Inclusive production processes will be important for the first observations of $XYZ$ states at new generation electron-hadron colliders, as they generally benefit from larger cross sections than their exclusive counterparts. We make predictions of semi-inclusive photoproduction of the ${\chi }_{c1}(1P)$ and $X(3872)$, whose peripheral production is assumed to be dominated by vector exchanges. We validate the applicability of vector meson dominance in the axial-vector charmonium sector and calculate production rates at center-of-mass energies relevant for future experimental facilities. We find the semi-inclusive cross sections near the threshold to be enhanced by a factor of $\sim 2–3$ compared to the exclusive reaction and well-suited for a first observation in photoproduction.

We study the double heavy baryon ${\mathrm{\Xi }}_{Q{Q}^{\prime }}$ and tetraquark $T_{QQ}$ production through photon-photon and photon-gluon fusion via ultraperipheral collisions at the LHC and Future Circular Collider (FCC) within the framework of nonrelativistic QCD factorization formalism. Various ion-ion collisions are taken into account, two $cc(bb)$-diquark configurations ($[cc(bb),{{}^{3}S}_1\text{−}\overline{\mathbf{3}}]$ and $[cc(bb),{{}^{1}S}_0\text{−}\mathbf{6}]$) and four $bc$-diquark configurations ($[bc,{{}^{3}S}_1\text{−}\overline{\mathbf{3}}]$, $[bc,{{}^{3}S}_1\text{−}\mathbf{6}]$, $[bc,{{}^{1}S}_0\text{−}\overline{\mathbf{3}}]$, and $[bc,{{}^{1}S}_0\text{−}\mathbf{6}]$) are considered in the calculation. Numerical results indicate that the $[cc,{{}^{3}S}_1\text{−}\overline{\mathbf{3}}]$ diquark provides dominant contribution for ${\mathrm{\Xi }}_{cc}$ ($T_{cc}$) production, and a considerable number of ${\mathrm{\Xi }}_{cc}$ ($T_{cc}$) can be produced. Because the event topologies for ultraperipheral collision are very clear, the background from various QCD interactions can be suppressed, hence the experimental investigation for ${\mathrm{\Xi }}_{cc}$ and $T_{cc}$ is feasible. The productions for ${\mathrm{\Xi }}_{bc/bb}$ are also discussed, leaving only a slight possibility for ${\mathrm{\Xi }}_{bc}$ through photon-gluon fusion with ultraperipheral collisions at the FCC.

We consider the instabilities of field perturbations around a homogeneous background color-electric and/or -magnetic field in SU(2) pure gauge theory. We investigate a number of distinct cases of background magnetic and electric fields, and we compute the dispersion relations in the linearized theory, identifying stable and unstable momentum modes. In the case of a net homogenous non-Abelian $B$ field, we compute the nonlinear (quadratic and cubic) corrections to the equation of motion and quantify to what extent the instabilities are tempered by these nonlinearities.

In light of recently found deviations of the experimental data from predictions from QCD factorization for $B_{(s)}\to D_{(s)}P$ decays, where $P=\{\pi ,K\}$, we systematically probe the current status of the ${\mathrm{SU}(3)}_F$ expansion from a fit to experimental branching ratio data without any further theory input. We find that the current data are in agreement with the power counting of the ${\mathrm{SU}(3)}_F$ expansion. While the ${\mathrm{SU}(3)}_F$ limit is excluded at $>5\sigma$, amplitude-level ${\mathrm{SU}(3)}_F$-breaking contributions of $\sim 20\%$ suffice for an excellent description of the data. ${\mathrm{SU}(3)}_F$ breaking is needed in tree ($>5\sigma$) and color-suppressed tree ($2.4\sigma$) diagrams. We are not yet sensitive to ${\mathrm{SU}(3)}_F$ breaking in exchange diagrams. From the underlying ${\mathrm{SU}(3)}_F$ parametrization we predict the unmeasured branching ratios $\mathcal{B}({\overline{B}}_s^0\to {\pi }^{-}{D}^{+})=2\mathcal{B}({\overline{B}}_s^0\to {\pi }^0{D}^0)=[0.3,7.2]\times {10}^{-6}$ of suppressed decays that can be searched for at the LHCb experiment.

