We calculate the masses and leptonic decay widths of the bottomonium $b\overline{b}$ and charmonium $c\overline{c}$ states in a constituent quark model where the Cornell-like potential and spin-dependent interaction are employed, with all model parameters predetermined by studying ground and first radial excited states of $S$- and $P$-wave heavy quarkonium mesons. By comparing the theoretical predictions for $J^{PC}=1^{--}$ quarkonium states with experimental data and considering possible mixtures of $nS$ and $(n-1)D$ states, we provide tentative assignments for all observed $J^{PC}=1^{--}$ heavy quarkonia. The work suggests that the $\mathrm{\Upsilon }(10860)$ and $\mathrm{\Upsilon }(11020)$ are $b\overline{b}$ $5S-4D$ mixture states, and the $\psi (4360)$ and $\psi (4415)$ are largely $4S$ and $3D$ $c\overline{c}$ states, respectively. The $\psi (4230)$ may not be accommodated with the conventional meson picture in the present work.

Recently, first-order phase transitions have been predicted as an effect of the inclusion of quark anomalous magnetic moment (AMM) in the hot and magnetized Nambu–Jona-Lasinio model (NJL). These transitions appear in the chiral condensate for different combinations of AMM and magnetic fields and could lead to inverse magnetic catalysis. However, in this work, we show that the predicted first-order phase transitions are related to regularization-dependent issues. To show this, we explore, in the context of the vacuum magnetic regularization (VMR) scheme, two different scenarios: when mass-dependent (MD) and mass-independent (MI) terms are present in the subtraction of the divergences. In the MD case, as we increase the AMM value, it is observed the appearance of a nonmassive minimum in the thermodynamical potential, which induces a first-order phase transition from the massive minimum. We argue that the MD terms must be avoided in order to satisfy the predictions of Lattice QCD, and we propose a MI solution that is valid in the limit which the magnetic fields are smaller than the squared of vacuum effective quark mass.

Event generators like pythia play an important role in physics studies at the Large Hadron Collider (LHC). While they make accurate predictions in the central region, i.e., at pseudorapidities $\eta <5$, a disagreement between pythia and measurements in the forward region $\eta >7$ has been observed. We introduce a dedicated forward physics tune for the pythia event generator to be used for forward physics studies at the LHC, which uses a more flexible modeling of beam remnant hadronization and is tuned to available particle spectra measured by LHCf. Furthermore, we provide an uncertainty estimate on the new tune in a data-driven way which can be used as a means of flux uncertainty for future forward physics studies. We demonstrate an application of our tune by showing the updated neutrino and dark photon spectra at the FASER experiment.

In the framework of chiral effective field theory of delta resonances, nucleons, and pions interacting with background gravitational field we calculate the gravitational form factors of the nucleon up to fourth order in the small scale expansion and obtain the long-range behavior of the corresponding contributions to the energy, spin, pressure, and shear force distributions. By comparing nucleon gravitational form factors with and without delta contributions we conclude that explicit inclusion of deltas plays an important role. Next we explore the Lorentz structure of the $N\mapsto N\pi$ transition matrix element of the conserved symmetric energy-momentum tensor and introduce its parametrization in terms of twelve transition form factors. We use the chiral effective field theory to calculate the tree-order contributions to the gravitational transition form factors of the pion graviproduction off the nucleon up to third order.

We investigate a new production mechanism of axionlike particle (ALP) from $B$ meson annihilation decays and its observation potential at the Belle and Belle II experiments. This mechanism allows for the production of ALP from $B$ meson decays in association with a large variety of mesons. In this article, we first estimate the branching ratios of such processes with a perturbative QCD method. Focusing on the most promising $B\to h{a}^{\prime }$ ($h=K^{\pm },{\pi }^{\pm },D^0$ and $D_s$) channels, we perform sensitivity studies for $a^{\prime }$ decaying invisibly or into diphoton with Belle and Belle II experiments.

