We analyze several aspects of detectors with uniform acceleration $a$ and uniform rotation $\mathrm{\Omega }$ in de Sitter ($\mathrm{\Lambda }>0$) and anti–de Sitter ($\mathrm{\Lambda }<0$) spacetimes, focusing particularly on the periodicity, in (Euclidean) proper time ${\tau }_{\mathrm{traj}}$, of geodesic interval ${\tau }_{\mathrm{geod}}$ between two events on the trajectory. For $\mathrm{\Lambda }<0$, ${\tau }_{\mathrm{geod}}$ is periodic in $\mathrm{i}{\tau }_{\mathrm{traj}}$ for specific values of $a$ and $\mathrm{\Omega }$. These results are used to obtain numerical plots for the response rate $\dot{\mathcal{F}}$ of Unruh-DeWitt detectors, which display nontrivial combined effects of rotation and curvature through the dimensionless parameter $\mathrm{\Lambda }{c}^2/{\mathrm{\Omega }}^2$. In particular, periodicity does not imply thermality due to additional poles in the Wightman function away from the imaginary axis. We then present some results for stationary rotational motion in arbitrary curved spacetime, as a perturbative expansion in curvature.

In nonminimally coupled theories where a scalar field $\varphi$ is coupled to the Ricci scalar, neutron stars (NSs) can have scalar charges through an interaction with matter mediated by gravity. On the other hand, the same theories do not give rise to hairy black hole (BH) solutions. The observations of gravitational waves (GWs) emitted from an inspiralling NS-BH binary system allows a possibility of constraining the NS scalar charge. Moreover, the nonminimally coupled scalar-tensor theories generate a breathing scalar mode besides two tensor polarizations. Using the GW200115 data of the coalescence of a BH-NS binary, we place observational constraints on the NS scalar charge as well as the nonminimal coupling strength for a subclass of massless Horndeski theories with a luminal GW propagation. Unlike past related works, we exploit a waveform for a mixture of tensor and scalar polarizations. Taking the breathing mode into account, the scalar charge is more tightly constrained in comparison to the analysis of the tensor GWs alone. In nonminimally coupled theories including Brans-Dicke gravity and spontaneous scalarization scenarios with/without a kinetic screening, we put new bounds on model parameters of each theory.

We consider antisymmetric metric-affine theories of gravity with a Lagrangian containing the most general terms up to dimension four and search for theories that are ghost- and tachyon-free when expanded around flat space. We find new examples that propagate only the graviton and one other massive degree of freedom of spin zero, one, or two. These models require terms of the form $(\nabla T{)}^2$ in the Lagrangian, that have been largely ignored in the literature.

We consider the effects of a bare mass term for the inflaton, when the inflationary potential takes the form $V(\varphi )=\lambda {\varphi }^k$ about its minimum with $k\ge 4$. We concentrate on $k=4$, but discuss general cases as well. Further, we assume $\lambda {\varphi }_{\mathrm{end}}^2\gg m_{\varphi }^2$, where ${\varphi }_{\mathrm{end}}$ is the inflaton field value when the inflationary expansion ends. We show that the presence of a mass term (which may be present due to radiative corrections or supersymmetry breaking) can significantly alter the reheating process, as the equation of state of the inflaton condensate changes from $w_{\varphi }=\frac{1}{3}$ to $w_{\varphi }=0$ when $\lambda {\varphi }^2$ drops below $m_{\varphi }^2$. We show that, for a mass $m_{\varphi }\gtrsim 3{\lambda }^{\frac{1}{4}}{T}_{\mathrm{RH}}$, the mass term will dominate at reheating. The value of $\lambda$ is relatively model independent as it is normalized by the cosmic microwave background perturbation spectrum. For T models of inflation, this leads to $m_{\varphi }\gtrsim T_{\mathrm{RH}}/250$. We compute the effects on the reheating temperature for cases where reheating is due to inflaton decay (to fermions, scalars, or vectors) or to inflaton scattering (to scalars or vectors). For scattering to scalars and in the absence of a decay, there is always a residual inflaton background that acts as cold dark matter. In this case, we derive a strong upper limit to the inflaton bare mass which for T models is $m_{\varphi }<350\mathrm{MeV}(T_{\mathrm{RH}}/{10}^{10}\mathrm{GeV}{)}^{3/5}$. We also consider the effect of the bare mass term on the fragmentation of the inflaton condensate.