Recent observations of the light component of the cosmic-ray spectrum have revealed unexpected features that motivate further and more precise measurements up to the highest energies. The Dark Matter Particle Explorer is a satellite-based cosmic-ray experiment that has been operational since December 2015, continuously collecting data on high-energy cosmic particles with very good statistics, energy resolution, and particle identification capabilities. In this work, the latest measurements of the energy spectrum of $\mathrm{proton}+\mathrm{helium}$ in the energy range from 46 GeV to 464 TeV are presented. Among the most distinctive features of the spectrum, a spectral hardening at 600 GeV has been observed, along with a softening at 29 TeV measured with a $6.6\sigma$ significance. Moreover, the detector features and the analysis approach allowed for the extension of the spectral measurement up to the sub-PeV region. Even if with small statistical significance due to the low number of events, data suggest a new spectral hardening at about 150 TeV.

We measure the branching fraction of the decay $B^{-}\to D^0\rho (770{)}^{-}$ using data collected with the Belle II detector. The data contain 387 million $B\overline{B}$ pairs produced in $e^{+}{e}^{-}$ collisions at the $\mathrm{\Upsilon }(4S)$ resonance. We reconstruct $8360\pm 180$ decays from an analysis of the distributions of the $B^{-}$ energy and the $\rho (770{)}^{-}$ helicity angle. We determine the branching fraction to be $(0.939\pm 0.021(\mathrm{stat})\pm 0.050(\mathrm{syst}))\%$, in agreement with previous results. Our measurement improves the relative precision of the world average by more than a factor of two.

Magnetic quivers have been an instrumental technique for advancing our understanding of Higgs branches of supersymmetric theories with eight supercharges. In this work, we present the “decay and fission” algorithm for unitary magnetic quivers. It enables the derivation of the complete phase (Hasse) diagram and is characterized by the following key attributes: First and foremost, the algorithm is inherently simple, just relying on convex linear algebra. Second, any magnetic quiver can only undergo decay or fission processes; these reflect the possible Higgs branch RG flows (Higgsings), and the quivers thereby generated are the magnetic quivers of the new RG fixed points. Third, the geometry of the decay or fission transition (i.e., the transverse slice) is simply read off. As a consequence, the algorithm does not rely on a complete list of minimal transitions, but rather outputs the transverse slice geometry automatically. As a proof of concept, its efficacy is showcased across various scenarios, encompassing superconformal field theories from dimensions 3 to 6, instanton moduli spaces, and little string theories.

We show that null cosmic strings disturb gravitational fields of massive bodies and create outgoing gravitational waves (GW). We find perturbations of the metric caused by a straight null string and a pointlike massive source as solutions to linearized Einstein equations on a flat space-time and derive an analytic approximation for their asymptotic at future null infinity. A space-time created by the source and the string is shown to have an asymptotically polyhomogeneous form. We calculate GW flux in such space-times and demonstrate that the averaged intensity of the radiation is maximal in the direction of the string motion. Opportunities to detect null string generated gravity waves are briefly discussed.

We revisit the quantum-amplitude-based derivation of the gravitational waveform emitted by the scattering of two spinless massive bodies at the third order in Newton’s constant, $h\sim G+G^2+G^3$ (one-loop level), and correspondingly update its comparison with its classically derived multipolar-post-Minkowskian counterpart. A spurious-pole-free reorganization of the one-loop five-point amplitude substantially simplifies the post-Newtonian expansion. We find complete agreement between the two results up to the fifth order in the small velocity expansion after taking into account three subtle aspects of the amplitude derivation: (1) in agreement with [A. Georgoudis et al., J. High Energy Phys. 03 (2024) 089], the term quadratic in the amplitude in the observable-based formalism [D. A. Kosower et al., J. High Energy Phys. 02 (2019) 137] generates a frame rotation by half the classical scattering angle; (2) the dimensional regularization of the infrared divergences of the amplitude introduces an additional $(d-4)/(d-4)$ finite term; and (3) zero-frequency gravitons are found to contribute additional terms both at order $h\sim G^1$ and at order $h\sim G^3$ when including disconnected diagrams in the observable-based formalism.

We construct some new dynamical $p$-brane solutions to gravity theories on curved backgrounds. We discuss the relations between dynamical branes, a new time-dependent solution on complex projective space $\mathbb{C}{\mathrm{P}}^n$, and the static $p$-branes on the orbifold ${\mathbb{C}}^n/{\mathbb{Z}}_n$.

Infrared divergence is a common feature of spinfoam models with a vanishing cosmological constant but is expected to disappear in presence of a nonvanishing cosmological constant. In this paper, we investigate the spinfoam amplitude with cosmological constant [1] on the melon graph, which is known as the melonic radiative correction. The amplitude closely relates to the state-integral model of complex Chern-Simons theory. We prove that the melonic radiative correction is finite in presence of a nonvanishing cosmological constant, in contrast to the infrared divergence of spinfoam models with a vanishing cosmological constant. In addition, we also analyze the scaling behavior of the radiative correction in the limit of small cosmological constant.

