In this work, we make the observation that the gravitational leptogenesis mechanism can be implemented without invoking new axial couplings in the inflaton sector. We show that, in the perturbed Robertson-Walker background emerging after inflation, the spacetime metric itself breaks parity symmetry and generates a nonvanishing Pontryagin density which can produce a matter-antimatter asymmetry. We analyze the produced asymmetry in different inflationary and reheating scenarios. We show that the generated asymmetry can be locally comparable to observations in certain cases, although the size of the matter-antimatter regions is typically much smaller than the present Hubble radius.

Bayesian hierarchical inference of phenomenological parametrized neutron star equations of state (EoS) from multiple gravitational wave observations of binary neutron star mergers is of fundamental importance in improving our understanding of neutron star structure, the general properties of matter at supra nuclear densities, and the strong nuclear force. However, such an analysis is computationally costly, as it is unable to reuse single-event EoS agnostic parameter estimation runs that are carried out regardless for generating gravitational wave transient catalogs. With the number of events expected to be observable during the fourth observing run (O4) of LIGO/Virgo/KAGRA, this problem can only be expected to worsen. We develop a novel and robust algorithm for rapid and computationally cheap hierarchical inference of parametrized EoS from gravitational wave data which reuses single-event EoS agnostic parameter estimation samples to significantly reduce computational cost. We efficiently include a priori knowledge of neutron star physics as Bayesian priors on the EoS parameters. The high speed and low computational cost of our method allow for efficient recomputation of EoS inference every time a new binary neutron star event is discovered or whenever new observations and theoretical discoveries change the prior on EoS parameters. We test our method on both real and simulated gravitational wave data to demonstrate its accuracy. We show that our computationally cheap method produces EoS constraints that are completely consistent with existing analysis for real data, the chosen fiducial EoS for simulated data. Armed with our fast analysis scheme, we also study the variability of EoS constraints with binary neutron star properties for sets of simulated events drawn in different signal-to-noise ratio and mass ranges.

Binary neutron-star mergers and heavy-ion collisions are related through the properties of the hot and dense nuclear matter formed during these extreme events. In particular, low-energy heavy-ion collisions offer exciting prospects to recreate such extreme conditions in the laboratory. However, it remains unexplored to what degree those collisions can actually reproduce hot and dense matter formed in binary neutron star mergers. As a way to understand similarities and differences between these systems, we discuss their geometry and perform a direct numerical comparison of the thermodynamic conditions probed in both collisions. To enable a direct comparison, we employ a finite-temperature equation of state able to describe the entire high-energy phase diagram of quantum chromodynamics. Putting side by side the evolution of both systems, we find that laboratory heavy-ion collisions at the energy range of $E_{\mathrm{lab}}=0.4–0.6A\mathrm{MeV}$ probe (thermodynamic) states of matter that are very similar to those created in binary neutron-star mergers. These results can inform future low-energy heavy-ion collisions probing this regime.

We study tidal disruption of white dwarfs in elliptic orbits with the eccentricity of $\sim 1/3–2/3$ by a nonspinning supermassive black hole of mass $M_{\mathrm{BH}}={10}^5{M}_{\odot }$ in fully general relativistic simulations targeting the extreme mass-ratio inspiral leading eventually to tidal disruption. Numerical-relativity simulations are performed by employing a suitable formulation in which the weak self-gravity of white dwarfs is accurately solved. We reconfirm that tidal disruption occurs for white dwarfs of the typical mass of $\sim 0.6M_{\odot }$ and radius $\approx 1.2\times {10}^4\mathrm{km}$ near the marginally bound orbit around a nonspinning black hole with $M_{\mathrm{BH}}\lesssim 4\times {10}^5{M}_{\odot }$.

In this paper we study azimuthal asymmetries of the muon pair production in ultraperipheral heavy-ion collisions within the joint impact parameter and transverse momentum-dependent framework. The final state QED radiation effects are resummed to all orders in perturbation theory, where the complete muon mass corrections are also taken into account. We further make numerical estimations for azimuthal asymmetries in the different kinematic regions accessible at RHIC and LHC with the derived resummation formula. We find that the lepton mass effects can give sizable corrections to the asymmetries at relatively large pair transverse momentum at RHIC energy.

