We systematically investigate theoretical uncertainties in perturbative analyses of first-order electroweak phase transitions (EWPTs). Utilizing the Standard Model effective field theory framework, we quantify the gauge dependence, renormalization scheme, and scale dependencies in predicting phase-transition parameters across both zero and finite chemical potential regimes. Our key findings reveal that: (1) The gauge-parameter dependence and the chemical potential are subdominant, and (2) Baryon number preservation criteria and phase transition observables exhibit pronounced sensitivity to the renormalization scale in the $\overline{\mathrm{MS}}$ scheme. Comparative analyses with the on-shell scheme demonstrate that within strongly first-order EWPT parameter spaces, the $\overline{\mathrm{MS}}$ scheme predicts enhanced phase transition strengths and prolonged transition durations.

Helicity selection rules can suppress the leading contributions from dimension-6 operators in the Standard Model effective field theory (SMEFT), reducing sensitivity to potential new physics. This paper explores how the interference contributions from the $\tau$ lepton’s anomalous dipole moment is restored in different observables, in particular comparing the sensitivity to SMEFT operators of quantum information observable and more traditional spin correlations. We compute the sensitivity of various observables—including entanglement measures, Bell inequality violations, and quantum uncertainties—to new physics effects using Monte Carlo simulations. Spin correlation observables are found to outperform both the integrated cross section and quantum information observables in sensitivity to both $CP$-conserving and -violating effects, improving the sensitivity to the scale of new physics by up to a factor of 3. Our results suggest that quantum information observables are suboptimal probes for resurrecting the interference, and more in general to disentangle the $CP$ properties of new physics.

In this article, we probe the trilinear $R$-parity violating (RPV) supersymmetric (SUSY) scenarios with specific nonzero interactions in the light of neutrino oscillation, Higgs, and flavor observables. We attempt to fit the set of observables using a state-of-the-art Markov Chain Monte Carlo (MCMC) setup and study its impact on the model parameter space. Our main objective is to constrain the trilinear couplings individually, along with some other SUSY parameters relevant to the observables. We present the constrained parameter regions in the form of marginalized posterior distributions on different two-dimensional parameter planes. We perform our analyses with two different scenarios characterized by our choices for the lightest SUSY particle (LSP), bino, and stop. Our results indicate that the lepton number violating trilinear couplings ${\lambda }_{i33}$ ($i=1$, 2) and ${\lambda }_{j33}^{\prime }$ ($j=1$, 2, 3) can be at most of the order of ${10}^{-4}$ or even smaller while $\tan \beta$ is restricted to below 15 even when $3\sigma$ allowed regions are considered. We further comment on the possible LHC signatures of these LSPs focusing on and around the best-fit regions.

A lattice implementation of the recently introduced center-symmetric Landau gauge is discussed and its predictions confronted with numerical Monte Carlo simulations. It is shown that the link average and the link correlators computed in that gauge are order parameters of the confinement-deconfinement transition at nonzero temperature. Strictly speaking, this requires a specific treatment of the Gribov copies that we discuss in detail. The numerical simulations comply with the theoretical predictions for the link average computed below and above the deconfinement temperature. Our results show that, within appropriately chosen gauges, one can construct local order parameters for center symmetry, as proxies for the nonlocal Polyakov loop.

Without invoking any cumulant determination at the input level, we present here the first calculations of direct estimates of the Lee-Yang zeros of the QCD partition function in ($2+1$)-flavor QCD. These zeros are obtained in the complex isospin chemical potential ${\mu }_I$ plane using the unbiased exponential resummation formalism on $N_{\tau }=8$ lattices and with physical quark masses. For different temperatures, we illustrate the stability of the zeros closest to the origin from which we subsequently procure the radius of convergence estimates. From the temperature-dependence study of the real and imaginary parts of these zeros, we try estimating one of the possible critical points forming the second-order pion condensate critical line in the isospin phase diagram. Further, we compare these resummed estimates with the corresponding Mercer-Roberts estimates of the subsequent Taylor series expansions of the first three partition function cumulants. We also outline comparisons between resummed and Taylor series results of these cumulants for real and imaginary values of ${\mu }_I$ and highlight the behavior of different expansion orders within and beyond the obtained resummed estimates of the radius of convergence. We also reestablish that this resummed radius of convergence can efficiently capture the onset of the overlap problem for finite real ${\mu }_I$ simulations.

