Interspacecraft ranging is crucial for the suppression of laser frequency noise via time-delay interferometry (TDI). So far, the effects of onboard delays and ambiguities on the Laser Interferometer Space Antenna (LISA) ranging observables were neglected in LISA modeling and data processing investigations. In reality, onboard delays cause offsets and timestamping delays in the LISA measurements, and pseudorandom noise (PRN) ranging is ambiguous, as it determines only the range up to an integer multiple of the PRN code length. In this article, we identify the four LISA ranging observables: PRN ranging, the sideband beat notes at the interspacecraft interferometer, TDI ranging, and ground-based observations. We derive their observation equations in the presence of onboard delays, noise, and ambiguities. We then propose a three-stage ranging sensor fusion to combine these observables in order to gain accurate and precise ranging estimates. We propose to calibrate the onboard delays on ground and to compensate the associated offsets and timestamping delays in an initial data treatment (stage 1). We identify the ranging-related routines, which need to run continuously during operation (stage 2) and implement them numerically. Essentially, this involves the reduction of ranging noise, for which we develop a Kalman filter combining the PRN ranging and the sideband beat notes. We further implement cross-checks for the PRN ranging ambiguities and offsets (stage 3). We show that both ground-based observations and TDI ranging can be used to resolve the PRN ranging ambiguities. Moreover, we apply TDI ranging to estimate the PRN ranging offsets.

The back-linked Fabry-Perot interferometer (BLFPI) is an interferometer topology proposed for space gravitational wave antennas with the use of intersatellite Fabry-Perot interferometers. The BLFPI offers simultaneous and independent control over all interferometer length degrees of freedom by controlling the laser frequencies. Therefore, BLFPI does not require an active control system for the physical lengths of the intersatellite Fabry-Perot interferometers. To achieve a high sensitivity, the implementation must rely on an offline signal process for subtracting laser frequency noises. However, the subtraction has not been experimentally verified to date. This paper reports a demonstration of the frequency noise subtraction in the frequency band of 100 Hz–50 kHz, including the cavity pole frequency, using Fabry-Perot cavities with a length of 46 cm. The highest reduction ratio of approximately 200 was achieved. This marks the first experimental verification of the critical function in the BLFPI.

We perform a study of the $B^{*+}{B}^0,B^{*0}{B}^{+}$ correlation functions using an extension of the local hidden gauge approach which provides the interaction from the exchange of light vector mesons and gives rise to a bound state of these components in $I=0$ with a binding energy of about 21 MeV. After that, we face the inverse problem of determining the low energy observables, scattering length and effective range for each channel, the possible existence of a bound state, and, if found, the couplings of such a state to each $B^{*+}{B}^0,B^{*0}{B}^{+}$ component as well as the molecular probabilities of each of the channels. We use the bootstrap method to determine these magnitudes and find that, with errors in the correlation function typical of present experiments, we can determine all these magnitudes with acceptable precision. In addition, the size of the source function of the experiment from where the correlation functions are measured can be also determined with a high precision.

We calculate the momentum spectrum of electron-positron pairs created via the Schwinger mechanism by a class of four-dimensional electromagnetic fields called e-dipole fields. To the best of our knowledge, this is the first time the momentum spectrum has been calculated for 4D, exact solutions to Maxwell’s equations. Moreover, these solutions give fields that are optimally focused, and are hence particularly relevant for future experiments. To achieve this we have developed a worldline instanton formalism where we separate the process into a formation and an acceleration region.

Single phonon excitations, with energies in the 1–100 meV range, are a powerful probe of light dark matter (DM). Utilizing effective field theory, we derive a framework to compute DM absorption rates into single phonons starting from general DM-electron, proton, and neutron interactions. We apply the framework to a variety of DM models: Yukawa coupled scalars, axionlike particles with derivative interactions, and vector DM coupling via gauge interactions or Standard Model electric and magnetic dipole moments. We find that GaAs or ${\mathrm{Al}}_2{\mathrm{O}}_3$ targets can set powerful constraints on a $U(1{)}_{B-L}$ model, and targets with electronic spin ordering are similarly sensitive to DM coupling to the electron magnetic dipole moment. Lastly, we make the code, phonodark-abs (an extension of the existing phonodark code which computes general DM–single phonon scattering rates), publicly available.

