We map the mean-field Ising model equation of state onto the QCD phase diagram, and reconstruct the full coexistence region in the case of a first order phase transition. Beyond the coexistence line, we maintain access to the spinodal region in the phase diagram, thus providing a description of metastable and unstable phases of matter as well. In this way, our approach includes the superheated hadronic phase and the supercooled quark-gluon plasma, which are useful for hydrodynamic simulations of the fireball created in a heavy-ion collision at low collision energy, where a first order phase transition is expected. We discuss the features of the pressure and other thermodynamic observables as functions of temperature and baryonic chemical potential, in particular their behavior in the coexistence region. Finally, we compare our equation of state to other 3D-Ising model ones available in the literature.

We present a calculation of the reduced cross section in the momentum-space approach utilizing the Block-Durand-Ha parametrization of the proton structure function $F_2(x,Q^2)$ and the leading-order longitudinal structure function $F_L(x,Q^2)$, proposed by Boroun and Ha [Phys. Rev. D 109, 094037 (2024)] using Laplace transform techniques. Our results are compared with the HERA data and extended to the Large Hadron electron Collider domain. We also examine the ratio $F_{L2}(x,Q^2)=F_L(x,Q^2)/F_2(x,Q^2)$ obtained from our work, comparing it with both the H1 data and the color dipole picture bounds. We find that our results for the reduced cross section and the ratio $F_{L2}(x,Q^2)$ agree with the H1 data. Finally, our evaluation of the gluon distribution functions $G(x,Q^2)$ in the momentum-space approach shows very good concordance with the NNPDF3.0LO gluon structure functions for moderate $Q^2$ in the range ${10}^{-5}\le x\le 1$.

A dispersive implementation of the $a_0(980)$ resonance to $(g-2{)}_{\mu }$ requires the knowledge of the double-virtual $S$-wave ${\gamma }^{*}{\gamma }^{*}\to \pi \eta /K{\overline{K}}_{I=1}$ amplitudes. To obtain these amplitudes, we used a modified coupled-channel Muskhelishvili–Omnès formalism, with input from the left-hand cuts and the hadronic Omnès matrix. The latter was derived using a data-driven $N/D$ method, where the hadronic left-hand cuts were approximated via a conformal expansion. Due to the absence of direct hadronic data in the $\pi \eta$ channel, the expansion coefficients were fitted to various experimental data sets on two-photon fusion processes with $\pi \eta$ and $K\overline{K}$ final states. The resulting dispersive estimate for the $a_0(980)$ contribution to $(g-2{)}_{\mu }$ is $a_{\mu }^{\text{HLbL}}[a_0(980){]}_{\mathrm{resc}}=-0.44(5)\times {10}^{-11}$, which presents an order of magnitude improvement in precision over the narrow resonance approximation.

Large neutrino liquid argon time projection chamber (LArTPC) experiments can broaden their physics reach by reconstructing and interpreting MeV-scale energy depositions, or blips, present in their data. We demonstrate new calorimetric and particle discrimination capabilities at the MeV energy scale using reconstructed blips in data from the MicroBooNE LArTPC at Fermilab. We observe a concentration of low-energy ($<3\mathrm{MeV}$) blips around fiberglass mechanical support struts along the time projection chamber edges with energy spectrum features consistent with the Compton edge of 2.614 MeV ${}^{208}\mathrm{Tl}$ decay $\gamma$ rays. These features are used to verify proper calibration of electron energy scales in MicroBooNE’s data to few percent precision and to measure the specific activity of ${}^{208}\mathrm{Tl}$ in the fiberglass composing these struts, $(11.7\pm 0.2(\mathrm{stat})\pm 3.1(\mathrm{syst}))\mathrm{Bq}/\mathrm{kg}$. Cosmogenically produced blips above 3 MeV in reconstructed energy are used to showcase the ability of large LArTPCs to distinguish between low-energy proton and electron energy depositions. An enriched sample of low-energy protons selected using this new particle discrimination technique is found to be smaller in data than in dedicated corsika cosmic-ray simulations, suggesting either incorrect corsika modeling of incident cosmic fluxes or particle transport modeling issues in geant4.

Obtaining insight into the constituents of dark matter and their interactions with normal matter has inspired a wide range of experimental efforts. Several approaches, particularly those involving searches for ultralight bosonic dark matter (UBDM) fields, involve the use of quantum systems or measurements performed at the limits imposed by quantum mechanics. While a classical treatment of UBDM and its detectors is satisfactory, a fully quantum description would assist in developing future detection strategies. Here, we present an open quantum systems approach that accomplishes this while providing intuition into the quantum nature of the detection process itself. Furthermore, we apply the quantum theory of optical coherence to characterize the statistical properties of the UBDM field. Using representative examples, we show that this theoretical treatment has implications in uncovering signatures of the cosmological production mechanism of the UBDM field and its galactic merger history. By adapting tools from quantum optics, this work will help facilitate the creation of novel methods to extract astrophysically relevant information from correlation measurements.

