components such as matter, radiation, and vacuum energy each remain fixed despite cosmological expansion. In previous analyses of the stasis phenomenon, these different energy components were modeled as fluids with fixed, unchanging equations of state. In this paper, by contrast, we consider more realistic systems involving dynamical scalars which pass through underdamping transitions as the universe expands. Indeed, such systems might be highly relevant for BSM scenarios involving higher-dimensional bulk moduli and inflatons. Remarkably, we find that stasis emerges even in such situations, despite the appearance of time-varying equations of state. Moreover, this stasis includes several new features which might have important phenomenological implications and applications. For example, in the presence of an additional “background” energy component, we find that the scalars evolve into a “tracking” stasis in which the stasis equation of state automatically tracks that of the background. This phenomenon exists even if the background has only a small initial abundance. We also discuss the intriguing possibility that our results might form the basis of a new “stasis inflation” scenario in which no ad hoc inflaton potential is needed and in which there is no graceful-exit problem. Within such a scenario, the number of $e$-folds of cosmological expansion produced is directly related to the hierarchies between physical BSM mass scales. Moreover, nonzero matter and radiation abundances can be sustained throughout the inflationary epoch.

We calculate the complete $T$ matrices with decuplet contributions for pion-nucleon scattering to order $\mathcal{O}({\epsilon }^3)$ in heavy baryon SU(3) chiral perturbation theory. The baryon mass in the chiral limit $M_0$ and the low-energy constants are determined by fitting to phase shifts of $\pi N$, the experimental octet-baryon masses, and the value of ${\sigma }_{\pi N}$ simultaneously. By using these constants, we obtain the $KN$ $\sigma$ terms, ${\sigma }_{KN}^{(1)}=(375.07\pm 33.02)\mathrm{MeV}$ and ${\sigma }_{KN}^{(2)}=(275.32\pm 32.24)\mathrm{MeV}$, with the errors being only statistical. An excellent description of the phase shifts is obtained for all partial waves. We also present results for scattering lengths and scattering volumes. In addition, the convergence of the approach is also discussed.