The structure of center vortices is studied in SU(4) Yang-Mills theory for the first time to illuminate the interplay between elementary (center charge $\pm 1$) and doubly charged vortices. Unlike in SU(3), where charge $+2$ vortices are simply elementary vortices with reversed orientations in spacetime, these possibilities are physically distinct in SU(4). Visualizations of the vortex structure in three-dimensional slices reveal the various ways in which doubly charged objects manifest, as the convergence and matching of elementary vortices or as isolated doubly charged loops. An algorithm is described to classify every doubly charged chain as one of these three types. A collection of vortex statistics is considered to quantify the vortex structure. Many of these pertain to the novel doubly charged objects, including their relative proportions and chain lengths, which are analyzed to highlight the differences between each chain type. Three different lattice spacings are employed to investigate the approach to the continuum limit. Vortex matching chains are found to be shorter on average but also more prevalent than vortex convergences, ascribed to their interpretation as extended center monopoles. In addition, the lengths of both vortex convergences and vortex matchings are observed to follow an exponential distribution, allowing the introduction of a constant probability for a doubly charged chain to split into two elementary vortices as it propagates. Combined, these findings provide a characterization of the vortices that comprise center-vortex structures in SU(4) Yang-Mills theory.

Minimally doubled fermions realize one pair of Dirac fermions on the lattice. Similarities to staggered fermions exist, namely, spin and taste degrees of freedom become intertwined, and a peculiar nonsinglet chiral symmetry and ultralocality are maintained. However, charge conjugation, some space-time reflection symmetries and isotropy are broken by the cutoff. We address the most simple variant, Karsten-Wilczek (KW) fermions, in its parallel and in its perpendicular version. We derive the correct spin-taste representation from first principles. The spin-taste representation on the quark level permits construction of local or extended hadron interpolating operators for any spin-taste combination, albeit with contamination by parity partners and taste-symmetry breaking. We classify all interpolating operators for mesons and diquarks, and give examples for baryons. We also discuss the appropriate discretizations for taste-singlet or taste-isovector mass or chemical potential terms. We explain the counterterms in the spin-taste framework, and derive generic constraints on the parametric form and cutoff effects from the KW determinant and hadronic correlation functions. We derive how and why nonperturbative tuning schemes for the counterterms work, and obtain analytic, assumption-free, nonperturbative predictions for taste-symmetry breaking and other hadronic properties from first principles. In particular, we identify the origin and nature of two different types of taste-symmetry breaking cutoff effects. The few available numerical results for KW fermions validate these predictions.

A mathematical duality exists between massless scalar fields and relativistic fluids governed by an ultrastiff equation of state, in which the pressure equals the mass-energy density, and the sound speed equals $c$. This duality entails that certain solutions of the wave equation (a linear theory) can be mapped to solutions of ideal relativistic hydrodynamics (an inherently nonlinear theory). Leveraging this correspondence, we explore some interesting properties of ultrastiff fluids. Specifically, we demonstrate that all nonlinear sound waves in such media are solitons. Moreover, we prove that, in $3+1$ dimensions, compactly supported configurations of an ultrastiff fluid inevitably evolve, in finite time, toward a singular state where the fluid’s flow velocity exits the future light cone. We also demonstrate that, prior to the formation of this singularity, first-order perturbation theory in the small parameter $c_s^{-2}-c^{-2}$ produces divergent results. As a consequence, a fluid whose speed of sound is, say, 0.995 $c$ exhibits markedly different behavior near the singularity compared to a fluid with a speed of sound exactly equal to $c$.