We show that a Universe with a nonminimally coupled scalar field can fit current measurements of the expansion rate of the Universe better than the standard $\mathrm{\Lambda }$-cold dark matter model or other minimally coupled dark energy models. In particular, the nonminimal coupling in this model allows for the dark energy model to exhibit stable phantom crossing behavior, which seems to be suggested by the constraints on the dark energy equation of state coming from the most recent data. While we find a clear improvement in the goodness of fit for this dark energy model with respect to others that have been considered in the recent literature, using information theoretic criteria, we show that the evidence for it is still inconclusive.

We suggest a resonant $c\overline{b}\to H^{+}$ production search, followed by bosonic $H^{+}\to W^{+}H$ weak decay at the Large Hadron Collider (LHC). In the general two-Higgs-doublet model (G2HDM) that has flavor-changing neutral Higgs couplings, $H^{+}$ is resonantly produced via the top-charm ${\rho }_{tc}{V}_{tb}$ coupling at tree level, while $H^{+}\to W^{+}H$ weak decay occurs within the exotic second doublet, leading eventually to same-sign dilepton signals. We perform a signal-to-background analysis at the 14 TeV LHC and show that discovery seems possible with LHC Run 2 data already at hand.

The number and position of unstable critical curves, as well as the nature of the accretion disk around compact objects, play a fundamental role in their optical appearance. Identifying differences in the optical spectrum of various observed compact objects can help classify them as black holes or black hole mimickers, such as traversable wormholes. Although multiple unstable critical curves have been reported to appear in asymmetric traversable wormholes, in this work, we construct symmetric traversable wormholes with multiple unstable critical curves. We propose a general rational redshift function that allows us to trace the number of critical points of the effective potential and determine their nature as maxima or minima. The ray-tracing method is used to study the trajectories of massless particles, particularly their behavior near the unstable critical points. Finally, a thin accretion disk model is implemented to analyze the optical appearance of the solution.

Near a gravitating compact object, massive particles traveling along timelike geodesics are gravitationally deflected similarly to light. In this paper, we study the deflection angles of these particles in the strong deflection limit. This analytical approximation applies when particles in unbound orbits approach the compact object very closely, circle around it at a radius close to that of the unstable circular orbit, and eventually escape. While previous studies have provided results for particular metrics, we offer a general solution applicable to any static, spherically symmetric and asymptotically flat spacetime. After briefly reviewing the exact expression for the deflection angle of massive particles, we present a strong deflection limit analysis for this general case. The developed formulas are then applied to three particular metrics: Schwarzschild, Reissner-Nordström and Janis-Newman-Winicour.

Topological stars are solutions of Einstein-Maxwell theory in $D=5$. For specific choices of the parameters, the solution is capped and thus smooth and horizonless and can be reduced to $D=4$ along a circle. We study the energy and angular momentum radiated by a scalar particle moving on a circular orbit in the $D=4$ noncompact directions, extending a previous study [Phys. Rev. D 110, 084077 (2024)]. We also discuss self-force effects on the motion of a spinless probe.

Accurate waveform templates of binary black holes (BBHs) with eccentric orbits are essential for the detection and precise parameter estimation of gravitational waves (GWs). While seobnre produces accurate time-domain waveforms for eccentric BBH systems, its generation speed remains a critical bottleneck in analyzing such systems. Accelerating template generation is crucial to data analysis improvement and valuable information extraction from observational data. We present seobnre_aiq5e2, an innovative artificial intelligence-based surrogate model that was crafted to accelerate waveform generation for eccentric, spin-aligned BBH systems. seobnre_aiq5e2 incorporates an advanced adaptive resampling technique during training, enabling the generation of eccentric BBH waveforms with mass ratios up to 5, eccentricities below 0.2, and spins $|{\chi }_z|$ up to 0.6. It achieves an impressive generation speed of 4.3 ms per waveform with a mean mismatch of $1.02\times {10}^{-3}$. With the exceptional accuracy and rapid performance, seobnre_aiq5e2 emerges as a promising waveform template for future analysis of eccentric gravitational wave data.

