The evolution of neutrinos in a fluctuating classical axionlike particles (ALPs) field is investigated. The equation for the neutrino density matrix is obtained in the Redfield form, and the corresponding dissipative matrix is derived. Estimates on the ALP-neutrino coupling constants are obtained using the limits on the decoherence parameter determined from the analysis of reactor neutrino experiments data.

The detection of the gravitational wave event GW230529, presumably a neutron star-black hole (NSBH) merger, by the LIGO-Virgo-KAGRA Collaboration marks an exciting discovery for multimessenger astronomy. The black hole (BH) has a high probability of falling within the “mass gap” (mg) between the neutron star and the BH mass distributions. Because of the relatively low primary mass, this system has a higher likelihood of producing an electromagnetic counterpart than previously detected NSBH mergers. We analyze the potential kilonova (KN) emission from GW230529 and find that, if the source was an NSBH merger, there is a $\sim 2–28\%$ probability (depending on the assumed equation of state) that it produced a KN peaking at $\sim 1\mathrm{day}$ postmerger with $g\lesssim 23.5$ and $i<23$. Hence, it could have been detected by ground-based telescopes. If instead the event was a binary neutron star merger, the probability of KN production drops to $\sim 0–10\%$. Motivated by these results, we simulate a broader population of mass gap NSBH mergers expected during the fifth LIGO/Virgo/KAGRA observing run (O5) and find a 2%–3% chance of KN production per event. Such KNe would typically be fainter than GW230529, with $g\lesssim 26$ and $i\lesssim 25$. Based on these findings, DECam-like instruments may be able to detect up to $\sim 70\%$ of future mgNSBH KNe, corresponding to 1–2 multimessenger mgNSBH per year in O5.

Neural density estimation has seen widespread applications in the gravitational-wave (GW) data analysis, which enables real-time parameter estimation for compact binary coalescences and enhances rapid inference for subsequent analysis such as population inference. In this work, we explore the application of using the Kolmogorov-Arnold network (KAN) to construct efficient and interpretable neural density estimators for lightweight posterior construction of GW catalogs. By replacing conventional activation functions with learnable splines, KAN achieves superior interpretability, higher accuracy, and greater parameter efficiency on related scientific tasks. Leveraging this feature, we propose a KAN-based neural density estimator, which ingests megabyte-scale GW posterior samples and compresses them into model weights of tens of kilobytes. Subsequently, analytic expressions requiring only several kilobytes can be further distilled from these neural network weights with minimal accuracy trade-off. In practice, GW posterior samples with fidelity can be regenerated rapidly using the model weights or analytic expressions for subsequent analysis. Our lightweight posterior construction strategy is expected to facilitate user-level data storage and transmission, paving a path for efficient analysis of numerous GW events in the next-generation GW detectors.

We investigate the high-energy behavior of the total cross section, ${\sigma }_{\mathrm{tot}}$, and the ratio of the real to imaginary parts of the scattering amplitude, $\rho$, in both proton-proton and antiproton-proton channels. Our analysis is based on a QCD-inspired model in which the rise of the cross sections is predominantly driven by semihard processes involving gluons. We address the tension between measurements from ATLAS/ALFA and TOTEM Collaborations, showing that independent analyses of their datasets can provide statistically consistent descriptions of the overall data, even though they do not fully reproduce the central values of the $\rho$ parameter at $\sqrt{s}=13\mathrm{TeV}$. The slight discrepancy between these central values and the model’s predicted values, obtained using an asymptotic dominant crossing-even elastic scattering amplitude, points to the potential presence of an odd component in the semihard amplitude at high energies.

