The ${\eta }_c$ photoproduction in $ep$ collision has long been proposed as an ideal process to probe the existence of Odderon. In the current work, we systematically investigate the photoproduction of various $C$-even heavy quarkonia (exemplified by ${\eta }_{c(b)}$, and ${\chi }_{c(b)J}$ with $J=0$, 1, 2) via one-photon exchange channel, at the lowest order in ${\alpha }_s$ and heavy quark velocity in the context of Non-relativistic quantum chromodynamics (NRQCD) factorization. We find that the photoproduction rates of ${\eta }_c$ through this mechanism are comparable in magnitude with that through the Odderon-initiated mechanism, even in the Regge limit ($s\gg -t$), though the latter types of predictions suffer from considerable theoretical uncertainties. The future measurements of these types of quarkonium photoproduction processes in EIC and EicC are crucial to ascertain which mechanism plays the dominant role.

In rich dark sector models, dark photons heavier than tens of MeV can behave as semivisible particles; their decays contain both visible and invisible final states. We present models containing multiple dark fermions which allow for such decays and inscribe them in the context of inelastic dark matter and heavy neutral leptons scenarios. Our models represent a generalization of the traditional inelastic dark matter model by means of a charge conjugation symmetry. We revisit constraints on dark photons from $e^{+}{e}^{-}$ colliders and fixed-target experiments, including the effect of analysis vetoes on semivisible decays, $A^{\prime }\to {\psi }_i({\psi }_j\to {\psi }_k{\ell }^{+}{\ell }^{-})$. We find that in some cases the BABAR and NA64 experiments no longer exclude large kinetic mixing, $\epsilon \sim {10}^{-2}$, and, specifically, the related explanation of the discrepancy in the muon ($g-2$). This reopens an interesting window in parameter space for dark photons with exciting discovery prospects. We point out that a modified missing-energy search at NA64 can target short-lived $A^{\prime }$ decays and directly probe the newly-open parameter space.

Fermionic Gaussian projected entangled pair states (PEPS) are fermionic tensor network state constructions that describe the physics of ground states of noninteracting fermionic Hamiltonians. As noninteracting states, one may study and analyze them very efficiently, in both analytical and numerical means. Recently it was shown that they may be used as the starting point—after applying so-called PEPS gauging mechanisms—for variational study of nontrivial, interacting states of lattice gauge theories. This is done using sign-problem free variational Monte Carlo techniques. In this work we show how to generalize such states from two to three spatial dimensions, focusing on spin representations and requirements of lattice rotations. We present constructions that are crucial for the application of the above-mentioned variational Monte Carlo techniques for studying nonperturbative lattice gauge theory physics, with fermionic matter, in $2+1\mathrm{D}$ and $3+1\mathrm{D}$ models. Thus, the constructions presented here are crucial for the study of nontrivial lattice gauge theories with fermionic tensor network states.

The relativistic chiral Lagrangians for both spin-$\frac{1}{2}$ and spin-$\frac{3}{2}$ doubly charmed baryons are constructed up to the order $\mathcal{O}(p^4)$. From $\mathcal{O}(p^2)$ to $\mathcal{O}(p^4)$, there are 19, 74, and 452 independent terms in the two-flavor case and 25, 112, and 864 independent terms in the three-flavor case. The chiral Lagrangians in the heavy diquark limit are also obtained. From $\mathcal{O}(p^2)$ to $\mathcal{O}(p^4)$, there are 7, 23, and 118 independent terms in the two-flavor case and 8, 31, and 189 independent terms in the three-flavor case. We present the low-energy constant relations between the relativistic case and the case in the heavy diquark limit up to the order $\mathcal{O}(p^3)$. With the heavy diquark-antiquark symmetry, the low-energy constant relations between the doubly charmed baryon case and the heavy-light meson case are also obtained up to the order $\mathcal{O}(p^3)$.

We present potential nonrelativistic quantum chromodynamics (pNRQCD) predictions for bottomonium suppression in $\sqrt{s_{NN}}=200\mathrm{GeV}$, 2.76 TeV, and 5.02 TeV heavy-ion collisions using an open quantum system (OQS) description of the reduced heavy-quark antiquark density matrix. Compared to prior $\mathrm{OQS}+\mathrm{pNRQCD}$ studies we include the rapidity dependence of bottomonium production and evolution, allowing for a fully three-dimensional description of bottomonium trajectories in the quark-gluon plasma. The underlying formalism used to compute the ground and excited state survival probabilities is based on a Lindblad equation that is accurate to next-to-leading order (NLO) in the binding energy over temperature. For the background evolution, we make use of a $3+1\mathrm{D}$ viscous hydrodynamics code which reproduces soft hadron observables at all three collision energies. We find good agreement between NLO $\mathrm{OQS}+\mathrm{pNRQCD}$ predictions and data taken at LHC energies; however, at RHIC energies, there is tension with recent bottomonium suppression measurements by the STAR Collaboration.