We compute the full one-loop radiative corrections for charged scalar pair production $e^{+}{e}^{-}\to H^{+}{H}^{-}$ in the inert doublet model. The on-shell renormalization scheme has been used. We take into account both the weak contributions as well as the soft and hard QED corrections. We compute both the real emission and the one-loop virtual corrections using the Feynman diagrammatic method. The resummed cross section is introduced to cure the Coulomb singularity which occurs in the QED corrections. We have analyzed the parameter space of the inert doublet model in three scenarios after taking into account theoretical constraints, the collider experimental bounds, and dark matter search bounds as well. It is found that the weak interaction dominates the radiative corrections, and its size is determined by the triple Higgs coupling ${\lambda }_{h^0{H}^{+}{H}^{-}}$, which is further connected to the mass of the charged scalar. In the scenario where all the constraints are taken into account, we find that for $\sqrt{s}=250\mathrm{GeV}$ and $\sqrt{s}=500\mathrm{GeV}$, the weak corrections are around $-6\%\sim -5\%$ and $-10\%\sim -3\%$, respectively. While for $\sqrt{s}=1000\mathrm{GeV}$, the weak corrections can reach $-15\%\sim +25\%$. The new feature is that the weak corrections can be positive near the threshold when the charged scalar is heavier than 470 GeV. Six benchmark points for future collider searches have been proposed.

Real-time scattering calculations on a noisy intermediate scale quantum (NISQ) quantum computer are disrupted by errors that accumulate throughout the circuits. To improve the accuracy of such physics simulations, one can supplement the application circuits with a recent error mitigation strategy known as noiseless output extrapolation (NOX). We tested these error mitigation protocols on a transverse field Ising model and improved upon previous phase shift calculations. Our proof-of-concept 4-qubit application circuits were run on several IBM quantum computing hardware architectures. We introduce metrics that show between 22% and 73% error reduction for circuit depths ranging from 13 to 37 hard cycles, confirming that the NOX technique applies to circuits with a broad range of failure rates. We also observed an approximate 28% improvement in the accuracy of the time delay calculation of the scattering phase shift. These observations on different cloud-accessible devices confirm that NOX improves performance even when circuits are executed in substantially time-separated batches. Finally, we provide a heuristic method to obtain systematic error bars on the mitigated results, compare them with empirical errors and discuss their effects on phase shift estimates.

Factorization underlies all predictions at the Large Hadron Collider, but has only been rigorously proven in a few cases. One of these cases is the Drell-Yan process, $pp\to Z/\gamma +X$, in the limit of small-boson transverse momentum. We introduce a one-parameter family of observables, that we call vector angularities, of which the transverse momentum is a special case. This enables the study of factorization violation, with a smooth transition to the limit for which factorization has been established. Like the angularity event shapes, vector angularities are a sum of transverse momenta weighted by rapidity, but crucially this is a vector sum rather than a sum of the magnitude of transverse momenta. We study these observables in pythia, using the effect of multiparton interactions (MPI) as a proxy factorization violation, finding a negligible effect in the case where factorization is established but sizable effects away from it. We also present a factorization formula for the cross section, that does not include factorization violating contributions from Glauber gluons, and thus offers a baseline for studying factorization violation experimentally using vector angularities. Our predictions at next-to-leading logarithmic accuracy are in good in agreement with pythia (not including MPI), and can be extended to higher order.

