In this work we report on the Landau gauge photon propagator computed for pure gauge 4D compact QED in the confined and deconfined phases and for large lattice volumes: ${32}^4$, ${48}^4$ and ${96}^4$. In the confined phase, compact QED develops mass scales that render the propagator finite at all momentum scales and no volume dependence is observed for the simulations performed. Furthermore, for the confined phase the propagator is compatible with a Yukawa massive type functional form. For the deconfined phase the photon propagator seems to approach a free field propagator as the lattice volume is increased. In both cases, we also investigate the static potential and the average value of the number of Dirac strings in the gauge configurations $m$. In the confined phase the mass gap translates into a linearly growing static potential, while in the deconfined phase the static potential approaches a constant at large separations. Results shows that $m$ is, at least, one order of magnitude larger in the confined phase and confirm that the appearance of a confined phase is connected with the topology of the gauge group.

The photoproduction reaction of $\gamma p\to {\eta }^{\prime }p$ is investigated based on an effective Lagrangian approach in the tree-level approximation, with the purpose being to understand the reaction mechanisms and to extract the resonance contents and the associated resonance parameters in this reaction. Apart from the $t$-channel $\rho$ and $\omega$ exchanges, $s$- and $u$-channel nucleon exchanges, and generalized contact term, the exchanges of a minimum number of nucleon resonances in the $s$ channel are taken into account in constructing the reaction amplitudes to describe the experimental data. It is found that a satisfactory description of the available data on both differential cross sections and photon beam asymmetries can be obtained by including in the $s$ channel the exchanges of the $N(1875)3/2^{-}$ and $N(2040)3/2^{+}$ resonances. The reaction mechanisms of $\gamma p\to {\eta }^{\prime }p$ are discussed and a prediction for the target nucleon asymmetries is presented.

We investigate the spontaneous breaking of chiral symmetry in QCD by means of a recently proposed approximation scheme in the Landau-gauge Curci-Ferrari model, which combines an expansion in the Yang-Mills coupling and in the inverse number of colors, without expanding in the quark-gluon coupling. The expansion allows for a consistent treatment of ultraviolet tails via renormalization group techniques. At leading order, it leads to the resummation of rainbow diagrams for the quark propagator, with, however, a trivial running of both the gluon mass and the quark-gluon coupling. In a previous work, by using a simple model for a more realistic running of these parameters, we could reproduce the known phenomenology of chiral symmetry breaking, including a satisfactory description of the lattice data for the quark mass function. Here, we get rid of this model-dependence by taking our approximation scheme to next-to-leading order. This allows us to consistently include the realistic running of the parameters and to access the unquenched gluon and ghost propagators to first nontrivial order, which we can compare to available lattice data for an even more stringent test of our approach. In particular, our results for the various two-point functions compare well with lattice data while the parameters of the model are strongly constrained.

Evolution of spin polarization in the presence of external electric field is studied for collision energies $\sqrt{s_{\mathrm{NN}}}=27\mathrm{GeV}$ and $\sqrt{s_{\mathrm{NN}}}=200\mathrm{GeV}$. The numerical analysis is done in the perfect-fluid Bjorken-expanding resistive magnetohydrodynamic background and novel results are reported. In particular, we show that the electric field plays a significant role in the competition between expansion and dissipation.

Recently the observation of a new pentaquark state, the hidden-charmed strange $P_{cs}(4459{)}^0$, was reported by the LHCb Collaboration. The spin-parity quantum numbers of this state were not determined as a result of insufficient statistics. To shed light on its quantum numbers, we investigate its decay, $P_{cs}(4459{)}^0\to J/\psi \mathrm{\Lambda }$, the mode that this state has been observed, within the QCD sum rule framework. We obtain the width of this decay assigning the spin-parity quantum numbers of the $P_{cs}(4459{)}^0$ state as $J^P={\frac{1}{2}}^{-}$ and its substructure as diquark-diquark-antiquark. To this end, we first calculate the strong coupling constants defining the considered decay and then use them in the width calculations. The obtained width is consistent with the experimental observation, confirming the quantum numbers $J^P={\frac{1}{2}}^{-}$ and compact pentaquark nature for the $P_{cs}(4459{)}^0$ state.