The chiral Lagrangians for singly heavy baryons are constructed up to the $\mathcal{O}(p^4)$ order. The involved baryons may be in a flavor antitriplet with spin $1/2$, a flavor sextet with spin $1/2$, or a flavor sextet with spin $3/2$ when one considers three light flavors. For the relativistic version of Lagrangian, from $\mathcal{O}(p^2)$ to $\mathcal{O}(p^4)$, there exist 48, 199, and 1242 independent terms in the $SU(2)$ case and 59, 307, and 2454 independent terms in the $SU(3)$ case, respectively. For the Lagrangian in the heavy-quark limit, from $\mathcal{O}(p^2)$ to $\mathcal{O}(p^4)$, the numbers of independent terms are reduced to 16, 64, and 412 in the $SU(2)$ case and to 17, 88, and 714 in the $SU(3)$ case, respectively. We obtain the low-energy constant relations between the relativistic case and the heavy-quark case up to the $\mathcal{O}(p^3)$ order. The relations between low-energy constants of independent relativistic terms are also presented up to this order by using the heavy-quark symmetry.

We report the first search for the Sagittarius tidal stream of axion dark matter around $4.55\mathrm{\mu eV}$ using CAPP-12 TB haloscope data acquired in March of 2022. Our result excluded the Sagittarius tidal stream of Dine-Fischler-Srednicki-Zhitnitskii and Kim-Shifman-Vainshtein-Zakharov axion dark matter densities of ${\rho }_a\gtrsim 0.184$ and $\gtrsim 0.025\mathrm{GeV}/{\mathrm{cm}}^3$, respectively, over a mass range from 4.51 to $4.59\mathrm{\mu eV}$ at a 90% confidence level.

The dust ball collapse is studied in the context of the “rainbow metric” approach (where the matter content is supplemented with a scalar field perturbation) to the Oppenheimer-Snyder collapse scenario within the framework of loop quantum cosmology. The global spacetime structure is determined for this scenario and subsequently used to evaluate the entanglement entropy via a slight adaptation of existing formulas. The resulting model is shown to qualitatively resemble the Reissner-Nordström black hole spacetime, in particular, it still contains singularities, which allows us to define the entropy only for portions of the null infinity. The consequence of these results for the black hole information loss paradox is discussed. Furthermore, the results in presence of the scalar field are used in discussion regarding the viability of the selected scenario, in particular, the assumption of stationarity used to determine the exterior metric.

An important feature of Schwarzschild spacetime is the presence of orbiting null geodesics and caustics. Their presence implies strong gravitational lensing effects for matter and radiation, i.e., for excitations of quantum fields. Here, we raise the question whether the lensing manifests itself also in the vacuum of quantum fields, namely by lensing the distribution of vacuum entanglement. To explore this possibility, we use the method of entanglement harvesting, where initially unentangled localized quantum systems are temporarily coupled to the field at different locations. We find that for the Boulware, Hartle-Hawking and Unruh vacua in $3+1$-dimensional Schwarzschild spacetime, the harvesting of vacuum entanglement is indeed greatly amplified near caustics. In particular, we establish that preexisting vacuum entanglement can also be harvested for lightlike separations.

We consider Bell inequalities in 2-2 scattering of photons, gravitons, fermions, and pions. We choose measurement settings that give maximum Bell violation for maximally entangled states and calculate the relevant Bell inequalities for these processes. For photon scattering at low energies, quantum electrodynamics exhibits Bell violation for all scattering angles except for a small transverse region. This leads to a fine-tuning problem. Incorporating a light axion/axionlike particle removes the fine-tuning problem and constrains the axion-coupling–axion-mass parameters. Allowing for graviton exchange and demanding Bell violation in photon scattering, we find that the weak-gravity conjecture is satisfied. Quantum gravity effects on axion coupling is discussed. For 2-2 graviton scattering, we find that CEMZ bounds allow for, at most, small Bell violations. Restriction on the Weinberg angle is found by demanding Bell violation in Bhabha scattering. We use recent $S$-matrix bootstrap data for pions and photons to study the Bell parameter in the space of allowed $S$-matrices. In the photon case, we study the Bell parameters as a function of energy and find support for the effective field theory observations. We discuss Bell parameter for pion $S$-matrices, which are qutrits. For pions, we find that there is a minimization of a suitable Bell parameter for $S$-matrices which exhibit Regge behavior.

