We investigate the radiative processes involving two entangled Unruh-DeWitt detectors that are moving on circular trajectories in ($2+1$)-dimensional Minkowski spacetime. We assume that the detectors are coupled to a massless, quantum scalar field, and calculate the transition probability rates of the detectors in the Minkowski vacuum as well as in a thermal bath. We also evaluate the transition probability rates of the detectors when they are switched on for a finite time interval with the aid of a Gaussian switching function. We begin by examining the response of a single detector before we go on to consider the case of two entangled detectors. As we shall see, working in ($2+1$)-spacetime dimensions makes the computations of the transition probability rates of the detectors relatively simpler. We find that the cross transition probability rates of the two entangled detectors can be comparable to the autotransition probability rates of the individual detectors. We discuss specific characteristics of the response of the entangled detectors for different values of the parameters involved and highlight the effects of the thermal bath as well as switching on the detector for a finite time interval.

The excitation of quadratic quasinormal modes is an important nonlinear phenomenon for a Kerr black hole ringing at a specific linear mode. The amplitude of this second-order effect is proportional to the square of the linear mode amplitude, with the ratio being linked to the nature of the Kerr black hole. Focusing on the linear $(l=m=2,n=0)$ mode, we compute the dependency of the ratio on the dimensionless spin of the black hole, ranging up to 0.99, with the method applicable for more general mode couplings. Our calculation makes use of the frequency-domain, second-order Teukolsky equation, which involves two essential steps: (a) analytically reconstructing the metric through the Chrzanowski-Cohen-Kegeles approach and (b) numerically solving the second-order Teukolsky equation using the shooting method along a complex contour. We find that the spin dependence of the ratio shows a strong correlation with the angular overlap between parent and child modes, providing qualitative insights into the origin of the dependence. Depending on the nature of the angular overlap, the ratio decreases with spin in scenarios such as the channel $(l=m=2,n=0)\times (l=m=2,n=0)\to (l=m=4)$ or increases in situations like $(l=m=2,n=0)\times (l=m=2,n=0)\to (l=5,m=4)$. For both cases, the ratios do not vanish in the extremal limit. Our studies may offer insights into the search for quadratic quasinormal modes from numerical relativity and gravitational wave detections. As a byproduct, we find that the Weyl scalars can be concisely expressed with the Hertz potential.

Thomson scattering of cosmic microwave background (CMB) photons imprints various properties of the baryons around galaxies on the CMB. One such imprint, called patchy screening, is a direct probe of the gas density profile around galaxies. It usefully complements the information from the kinematic and thermal Sunyaev-Zel’dovich effects and does not require individual redshifts. In this paper, we derive new estimators of patchy screening called the “temperature inversion” (TI) and “signed” estimators, analogous to the gradient inversion estimator of CMB lensing. Pedagogically, we clarify the relation between these estimators and the standard patchy screening quadratic estimator (QE). The new estimators trade optimality for robustness to biases caused by the dominant CMB lensing and foreground contaminants, allowing the use of smaller angular scales. We perform a simulated analysis to realistically forecast the expected precision of patchy screening measurements from four CMB experiments, ACT, SPT, Simons Observatory (SO) and CMB-S4, cross-correlated with three galaxy samples from BOSS, unWISE and the simulated Rubin LSST Data Challenge 2 catalog. Our results give further confidence in the first detection of this effect from the $\mathrm{ACT}\times \mathrm{unWISE}$ data in the companion paper and show patchy screening will be a powerful observable for future surveys like SO, CMB-S4 and LSST. Implementations of the patchy screening QE and the TI and signed estimators are publicly available in our lensquest and thumbstack software packages, respectively.

https://github.com/EmmanuelSchaan/LensQuEst.

https://github.com/EmmanuelSchaan/ThumbStack.

Asymmetric reheating is a generic requirement for models of dark sectors with light species, but its implementation is usually in tension with unique phenomenologies otherwise possible in compelling theories containing dark copies of the Standard Model. We present a simple module to implement asymmetric reheating during a ${\mathbb{Z}}_2$-breaking phase above some critical temperature. This reinvigorates the possibility of an exactly degenerate mirror sector and the striking phenomenology of composite particles oscillating into their mirror counterparts.

An exciting possibility to constrain dark matter (DM) scenarios is to search for their gravitational imprints on black hole (BH) observations. In this paper, we investigate the impact of self-interacting scalar field DM on the shadow radius of a Schwarzschild BH. We implement a self-consistent formulation, paying attention to the enhancement of the DM density due to the BH gravitational influence and the accretion flow onto the BH. First, we calculate the first-order correction to the shadow radius caused by a general DM environment. Then, we apply this perturbative method to the case of self-interacting scalar field DM and derive analytical expressions for the critical impact parameter. We find that self-consistency requirements, involving the lifetime and the mass of the central DM soliton, or the mass and the size of the extended virialized DM halo, ensure that the impact of the DM environment on the shadow radius is below the observational upper bound. This emphasizes the importance of taking into account the self-consistency constraints of the underlying DM scenario, which can strongly limit the range of possible DM density profiles and their impact on the shadow radius.