A series of pulsar timing arrays (PTAs) recently observed gravitational waves at the nanohertz frequencies. Motivated by this remarkable result, we present a novel class of Pati-Salam models that give rise to a network of metastable cosmic strings, offering a plausible explanation for the observed PTA data. Additionally, we introduce a hybrid inflationary scenario to eliminate magnetic monopoles that arise during the subsequent phase transitions from the Pati-Salam symmetry to the Standard Model gauge group. The resulting scalar spectral index is compatible with Planck data, and the tensor-to-scalar ratio is anticipated to be extremely small. Moreover, we incorporate a nonthermal leptogenesis to generate the required baryon asymmetry in our framework. Finally, the gravitational wave spectra generated by the metastable cosmic strings not only correspond to signals observed in recent PTAs, including NANOGrav, but are also within the exploration capacity of both present and future ground- and space-based experiments.

It is well known that the $SU(5)$ grand unified theory, with the standard model quarks and leptons unified in $\overline{5}$ and 10 and the electroweak Higgs doublet residing in five-dimensional representations, leads to the relation $Y_d=Y_e^T$ between the Yukawa couplings of the down-type quarks and the charged leptons. We show that this degeneracy can be lifted in a phenomenologically viable way when quantum corrections to the tree-level matching conditions are taken into account in the presence of one or more copies of gauge singlet fermions. The one-loop threshold corrections arising from heavy leptoquark scalar and vector bosons, already present in the minimal model, and heavy singlet fermions can lead to realistic Yukawa couplings, provided their masses differ by at least 2 orders of magnitude. The latter can also lead to a realistic light neutrino mass spectrum through the type I seesaw mechanism if the color partner of the Higgs stays close to the Planck scale. Most importantly, our findings demonstrate the viability of the simplest Yukawa sector when quantum corrections are considered and sizable threshold effects are present.

We present preliminary numerical evidence for the hypothesis that the Hamiltonian SU(2) gauge theory discretized on a lattice obeys the eigenstate thermalization hypothesis (ETH). To do so we study three approximations: (a) a linear plaquette chain in a reduced Hilbert space limiting the electric field basis to $j=0,\frac{1}{2}$, (b) a two-dimensional honeycomb lattice with periodic or closed boundary condition and the same Hilbert space constraint, and (c) a chain of only three plaquettes but such a sufficiently large electric field Hilbert space ($j\le \frac{7}{2}$) that convergence of all energy eigenvalues in the analyzed energy window is observed. While an unconstrained Hilbert space is required to reach the continuum limit of SU(2) gauge theory, numerical resource constraints do not permit us to realize this requirement for all values of the coupling constant and large lattices. In each of the three studied cases we check first for random matrix theory (RMT) behavior in the eigenenergy spectrum and then analyze the diagonal as well as the off-diagonal matrix elements between energy eigenstates for a few operators. Within current uncertainties all results for (a), (b) and (c) agree with ETH predictions. Furthermore, we find the off-diagonal matrix elements of the electric energy operator exhibit RMT behavior in frequency windows that are small enough in (b) and (c). To unambiguously establish ETH behavior and determine for which class of operators it applies, an extension of our investigations is necessary.

The effects of a finite system volume on thermodynamic quantities, such as the pressure, energy density, specific heat, speed of sound, conserved charge susceptibilities, and correlations, in hot and dense strongly interacting matter are studied within the parity-doublet chiral mean field model. Such an investigation is motivated by relativistic heavy-ion collisions, which create a blob of hot QCD matter of a finite volume, consisting of strongly interacting hadrons and potentially deconfined quarks and gluons. The effect of the finite volume of the system is incorporated by introducing lower momentum cutoffs in the momentum integrals appearing in the model, the numerical value of the momentum cutoff being related to the de Broglie wavelength of the given particle species. It is found that some of these quantities show a significant volume dependence, in particular, those sensitive to pion degrees of freedom, and the crossover transition is generally observed to become smoother in finite volume. These findings are relevant for the effective equation of state used in fluid dynamical simulations of heavy-ion collisions and efforts to extract the freeze-out properties of heavy-ion collisions with susceptibilities involving electric charge and strangeness.