The lepton sector of the Standard Model is at present haunted by several intriguing anomalies, including an emerging pattern of deviations in $b\to s\ell \ell$ processes, with hints of lepton flavor universality violation, and a discrepancy in the muon anomalous magnetic moment. More importantly, it cannot explain neutrino oscillation data, which necessarily imply the existence of nonzero neutrino masses and lepton mixings. We propose a model that accommodates all the aforementioned anomalies, induces neutrino masses and provides a testable dark matter candidate. This is achieved by introducing a dark sector contributing to the observables of interest at the 1-loop level. Our setup provides a very economical explanation to all these open questions in particle physics and is compatible with the current experimental constraints.

A renormalizable UV model for axionlike particles or hidden photons, which may explain the dark matter, usually involves a dark Higgs field, which is a singlet under the standard model (SM) gauge group. The dark sector can couple to the SM particles via the portal coupling between the SM-like Higgs and dark Higgs fields. Through this coupling, the dark sector particles can be produced in either the early Universe or the collider experiments. Interestingly, not only the SM-like Higgs boson can decay into the light dark bosons, but also a light dark Higgs boson may be produced and decay into the dark bosons in a collider. In this paper, we perform the first collider search for invisible decays by taking both the Higgs bosons into account. We use a multivariate technique to best discriminate the signal from the background. We find that a large parameter region can be probed at the International Linear Collider operating at the center-of-mass energy of 250 GeV. In particular, even when the SM-like Higgs invisible decay is a few orders of magnitude below the planned sensitivity reaches of the International Linear Collider and the high luminosity LHC, the scenario can be probed by the invisible decay of the dark Higgs boson produced via a similar diagram. Measuring the dark Higgs boson decay into the dark sector will be a smoking gun signal of the light dark sector. A similar search of the dark sector would be expected in, e.g., the Cool Copper Collider, the Circular Electron Positron Collider, the Compact Linear Collider, and the Future Circular electron-positron Collider.

The scattering of neutral particles by an atomic nucleus can lead to electronic ionization and excitation through a process known as the Migdal effect. We revisit and improve upon previous calculations of the Migdal effect, using the Dirac-Hartree-Fock method to calculate the atomic wave functions. Our methods do not rely on the use of the dipole approximation, allowing us to present robust results for higher nuclear recoil velocities than was previously possible. Our calculations provide the theoretical foundations for future measurements of the Migdal effect using neutron sources, and searches for dark matter in direct detection experiments. We show that multiple ionization must be taken into account in experiments with fast neutrons, and derive the semi-inclusive probability for processes that yield a hard electron above a defined energy threshold. We present results for the noble elements up to and including xenon, as well as carbon, fluorine, silicon and germanium. The transition probabilities from our calculations are publicly available.

The Georgi-Machacek model, introducing a complex and a real scalar triplet as additional components of the electroweak symmetry breaking sector, enables substantial triplet contributions to the weak gauge boson masses, subject to the equality of the complex and the real triplet vacuum expectation values (vev) via a custodial SU(2) symmetry. We present an updated set of constraints on this scenario, from collider data (including those from $137/139{\mathrm{fb}}^{-1}$ of luminosity at the Large Hadron Collider), available data on the 125 GeV scalar, indirect limits, and also theoretical restrictions from vacuum stability and unitarity. It is found that some bounds get relaxed, and the phenomenological potential of the scenario is more diverse, if the doubly charged scalar in the spectrum can decay not only into two like-sign $W$’s but also into one or two singly charged scalars. Other interesting features are noticed in a general approach, such as substantial $\gamma \gamma$ and $Z\gamma$ branching ratios of the additional custodial singlet scalar and appreciable strength of the trilinear interaction of a charged scalar, the $W$ and the $Z$. Finally, we take into account the possibility of custodial SU(2) breaking, resulting in inequality of the real and the complex scalar vevs which, too, in principle may allow large triplet contribution to weak boson masses. Illustrative numerical results on the modified limits and predictions are presented, once more taking into account all the constraints mentioned above.