Collective neutrino oscillations are typically studied using the lowest-order quantum kinetic equation, also known as the mean-field approximation. However, some recent quantum many-body simulations suggest that quantum entanglement among neutrinos may be important and may result in flavor equilibration of the neutrino gas. In this work, we develop new quantum models for neutrino gases in which any pair of neutrinos can interact at most once in their lifetimes. A key parameter of our models is $\gamma =\mu \mathrm{\Delta }z$, where $\mu$ is the neutrino coupling strength, which is proportional to the neutrino density, and $\mathrm{\Delta }z$ is the duration over which a pair of neutrinos can interact each time. Our models reduce to the mean-field approach in the limit $\gamma \to 0$ and achieve flavor equilibration in time $t\gg (\gamma \mu {)}^{-1}$. These models demonstrate the emergence of coherent flavor oscillations from the particle perspective and may help elucidate the role of quantum entanglement in collective neutrino oscillations.

The analysis of gravitational-wave signals is one of the most challenging application areas of signal processing, because of the extreme weakness of these signals and of the great complexity of gravitational-wave detectors. Wavelet transforms are specially helpful in detecting and analyzing gravitational-wave transients and several analysis pipelines are based on these transforms, both continuous and discrete. While discrete wavelet transforms have distinct advantages in terms of computing efficiency, continuous wavelet transforms (CWT) produce smooth and visually stunning time-frequency maps where the wavelet energy is displayed in terms of time and frequency. In addition to wavelets, short-time Fourier transforms (STFT) and Stockwell transforms (ST) are also used, or the $Q$-transform, which is a Morlet waveletlike transform where the width of the Gaussian envelope is parametrized by a parameter denoted by $Q$ [Chatterji et al., Classical Quantum Gravity 21, S1809 (2004)]. To date, the use of CWTs in gravitational-wave data analysis has been limited by the higher computational load when compared with discrete wavelets, and also by the lack of an inversion formula for wavelet families that do not satisfy the admissibility condition. In this paper we consider Morlet wavelets parametrized in the same way as the Q-transform (hence the name wavelet Q-transform) which have all the advantages of the Morlet wavelets and where the wavelet transform can be inverted with a computationally efficient specialization of the nonstandard inversion formula of Lebedeva and Postnikov [Lebedeva and Postnikov, R. Soc. Open Sci. 1, 140124 (2014)]. We also introduce a two-parameter extension (the wavelet Qp-transform) which is well adapted to chirping signals like those originating from compact binary coalescences (CBC), and show that it is also invertible just like the wavelet Q-transform. The inversion formulas of both transforms allow for effective noise filtering and produce very clean reconstructions of gravitational-wave signals. Our preliminary results indicate that the method could be well suited to perform accurate tests of general relativity by comparing modeled and unmodeled reconstructions of CBC gravitational-wave signals.

Recently, the peak structure of the sound velocity was observed in the lattice simulation of two-color and two-flavor QCD at the finite quark chemical potential. The comparison with the chiral perturbation theory (ChPT) result was undertaken; however, the ChPT failed in reproducing the peak structure. In this study, to extend the ChPT framework, we incorporate contributions of the $\sigma$ meson, that is identified as the chiral partner of pions, on top of the low-energy pion dynamics by using the linear sigma model (LSM). Based on the LSM, we derive analytic expressions of the thermodynamic quantities as well as the sound velocity within a mean-field approximation. As a result, we find that those quantities are provided by sums of the ChPT results and corrections, where the latter is characterized by a mass difference between the chiral partners, the $\sigma$ meson and pion. The chiral partner contributions are found to yield a peak in the sound velocity successfully. We furthermore show that the sound velocity peak emerges only when $m_{\sigma }>\sqrt{3}{m}_{\pi }$ and ${\mu }_q>m_{\pi }$, with $m_{\sigma (\pi )}$ and ${\mu }_q$ being the $\sigma$ meson (pion) mass and the quark chemical potential, respectively. The correlation between the sound velocity peak and the sign of the trace anomaly is also addressed.