We study gauge theories and quantum gravity diagrammatically in a finite interval of time $\tau$, on a compact space manifold $\mathrm{\Omega }$. The initial, final, and boundary conditions are formulated in gauge invariant and general covariant ways by means of purely virtual extensions of the theories, which allow us to “trivialize” the local symmetries and switch to invariant fields (the invariant metric tensor, invariant quark, and gluon fields, etc.). The evolution operator $U(t_{\mathrm{f}},t_{\mathrm{i}})$ is worked out for arbitrary initial and final states, as well as general boundary conditions on $\partial \mathrm{\Omega }$. We show that $U(t_{\mathrm{f}},t_{\mathrm{i}})$ is well defined and diagrammatically unitary for every $\tau =t_{\mathrm{f}}-t_{\mathrm{i}}<\infty$. The formulation is extended to include purely virtual particles. In quantum gravity, where the cosmological constant ${\mathrm{\Lambda }}_C$ challenges the definition of an $S$ matrix, the results allow us to prove unitarity at $\tau <\infty$. We work out the frequencies and eigenfunctions in some explicit examples, including Yang-Mills theory on the finite cylinder.

Tests of general relativity with gravitational-wave observations from merging compact binaries continue to confirm Einstein’s theory of gravity with increasing precision. However, these tests have so far been applied only to signals that were first confidently detected by matched-filter searches assuming general relativity templates. This raises the question of selection biases: What is the largest deviation from general relativity that current searches can detect, and are current constraints on such deviations necessarily narrow because they are based on signals that were detected by templated searches in the first place? In this paper, we estimate the impact of selection effects for tests of the inspiral phase evolution of compact binary signals with a simplified version of the gstlal search pipeline. We find that selection biases affect the search for very large values of the deviation parameters, much larger than the constraints implied by the detected signals. Therefore, combined population constraints from confidently detected events are mostly unaffected by selection biases, with the largest effect being a broadening at the $\sim 10\%$ level for the $-1\mathrm{PN}$ term. These findings suggest that current population constraints on the inspiral phase are robust without factoring in selection biases. Our study does not rule out a disjoint, undetectable binary population with large deviations from general relativity or stronger selection effects in other tests or search procedures.

Gravitational microlensing is one of the strongest observational techniques to observe nonluminous astrophysical bodies. Existing microlensing observations provide tantalizing evidence of a population of low-mass objects whose origin is unknown. These events may be caused by terrestrial-mass free-floating planets or by exotic objects such as primordial black holes. However, the nature of these objects cannot be resolved on an event-by-event basis, as the induced light curve is degenerate for lensing bodies of identical mass. One must instead statistically compare distributions of lensing events to determine the nature of the lensing population. While existing surveys lack the statistics required to identify multiple subpopulations of lenses, this will change with the launch of the Nancy Grace Roman Space Telescope. Roman’s Galactic Bulge Time Domain Survey is expected to observe hundreds of low-mass microlensing events, enabling a robust statistical characterization of this population. In this paper, we show that by exploiting features in the distribution of lensing event durations, Roman will be sensitive to a subpopulation of primordial black holes hidden amongst a background of free-floating planets. Roman’s reach will extend to primordial black hole dark matter fractions as low as $f_{\mathrm{PBH}}={10}^{-4}$ at peak sensitivity, and will be able to conclusively determine the origin of existing ultrashort-timescale microlensing events. A positive detection would provide evidence that a significant fraction of the cosmological dark matter consists of macroscopic, nonluminous objects.

We present a comprehensive study on the occurrences of the collisional flavor instability (CFI) and the fast flavor instability (FFI) of neutrinos based on a 2D core-collapse supernova simulation performed with a Boltzmann radiation hydrodynamics code. We find that CFI occurs in a region with the baryon-mass density of ${10}^{10}\lesssim \rho \lesssim {10}^{12}\mathrm{g}{\mathrm{cm}}^{-3}$, which is similar to the previous results in 1D core-collapse supernova models. In contrast to 1D, however, the CFI region varies with time vigorously in the 2D model, whereas it had a quiescent structure in 1D. This is attributed to the fact that the turbulent flows advected from a gain region account for the temporal variations. Another noticeable difference from the 1D models is the appearance of resonancelike CFI where number densities of ${\nu }_e$, ${\overline{\nu }}_e$ nearly coincide each other. The CFI growth rate there is enhanced and can reach $\sim {10}^8{\mathrm{s}}^{-1}$. As for FFI, on the other hand, it appears in three different regions: (1) the region overlapped with the resonancelike CFI, (2) neutrino decoupling regions where ${\overline{\nu }}_e\mathrm{s}$ are strongly emitted, and (3) optically thin regions where neutral-current scatterings dominate over charged-current reactions. Although overall properties for FFI are consistent with previous studies, we find that the number of electron-neutrinos lepton number crossing temporarily becomes multiple, which can be assessed accurately only by multiangle treatments in neutrino transport. We find that the growth rate of FFI is always higher than CFI if both of them occur, which suggests that the former is dominant for the linear evolution.