In this work, we discuss a distinctive $pp\to \text{Higgs}\to Z^{\prime }{Z}^{\prime }\to 4l$ ($l=e$, $\mu$) signal at the LHC, where the “Higgs” label refers to the Standard Model–like Higgs state discovered in 2012 or a lighter one in the framework of a theoretical model embedding a spontaneously broken $U(1{)}^{\prime }$ symmetry in addition to the Standard Model gauge group. The additional $U(1{)}^{\prime }$ symmetry generates a very light $Z^{\prime }$ state, with both vector and axial (nonuniversal) couplings to fermions, which are able to explain the so-called Atomki anomaly, compliant with current measurements of the anomalous magnetic moments of electron and muon as well as beam dump experiments. We show that the cross section for this process should be sufficiently large to afford one with significant sensitivity during run 3 of the LHC.

We discuss the discovery prospects for kg-scale dark matter with a Yukawa-like long-range interaction in Kamioka Gravitational Wave Detector (KAGRA). We consider the interaction range to be in the order of kilometers, thus the dark matter may interact with multiple KAGRA mirrors simultaneously. The induced signal strain is in many cases dominated by frequencies below about 130 Hz. Due to the geometry of the detector there is some strong directional sensitivity. It turns out that KAGRA would be able to constrain such kind of dark matter within a few years of operation. With our set of assumptions we expect that KAGRA could detect a few events per year for 10 kg dark matter, with a Yukawa interaction with a range of 10 km and an effective coupling constant around ${10}^6$.

Removing ultraviolet noise from the gauge fields is necessary for glueball spectroscopy in lattice QCD. It is known that the Yang-Mills gradient flow method is an alternative approach instead of link smearing or link fuzzing in various aspects. In this work we study the application of the gradient flow technique to the construction of the extended glueball operators. We examine a simple application of the gradient flow method, which has some problems in glueball mass calculations at large flow time because of its nature of diffusion in space-time. To avoid this problem, the spatial links are evolved by the “spatial gradient flow”, that is defined to restrict the diffusion to spatial directions only. We test the spatial gradient flow in calculations of glueball two-point functions and Wilson loops as a new smearing method, and then discuss its efficiency in comparison with the original gradient flow method and the conventional method. Furthermore, to demonstrate the feasibility of our proposed method, we determine the masses of the three lowest-lying glueball states, corresponding to the $0^{++}$, $2^{++}$, and $0^{-+}$ glueballs, in the continuum limit in pure Yang-Mills theory.

The production of Higgs bosons in weak boson fusion has the second largest cross section among Higgs-production processes at the Large Hadron Collider. As such, this process plays an important role in detailed studies of Higgs interactions with vector bosons. In this paper we extend the available description of Higgs boson production in weak boson fusion by considering anomalous weak interactions of the Higgs boson and next-to-next-to-leading order (NNLO) QCD radiative corrections at the same time. We find that, while leading order QCD predictions are too uncertain to allow for detailed studies of the anomalous couplings, next-to-leading order (NLO) QCD results are sufficiently precise, most of the time. The NNLO QCD corrections alter the NLO QCD predictions only marginally, but their availability enhances the credibility of conclusions based on NLO QCD computations.

A recent global QCD analysis of jet production and other polarized scattering data has found the presence of negative solutions for the gluon helicity distribution in the proton, $\mathrm{\Delta }g$, along with the traditional $\mathrm{\Delta }g>0$ solutions. We consider polarized semi-inclusive deep-inelastic scattering for hadrons produced with large transverse momentum as a means of constraining the dependence of $\mathrm{\Delta }g$ on the parton momentum fraction, $x$. Focusing on the double longitudinal spin asymmetry, we identify the kinematics relevant for future experiments at Jefferson Lab and the Electron-Ion Collider that are particularly sensitive to the polarized gluon channel and could discriminate between the different $\mathrm{\Delta }g$ behaviors. We find that a $\sim 20\mathrm{GeV}$ beam at the high luminosity Jefferson Lab may be especially well-suited for discriminating between the positive and negative solutions.