Effects of tensor spin polarization (TSP) on the chiral restoration and deconfinement phase transitions are studied in Polyakov loop extended Nambu–Jona-Lasinio (PNJL) model. For chiral phase transition, the higher the polarized degree of quark-antiquark pairs under the strong magnetic field, the higher the phase transition temperature. The TSP corrects the position of the critical end point. The small impact of TSP on the phase transition temperature is found for the deconfinement phase transition. On the other hand, we divide the phase space into three ranges based on the phase diagram obtained from the PNJL model: the confinement phase with chiral symmetry broken, the deconfinement phase with restored chiral symmetry, and the confinement phase with restored chiral symmetry (quarkyonic phase). It is found that TSP has only a very small effect on the anisotropic pressure in the deconfined phase with chiral symmetry restored and the quarkyonic phase, but it has a very strong effect on the anisotropic pressure in the confined phase with chiral symmetry broken. This is because TSP is closely related to chiral symmetry. The restoration of chiral symmetry means the dissociation of spin polarization condensate.

The $B_c$ meson pair, including pairs of pseudoscalar states and vector states, productions in proton-proton collisions are investigated at the next-to-leading order (NLO) accuracy in the nonrelativistic quantum chromodynamics factorization formalism. The corresponding cross sections at the Large Hadron Collider (LHC) with $\sqrt{s}=14\mathrm{TeV}$ are evaluated. Numerical results indicate that the NLO corrections are substantial, and even dominate over the leading order contributions. Considering the predicted cross sections are sizable, the $B_c$-pair production is expected to be observable at the high-luminosity LHC experiment.

In many well-motivated models of the electroweak scale, cascade decays of new particles can result in highly boosted hadronic resonances (e.g., $Z/W/h$). This can make these models rich and promising targets for recently developed resonant anomaly detection methods powered by modern machine learning. We demonstrate this using the state-of-the-art classifying anomalies through outer density estimation (cathode) method applied to supersymmetry scenarios with gluino pair production. We show that cathode, despite being model agnostic, is nevertheless competitive with dedicated cut-based searches, while simultaneously covering a much wider region of parameter space. The gluino events also populate the tails of the missing energy and $H_T$ distributions, making this a novel combination of resonant and tail-based anomaly detection.

As the study of three-hadron physics from lattice QCD matures, it is necessary to develop proper analysis tools in order to reliably study a variety of phenomena, including resonance spectroscopy and nuclear structure. Reconstructing the three-particle scattering amplitude requires solving integral equations, which can be written in terms of data-constrained dynamical functions and physical on shell quantities. The driving term in these equations is the so-called one-particle exchange, which leads to a kinematic divergence for particles on mass shell. A vital component in defining three-particle amplitudes with definite parity and total angular momentum, which are used in spectroscopic studies, is to project the one-particle exchange into definite partial waves. We present a general procedure to construct exact analytic partial-wave projections of the one-particle exchange contribution for any system composed of three spinless hadrons. Our result allows one full control over the analytic structure of the projection, which we explore for some low-lying partial waves with applications to three pions.

We demonstrate that the longitudinal single target-spin asymmetry in exclusive ${\pi }^0$ production in $ep$ collisions can give access to the imaginary part of the gluon generalized transverse momentum distribution (GTMD) $F_{1,4}$. Such a longitudinal spin asymmetry that results from the Coulomb-nuclear interference effect, leads to a characteristic azimuthal angular correlation of $\sin 2\varphi$, where $\varphi$ is the azimuthal angle between the scattered lepton transverse momentum and the recoil proton’s transverse momentum. We also present a numerical estimate of the asymmetry for the kinematics accessible at EIC and EicC.

Axionlike particles (ALPs), the pseudo Nambu-Goldstone bosons associated to the spontaneous breaking of global symmetry, have emerged as promising dark matter candidates. Conventionally, in the context of misalignment mechanism, the nonthermally produced ALPs happen to stay frozen due to Hubble friction initially, and at a later stage, they begin to oscillate (before matter-radiation equality) at characteristic frequencies defined by their masses and behaving like cold dark matter. In this work, we study the influence of electroweak symmetry breaking (EWSB), through a higher order Higgs portal interaction, on the evolution of ALPs. Such an interaction is found to contribute partially to the ALP’s mass during EWSB, thereby modifying oscillation frequencies during EWSB as well as impacting upon the existing correlation between the scale of symmetry breaking and their masses. The novelty of the work lies in broadening the relic satisfied parameter space so as to probe it in near future via a wide range of experiments.

We consider a model where the interaction between dark matter and the Standard Model particles is mediated by a ghost-free bigravity portal. The bigravity model invokes a massive spin-2 particle coupled to the usual massless graviton as well as generic bimetric matter couplings. The cross sections for dark matter direct detection are computed and confronted with the experimental bounds. The presence of the massive spin-2 mediator resolves the core-cusp problem, which in turn significantly constrains the dark matter coupling in such a bigravity theory. Yet, there remains a window of the parameter space where the model can be tested in the upcoming direct detection experiments such as XENONnT and PandaX-30T. The model also predicts a reheating temperature on the order of ${10}^6\mathrm{GeV}$.