A quantum theory of asymptotically flat spacetimes is presented using the solutions of the null surface formulation (NSF) field equations in a perturbative scheme. Free-field commutation relations are given for the null free data of NSF at future or past null infinity, and the main variables of NSF are then used to define the interior points of the spacetime as labels and the metric of the spacetime as a derived quantum operator. A nontrivial scattering of gravitons is given.

In tests of gravity using gravitational waves (GWs), GW events analyzed are often selected based on specific criteria, particularly the signal-to-noise ratio. However, such event selection can introduce bias into parameter estimation unless the selection effect is appropriately taken into account in the analysis. In this paper, we investigate how event selection with certain prior information affects parameter inference within the scalar-tensor polarization framework, focusing on the measurement of the scalar mode amplitude parameters. We find that for the $\text{Tensor}+\text{Scalar}(\text{dipole})$ model, the amplitude of the scalar dipole radiation is overestimated when its true value is nonzero, while there is no false deviation in the absence of the scalar mode. The same bias is expected to occur also for the $\text{Tensor}+\text{Scalar}(\text{quadrupole})$ model. However, the error typically exceeds the bias, as the scalar quadrupole mode is difficult to be distinguished from the tensor mode.

The study of dark matter substructure through strong gravitational lensing has shown enormous promise in probing the properties of dark matter on subgalactic scales. This approach has already been used to place strong constraints on a wide range of dark matter models including self-interacting dark matter, fuzzy dark matter and warm dark matter. One major uncertainty in these studies is the strength of tidal stripping experienced by subhalos. We study theoretical predictions for the statistical properties of subhalos in strong gravitational lenses using the semianalytic galaxy formation toolkit galacticus. We present a large suite of dark matter only galacticus models, spanning nearly 2 orders of magnitude in host halo mass (from Milky Way to group mass halos between redshifts from 0.2 to 0.8). Additionally, to address potential shortcomings of including only dark matter physics we include a smaller set of galacticus runs with the potential of a central massive elliptical to complement our dark matter only suite of models. We place particular focus on quantities relevant to strong gravitational lensing; namely the projected number density of substructure near the Einstein radius as a function of the host stellar mass and redshift. In the innermost region in projection, we find that our galacticus models agree with N-body simulations within a factor of $\sim 2$ within the Einstein radius. We find that the addition of a central galaxy suppresses the projected number density of subhalos within the Einstein radius by around 15% relative to dark matter only simulations.

Gravitational wave (GW) sources offer a valuable window to the physical processes that govern the formation of binary compact objects (BCOs). However, deciphering such information from GW data is substantially challenging due to the difficulty in mapping from the space of observation to the space of numerous theoretical models. We introduce the concept of BCO phase space that connects the observable space to the evolution trajectories of the BCO formation channels with cosmic time and apply it to the third GW transient catalog that brings new insights into probable astrophysical formation scenarios of nearly 90 events. Our study reveals that two events, GW190425 and GW230529, show an overlap with a BCO phase space trajectory of the same formation channel arising from a subsolar mass black hole scenario that has grown into a higher mass by accretion, hinting towards the common primordial origin of both these sources. Though the actual formation channel is yet to be confirmed, with the availability of more GW events, the BCO phase space can delve into distinguishing features of different formation channels for both astrophysical and primordial origin and opens the possibility of bringing new and deeper insights on the formation and evolution of BCOs across all observable masses over most of the cosmic time.

The next generation of galaxy surveys will provide highly precise measurements of galaxy clustering, therefore requiring a corresponding accuracy. Current approaches, which rely on approximations and idealized assumptions, may fall short in capturing the level of detail required for high-precision observations. In order to increase the modeling accuracy, recently, unequal-time contributions to the galaxy power spectrum have been introduced in order to include the effects of radial correlations. We present a generalization of the formalism for the observed unequal-time power spectrum, that includes Doppler and local general relativistic corrections, plus local primordial non-Gaussianity. We find that unequal-time corrections can potentially mimic an effective $f_{\mathrm{NL}}$ of order unity. We provide a first assessment of the significance of unequal-time corrections for future galaxy clustering experiments, estimating a signal-to-noise ratio of $\sim 3$ for stage-IV- like surveys.