The curvature in the blazar spectrum has the potential to understand the particle dynamics in jets. We performed a detailed analysis of simultaneous Swift-XRT (0.3–10 keV) and NuSTAR (3–79 keV) observations of Mkn 421. Our analysis of NuSTAR observations alone reveals that, during periods of low flux, the hard x-ray spectra are best represented by a steep power-law with photon index reaching $\sim 3$. However, the spectrum exhibits significant curvature during its high flux states. To investigate this, we explore plausible diffusion processes facilitating shock acceleration in the emission region that can contribute to the observed spectral curvature. Particularly, such processes can cause gradual fall of the photon spectrum at high energies which can be represented by a subexponential function. The parameter that decides this spectral change can be used to characterize the energy dependence of the diffusive process. Our results suggest that the x-ray spectra of Mkn 421 are consistent with a scenario where particle acceleration is mediated through Bohm-type diffusion and the spectra beyond the synchrotron peak is modulated by the radiative loss process.

For the study of the structure of baryons it is necessary to investigate the production of a baryon pair in $e^{+}{e}^{-}$ annihilation. The baryon-antibaryon pair production at the electron-positron linear collider makes it possible to investigate in detail the basic structure of the Standard Model. The creation of baryon-antibaryon pairs in electron-positron annihilation provides an increasingly powerful tool at higher c.m. energies. We present phenomenological results for ${\mathrm{\Sigma }}^0{\overline{\mathrm{\Sigma }}}^0$ production in $e^{+}{e}^{-}$ interaction at the BESIII and BABAR Colliders. In the present work, we investigate a hyperon pair produced in the reaction $e^{+}{e}^{-}\to {\mathrm{\Sigma }}^0{\overline{\mathrm{\Sigma }}}^0$. We calculate the total cross section of the process $e^{+}{e}^{-}\to {\mathrm{\Sigma }}^0{\overline{\mathrm{\Sigma }}}^0$ taking into account the contributions of the $D$-meson loop and three gluon loops as well as the interference of all diagrams to the Born approximation. For these contributions large relative phases are generated with respect to the pure electromagnetic mechanism. For the large momentum transferred region we obtain as a byproduct a fit of the electromagnetic form factor of the $\mathrm{\Sigma }$ hyperon.

Experimental particle physics uses machine learning for many tasks, where one application is to classify signal and background events. This classification can be used to bin an analysis region to enhance the expected significance for a mass resonance search. In natural language processing, one of the leading neural network architectures is the transformer. In this work, an event classifier transformer is proposed to bin an analysis region, in which the network is trained with special techniques. The techniques developed here can enhance the significance and reduce the correlation between the network’s output and the reconstructed mass. It is found that this trained network can perform better than boosted decision trees and feed-forward networks.

Axions and axionlike particles are well-motivated dark matter candidates. We propose a novel experiment that uses single-photon detection interferometry to search for axions and axionlike particles in the Galactic halo. We show that photon counting with a dark count rate of $6\times {10}^{-6}\mathrm{Hz}$ can improve the quantum sensitivity of axion interferometry by a factor of 50 compared to the quantum-enhanced heterodyne readout for 5-m-long optical resonators. The proposed experimental method has the potential to be scaled up to kilometer-long facilities, enabling the detection or setting of constraints on the axion-photon coupling coefficient of ${10}^{-17}-{10}^{-16}{\mathrm{GeV}}^{-1}$ for axion masses ranging from 0.1 to 1 neV.

Finding all possible UV resonances of effective operators is an important task in the bottom-up approach of effective field theory. We present all the tree-level UV resonances for the dimension-5, -6, and -7 operators in the Standard Model effective field theory (SMEFT) and then obtain the correspondence between the UV resonances and the effective operators from the relations among their Wilson coefficients, through the functional matching and operator reduction procedure. This provides a cross-dimension UV/IR dictionary for the SMEFT at tree level, and the methods used here, especially the on shell construction of general UV Lagrangian and the systematic reduction of operators, are extendable for UV resonances of $d\ge 8$ operators in SMEFT and other effective field theories.

We present a novel artificial intelligence approach for beyond the Standard Model parameter space scans by augmenting an evolutionary strategy with novelty detection. Our approach leverages the power of evolutionary strategies, previously shown to quickly converge to the valid regions of the parameter space, with a novelty reward to continue exploration once converged. Taking the $Z_3$ 3HDM as our physics case, we show how our methodology allows us to quickly explore highly constrained multidimensional parameter spaces, providing up to eight orders of magnitude higher sampling efficiency when compared with pure random sampling and up to four orders of magnitude when compared to random sampling around the alignment limit. In turn, this enables us to explore regions of the parameter space that have been hitherto overlooked, leading to the possibility of novel phenomenological realizations of the $Z_3$ three Higgs doublet model that had not been considered before.