We study the possibility of constraining a scenario with high scale first order phase transition (FOPT) responsible for the cogenesis of baryon and dark matter using gravitational wave (GW) (non)observations. While the FOPT at high scale is responsible for generating baryon asymmetry through leptogenesis and dark matter via the mass-gain mechanism, the resulting GW spectrum falls within the ongoing LIGO-Virgo experimental sensitivity. The dark matter is preferred to be in the nonthermal ballpark with sub-GeV masses and the criteria of successful dark matter relic rules out a large portion of the parameter space consistent with high scale FOPT and successful leptogenesis. Some part of the parameter space allowed from dark matter and leptogenesis criteria also gives rise to a large signal-to-noise ratio at ongoing experiments and hence can be disfavored in a conservative way from the nonobservation of such stochastic GW background. Future data from ongoing and planned experiments will offer a complementary and indirect probe of the remaining parameter space which is typically outside the reach of any direct experimental probe.

By extracting the transition amplitudes, we give the first lattice QCD prediction of the two-body decay partial widths of the $1^{-+}$ charmoniumlike hybrid ${\eta }_{c1}$. Given the calculated mass value $m_{{\eta }_{c1}}=4.329(36)\mathrm{GeV}$, the ${\eta }_{c1}$ decay is dominated by the open charm modes $D_1\overline{D}$, $D^{*}\overline{D,}$ and $D^{*}{\overline{D}}^{*}$ with partial widths of 258(133), 88(18), and 150(118) MeV, respectively. The coupling of ${\eta }_{c1}$ to ${\chi }_{c1}$ plus a flavor singlet pseudoscalar is not small, but ${\chi }_{c1}\eta$ decay is suppressed by the small $\eta -{\eta }^{\prime }$ mixing angle. The partial width of ${\eta }_{c1}\to {\eta }_c{\eta }^{\prime }$ is estimated to be around 1 MeV. We suggest experiments to search for ${\eta }_{c1}$ in the $P$-wave $D^{*}\overline{D}$ and $D^{*}{\overline{D}}^{*}$ systems. Especially, the polarization of $D^{*}{\overline{D}}^{*}$ can be used to distinguish the $1^{-+}$ product (total spin $S=1$) from $1^{--}$ products ($S=0$).

We report the results of lattice numerical studies of the $Sp(4)$ gauge theory coupled to fermions (hyperquarks) transforming in the fundamental and two-index antisymmetric representations of the gauge group. This strongly coupled theory is the minimal candidate for the ultraviolet completion of composite Higgs models that facilitate the mechanism of partial compositeness for generating the top-quark mass. We measure the spectrum of the low-lying, half-integer spin, bound states composed of two fundamental and one antisymmetric hyperquarks, dubbed chimera baryons, in the quenched approximation. In this first systematic, nonperturbative study, we focus on the three lightest parity-even chimera-baryon states, in analogy with QCD, denoted as ${\mathrm{\Lambda }}_{\mathrm{CB}}$, ${\mathrm{\Sigma }}_{\mathrm{CB}}$ (both with spin $1/2$), and ${\mathrm{\Sigma }}_{\mathrm{CB}}^{*}$ (with spin $3/2$). The spin-$1/2$ such states are candidates of the top partners. The extrapolation of our results to the continuum and massless-hyperquark limit is performed using formulas inspired by QCD heavy-baryon Wilson chiral perturbation theory. Within the range of hyperquark masses in our simulations, we find that ${\mathrm{\Sigma }}_{\mathrm{CB}}$ is not heavier than ${\mathrm{\Lambda }}_{\mathrm{CB}}$.

Using Laplace transform techniques, we describe the determination of the longitudinal structure function $F_L(x,Q^2)$, at the leading-order approximation in momentum space, from the structure function $F_2(x,Q^2)$ and its derivative with respect to $\ln Q^2$ in a kinematical region of low values of the Bjorken variable $x$. Since the $x$ dependence of $F_2(x,Q^2)$ and its evolution with $Q^2$ are determined much better by the data than $F_L(x,Q^2)$, this method provides both a direct check on $F_L(x,Q^2)$ where measured, and a way of extending $F_L(x,Q^2)$ into regions of $x$ and $Q^2$ where there are currently no data. In our calculations, we ultilize the Block-Durand-Ha parametrization for the structure function $F_2(x,Q^2)$ [M. M. Block et al., Phys. Rev. D 89, 094027 (2014).]. We find that the Laplace transform method in momentum space provides correct behaviors of the extracted longitudinal structure function $F_L(x,Q^2)$ and that our obtained results are in line with data from the H1 Collaboration and other results for $F_L(x,Q^2)$ obtained using Mellin transform method.