Models of interacting dark radiation have been shown to alleviate the Hubble tension. Extensions incorporating a coupling between dark matter and dark radiation (DM-DR) have been proposed as combined solutions to both the Hubble and $S_8$ tensions. A key feature of these extended models is a break in the matter power spectrum (MPS), suppressing power for modes that enter the horizon before the DM-DR interactions turn off. In scenarios with a massless mediator, modes that enter before matter-radiation equality get suppressed, whereas for massive mediators, the break is determined by the mediator mass, a free parameter. In this work, we test these models against probes of LSS: weak lensing, CMB lensing, full-shape galaxy clustering, and eBOSS measurements of the 1D $\mathrm{Ly}\alpha$ forest flux power spectrum. The latter are the most constraining since they probe small scales where many models predict the largest deviations. In fact, already within $\mathrm{\Lambda }\mathrm{CDM}$, the eBOSS $\mathrm{Ly}\alpha$ data are in significant tension with Planck CMB data, with the $\mathrm{Ly}\alpha$ data preferring a steeper slope of the MPS at $k\sim h{\mathrm{Mpc}}^{-1}$. We find that the simplest dark radiation models, which improve the Hubble tension, worsen the fit to the $\mathrm{Ly}\alpha$ data. However, models with DM-DR interactions can simultaneously address both tensions.

Wide, highly eccentric ($e>0.9$) compact binaries can naturally arise as progenitors of gravitational wave (GW) mergers. These systems are expected to have a significant population in the mHz band (e.g., $\sim 3–45$ detectable stellar-mass binary black holes with $e>0.9$ in the Milky Way), with their GW signals characterized by “repeated bursts” emitted upon each pericenter passage. In this study, we show that the detection of mHz GW signals from highly eccentric stellar mass binaries in the local universe can strongly constrain their orbital parameters. Specifically, it can achieve a relative measurement error of $\sim {10}^{-6}$ for orbital frequency and $\sim 1\%$ for eccentricity (as $1-e$) in most of the detectable cases. On the other hand, the binary’s mass ratio, distance, and intrinsic orbital orientation may be less precisely determined due to degeneracies in the GW waveform. We also perform mock LISA data analysis to evaluate the realistic detectability of highly eccentric compact binaries. Our results show that highly eccentric systems could be efficiently identified when multiple GW sources and stationary Gaussian instrumental noise are present in the detector output. This work highlights the potential of extracting the signal of “bursting” LISA sources to provide valuable insights into their orbital evolution, surrounding environment, and formation channels.

In extreme environments such as core-collapse supernovae, neutron-star mergers, and the early Universe, neutrinos are dense enough that their self-interactions significantly affect, if not dominate, their flavor dynamics. In order to develop techniques for characterizing the resulting quantum entanglement, I present the results of simulations of Dirac neutrino-neutrino interactions that include all three physical neutrino flavors and were performed on D-Wave Inc.’s Advantage $5000+$ qubit quantum annealer. These results are checked against those from exact classical simulations, which are also used to compare the Dirac neutrino-neutrino interactions to neutrino-antineutrino and Majorana neutrino-neutrino interactions. The D-Wave Advantage annealer is shown to be able to reproduce time evolution with the precision of a classical machine for small numbers of neutrinos and to do so without Trotter errors. However, it suffers from poor scaling in qubit-count with the number of neutrinos.

Brownian thermal noise of thin-film coatings is a fundamental limit for high-precision experiments based on optical resonators such as gravitational-wave interferometers. Here we present the results of a research activity aiming to develop lower-noise ion-beam sputtered silicon nitride thin films compliant with the very stringent requirements on optical loss of gravitational-wave interferometers. In order to test the hypothesis of a correlation between the synthesis conditions of the films and their elemental composition and optical and mechanical properties, we varied the voltage, current intensity, and composition of the sputtering ion beam, and we performed a broad campaign of characterizations. While the refractive index was found to monotonically depend on the beam voltage and linearly vary with the N/Si ratio, the optical absorption appeared to be strongly sensitive to other factors, as yet unidentified. However, by systematically varying the deposition parameters, an optimal working point was found. Thus we show that the loss angle and extinction coefficient of our thin films can be as low as $(1.0\pm 0.1)\times {10}^{-4}\mathrm{rad}$ at $\sim 2.8\mathrm{kHz}$ and $(6.4\pm 0.2)\times {10}^{-6}$ at 1064 nm, respectively, after thermal treatment at $900°\mathrm{C}$. To the best of our knowledge, such loss angle value is the lowest ever measured on this class of thin films. We then used our silicon nitride thin films to design and produce a multimaterial mirror coating showing a thermal noise amplitude of $(10.3\pm 0.2)\times {10}^{-18}\mathrm{m}{\mathrm{Hz}}^{-1/2}$ at 100 Hz, which is 25% lower than in current mirror coatings of the Advanced LIGO and Advanced Virgo interferometers, and an optical absorption as low as ($1.6\pm 0.5$) parts per million at 1064 nm.