At the beginning of 2020, MAGIC reported a very-high-energy (VHE) flaring activity from the FSRQ QSO $\mathrm{B}1420+326$. It is now the fourth known most distant blazar ($z=0.682$) with an observed VHE gamma-ray emission. In this work, we investigate the effect of photon-axionlike particle (ALP) oscillations in the gamma-ray spectra measured by Fermi-LAT and MAGIC around the flaring state. We set 95% C.L. upper limit on the ALP parameters and obtain a constraint on the photon-ALP coupling constant $g_{a\gamma }<2\times {10}^{-11}{\mathrm{GeV}}^{-1}$ for ALP masses $m_a\sim {10}^{-10}–{10}^{-9}\mathrm{eV}$. Assuming the hadronic origin of VHE photons, we also estimate the expected neutrino flux from this source and the contribution to diffuse neutrino flux from QSO $\mathrm{B}1420+326$-like FSRQs at sub-PeV energies. Furthermore, we study the implications of photon-ALP oscillations on the counterpart $\gamma$-rays of the sub-PeV neutrinos. Finally, we investigate a viable scenario of invisible neutrino decay to ALPs on the gamma-ray spectra and diffuse $\gamma$-ray flux at sub-PeV energies. Interestingly, we find that for the choice of neutrino decay lifetime ${\tau }_2/m_2={10}^3\mathrm{s}{\mathrm{eV}}^{-1}$, the $\gamma$-ray flux has a good observational sensitivity towards LHAASO-KM2A.

Dark matter is five times more abundant than ordinary visible matter in our Universe. While laboratory searches hunting for dark matter have traditionally focused on the electroweak scale, theories of low mass hidden sectors motivate new detection techniques. Extending these searches to lower mass ranges, well below $1\mathrm{GeV}/c^2$, poses new challenges as rare interactions with standard model matter transfer progressively less energy to electrons and nuclei in detectors. Here, we propose an approach based on phonon-assisted quantum evaporation combined with quantum sensors for detection of desorption events via tracking of spin coherence. The intent of our proposed dark matter sensors is to extend the parameter space to energy transfers in rare interactions to as low as a few meV for detection of dark matter particles in the $\mathrm{keV}/{\mathrm{c}}^2$ mass range.

The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, is currently the largest array of radio antenna stations deployed for the detection of cosmic rays, spanning an area of $17{\mathrm{km}}^2$ with 153 radio stations. It detects the radio emission of extensive air showers produced by cosmic rays in the 30–80 MHz band. Here, we report the AERA measurements of the depth of the shower maximum ($X_{\max }$), a probe for mass composition, at cosmic-ray energies between ${10}^{17.5}$ and ${10}^{18.8}\mathrm{eV}$, which show agreement with earlier measurements with the fluorescence technique at the Pierre Auger Observatory. We show advancements in the method for radio $X_{\max }$ reconstruction by comparison to dedicated sets of corsika/coreas air-shower simulations, including steps of reconstruction-bias identification and correction, which is of particular importance for irregular or sparse radio arrays. Using the largest set of radio air-shower measurements to date, we show the radio $X_{\max }$ resolution as a function of energy, reaching a resolution better than $15\mathrm{g}{\mathrm{cm}}^{-2}$ at the highest energies, demonstrating that radio $X_{\max }$ measurements are competitive with the established high-precision fluorescence technique. In addition, we developed a procedure for performing an extensive data-driven study of systematic uncertainties, including the effects of acceptance bias, reconstruction bias, and the investigation of possible residual biases. These results have been cross-checked with air showers measured independently with both the radio and fluorescence techniques, a setup unique to the Pierre Auger Observatory.