We perform a theoretical study of the decay process $\mathrm{\Upsilon }\to D^{-}{\overline{B}}^0{D}_s^{+}$ in search of the doubly heavy tetraquark states $T_{bc\overline{s}}$ with quark content $bc\overline{s}\overline{d}$. These $T_{bc\overline{s}}$ states are assumed to be dynamically generated molecular states from the S-wave interactions between ${\overline{B}}_s^{(*)0}{D}^{(*)+}$ and ${\overline{B}}^{(*)0}{D}_s^{(*)+}$ meson pairs. Based on the total angular momentum and the type of the constituent mesons (pseudoscalars $P$ or vectors $V$), they are labeled as $T_{bc\overline{s}}^{0,PP}$, $T_{bc\overline{s}}^{0,VV}$, and $T_{bc\overline{s}}^{2,VV}$, respectively. The ${\overline{B}}^0{D}_s^{+}$ invariant mass distribution for this decay is calculated using current algebra, incorporating contributions from $T_{bc\overline{s}}$ states arising from final-state interactions. Our results reveal a clear peak structure in the 7415–7425 MeV region, which is attributed to the $T_{bc\overline{s}}^{2,VV}$ state. Additionally, a distinct dip structure appears near the ${\overline{B}}^{*0}{D}_s^{*+}$ threshold, characteristic of the $T_{bc\overline{s}}^{2,VV}$ as a hadronic molecular state. A near-threshold enhancement associated with the $T_{bc\overline{s}}^{0,PP}$ state and a dip arising from the $T_{bc\overline{s}}^{0,VV}$ state are also identified, though the manifestation of these features depends sensitively on model parameter fine-tuning. Therefore, with increased experimental statistics, the decay channel $\mathrm{\Upsilon }\to D^{-}{\overline{B}}^0{D}_s^{+}$ offers a promising avenue for discovering and characterizing the $T_{bc\overline{s}}$ states.

The proposed $e^{+}{e}^{-}$ collider offers an ideal environment for precise estimation of Higgs boson properties which are of utmost importance to validate the Standard Model of particle physics. We investigate $hVV$ couplings, where $V\in \{Z,\gamma \}$ with single Higgs production associated with $Z$ boson at the proposed $e^{+}{e}^{-}$ machine with $\sqrt{s}=250\mathrm{GeV}$, within the Standard Model effective field theory framework. We employ the recoil mass of the dilepton system, to select the signal phase space, i.e, $Zh\to l^{+}{l}^{-}b\overline{b}$ events. The constraints on the Wilson coefficients (WCs) are obtained using the optimal observable technique. On comparison with the current experimental limits at 68% CL with $138{\mathrm{fb}}^{-1}$ luminosity, our limits are tighter by a factor ranging from 1.5–10 for $CP$-even operators, while $CP$-odd WCs shows comparable limits.

We propose a novel scale-invariant model with the 3-3-1-1 gauge symmetry featuring a universal seesaw mechanism for all fermion masses, which, through the inclusion of additional vectorlike quarks, provides a partial explanation for the observed fermion mass hierarchies. A discrete remnant of the gauge group, the matter parity ($P_M$), stabilizes a fermionic dark matter candidate, and the scalar sector includes two triplets (minimal for $3\text{−}3\text{−}1$ breaking) and two scalar singlets. We identify the lightest $P_M$-odd fermion, $f_{\mathrm{d}}$, as a viable dark matter candidate. Our analysis shows that $f_{\mathrm{d}}$ satisfies the observed relic density constraint within the mass range $220\mathrm{GeV}\lesssim m_{f_{\mathrm{d}}}\lesssim 555\mathrm{GeV}$, primarily due to resonant annihilation via the new scalar $H_2$. While this mass range depends on the symmetry-breaking scale $v_{\chi }$, which has a lower bound of $v_{\chi }\gtrsim 3.6\mathrm{TeV}$ from LEP constraints on the ${\rho }_0$ parameter, we adopt a more conservative lower bound of $v_{\chi }>10\mathrm{TeV}$. This choice is made to ensure that the $Z^{\prime }$ boson mass remains above approximately 4 TeV, and is motivated by recent LHC results and future projections for $Z^{\prime }$ boson searches, which provide more stringent constraints than previous bounds or those from the ${\rho }_0$ parameter. Spin-independent (SI) interactions dominate the direct detection phenomenology of $f_{\mathrm{d}}$. We calculate the SI elastic scattering cross section and find that parameter points satisfying the relic density constraint are consistent with current experimental limits from LZ and PandaX-4T for certain parameter choices, particularly depending on the ${\alpha }_{12}$ angle. Some regions of the viable parameter space lie below the neutrino floor. Prospects for detection by future experiments like XLZD and PandaX-xT are also presented and discussed.