Modeled searches of gravitational wave signals from compact binary mergers rely on template waveforms determined by the theory of general relativity (GR). Once a signal is detected, one generally performs the model agnostic test of GR, either looking for consistency between the GR waveform and data or introducing phenomenological deviations to detect the departure from GR. The nontrivial presence of beyond-GR physics can alter the waveform and could be missed by the GR template-based searches. A recent study [H. Narola et al., Beyond general relativity: Designing a template-based search for exotic gravitational wave signals, Phys. Rev. D 107, 024017 (2023)] targeted the binary black hole merger, assuming the parametrized deviation in lower post-Newtonian terms, and demonstrated a mild effect on the search sensitivity. Surprisingly, for the search space of binary neutron star (BNS) systems where component masses range from 1 to $2.4M_{\odot }$ and parametrized deviations span $1\sigma$ width of the deviation parameters measured from the GW170817 event, the GR template bank is highly ineffectual for detecting the non-GR signals. Here, we present a new hybrid method to construct a non-GR template bank for the BNS search space. The hybrid method uses the geometric approach of three-dimensional lattice placement to cover most of the parameter space volume, followed by the random method to cover the boundary regions of parameter space. We find that the non-GR bank size is $\sim 15$ times larger than the conventional GR bank and is effectual toward detecting non-GR signals in the target search space.

We investigate the impact of postadiabatic (1PA) terms on parameter estimation for extreme and intermediate mass-ratio inspirals using state-of-the-art waveform models. Our analysis is the first to employ Bayesian inference to assess systematic errors for 1PA waveforms. We find that neglecting 1PA terms introduces significant biases for the (small) mass ratio $\epsilon \gtrsim {10}^{-5}$ for quasi circular orbits in Schwarzschild spacetime, which can be mitigated with resummed 3PN expressions at 1PA order. Moreover, we show that the secondary spin is strongly correlated with the other intrinsic parameters, and it can not be constrained for $\epsilon \lesssim {10}^{-5}$. Finally, we highlight the need for addressing eccentric waveform systematics in the small-mass-ratio regime, as they yield stronger biases than the circular limit in both intrinsic and extrinsic parameters.

We study the scalar modes that, being observable today, were trans-Planckian before inflation, within the context of hybrid loop quantum cosmology (LQC). We analyze the dynamics of these highly ultraviolet modes by introducing modified dispersion relations to their equations of motion and discuss the impact that these relations would introduce in the power spectrum by computing the adiabaticity coefficient. More precisely, we consider two different models compatible with observations for the standard linear dispersion relation which are based on different initial conditions for the perturbations and background. One of these models avoids the issue altogether by generating less $e$-folds of inflation, so that the observable modes are never trans-Planckian, whereas the other suffers (arguably softly) from the trans-Planckian problem. This shows that the existence of the trans-Planckian problem in LQC is model dependent.

We use a recent $\mathrm{Pantheon}+\mathrm{SH}0\mathrm{ES}$ compilation of type Ia supernova distance measurements at low-redshift, i.e., $0.01\le z\le 0.10$, in order to investigate the directional dependency of the deceleration parameter ($q_0$) in different patches (60° size) across the sky, as a probe of the statistical isotropy of the Universe. We adopt a cosmographic approach to compute the cosmological distances, fixing $H_0$ and $M_B$ to reference values provided by the collaboration. By looking at 500 different patches randomly taken across the sky, we find a maximum $\sim 3\sigma$ CL anisotropy level for $q_0$, whose direction points orthogonally to the cosmic microwave background (CMB) dipole axis, i.e., $(R{A}^{\mathrm{SN}},DE{C}^{\mathrm{SN}})=(267°,6°)$ vs $(R{A}^{\mathrm{CMB}},DE{C}^{\mathrm{CMB}})=(167°,-7°)$. We assessed the statistical significance of those results, finding that such a signal is expected due to the limitations of the observational sample. These results support that there is no significant evidence for a departure from the cosmic isotropy assumption, one of the pillars of the standard cosmological model.