We study the issue of separating hadronic jets that contain bottom quarks ($b$ jets) from jets featuring light partons only. We develop a novel approach to $b$ tagging that exploits the application of QCD-inspired jet substructure observables such as one-dimensional jet angularities and the two-dimensional primary Lund plane. We demonstrate that these observables can be used as inputs to modern machine-learning algorithms to efficiently separate $b$ jets from light ones. In order to test our tagging procedure, we consider simulated events where a $Z$ boson is produced in association with jets and show that using jet angularities as an input for a deep neural network, as well as using images obtained from the primary Lund jet plane as input to a convolutional neural network, one can achieve tagging accuracy comparable with the accuracy of conventional track-based taggers. We argue that the complementary usage of the track-based taggers together with the ones based upon QCD-inspired observables could improve $b$-tagging accuracy.

The total decay widths of the charmed baryons are calculated by means of the ${}^3{P}_0$ model. Our calculations consider in the final states: the charmed baryon-(vector/pseudoscalar) meson pairs and the (octet/decuplet) baryon-(pseudoscalar/vector) charmed meson pairs, within a constituent quark model. Furthermore, we calculate the masses of the charmed baryon ground states and their excitations up to the $D$-wave in a constituent quark model both in the three-quark and in the quark-diquark schemes, utilizing a Hamiltonian model based on a harmonic oscillator potential plus a mass splitting term that encodes the spin, spin-orbit, isospin, and flavor interactions. The parameters of the Hamiltonian model are fitted to the experimental data of the charmed baryon masses and decay widths. As the experimental uncertainties of the data affect the fitted model parameters, we have thoroughly propagated these uncertainties into our predicted charmed baryon masses and decay widths via a Monte Carlo bootstrap approach, which is often absent in other theoretical studies on this subject. Our quantum number assignments and predictions of the masses and strong partial decay widths are in reasonable agreement with the available data. Thus, our results show the ability to guide future measurements in LHCb, Belle and Belle II experiments. Finally, the appendices provide some details of our calculations, in which we include the flavor coupling coefficients, which are useful for further theoretical investigations.

In this paper, we study the structure around the $p\overline{p}$ threshold that appears in ${\eta }^{\prime }{\pi }^{+}{\pi }^{-}$, $3({\pi }^{+}{\pi }^{-})$ and $K_S^0{K}_S^0\eta$ invariant mass spectra in the processes of relevant $J/\psi$ radiative decays. The $N\overline{N}$ rescattering is taken into account, and the distorted-wave Born approximation is applied to get the decaying amplitude through a two-step process: $J/\psi \to \gamma N\overline{N}\to \gamma {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$, $\gamma 3({\pi }^{+}{\pi }^{-})$, and $\gamma K_S^0{K}_S^0\eta$. The $N\overline{N}$ scattering amplitudes are obtained by solving the Lippmann-Schwinger equation with the potentials given by chiral effective field theory. To fix the unknown couplings, we fit the amplitudes to the datasets of the latest measurements on the invariant mass spectra of $J/\psi$ radiative decays, as well as the phase shifts and inelasticities given by partial wave analysis. We vary the cutoffs ($R=0.9$, 1.0, and 1.1 fm) and find that the solutions are stable. The structures around $p\overline{p}$ threshold found in the processes of $J/\psi \to \gamma {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$, $J/\psi \to \gamma 3({\pi }^{+}{\pi }^{-})$, and $J/\psi \to \gamma K_S^0{K}_S^0\eta$ can be attributed to threshold behavior of $N\overline{N}$ intermediate states.