We study the two-flavor Nambu-Jona-Lasinio model under the rotation and chiral chemical potential ${\mu }_5$. First, the influence of chiral imbalance on the chiral phase transition in the $T_{pc}-\omega$ plane is investigated. Research manifests that, as ${\mu }_5$ increases, the critical point of the $T_{pc}-\omega$ plane chiral phase transition will move closer to the $T$ axis. This means that the chiral chemical potential ${\mu }_5$ can significantly affect the $T_{pc}-\omega$ phase diagram and phase transition behavior. While discussing the $T_{pc}-\omega$ phase diagram, we also study the spin alignment of the $\rho$ vector meson under rotation. In the study of the spin alignment of the vector meson $\rho$, ${\rho }_{00}$ is the 00 element of the spin density matrix of vector mesons. At high temperatures, ${\rho }_{00}$ is close to $1/3$, which indicates that the spin alignment of the vector meson $\rho$ is isotropic. The study found that, under finite rotation, increasing the chiral chemical potential ${\mu }_5$ can significantly enhance ${\rho }_{00}$ around the phase transition temperature. When rotational angular velocity is zero, ${\rho }_{00}$ is close to $1/3$, but as $\omega$ increases, ${\rho }_{00}$ significantly decreases and deviates $1/3$, indicating that rotation can significantly cause polarization characteristics. The ${\rho }_{00}-r$ relationship near the phase transition temperature is studied. It is found that the farther away from the center of rotation, the lower the degree of spin polarization of the system. It is also found that the influence of chiral imbalance on the ${\rho }_{00}-r$ relationship is also significant.

The study of quantum chromodynamics (QCD) at ultrarelativistic energies can be performed in a controlled environment through lepton-hadron deep inelastic scatterings. In such collisions, the high-energy partonic emissions that follow from the ejected hard partons are accurately described by perturbative QCD. However, the lower energy scales at which quarks and gluons experience color confinement, i.e., hadronization mechanism, fall outside the validity regions for perturbative calculations, requiring phenomenological models tuned to data to describe it. As such, hadronization physics cannot be currently derived from first principles alone. Monte Carlo event generators are useful tools to describe these processes as they simulate both the perturbative and the nonperturbative interactions, with model-dependent energy scales that control parton dynamics. This work employs jets—experimental reconstructions of final-state particles likely to have a common partonic origin—to inspect this transition further. Although originally proposed to circumvent hadronization effects, we show that jets can be utilized as probes of nonperturbative phenomena via their substructure. The charge correlation ratio was recently shown to be sensitive to hadronization effects. Our work further improves this sensitivity to nonperturbative scales by introducing a new selection based on the relative placement of the resolved SoftDrop splitting within the clustering tree, defined as the unclustering that resolves the jet’s leading charged particles.

Ideally, all analyses of normally distributed data should include the full covariance information between all data points. In practice, the full covariance matrix between all data points is not always available. Either because a result was published without a covariance matrix or because one tries to combine multiple results from separate publications. For simple hypothesis tests, it is possible to define robust test statistics that will behave conservatively in the presence of unknown correlations. For model parameter fits, one can inflate the variance by a factor to ensure that things remain conservative at least up to a chosen confidence level. This paper describes a class of robust test statistics for simple hypothesis tests, as well as an algorithm to determine the necessary inflation factor for model parameter fits and goodness of fit tests and composite hypothesis tests. It then presents some example applications of the methods to real neutrino interaction data and model comparisons.

A device filled with pure xenon first demonstrated the ability to operate simultaneously as a bubble chamber and scintillation detector in 2017. Initial results from data taken at thermodynamic thresholds down to $\sim 4\mathrm{keV}$ showed sensitivity to $\sim 20\mathrm{keV}$ nuclear recoils with no observable bubble nucleation by $\gamma$-ray interactions. This paper presents results from further operation of the same device at thermodynamic thresholds as low as 0.50 keV, hardware limited. The bubble chamber has now been shown to have sensitivity to $\sim 1\mathrm{keV}$ nuclear recoils while remaining insensitive to bubble nucleation by $\gamma$-rays. A data-driven calibration of the chamber’s nuclear recoil nucleation response, as a function of nuclear recoil energy and thermodynamic state, is presented. Stringent upper limits are established for the probability of bubble nucleation by $\gamma$-ray-induced Auger cascades, with a limit of $<1.1\times {10}^{-6}$ set at 0.50 keV, the lowest thermodynamic threshold explored.

Motivated by recent developments in the application of light-ray operators (LROs) in high energy physics, we propose a new strategy to study correlation functions of LROs through real-time quantum simulations. We argue that quantum simulators provide an ideal laboratory to explore the properties LROs in lower-dimensional quantum field theories. This is exemplified in the $1+1$-d Schwinger model, employing tensor network methods, focusing on the calculation of energy and charge correlators. Despite some challenges in extracting the necessary correlation functions from the lattice, the methodology used can be extended to real quantum devices.