The baryon axial vector current is computed in heavy baryon chiral perturbation theory in the large-$N_c$ limit, where $N_c$ is the number of color charges. One-loop nonanalytic corrections of the order $m_q\ln m_q$ are comprised in the analysis, with contributions of both intermediate octet and decuplet baryon states, to all orders in the $1/N_c$ expansion of the axial vector current relevant for $N_c=3$. Theoretical expressions are obtained in the limit of vanishing decuplet-octet mass difference only, which allows one to carry out a full comparison with conventional heavy baryon chiral perturbation theory results for three flavors of light quarks and at the physical value $N_c=3$. Both approaches perfectly agree to all orders considered. Furthermore, a numerical analysis via a least-squares fit is performed in order to extract the values of the free parameters of the theory, using the experimental data available. The predictions of formalism are in good agreement with the experimental data.

We developed a CANDLES-III system to study the neutrinoless double beta ($0\nu \beta \beta$) decay of ${}^{48}\mathrm{Ca}$. The proposed system employs 96 ${\mathrm{CaF}}_2$ scintillation crystals (305 kg) with natural Ca (${}^{\mathrm{nat}}\mathrm{Ca}$) isotope which corresponds 350 g of ${}^{48}\mathrm{Ca}$. External backgrounds were rejected using a $4\pi$ active shield of a liquid scintillator surrounding the ${\mathrm{CaF}}_2$ crystals. The internal backgrounds caused by the radioactive impurities within the ${\mathrm{CaF}}_2$ crystals can be reduced effectively through analysis of the signal pulse shape. We analyzed the data obtained in the Kamioka underground for a live-time of 130.4 days to evaluate the feasibility of the low background measurement with the CANDLES-III detector. Using Monte Carlo simulations, we estimated the background rate from the radioactive impurities in the ${\mathrm{CaF}}_2$ crystals and the rate of high energy $\gamma$-rays caused by the $(\mathrm{n},\gamma )$ reactions induced by environmental neutrons. The expected background rate was in a good agreement with the measured rate, i.e., approximately ${10}^{-3}$ events/keV/yr/(kg of ${}^{\mathrm{nat}}\mathrm{Ca}$), in the $0\nu \beta \beta$ window. In conclusion, the background candidates were estimated properly by comparing the measured energy spectrum with the background simulations. With this measurement method, we performed the first search for $0\nu \beta \beta$ decay in a low background condition using a detector on the scale of hundreds of kg of nonenriched Ca. Deploying scintillators enriched in ${}^{48}\mathrm{Ca}$ will increase the sensitivity strongly. ${}^{48}\mathrm{Ca}$ has a high potential for use in $0\nu \beta \beta$ decay search, and is expected to be useful for the development of a next-generation detector for highly sensitive measurements.

The problem of computing quantum mechanical propagators can be recast as a computation of a Wilson line operator for parallel transport by a flat connection acting on a vector bundle of wave functions. In this picture, the base manifold is an odd-dimensional symplectic geometry, or quite generically a contact manifold that can be viewed as a “phase-spacetime,” while the fibers are Hilbert spaces. This approach enjoys a “quantum Darboux theorem” that parallels the Darboux theorem on contact manifolds which turns local classical dynamics into straight lines. We detail how the quantum Darboux theorem works for anharmonic quantum potentials. In particular, we develop a novel diagrammatic approach for computing the asymptotics of a gauge transformation that locally makes complicated quantum dynamics trivial.

We present imrphenomxphm, a phenomenological frequency-domain model for the gravitational-wave signal emitted by quasicircular precessing binary black holes, which incorporates multipoles beyond the dominant quadrupole in the precessing frame. The model is a precessing extension of imrphenomxhm, [C. García-Quirós et al., Phys. Rev. D 102, 064002 (2020)] based on approximate maps between aligned-spin waveform modes in the coprecessing frame and precessing waveform modes in the inertial frame, which is commonly referred to as “twisting up” the nonprecessing waveforms. imrphenomxphm includes imrphenomxp as a special case, the restriction to the dominant quadrupole contribution in the coprecessing frame. We implement two alternative mappings, one based on a single-spin post-Newtonian approximation, as used in imrphenompv2 [M. Hannam et al., Phys. Rev. Lett. 113, 151101 (2014).], and one based on the double-spin multiple scale analysis approach of [K. Chatziioannou et al., Phys. Rev. D 95, 104004 (2017).]. We include a detailed discussion of conventions used in the description of precessing binaries and of all choices made in constructing the model. The computational cost of imrphenomxphm is further reduced by extending the interpolation technique of [C. García-Quirós et al., Classical Quant. Grav. 38, 015006 (2021).] to the Euler angles. The accuracy, speed, robustness, and modularity of the imrphenomx family will make these models productive tools for gravitational wave astronomy in the current era of greatly increased number and diversity of detected events.