The search for non-Gaussian signatures in the cosmic microwave background (CMB) is crucial for understanding the physics of the early Universe. Given the possibility of non-Gaussian fluctuations in the CMB, a recent revision to the standard $\mathrm{\Lambda }$-cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$) model has been proposed, dubbed “super-$\mathrm{\Lambda }\mathrm{CDM}$.” This model introduces additional free parameters to account for the potential effects of a trispectrum in the primordial fluctuations. In this study, we explore the impact of the super-$\mathrm{\Lambda }\mathrm{CDM}$ model on current constraints in neutrino physics. In agreement with previous research, our analysis reveals that, for most of the datasets, the super-$\mathrm{\Lambda }\mathrm{CDM}$ parameter $A_0$ significantly deviates from zero at over a 95% confidence level. We then demonstrate that this signal might influence current constraints in the neutrino sector. Specifically, we find that the current constraints on neutrino masses may be relaxed by over a factor of 2 within the super-$\mathrm{\Lambda }\mathrm{CDM}$ framework, thanks to the correlation present with $A_0$; such relaxation persists even when we apply constraints to the trispectrum from local measurements, assuming a strong similarity between the two forms. Consequently, locking $A_0=0$ might introduce a bias, leading to overly stringent constraints on the total neutrino mass.

We present a new mechanism for the primordial black hole (PBH) production within the QCD axion framework. We take the case where the Peccei-Quinn symmetry breaks during inflation, resulting in a $N_{\mathrm{DW}}=1$ string-wall network that reenters the horizon sufficiently late. Therefore, closed axion domain walls naturally arising in the network are sufficiently large to collapse into PBHs. Our numerical simulation shows that $\sim 0.3\%$ of the total wall area is in the form of closed walls. In addition, the relic abundance of dark matter is dominantly accounted for by free axions from the collapse of open walls bounded by strings. In this framework, the abundance of PBH within dark matter is calculated to be $\sim 0.9\%$. This fraction remains unaffected by axion parameters or the reentering horizon temperature, as it is determined by the fixed proportion of closed walls in the network, governed by the principles of percolation theory. The resultant PBHs uniformly share the same mass, which spans from about ${10}^{-9}$ to 1 solar mass, corresponding to the classical QCD axion mass window ${10}^{-5}–{10}^{-2}\mathrm{eV}$ and the reentering horizon temperature $300-1\mathrm{MeV}$. Intriguingly, PBHs in this mechanism can naturally account for the ultrashort-timescale gravitational microlensing events observed by the OGLE collaboration.

The tentative identification of approximately ten relativistic antihelium ($\overline{\mathrm{He}}$) cosmic-ray events at AMS-02 would, if confirmed, challenge our understanding of the astrophysical synthesis of heavy antinuclei. We propose a novel scenario for the enhanced production of such antinuclei that is triggered by isolated, catastrophic injections of large quantities of energetic Standard Model (SM) antiquarks in our galaxy by physics beyond the Standard Model (BSM). We demonstrate that SM antinucleosynthetic processes that occur in the resulting rapidly expanding, thermalized fireballs of SM plasma can, for a reasonable range of parameters, produce the reported tentative $\sim 2:1$ ratio of ${}^3\overline{\mathrm{He}}$ to ${}^4\overline{\mathrm{He}}$ events at AMS-02, as well as their relativistic boosts. Moreover, we show that this can be achieved without violating antideuterium or antiproton flux constraints for the appropriate antihelium fluxes. A plausible BSM paradigm for the catastrophic injections is the collision of macroscopic composite dark-matter objects carrying large net antibaryon number. Such a scenario would require these objects to be cosmologically stable, but to destabilize upon collision, promptly releasing a fraction of their mass energy into SM antiparticles within a tiny volume. We show that, in principle, the injection rate needed to attain the necessary antihelium fluxes and the energetic conditions required to seed the fireballs appear possible to obtain in such a paradigm. We leave open the question of constructing a BSM particle physics model to realize this, but we suggest two concrete scenarios as promising targets for further investigation.

We compute the one-loop QCD correction to the photon-quark-antiquark vertex in an extremely strong magnetic background, i.e., one in which $\sqrt{eB}$ is much larger than all other mass scales. We resort to the lowest-Landau level approximation, and consider on-shell fermions. We find that the total magnetic moment is such that the anomalous magnetic moment contributes to the electric part $\sim i{E}_3{\sigma }_3$, the other contributions to $\mathit{B}·\mathit{\sigma }$ and $i\mathit{E}·{\mathit{\sigma }}_{\perp }$ being completely suppressed. We show results for the anomalous magnetic moment of quarks up and down, scaled by their values in the vacuum, as a function of the external magnetic field, considering dressed gluons and a renormalization scale ${\mu }_{\overline{\mathrm{MS}}}=\sqrt{|eB|}$.