Understanding the production mechanisms and utilizing them as probes to investigate the structure of exotic states represent some of the most actively studied research areas in particle physics. In this study, we present a theoretical analysis of the charmed meson $T_{cc}^{-}$ in the $\gamma p\to D^{+}{T}_{cc}^{-}{\mathrm{\Lambda }}_c^{+}$ and $\gamma \gamma \to D^{+}{T}_{cc}^{-}{D}^{*0}$ reactions, considering $T_{cc}^{+}$ as a $D{D}^{*}$ molecule. The differential cross section and total cross section for the photoproduction of $T_{cc}^{-}$ in the $\gamma p\to D^{+}{T}_{cc}^{-}{\mathrm{\Lambda }}_c^{+}$ and $\gamma \gamma \to D^{+}{T}_{cc}^{-}{D}^{*0}$ reactions are presented for nucleus-nucleus (nucleon-nucleon) ultraperipheral collisions at HL-LHC and RHIC, respectively. Taking into account the integrated luminosity per typical run and the luminosity of photons from the nucleus (nucleon), we observe a significant event count for $T_{cc}^{-}$ production in $p\text{−}p$ ultraperipheral collisions at HL-LHC.

Motivated by the recent LHCb observations of $T_{c\overline{s}0}(2900{)}^0$ and $T_{c\overline{s}0}(2900{)}^{++}$ in the processes $B^0\to {\overline{D}}^0{D}_s^{+}{\pi }^{-}$ and $B^{+}\to D^{-}{D}_s^{+}{\pi }^{+}$, we have investigated the decay $B^{-}\to D_s^{+}{K}^{-}{\pi }^{-}$ by taking into account the contributions from the $S$-wave vector-vector interactions, and the $S$-wave $D_s^{+}{K}^{-}$ interactions. Our results show that the $D_s^{+}{K}^{-}$ invariant mass distribution has an enhancement structure near the threshold, associated with the $D_0^{*}(2300)$, which is in good agreement with the Belle measurements. We have also predicted the $D_s^{+}{\pi }^{-}$ invariant mass distribution and the Dalitz plot, which show the significant signal of the $T_{c\overline{s}0}(2900)$. With the same formalism, the $D_s^{-}{K}_s^0$ invariant mass distribution of the process $B^0\to D_s^{-}{K}_s^0{\pi }^{+}$ measured by Belle could be well reproduced, and the peak of $T_{c\overline{s}0}(2900)$ is expected to be observed around 2900 MeV in the $D_s^{-}{\pi }^{+}$ invariant mass distribution. Our results could be tested by the Belle II and LHCb experiments in the future.

Under flavor $SU(3)$ symmetry (${\mathrm{SU}(3)}_F$), the final-state particles in $B\to PPP$ decays ($P$ is a pseudoscalar meson) are treated as identical, and the $PPP$ must be in a fully-symmetric (FS) state, a fully-antisymmetric (FA) state, or in one of four mixed states. In this paper, we present the formalism for the FA states. We write the amplitudes for the $22B\to PPP$ decays that can be in an FA state in terms of both the ${\mathrm{SU}(3)}_F$ reduced matrix elements and diagrams. This shows the equivalence of diagrams and ${\mathrm{SU}(3)}_F$. We also give 15 relations among the amplitudes in the ${\mathrm{SU}(3)}_F$ limit as well as the additional four that appear when the diagrams $E/A/PA$ are neglected. We present sets of $B\to PPP$ decays that can be used to extract $\gamma$ using the FA amplitudes. The value(s) of $\gamma$ found in this way can be compared with the value(s) found using the FS states.

The Schwarzschild geometry is investigated within the context of effective field theory models of gravity. Starting from its harmonic-coordinate expression, we derive the metric in standard coordinates by keeping the leading one-loop quantum contributions in their most general form. We examine the metric horizons and the nature of the hypersurfaces having constant radius; furthermore, a possible energy-extraction process that violates the null energy condition is described, and both timelike and null geodesics are studied. Our analysis shows that there is no choice of the sign of the constant parameter embodying the quantum correction to the metric which leaves all the features of the classical Schwarzschild solution almost unaffected.