Teukolsky equations for $|s|=2$ provide efficient ways to solve for curvature perturbations around Kerr black holes. Imposing regularity conditions on these perturbations on the future (past) horizon corresponds to imposing an ingoing (outgoing) wave boundary condition. For exotic compact objects (ECOs) with external Kerr spacetime, however, it is not yet clear how to physically impose boundary conditions for curvature perturbations on their boundaries. We address this problem using the membrane paradigm, by considering a family of zero-angular-momentum fiducial observers (FIDOs) that float right above the horizon of a linearly perturbed Kerr black hole. From the reference frame of these observers, the ECO will experience tidal perturbations due to ingoing gravitational waves, respond to these waves, and generate outgoing waves. As it also turns out, if both ingoing and outgoing waves exist near the horizon, the Newman-Penrose (NP) quantity ${\psi }_0$ will be numerically dominated by the ingoing wave, while the NP quantity ${\psi }_4$ will be dominated by the outgoing wave—even though both quantities contain full information regarding the wave field. In this way, we obtain the ECO boundary condition in the form of a relation between ${\psi }_0$ and the complex conjugate of ${\psi }_4$, in a way that is determined by the ECO’s tidal response in the FIDO frame. We explore several ways to modify gravitational-wave dispersion in the FIDO frame and deduce the corresponding ECO boundary condition for Teukolsky functions. Using the Starobinsky-Teukolsky identity, we subsequently obtain the boundary condition for ${\psi }_4$ alone, as well as for the Sasaki-Nakamura and Detweiler functions. As it also turns out, the reflection of spinning ECOs will generically mix between different $\ell$ components of the perturbation fields, and it will be different for perturbations with different parities. It is straightforward to apply our boundary condition to computing gravitational-wave echoes from spinning ECOs, and to solve for the spinning ECOs’ quasinormal modes.

We analyze recent AMS-02 comic-ray measurements of lithium, beryllium, boron, carbon, nitrogen, and oxygen. The emphasis of the analysis is on systematic uncertainties related to propagation and nuclear cross sections. To investigate the uncertainties in the propagation scenario, we consider five different frameworks, differing with respect to the inclusion of a diffusion break at a few GV, the presence of reacceleration, and the presence of a break in the injection spectra of primaries. For each framework we fit the diffusion equations of cosmic rays and explore the parameter space with Monte Carlo methods. At the same time, the impact of the uncertainties on the nuclear production cross sections of secondaries is explicitly considered and included in the fit through the use of nuisance parameters. We find that all of the considered frameworks are able to provide a good fit. In particular, two competing scenarios—one including a break in diffusion but no reacceleration and the other with reacceleration but no break in diffusion—are both allowed. The inclusion of cross-section uncertainties is, however, crucial to this result. Thus, at the moment these uncertainties represent a fundamental systematic preventing a deeper understanding of the properties of cosmic-ray propagation. Nonetheless, we find that the slope of diffusion at intermediate rigidities is robustly constrained in the range $\delta \simeq 0.45–0.5$ in models without convection, or $\delta \simeq 0.4–0.5$ if convection is included in the fit. Furthermore, we find that the use of the AMS-02 beryllium data provides a lower limit on the vertical size of the Galactic propagation halo of $z_h\gtrsim 3\mathrm{kpc}$.

An automated treatment of iterated integrals based on letters induced by real-valued quadratic forms and Kummer–Poincaré letters is presented. These quantities emerge in analytic single and multiscale Feynman diagram calculations. To compactify representations, one wishes to apply general properties of these quantities in computer-algebraic implementations. We provide the reduction to basis representations, expansions, analytic continuation and numerical evaluation of these quantities.