The particle origin of dark matter (DM) remains elusive despite decades of direct, indirect, and collider searches. Several groups have reported a $\gamma$-ray excess toward the Galactic Center commonly referred to as the Galactic Center excess (GCE). Its spectrum is consistent with annihilation of weakly interacting massive particles (WIMPs) of mass $\mathcal{O}(10-100)\mathrm{GeV}$ and a thermal-relic cross section. Although many concrete WIMP models reproduce the GCE spectrum, most are now excluded by direct detection experiments that are approaching the neutrino floor. We investigate a class of anomaly-free extensions of the Standard Model featuring gauged differences of lepton number, $U(1{)}_{L_i-L_j}$, and gauged baryon minus lepton number, $U(1{)}_{B-L}$. We show that these models can reproduce the GCE while remaining compatible with the observed relic abundance. We then impose collider and direct detection constraints, accounting for both tree-level and loop-induced kinetic mixing. The $L_{\mu }-L_e$ model gives the best fit to the GCE: a DM mass of $m_{\chi }\sim 40-50\mathrm{GeV}$ remains consistent with the muon and electron magnetic moment anomalies, $(g-2{)}_{\mu ,e}$, as well as current collider and direct detection limits, for mediator masses in the range $m_{A^{\prime }}\sim 70-86\mathrm{GeV}$ and a DM mediator coupling of $(1-5)\times {10}^{-2}$. By contrast, the $L_e-L_{\tau }$ and $L_{\mu }-L_{\tau }$ models yield poorer fits; satisfying both the relic density and experimental bounds forces the DM mass to lie very close to resonance (i.e. approximately half the mediator mass). Finally, while the $B-L$ model also matches the GCE well, its parameter space is almost entirely ruled out by strong direct detection limits, except for the narrow resonance region where $m_{\chi }$ should be equal to $m_{A^{\prime }}/2$ requiring a fine-tuning at the few-percent level.

We present a complete classification of domain wall solutions in the two-Higgs-doublet model (2HDM) with a global ${\mathbb{Z}}_2$ symmetry, categorized as superconducting, $CP$-violating, or neither, depending on the scalar particle masses and the ratio of the two Higgs doublets’ vacuum expectation values. We demonstrate that any domain wall solution can be reduced to depend on only six of the eight general field components, with further field reductions possible within different regions of the parameter space. Furthermore, we show that the superconducting solutions can be used to construct stable, current-carrying domain walls in two spatial dimensions. Similarly, the $CP$-violating solutions allow for two-dimensional configurations where $CP$ symmetry is locally broken on the ${\mathbb{Z}}_2$-symmetric wall, which could provide an out-of-equilibrium environment for $CP$-violating processes to occur.

We propose and study a purely inelastic scalar dark matter model, where two real scalars-dark matter ${\varphi }_1$ and its excited partner ${\varphi }_2$ interact with the Standard Model via a Higgs portal. After mass diagonalization, only inelastic couplings remain, allowing the model to evade stringent bounds from direct detection. We show that thermal (co)annihilation between ${\varphi }_1$ and ${\varphi }_2$ naturally yields the observed dark matter relic abundance. The same interaction structure can induce a strongly first-order phase transition in the early Universe, generating detectable gravitational waves in upcoming experiments. Meanwhile, the slight mass splitting between ${\varphi }_1$ and ${\varphi }_2$, along with the heavy off shell mediator SM Higgs, leads to long-lived particle signatures of ${\varphi }_2$ at the HL-LHC via the displaced muon-jets technique. We pinpoint a feasible parameter space where the correct relic abundance, observable gravitational waves, and collider signals can all be achieved concurrently, presenting a valuable chance to validate this scenario through a comprehensive examination encompassing cosmological, astrophysical, and collider investigations.