We calculate the mass spectrum of the $Qs\overline{q}\overline{q}$ ($Q=c$, $b$) tetraquark states with $J^P=(0,1,2{)}^{+}$ using the AL1 quark potential model, which successfully describes the conventional hadron spectrum. We employ the Gaussian expansion method to solve the four-body Schrödinger equation and use the complex scaling method to identify the resonances. With the notation $T_{Qs,I(J)}^{\mathrm{Theo}.}(M)$, we find several near-threshold bound states and resonances, including $T_{cs,0(0)}^{\mathrm{Theo}.}(2350)$, $T_{cs,0(0)}^{\mathrm{Theo}.}(2906)$, $T_{bs,0(0)}^{\mathrm{Theo}.}(5781)$, $T_{bs,0(1)}^{\mathrm{Theo}.}(5840)$, and $T_{bs,0(0)}^{\mathrm{Theo}.}(6240)$, which are close to the $D\overline{K}$, $D^{*}{\overline{K}}^{*}$, $\overline{B}\overline{K}$, ${\overline{B}}^{*}\overline{K}$, and ${\overline{B}}^{*}{\overline{K}}^{*}$ thresholds, respectively. Furthermore, their spatial structures clearly support their molecular natures. The resonance $T_{cs,0(0)}^{\mathrm{Theo}.}(2906)$ with a mass of 2906 MeV, a width of 20 MeV, and quantum numbers $I(J^P)=0(0^{+})$ may serve as a good candidate for the experimental $T_{cs0}(2900)$ state. We strongly urge the experimental search of the predicted states.

The Darboux-Kadomtsev-Petviashvili system is a universal three-dimensional integrable field theory, which is a generating system for the entire Kadomtsev-Petviashvili hierarchy, and at the same time generalizes the Darboux system, describing orthogonal curvilinear coordinates. In this paper, we establish a hierarchy of Lagrangian multiforms for the Darboux-Kadomtsev-Petviashvili system, derived from a hierarchy of Chern-Simons actions in an infinite-dimensional space of Miwa variables. This provides an integrable variational description of this multidimensionally consistent field theory embedded in infinite dimensional space.

We present a novel approach to solving combinatorial assignment problems in particle physics. The correct assignment of decay products to parent particles is achieved in a model-agnostic fashion by introducing a neural network architecture, passwd-abc, which combines a custom layer based on attention mechanisms and dual autoencoders. We demonstrate how the network, trained purely on background events in an unsupervised setting, is capable of reconstructing correctly hypothetical new particles regardless of their mass, decay multiplicity, and substructure, and produces simultaneously an anomaly score that can be used to efficiently suppress the background. This model allows the extension of the suite of searches for localized excesses to include nonresonant particle pair production where the reconstruction of the two resonant masses is thwarted by combinatorics.

We study the double-gluon charmonium hybrid states with various quantum numbers, each of which is composed of one valence charm quark and one valence charm antiquark as well as two valence gluons. We concentrate on the exotic quantum numbers $J^{PC}=0^{--}/0^{+-}/1^{-+}/2^{+-}/3^{-+}$ that the conventional $\overline{q}q$ mesons cannot reach. We apply the QCD sum rule method to calculate their masses to be ${7.28}_{-0.43}^{+0.38}$, ${5.19}_{-0.46}^{+0.36}$, ${5.46}_{-0.62}^{+0.41}$, ${4.48}_{-0.31}^{+0.25}$, and ${5.54}_{-0.43}^{+0.35}\mathrm{GeV}$, respectively. We study their possible decay patterns and propose to search for the $J^{PC}=2^{+-}/3^{-+}$ states in the $D^{*}{\overline{D}}^{(*)}/D_s^{*}{\overline{D}}_s^{(*)}/{\mathrm{\Sigma }}_c^{*}{\overline{\mathrm{\Sigma }}}_c^{(*)}/{\mathrm{\Xi }}_c^{*}{\overline{\mathrm{\Xi }}}_c^{(\prime ,*)}$ channels. Experimental investigations on these states and decay channels can be useful in classifying the nature of the hybrid state, thus serving as a direct test of QCD in the low energy sector.