We investigate the impact of the $d^{*}(2380)$ hexaquark on the equation of state (EOS) of dense matter within hybrid stars (HSs) using the chiral mean-field model (CMF). The hexaquark is included as a new degree of freedom in the hadronic phase, and its influence on the deconfinement transition to quark matter is explored. We reparametrize the CMF model to ensure compatibility with recent astrophysical constraints, including the observation of massive pulsars and gravitational wave events. Our results show that the presence of $d^{*}$ significantly modifies the EOS, leading to a softening at high densities and a consequent reduction in the predicted maximum stellar masses. Furthermore, we examine the possibility of a first-order deconfinement phase transition within the context of the extended stability branch of slow stable HSs (SSHSs). We find that the presence of hexaquarks can delay the deconfinement phase transition and reduce the associated energy density gap, affecting the structure and stability of HSs. Our results suggest that, as the hexaquark appearance tends to destabilize stellar configurations, fine-tuning of model parameters is required to obtain both the presence of hexaquarks and quark deconfinement in these systems. In this scenario, the SSHS branch plays a crucial role in obtaining HSs with hexaquarks that satisfy current astrophysical constraints. Our work provides new insights into the role of exotic particles like $d^{*}$ in dense matter and the complex interplay between hadronic and quark degrees of freedom inside compact stellar objects.

Dark photons that are sufficiently light and/or weakly interacting represent a compelling vision of dark matter. Dark photon decay into three photons, which we call the dark photon trident, can be the dominant channel when the dark photon mass falls below the electron pair threshold and can produce a significant flux of x rays. We use 16 years of data from Interrnational Gamma-Ray Astro Physics Laboratory (INTEGRAL)/Spectrometer of INTEGRAL (SPI) to constrain sub-MeV dark photon decay, producing new worlds-best constraints on the kinetic mixing parameter for dark photon masses between 90 and 1022 keV, and comment on the potential for future x-ray observatories to discover the trident decay process.

We probe dark matter-electron scattering using high-energy neutrino observations from the Sun. Dark matter (DM) interacting with electrons can get captured inside the Sun. These captured DM may annihilate to produce different Standard Model (SM) particles. Neutrinos produced from these SM states can be observed in IceCube and DeepCore. Although there is no excess of neutrinos in the solar direction, we find that the current datasets of IceCube and DeepCore set the strongest constraint on the DM-electron scattering cross section in the DM mass range 10–${10}^5\mathrm{GeV}$. Therefore our work implies that future observations of the Sun by neutrino telescopes have the potential to discover the DM-electron interaction.

The detection of neutrinos from future core-collapse supernovae holds the potential to uncover critical insights into the explosion mechanism and to address key open questions in particle physics, especially the aspects beyond the Standard Model. In this work, we investigate the feasibility of detecting supernova neutrinos using the proposed Indian Coherent Neutrino Scattering Experiment (ICNSE), considering two detector materials: high purity germanium (HPGe) and sapphire. We show that the ICNSE setup is capable of detecting supernovae occurring within 750 pc at a significance level of $3\sigma$ above the targeted background. More significantly, we demonstrate that sapphire-based detectors can track the time evolution of the neutrino flux, which enables the distinction between different explosion models and the extraction of supernova explosion parameters like the shock revival time. We assess the impact of uncertainties in the quenching factor on the interpretation of the detected signal. Additionally, we explore the sensitivity of the experiment to the absolute neutrino mass scale and potential signatures of large secret neutrino interactions.