We compute the conformal anomalies for some higher-derivative (nonunitary) 6D Weyl invariant theories using the heat-kernel expansion in the background-field method. To this aim we obtain the general expression for the Seeley-DeWitt coefficient $b_6$ for 4-derivative differential operators with background curved geometry and gauge fields, which was known only in flat space so far. We consider 4-derivative scalars and Abelian vectors as well as 3-derivative fermions, confirming the result of the literature obtained via indirect methods. We generalize the vector case by including the curvature coupling $FF\text{Weyl}$.

The merger remnant of a binary neutron star coalescence is initially strongly differentially rotating. Some properties of these remnants can be accurately modeled through building equilibrium neutron star models. In the present paper, we study how a modification of general relativity, namely scalar-tensor theory with a massive scalar field, will alter the picture. In contrast to previous studies, we implement a realistic phenomenological differential rotational law which allows for neutron star models to attain maximal angular velocity away from the center. We find that solutions with much higher masses and angular momenta exist in scalar-tensor theory compared with general relativity. They keep their quasispherical energy-density distribution for significantly higher values of the angular momentum before transitioning to quasitoroidal models, in contrast to pure general relativity. Constructing such neutron star solutions is the first step to our final goal that is studying how scalarization alters the stability and gravitational wave emission of postmerger remnants.

We consider the Quartic Horndeski theory with torsion on a Friedmann-Lemaître-Robertson-Walker background in the second-order formalism. We show that there is a one parameter family of Quartic Horndeski Cartan Lagrangians and all such theories only modify the dispersion relations of the graviton and the scalar perturbation that are usually found in the standard Horndeski theory on a torsionless spacetime. In other words, for the theories in this class, torsion does not induce new degrees of freedom, but it only modifies the propagation. This holds for first-order perturbations in spite of a kinetic mixing between the Horndeski scalar with the torsion field in the action. We also show that for most Lagrangians within the family of Quartic Horndeski-Cartan theories the dispersion relation of the scalar mode is radically modified. We find only one theory within the family whose scalar mode has a regular wavelike dispersion relation.

We derive novel analytical solutions describing timelike and null geodesics in the Kerr spacetime. The solutions are parametrized explicitly by constants of motion—the energy, the angular momentum, and the Carter constant—and initial coordinates. A single set of formulas is valid for all null and timelike geodesics, irrespectively of their radial and polar type. This uniformity has been achieved by applying a little-known result due to Biermann and Weierstrass, regarding solutions of a certain class of ordinary differential equations. Different from other expressions in terms of Weierstrass functions, our solution is explicitly real for all types of geodesics. In particular, for the first time the so-called transit orbits are now expressed by explicitly real Weierstrass functions.

We study the axial gravitational quasinormal modes of a self-dual black hole in loop quantum gravity. Considering the axial perturbation of the background spacetime, we obtain the Schrödinger-like master equation. Then we calculate the quasinormal frequencies with the Wentzel-Kramers-Brillouin approximation and the asymptotic iteration method. We also investigate the numerical evolution of an initial wave packet on the self-dual black hole spacetime. We find the quantum correction parameter $P$ positively affects the absolute values of both the real and imaginary parts of quasinormal frequencies. We derive the relation between the parameters of the circular null geodesics and quasinormal frequencies in the eikonal limit for the self-dual black hole, and numerically verify this relation.