Recent experimental results on the ${\mathrm{\Lambda }}_c^{+}/D^0$ ratio in proton-proton ($pp$) collisions have revealed a significant enhancement compared to expectations based on universal fragmentation fractions/functions across different colliding systems, from $e^{+}{e}^{-}$ to $pp$. This unexpected enhancement has sparked speculation about the potential effects of a deconfined medium impacting hadronization, previously considered exclusive to heavy-ion collisions. In this study, we propose a novel approach that assumes the formation of a small, deconfined, and expanding fireball even in $pp$ collisions, where charm quarks can undergo rescattering and hadronization. We make use of the same in-medium hadronization mechanism developed for heavy-ion collisions, which involves local color-neutralization through recombination of charm quarks with nearby opposite color charges from the background fireball. Our model incorporates the presence of diquark excitations in the hot medium, which promotes the formation of charmed baryons. Moreover, the recombination process, involving closely aligned partons from the same fluid cell, effectively transfers the collective flow of the system to the final charmed hadrons. We show that this framework can qualitatively reproduce the observed experimental findings in heavy-flavor particle-yield ratios, $p_T$-spectra and elliptic-flow coefficients. Our results provide new, complementary supporting evidence that the collective phenomena observed in small systems naturally have the same origin as those observed in heavy-ion collisions.

In this paper, we study polarization modes of gravitational waves in generalized Proca theory in the homogeneous and isotropic Minkowski background. The results show that the polarizations of gravitational waves depend on the parameter space of this gravity theory and can be divided into quite rich cases by parameters. In some parameter space, it only allows two tensor modes, i.e., the $+$ and $\times$ modes. In some parameter space, besides tensor modes, it also allows one scalar mode, or two vector (vector-$x$ and vector-$y$) modes, or both one scalar mode and two vector modes. The scalar mode is a mixture mode of a breathing mode and a longitudinal mode, or just a pure breathing mode. Interestingly, it is found that the amplitude of the vector modes is related to the speed of the tensor modes. This allows us to give the upper bound of the amplitude of the vector modes by detecting the speed of the tensor modes. Specifically, if the speed of tensor modes is strictly equal to the speed of light, then the amplitude of vector modes is zero.

It was shown in previous work that when a gravitational wave (GW) passes through a viscous shell of matter the magnitude of the GW will be damped and there are astrophysical circumstances in which the damping is almost complete. The energy transfer from the GWs to the fluid will increase its temperature. We construct a model for this process and obtain an expression for the temperature distribution inside the shell in terms of spherical harmonics. Further, it is shown that this effect is astrophysically significant: a model problem is constructed for which the temperature increase is of order ${10}^6\mathrm{K}$.

We study linear perturbations against static spherically symmetric background configurations of general relativity with a real scalar field (SF), which is minimally coupled with gravity; it is nonlinear due to the presence of the self-action potential. The background solutions have a naked singularity at the center of the configuration. The focus is on the stability of the background and fundamental frequencies of the quasinormal modes (QNM) of the axial perturbations in the Regge-Wheeler gauge. The problem is reduced to one hyperbolic master equation with an effective potential $W_{\mathrm{eff}}$, which turns out to be positive for a general non-negative SF potential; this ensures the linear stability with respect to this kind of perturbations. For numerical simulations, the SF potential was chosen in the power-law form $V(\varphi )\sim {\varphi }^{2n}$ with $2<n\le 40$. We extracted the fundamental frequencies of QNM for different $n$ and various sets of the background configuration parameters. The results show that even for a small background SF, there is a significant difference between the fundamental frequencies and ones in case of the Schwarzschild background. The results are also compared with the case of the Fisher-Janis-Newman-Winicour background dealing with a massless linear scalar field.