Proton decay in six-dimensions orbifolded on square $T^2/Z_2$ is highly suppressed at tree level. This is because baryon number violating (BNV) operators containing only the zero mode of bulk fermions must satisfy the selection rule $\frac{3}{2}\mathrm{\Delta }B\pm \frac{1}{2}\mathrm{\Delta }L=0\mathrm{mod}4$. In this article, we show that the above relation does not prohibit mass dimension-six BNV operators containing Kaluza-Klein partners of the bulk fermions. Together with a “spinless” adjoint scalar partner of hypercharge gauge boson (the dark matter candidate), these novel operators generate dark matter assisted proton decay at mass dimension eight. Here, with explicit examples of scalar and vector baryon number violating interactions, we discuss the importance of such $\mathrm{\Delta }B=1=\mathrm{\Delta }L$ and $\mathrm{\Delta }B=2=\mathrm{\Delta }L$ operators and derive the limit on new physics.

In this paper we have studied the phenomenon of nonstandard interaction mediated by a scalar field (SNSI) in the context of P2SO experiment and compared its sensitivity with DUNE. In particular, we have studied the capability of these two experiments to put bounds on the diagonal SNSI parameters, i.e., ${\eta }_{ee}$, ${\eta }_{\mu \mu }$, and ${\eta }_{\tau \tau }$ and studied the impact of these parameters on the determination of neutrino mass ordering, octant of ${\theta }_{23}$ and $CP$ violation (CPV). In our analysis we find that, the parameter $\mathrm{\Delta }{m}_{31}^2$ has a nontrivial role if one wants estimate the bounds on ${\eta }_{\mu \mu }$ and ${\eta }_{\tau \tau }$ assuming SNSI does not exist in nature. Our results show that sensitivity of P2SO and DUNE to constraint ${\eta }_{\mu \mu }$ and ${\eta }_{\tau \tau }$ are similar whereas the sensitivity of DUNE is slightly better for ${\eta }_{ee}$. We find that the mass ordering and CPV sensitivities are mostly affected by ${\eta }_{ee}$ compared to ${\eta }_{\mu \mu }$ and ${\eta }_{\tau \tau }$ if one assumes SNSI exists in nature. On the other hand, octant sensitivity is mostly affected by ${\eta }_{\mu \mu }$ and ${\eta }_{\tau \tau }$. These sensitivities can be either higher or lower than the standard three flavor scenario depending on the relative sign of the SNSI parameters. Regarding the precision of atmospheric mixing parameters, we find that the precision of ${\theta }_{23}$ deteriorates significantly in the presence of ${\eta }_{\mu \mu }$ and ${\eta }_{\tau \tau }$.

We report new experimental results on the search for dark photons based on a near-quantum-limited haloscope equipped with a superconducting cavity. The loaded quality factor of the superconducting cavity is $6\times {10}^5$, so that the expected signal from dark-photon dark matter can be enhanced by more than one order compared to a copper cavity. A Josephson parametric amplifier with a near-quantum-limited noise temperature has been utilized to minimize the noise during the search. Furthermore, a digital acquisition card based on field programmable gate arrays has been utilized to maximize data collection efficiency with a duty cycle being 100%. This work has established the most stringent constraints on dark photons at around $26.965\mathrm{\mu }\mathrm{eV}$. In the future, our apparatus can be extended to search for other dark matter candidates, such as axions and axionlike particles, and scrutinize new physics beyond the Standard Model.

Machine-learned normalizing flows can be used in the context of lattice quantum field theory to generate statistically correlated ensembles of lattice gauge fields at different action parameters. This work demonstrates how these correlations can be exploited for variance reduction in the computation of observables. Three different proof-of-concept applications are demonstrated using a novel residual flow architecture: continuum limits of gauge theories, the mass dependence of QCD observables, and hadronic matrix elements based on the Feynman–Hellmann approach. In all three cases, it is shown that statistical uncertainties are significantly reduced when machine-learned flows are incorporated as compared with the same calculations performed with uncorrelated ensembles or direct reweighting.

We present a succinct formulation of the energy-momentum tensor of the glasma characterizing the initial color fields in relativistic heavy-ion collisions in the color glass condensate effective theory. We derive concise expressions for the $(3+1)\mathrm{D}$ dynamical evolution of symmetric nuclear collisions in the weak field approximation employing a generalized McLerran-Venugopalan model with nontrivial longitudinal correlations. Utilizing Monte Carlo integration, we calculate in unprecedented detail non-trivial rapidity profiles of early time observables at RHIC and LHC energies, including transverse energy densities and eccentricities. For our setup with broken boost invariance, we carefully discuss the placement of the origin of the Milne frame and interpret the components of the energy-momentum tensor. We find longitudinal flow that deviates from standard Bjorken flow in the $(3+1)\mathrm{D}$ case and provide a geometric interpretation of this effect. Furthermore, we observe a universal shape in the flanks of the rapidity profiles regardless of collision energy and predict that limiting fragmentation should also hold at LHC energies.