Universal quantum simulations of gauge field theories are exposed to the risk of gauge symmetry violations when it is not known how to compile the desired operations exactly using the available gate set. In this article, we show how time evolution can be compiled in an Abelian gauge theory—if only approximately—without compromising gauge invariance, by graphically motivating a block-diagonalization procedure. When gauge-invariant interactions are associated with a “spatial network” in the space of discrete quantum numbers, it is seen that cyclically shearing the spatial network converts simultaneous updates to many quantum numbers into conditional updates of a single quantum number; ultimately, this eliminates any need to pass through (and acquire overlap onto) unphysical intermediate configurations. Shearing is explicitly applied to gauge-matter and magnetic interactions of lattice quantum electrodynamics. The features that make shearing successful at preserving Abelian gauge symmetry may also be found in non-Abelian theories, bringing one closer to gauge-invariant simulations of quantum chromodynamics.

We study Drell-Yan production in universal theories consistently including effects beyond dimension six in the Standard Model effective field theory (SMEFT). Within universal SMEFT and with $C$ and $P$ conservation we find that 11 dimension-eight operators contribute in addition to the six contributing at dimension six. We first work in an operator basis in which operators with higher derivatives of the bosonic fields have been rotated by equations of motion in favor of combinations of operators involving SM fermion currents. We derive the general form of the amplitudes consistently in the expansion to $\mathcal{O}({\mathrm{\Lambda }}^{-4})$ and identify eight combinations of the 17 Wilson coefficients which are physically distinguishable by studying the invariant mass distribution of the lepton pairs produced. We then introduce an extension of the parametrization of universal effects in terms of oblique parameters obtained by linearly expanding the self-energies of the electroweak gauge bosons to $\mathcal{O}(q^6)$. It contains 11 oblique parameters of which only eight are generated within SMEFT at dimension eight: $\widehat{S}$, $\widehat{T}$, $W$, $Y$, $\widehat{U}$, $X$, plus two additional which we label $W^{\prime }$ and $Y^{\prime }$ and show how they match at linear order with the eight identified combinations of operator coefficients. We then perform a combined analysis of a variety of LHC data on the neutral- and charged-current Drell-Yan processes with the aim of constraining the eight combinations. We compare and combine the LHC bounds with those from electroweak precision $W$ and $Z$ pole observables which can only provide constraints in four directions of the eight-parameter space. We present the results in terms of limits on the eight effective Wilson coefficients as well as on the eight oblique parameters. In each case, we study the dependence of the derived constraints on the order of the expansion considered.

A search for leptons displaced from the primary vertex is performed with the ATLAS detector at the Large Hadron Collider. The search includes the full proton-proton collision dataset collected during Run 2 at $\sqrt{s}=13\mathrm{TeV}$ and a partial dataset collected during Run 3 in 2022–2023 at $\sqrt{s}=13.6\mathrm{TeV}$, corresponding to integrated luminosities of $140{\mathrm{fb}}^{-1}$ and $56.3{\mathrm{fb}}^{-1}$, respectively. Final states with displaced electrons or muons are considered, and novel triggers introduced in Run 3 are employed that use large impact parameter tracking to reconstruct displaced tracks with low momentum. In addition, photon reconstruction and multivariate techniques are employed to broaden the sensitivity to channels with large background rates or highly displaced electrons, respectively. The results are consistent with the Standard Model background expectations and are used to set model-independent limits on the production of displaced electrons and muons. The analysis is also interpreted in the context of a gauge-mediated supersymmetry breaking model with pair-produced long-lived sleptons and a dark sector model with pair-produced chargino-like states. The results include 95% confidence level exclusions of selectrons with lifetimes from 4 ps to 60 ns and a mass of 150 GeV, and exclusions of selectrons, smuons, and staus with a lifetime of 0.3 ns for masses up to 740, 830, and 440 GeV, respectively. Dark charginos with masses up to 380 GeV are excluded for a mass difference with the neutral state of 40 GeV, and mass differences down to 17 GeV are excluded for dark charginos with a 100 GeV mass.