This study explores the link between modified gravity and modifications of phase space volume. Analyzing Fermi gas modifications in the nonrelativistic limit of the Ricci-based gravities, we derive a generalized partition function in the grand-canonical ensemble, connecting modified gravity models with the generalized uncertainty principle. Using this correspondence, we also establish bounds on the linear generalized uncertainty principle: $-6\times {10}^{22}\lesssim \sigma \lesssim 3\times {10}^{22}\mathrm{s}/\mathrm{kg}\mathrm{m}$, as well as lower bounds for Palatini $f(R)$ gravity $\beta >-7.51587\times {10}^7{\mathrm{m}}^2$ and Eddington-inspired Born-Infeld gravity $\epsilon >-1.88\times {10}^7{\mathrm{m}}^2$, ensuring microscopic stability. This connection also facilitates testing gravity proposals through tabletop experiments.

We explore a generalized unified dark energy model that incorporates a nonminimal interaction between a tachyonic fluid and an additional scalar field. Specifically, we require that the second field possesses a vacuum energy, introducing an ineliminable offset due to a symmetry-breaking mechanism. After the transition (occurring as due to the symmetry-breaking mechanism of the second field), the corresponding equation of state (EoS) takes the form of a combination between a generalized Chaplygin gas (GCG) component and a cosmological constant contribution. We reinterpret this outcome by drawing parallels to the so-called Murnaghan EoS, widely-employed in the realm of solid-state physics to characterise fluids that, under external pressure, counteract the pressure’s effect. We examine the dynamic behavior of this model and highlight its key distinctions compared to the GCG model. We establish parameter bounds that clarifies the model’s evolution across cosmic expansion history, showing that it, precisely, exhibits behavior akin to a logotropic fluid that eventually converges to the $\mathrm{\Lambda }\mathrm{CDM}$ model in the early universe, while behaving as a logotropic or Chaplygin gas at intermediate and late times respectively. We explain our findings from a thermodynamic perspective, and determine the small perturbations in the linear regime. At very early times, the growth factor flattens as expected while the main departures occur at late times, where the Murnagham EoS results in a more efficient growth of perturbations. We discuss this deviation in view of current observations and conclude that our model is a suitable alternative to the standard cosmological paradigm, introducing the concept of a matterlike field with nonzero pressure.

This paper explores the physics of second-order gravitational waves (GWs) induced by scalar-tensor perturbation interactions in the radiation-dominated Universe. We investigate the distinctive signatures of these GWs and their detectability compared to scalar-induced GWs. Unlike scalar-scalar induced GWs, scalar-tensor induced GWs do not present resonances or a logarithmic running in the low frequency tail in the case of peaked primordial spectra. But, interestingly, they partly inherit any primordial parity violation of tensor modes. We find that chirality in primordial GWs can lead to distinguishing effects in scalar-tensor induced GWs in the ultraviolet (UV) region. We also address a potential divergence in our GWs and explore possible solutions. This study contributes to our understanding of GWs in the early Universe and their implications for cosmology and GWs detection.

One of the promising new proposals to search for axions in astrophysical environments is to look for narrow radio lines produced from the resonant conversion of axion dark matter falling through the magnetospheres of neutron stars. For sufficiently strong magnetic fields, axion masses in the $\mathcal{O}(10\mathrm{\mu }\mathrm{eV})$ range, and axion-photon couplings $g_{a\gamma }\gtrsim {10}^{-12}{\mathrm{GeV}}^{-1}$, the conversion can become hyperefficient, allowing axion-photon and photon-axion transitions to occur with $\mathcal{O}(1)$ probabilities. Despite the strong mixing between these particles, the observable radio flux emanating from the magnetosphere is expected to be heavily suppressed—this is a consequence of the fact that photons sourced by infalling axions have a high probability of converting back into axions before escaping the magnetosphere. In this work, we study the evolution of the axion and photon phase space near the surface of highly magnetized neutron stars in the adiabatic regime, quantifying for the first time the properties of the radio flux that arise at high axion-photon couplings. We show that previous attempts to mimic the scaling in this regime have been overly conservative in their treatment, and that the suppression can be largely circumvented for radio observations targeting neutron star populations.