We investigate static and dynamical aspects of string breaking in a ${\mathbb{Z}}_2$ lattice gauge theory coupled to Kogut-Susskind staggered fermions. Using tensor network simulations, we demonstrate that the static potential as well as the site-resolved configuration of the matter sites and gauge links allows us to identify the regimes in which string breaking occurs. Furthermore, we develop a variational quantum eigensolver that allows for reliably preparing the ground state of the theory in both the absence and presence of static charges and to capture the static aspects of the phenomenon. Carrying out state preparation on real quantum hardware for up to 19 qubits, we demonstrate its suitability for current quantum devices. In addition, we study the real-time dynamics of a flux tube between two static charges using both tensor networks and quantum hardware. Using a trotterization for the time-evolution operator, we are able to show that the breaking process starts with the creation of charges inside the string. These eventually redistribute toward the static charges and screen them, which leads to the breaking of the flux tube.

We investigate thermal properties of a $U(1)$ lattice gauge theory in $1+1$ dimensions through real-time simulations. We extract the spectral functions directly coupling to the pseudoscalar and scalar mesons, demonstrating the thermal modifications of these states with increasing temperatures. Introducing the notion of energy-flow operators, we quantify the temporal buildup of correlations in the energy flows across the lattice. We demonstrate that energy-energy correlators fail to factorize to products of energy flows, both in the vacuum and at nonzero temperature, indicating the presence of nontrivial correlations in the quantum states. Our results constitute a first real-time ab initio study of bound-state thermal broadening and finite temperature energy-flow correlations in a gauge theory, providing a benchmark for future studies of hadronic matter under extreme conditions.

The calculation of generalized parton distributions (GPDs) in lattice QCD was traditionally done by calculating matrix elements in the symmetric frame. Recent advancements have significantly reduced computational costs by calculating these matrix elements in the asymmetric frame, allowing us to choose the momentum transfer to be in either the initial or final states only. The theoretical methodology requires a new parametrization of the matrix element to obtain Lorentz-invariant amplitudes, which are then related to the GPDs. The formulation and implementation of this approach have already been established for the unpolarized and helicity GPDs. Building upon this idea, we extend this formulation to the four leading-twist quark transversity GPDs ($H_T$, $E_T$, ${\tilde{H}}_T$, ${\tilde{E}}_T$). We also present numerical results for zero skewness using an $N_f=2+1+1$ ensemble of twisted mass fermions with a clover improvement. The light quark masses employed in these calculations correspond to a pion mass of about 260 MeV. Furthermore, we include a comparison between the symmetric and asymmetric frame calculations to demonstrate frame independence of the Lorentz-invariant amplitudes. Analysis of the matrix elements in the asymmetric frame is performed at several values of the momentum transfer squared, $-t$, ranging from $0.17$ to $2.29{\mathrm{GeV}}^2$.