Correlation functions are important probes for the behavior of quantum field theories. Already at tree-level, the refined Gribov-Zwanziger (RGZ) effective action for Yang-Mills theories provides a good approximation for the gluon propagator, as compared to that calculated by nonperturbative methods such as lattice field theory and Dyson-Schwinger equations. However, the study of higher correlation functions of the RGZ theory is still at its beginning. In this work we evaluate the ghost-gluon vertex function in Landau gauge at one-loop level, in $d=4$ space-time dimensions for the gauge groups SU(2) and SU(3). More precisely, we extend the analysis conducted in [1] for the soft-gluon limit to an arbitrary kinematic configuration. We introduce renormalization group effects by means of a toy model for the running coupling and investigate the impact of such a model in the ultraviolet tails of our results. We find that RGZ results match fairly closely those from lattice simulations, Schwinger-Dyson equations and the Curci-Ferrari model for three different kinematic configurations. This is compatible with RGZ being a feasible theory for the strong interaction in the infrared regime.

The logarithm of the soft function can be organised into sets of Feynman diagrams known as correlator webs(cwebs). We introduced a new formalism in Agarwal et al. [J. High Energy Phys. 06 (2022) 020] that allows one to determine several of the building blocks of cweb mixing matrices without explicit computations. In Agarwal et al. [J. High Energy Phys. 02 (2023) 258], we used this formalism to obtain the diagonal blocks of four general classes of cwebs to all orders in perturbation theory which also covered all the four-loop boomerang cwebs connecting four Wilson lines. In this work, we present complete mixing matrices and exponentiated color factors for boomerang cwebs at four loops that connect three and four Wilson lines. Also, we present a more efficient version of the algorithm of generating cwebs that was presented in Agarwal et al. [J. High Energy Phys. 05 (2020) 128]. This new algorithm has been used to generate the cwebs in the present work.

As one of the hypothetical principles in the Standard Model (SM), lepton flavor universality (LFU) should be tested with a precision as high as possible such that the physics violating this principle can be fully examined. The run of a $Z$ factory at a future $e^{+}{e}^{-}$ collider, such as the Circular Electron-Positron Collider or Future Circular Collider (electron/positron), provides a great opportunity to perform this task because of the large statistics and high reconstruction efficiencies for $b$ hadrons at the $Z$ pole. In this paper, we present a systematic study on the LFU test in future $Z$ factories. The goal is threefold. First, we study the sensitivities of measuring the LFU-violating observables of $b\to c\tau \nu$, i.e., $R_{J/\psi }$, $R_{D_s}$, $R_{D_s^{*}}$, and $R_{{\mathrm{\Lambda }}_c}$, where $\tau$ decays muonically. For this purpose, we develop the strategies for event reconstruction, based on the track information significantly. Second, we explore the sensitivity robustness against detector performance and its potential improvement with the message of event shape or beyond the $b$-hadron decays. A picture is drawn on the variation of analysis sensitivities with the detector tracking resolution and soft photon detectability, and the impact of Fox-Wolfram moments is studied on the measurement of relevant flavor events. Finally, we interpret the projected sensitivities in the SM effective field theory, by combining the LFU tests of $b\to c\tau \nu$ and the measurements of $b\to s{\tau }^{+}{\tau }^{-}$ and $b\to s\overline{\nu }\nu$. We show that the limits on the LFU-violating energy scale can be pushed up to $\sim \mathcal{O}(10)\mathrm{TeV}$ for $\lesssim \mathcal{O}(1)$ Wilson coefficients at Tera-$Z$.

We propose a symmetry resolution of entanglement for categorical noninvertible symmetries (CaT-SREE) in ($1+1$)-dimensional conformal field theories. The definition parallels that of grouplike invertible symmetries, employing the concept of symmetric boundary states with respect to a categorical symmetry. Our examination extends to rational conformal field theories, where the behavior of CaT-SREE mirrors that of grouplike invertible symmetries. We find that CaT-SREE can be defined if there is no obstruction to gauging the categorical symmetry, as happens in the case of grouplike symmetries. We also provide instances of the breakdown of entanglement equipartition at the next-to-leading order in the cutoff expansion. Our findings shed light on how the interplay between conformal boundary conditions and categorical symmetries lead to specific patterns in the entanglement entropy.

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.