Recently, machine learning (ML) techniques have led to a range of numerous developments in the field of nuclear and high-energy physics. In heavy-ion collisions, the impact parameter of a collision is one of the crucial observables that has a significant impact on the final state particle production. However, the calculation of such a quantity is nearly impossible in experiments as the length scale ranges in the level of a few fermi. In this work, we implement the ML-based regression technique via boosted decision trees to obtain a prediction of the impact parameter in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02\mathrm{TeV}$ using a multiphase transport model. In addition, we predict an event shape observable, transverse spherocity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ and 5.02 TeV using a multiphase transport and pythia8 based on Angantyr model. After a successful implementation in small collision systems, the use of transverse spherocity in heavy-ion collisions has potential to reveal new results from heavy-ion collisions where the production of a quark gluon plasma medium is already established. We predict the centrality dependent spherocity distributions from the training of minimum bias simulated data and find that the predictions from the boosted decision trees based ML technique match with true simulated data. In the absence of experimental measurements, we propose to implement a machine learning based regression technique to obtain transverse spherocity from the known final state observables in heavy-ion collisions.

We study the thermodynamics of helical matter, namely quark matter in which a net helicity $n_H$ is in equilibrium. Interactions are modeled by the renormalized quark-meson model with two flavors of quarks. Helical density is described within the grand-canonical ensemble formalism via a chemical potential ${\mu }_H$. We study the transitions from the normal quark matter and hadron gas to the helical matter, drawing the phase diagram at zero temperature. We study the restoration of chiral symmetry at finite temperature and show that the net helical density softens the transition, moving the critical end point to lower temperature and higher baryon chemical potential. Finally, we discuss briefly the effect of a rigid rotation on the helical matter, in particular on the fluctuations of $n_H$, and show that these are enhanced by the rotation.

We study the radial distribution function of the color sources (strings) formed in hadronic collisions and the requirements to obtain a liquid. As a repulsive interaction is needed, we incorporate a concentric core in the strings as well as the probability that a string allows core-core overlaps. We find systems where the difference between the gas-liquid and confined-deconfined phase transition temperatures is small. This explains the experimentally observed liquid behavior of the quark-gluon plasma above the confined-deconfined transition temperature.

We study the thermodynamic properties of a two-site coupled complex $q$-body Sachdev-Ye-Kitaev (SYK) model in the large-$N$ limit by solving the saddle-point Schwinger-Dyson (SD) equations. We find that its phase diagram is richer than in the Majorana case. In the grand canonical ensemble, we identify a region of small chemical potential and weak coupling between the two SYKs, for which two first order thermodynamic phase transitions occur as a function of temperature. First, we observe a transition from a cold wormhole phase to an intermediate phase that may correspond to a charged wormhole. For a higher temperature, there is another first order transition to the black hole phase. As in the Majorana case, the low temperature wormhole phase is gapped, and for sufficiently large coupling between the two complex SYK, or chemical potential, the first order transitions become crossovers. The total charge is a good indicator to study the phase diagram of the model; it is zero in the cold wormhole phase and jumps discontinuously at the temperatures at which the transitions take place. Based on the approximate conformal symmetry of the ground state, expected to be close to a thermofield double state, we identify the effective low energy action of the model. It is a generalized Schwarzian action with $SL(2,R)\times U(1)$ symmetry with an additional potential and an extra degree of freedom related to the charge. In the large $N$ and low temperature limit, results from this low energy action are consistent with those from the solution of the SD equations. Likewise, a large-$q$ analytical calculation of thermodynamic properties confirms the existence of the wormhole phase. Our findings are a preliminary step toward the characterization of traversable wormholes by its field theory dual, a charged strongly interacting fermionic system, that is easier to model experimentally.

Strong gravitational lensing is a gravitational wave (GW) propagation effect that influences the inferred GW source parameters and the cosmological environment. Identifying strongly lensed GW images is challenging as waveform amplitude magnification is degenerate with a shift in the source intrinsic mass and redshift. However, even in the geometric-optics limit, type II strongly lensed images cannot be fully matched by type I (or unlensed) waveform templates, especially with large binary mass ratios and orbital inclination angles. We propose to use this mismatch to distinguish individual type II images. Using planned noise spectra of Cosmic Explorer, Einstein Telescope and LIGO Voyager, we show that a significant fraction of type II images can be distinguished from unlensed sources, given sufficient SNR ($\sim 30$). Incorporating models on GW source population and lens population, we predict that the yearly detection rate of lensed GW sources with detectable type II images is 172.2, 118.2 and 27.4 for CE, ET and LIGO Voyager, respectively. Among these detectable events, 33.1%, 7.3% and 0.22% will be distinguishable via their type II images with a log Bayes factor larger than 10. We conclude that such distinguishable events are likely to appear in the third-generation detector catalog; our strategy will significantly supplement existing strong lensing search strategies.