Recently, the LHCb Collaboration has reported two strange hidden-charm pentaquark states named $P_{\psi s}^{\mathrm{\Lambda }}(4459)$ and $P_{\psi s}^{\mathrm{\Lambda }}(4338)$ in the $J/\psi \mathrm{\Lambda }$ invariant mass spectra of decays ${\mathrm{\Xi }}_b^{-}\to J/\psi \mathrm{\Lambda }{K}^{-}$ and $B^{-}\to J/\psi \mathrm{\Lambda }\overline{p}$, respectively. In this work, we perform a coupled-channel study of the interactions ${\mathrm{\Xi }}_c^{*}{\overline{D}}^{*}$, ${\mathrm{\Xi }}_c^{\prime }{\overline{D}}^{*}$, ${\mathrm{\Xi }}_c^{*}\overline{D}$, ${\mathrm{\Xi }}_c{\overline{D}}^{*}$, ${\mathrm{\Xi }}_c^{\prime }\overline{D}$, ${\mathrm{\Lambda }}_c{\overline{D}}_s^{*}$, ${\mathrm{\Xi }}_c\overline{D}$, ${\mathrm{\Lambda }}_c{\overline{D}}_s$, and $\mathrm{\Lambda }J/\psi$ in the quasipotential Bethe-Salpeter equation approach to estimate the $J/\psi \mathrm{\Lambda }$ invariant mass spectra. With the help of effective Lagrangians, the potential kernel can be constructed by meson exchanges to obtain the scattering amplitudes, from which the poles of the bound states and the invariant mass spectra can be reached. The coupled-channel calculation results in that the width of state ${\mathrm{\Xi }}_c{\overline{D}}^{*}(1/2^{-})$ is about 18 MeV and that of state ${\mathrm{\Xi }}_c{\overline{D}}^{*}(3/2^{-})$ is only about 1.6 MeV. By comparison with experimental data, it indicates that the structure $P_{\psi s}^{\mathrm{\Lambda }}(4459)$ is mainly from the contribution from the ${\mathrm{\Xi }}_c{\overline{D}}^{*}(1/2^{-})$ state while the role of state ${\mathrm{\Xi }}_c{\overline{D}}^{*}(3/2^{-})$ cannot be excluded. The line shape of the structure $P_{\psi s}^{\mathrm{\Lambda }}(4338)$ can be reproduced roughly by a narrow molecular state from the ${\mathrm{\Xi }}_c\overline{D}$ interaction with $J^P=1/2^{-}$, which is extremely close to the threshold, with a large interference effect. Besides, an additional state ${\mathrm{\Xi }}_c^{\prime }\overline{D}(1/2^{-})$ is suggested to be observed as a dip structure in the $J/\psi \mathrm{\Lambda }$ invariant mass spectrum.

The next generation of radio telescopes will be sensitive to low-scale quantum gravity by measuring ultrahigh-energy neutrinos. In this work, we demonstrate for the first time that neutrino-nucleon soft interactions induced by TeV-scale gravity would significantly increase the number of events detected by the IceCube-Gen2 radio array in the EeV regime. However, we show that these experiments cannot measure the total cross section using only the angular and energy information of the neutrino flux, unless assumptions on the underlying inelasticity distribution of neutral interactions are made.

We study the decay $B^{+}\to K^{+}{K}^{-}{\pi }^{+}$ and investigate the angular distribution of $K^{+}{K}^{-}$ pairs with invariant mass below $1.1\mathrm{GeV}/c^2$. This region exhibits both a strong enhancement in signal and very large direct $CP$ violation. We construct a coherent sum model for the angular distribution of the $S$- and $P$-wave, and report the ratio of their amplitudes, the relative phase and the forward-backward asymmetry. We also report absolute differential branching fractions and direct $CP$ asymmetry for the decay in bins of $M_{K^{+}{K}^{-}}$ and the differential branching fractions in bins of $M_{K^{+}{\pi }^{-}}$. The results are based on a data sample that contains $772\times {10}^6$ $B\overline{B}$ pairs collected at the $\mathrm{\Upsilon }(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The result favors the presence of $S$- and $D$-waves in low $M_{K^{+}{K}^{-}}$ region to the detriment of a $P$-wave.