Measurements of the $H_0$ and ${\sigma }_8$ parameters within the standard cosmological model recently highlighted significant statistical tensions between the cosmic microwave background and low-redshift probes, such as local distance ladder, weak lensing, and galaxy clustering surveys. In this work, we frame geometrical distances in a model-independent way by means of cosmographic approximations in the range $z\in (0,2.3)$ to take into account a robust dataset composed of baryon acoustic oscillations (BAOs), type Ia supernovae (SN), cosmic chronometer (CC) data, and measurements from redshift space distortions (RSDs). From the joint analysis $\mathrm{BAO}+\mathrm{SN}+\mathrm{CC}+\mathrm{RSD}$, we find an accuracy of $\sim 1.4\%$ and $\sim 3.7\%$ on $H_0$ and ${\sigma }_8$, respectively. Our result for $H_0$ is at $2\sigma$ tension with local measurements by the SH0ES team, while our ${\sigma }_8$ estimate is at $2.6\sigma$ tension with Planck-CMB analysis. This inference shows a tension statistically smaller when compared to those estimated via the Lambda cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$) model. We also find that the jerk parameter can deviate more than $3\sigma$ from the $\mathrm{\Lambda }\mathrm{CDM}$ prediction. Under the same cosmographic setup, we also present results by considering a SH0ES Gaussian prior on $H_0$ that allows for improved accuracy of the parameter space of the models. The present work brings observational constraints on $H_0$ and ${\sigma }_8$ into a new model-independent perspective, which differs from the predictions obtained within the $\mathrm{\Lambda }\mathrm{CDM}$ paradigm.

Relativistic and free-streaming particles like neutrinos leave imprints in large scale structures (LSS), providing probes of the effective number of neutrino species $N_{\mathrm{eff}}$. In this paper, we use the Fisher formalism to forecast $N_{\mathrm{eff}}$ constraints from the bispectrum (B) of LSS for current and future galaxy redshift surveys, specifically using information from the baryon acoustic oscillations (BAOs). Modeling the galaxy bispectrum at the tree-level, we find that adding the bispectrum constraints to current CMB constraints from Planck can improve upon the Planck-only constraints on $N_{\mathrm{eff}}$ by about 10%–40% depending on the survey. Compared to the $\mathrm{Planck}+\text{power}$ spectrum (P) constraints previously explored in the literature, using $\mathrm{Planck}+\mathrm{P}+\mathrm{B}$ provides a further improvement of about 5%–30%. Besides using BAO wiggles alone, we also explore using the total information which includes both the wiggles and the broadband information (which is subject to systematics challenges), generally yielding better results. Finally, we exploit the interference feature of the BAOs in the bispectrum to select a subset of triangles with the most information on $N_{\mathrm{eff}}$. This allows for the reduction of computational cost while keeping most of the information, as well as for circumventing some of the shortcomings of applying directly to the bispectrum the current wiggle extraction algorithm valid for the power spectrum. In sum, our study validates that the current Planck constraint on $N_{\mathrm{eff}}$ can be significantly improved with the aid of galaxy surveys before the next-generation CMB experiments like CMB-Stage 4.

In this work we study the influence of external electric field and temperature on the chiral phase transition of quantum chromodynamics. We use the two-flavor linear sigma model coupled with quarks in a thermal and electrized medium to evaluate the effective quark mass and the Schwinger pair production. To this end, we apply one-loop correction to the fermionic sector of the model and the simple tree-level approximation in the mesonic contributions. The electric fields strengthen the partial restoration of the chiral symmetry when applied with finite temperature in a crossover transition. The expected decrease of the pseudocritical temperature as a function of the electric field is observed until electric fields reach $eE\approx 13.5m_{\pi }^2$. For stronger electric fields, the effect is the opposite, which is in a very good agreement with previous results obtained with four-point nonrenormalizable models, showing that this effect is independent of renormalizability issues. We also show the thermal and electric effects on the behavior of the Schwinger pair production.

We show that the analyticity and crossing symmetry of the $S$ matrix, together with the optical theorem, impose restrictions on the renormalization group evolution of dimension-8 operators in the Standard Model effective field theory. Moreover, in the appropriate basis of operators, the latter manifest as zeros in the anomalous dimension matrix that, to the best of our knowledge, have not been anticipated anywhere else in the literature. Our results can be trivially extended to other effective field theories.

We study the production of right-handed bosons $W_R$ and heavy neutrinos $N$ at a future 100 TeV high-energy hadron collider in the context of left-right symmetry, including the effects of $W_L\text{−}{W}_R$ gauge boson mixing. We estimate the collider reach for up to $3/\mathrm{ab}$ integrated luminosity using a multibinned sensitivity measure. In the Keung-Senjanović and missing-energy channels, the $3\sigma$ sensitivity extends up to $M_{W_R}=35$ and 37 TeV, respectively. We further clarify the interplay between the missing-energy channel and the (expected) limits from neutrinoless double beta decay searches and big bang nucleosynthesis (and dark matter).