It is of great interest to explore matter in nontrivial quantum arrangements, including Schrödinger catlike states. Such states are sensitive to decoherence from their environment. Recently, in Allali and Hertzberg [Gravitational decoherence of dark matter, J. Cosmol. Astropart. Phys. 07 (2020) 056] we computed the rate of decoherence of a piece of superposed matter that primarily interacts only gravitationally, a dark-matter-Schrödinger-cat state (DMSCS), within the nonrelativistic approximation. In this work we improve this to a general relativistic analysis. We first derive a single particle relativistic Schrödinger equation for a probe particle that passes through the DMSCS; the interaction is provided by the weak field metric of general relativity from the source. For a static DMSCS we find a neat generalization of our previous results. We then turn to the interesting new case of a time dependent DMSCS, which can be provided by a coherently oscillating axion field leading to superposed time dependent oscillations in the metric: a truly quantum-general relativistic phenomenon. We use scattering theory to derive the decoherence rate in all these cases. When the DMSCS is in a superposition of distinct density profiles, we find that the decoherence rate can be appreciable. We then consider the novel special case in which the density is not in a superposition, but the phase of its field oscillation is; this is a property that cannot be decohered within the nonrelativistic framework. We find that if the probe particle and/or the DMSCS’s velocity dispersion is slow, then the rate of decoherence of the phase is exponentially suppressed. However, if both the probe and the DMSCS’s velocity dispersion are relativistic, then the phase can decohere more rapidly. As applications, we find that diffuse galactic axions with superposed phases are robust against decoherence, while dense boson stars and regions near black hole horizons are not, and we discuss implications for experiment.

Gravitational waves (GWs) of astrophysical origin were detected for the first time in 2015 through strain deformation measured at the Earth’s surface. The inertia tensor of the deformable Earth is also disturbed resulting in the perturbation of its rotation vector and excitation of the rotational normal modes. Using a linearized theory of gravitation and the linearized equations of conservation of the angular momentum, we compute the equatorial polar motion and length of day changes generated by GWs. We show that GWs of strain amplitude $h_0$ and frequency $f_g$ give rise to perturbations of the inertia tensor of the Earth with an amplitude of ${10}^{14}{h}_0{f}_g^2$, resulting in relative perturbation of the Earth’s rotation rate and equatorial polar motion respectively of the order ${10}^6{h}_0{f}_g^2$ and ${10}^{14}{h}_0{f}_g^2$. The amplitude of the rotational effect is much smaller than the geophysically induced rotational perturbation even if a resonance with the Earth’s rotational normal modes would be possible. The amplitude of this rotational effect increases with the frequency but is several orders of magnitude below the theoretical sensitivity level of current geodetic instruments. The centrifugal deformation associated with the GW-induced polar motion would be $\sim {10}^6{f}_g^2{h}_0\sim {10}^{-17}/\sqrt{\mathrm{Hz}}$ for $f_g={10}^{-4}\mathrm{Hz}$ and $h_0={10}^{-16}$. The strain amplitudes of such centrifugal deformation are beyond the detectability of current laser strainmeters used to detect GWs. In the future, improvement in the sensitivities of geophysical instruments to measure Earth’s rotation fluctuations, particularly at subdaily periods, and the development of the Laser Interferometer Space Antenna would make the present quantifications worth considering.

Fuzzy dark matter (FDM) has been a promising alternative to standard cold dark matter. The model consists of ultralight bosons with mass $m_b\sim {10}^{-22}\mathrm{eV}$ and features a quantum-pressure-supported solitonic core that oscillates. In this work, we show that the soliton density oscillations persist even after significant tidal stripping of the outer halo. We report two intrinsic yet distinct timescales associated, respectively, with the ground-state soliton wave function ${\tau }_{00}$ and the soliton density oscillations ${\tau }_{\text{soliton}}$, obeying ${\tau }_{\text{soliton}}/{\tau }_{00}\simeq 2.3$. The central star cluster (SC) in Eridanus II has a characteristic timescale ${\tau }_{\text{soliton}}/{\tau }_{\mathrm{SC}}\sim 2–3$ that deviates substantially from unity. As a result, we demonstrate, both analytically and numerically with three-dimensional self-consistent FDM simulations, that the gravitational heating of the SC owing to soliton density oscillations is negligible irrespective of $m_b$. We also show that the subhalo mass function to form Eridanus II does not place a strong constraint on $m_b$. These results are contrary to the previous findings by Marsh and Niemeyer (2019).