In the heavy quarkonium decay process $V\to ggg$ ($V=J/\psi ,\mathrm{\Upsilon }$), making a definite prediction including relativistic corrections has so far remained a significant challenge. In this work, we study this decay process by taking into account the relativistic corrections in the Bethe-Salpeter formalism, where the relativistic bound-state wave function of quarkonium is obtained by solving the Bethe-Salpeter equation under the covariant instantaneous ansatz. Through analytical calculation, we find that some polarized decay widths vanish due to the helicity selection rule, which suppresses the corresponding helicity amplitudes. Owing to helicity flip symmetry and phase space symmetry, the nonvanishing polarized decay widths are not all independent; they are related through a set of symmetry relations. Then we obtain the unpolarized decay width formula $\mathrm{\Gamma }(V\to ggg)=\frac{80({\pi }^2-9){\alpha }_s^3{N}_V^2{\beta }_V^3}{81{\pi }^{9/2}M}(1-\kappa \frac{{\beta }_V^2}{M^2})$, where the factor $\kappa \frac{{\beta }_V^2}{M^2}$ arises from the relativistic corrections with $\kappa \equiv \frac{3(112+25{\pi }^2)}{16({\pi }^2-9)}$. Furthermore, including both relativistic and QCD radiative corrections within the factorization assumption, our predictions of $\mathcal{B}(V\to ggg)$ and $\mathcal{B}(V\to e^{+}{e}^{-})$ agree well with their experimental data. As a crossing check, with the experimental value of the ratio $R_V=\frac{\mathrm{\Gamma }(V\to ggg)}{\mathrm{\Gamma }(V\to e^{+}{e}^{-})}$ and our result for $R_V$, we extract ${\alpha }_s(M_{J/\psi }/2)=0.31$ and ${\alpha }_s(M_{\mathrm{\Upsilon }}/2)=0.20$, respectively.

We investigate the electromagnetic properties of the axial-vector molecular states $D^{*}K$, $D{K}^{*}$, $B^{*}K$, and $B{K}^{*}$, which are used to model the charmed states $D_{s1}^{+}(2460)$, $D_{s1}^{+}(2536)$, and their bottom partners with quantum numbers $J^P=1^{+}$. To our knowledge, this presents the first comprehensive calculation of the magnetic and quadrupole moments for these specific molecular configurations. Employing the QCD light-cone sum rule method with molecular-type interpolating currents, we compute these moments and perform a detailed flavor decomposition to reveal the internal distribution of the electromagnetic charge and spin. Our results demonstrate that the light up and down quarks dominate the electromagnetic response, with negligible contributions from the heavy quarks. The $D^{*}K$ and $B^{*}K$ states exhibit negative quadrupole moments and slightly oblate charge distributions, whereas the $D{K}^{*}$ and $B{K}^{*}$ states possess positive quadrupole moments and prolate distributions, with significant contributions from the strange quark. The predicted moments provide benchmarks for lattice QCD calculations and are testable through their influence on radiative transitions and photo- and electroproduction observables at high-luminosity facilities, offering crucial insights into the internal structure and nature of these axial-vector states.

The study of symmetry plane correlations (SPCs) can be useful in characterizing the direction of the anisotropic emission of produced particles in the final state. The study of SPCs provides an independent method to understand the transport properties of the system formed in heavy-ion collisions. Similar to anisotropic flow coefficients, which are largely influenced by the initial spatial anisotropy, SPCs also depend on the participant plane correlations measured using the participating nucleons of the collision overlap region. In this paper, SPCs are studied in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02\mathrm{TeV}$ using the event generator AMPT. In addition to their behavior with the changing centrality of the collision, their event shape dependence is studied for the first time, using the event shape classifier transverse spherocity. The Gaussian estimator is used to evaluate the correlations, and these are compared with the participant plane correlations defined in an analogous way to the symmetry plane correlations, and a qualitative match is found between them. These event-shape-differentiated symmetry plane correlations can be used to deduce the presence of higher-order anisotropies in the initial energy distribution, thus giving insight into the initial geometry of the colliding system, among other applications, like model development and model testing using Bayesian analyses.

Parton distribution functions (PDFs) are comprehensive and not reliant on the process. They are affected by nuclear matter during nuclear scattering process. As a recent approach, in order to study the nuclear PDFs (nPDFs), the nucleon pair PDFs are utilized to describe parton distributions in the nucleon pair which are confined to a nucleus. Nucleon pair PDFs stem from nucleon-nucleon correlation, which is called short range correlation (SRC) and are proportional to common nucleon PDFs. In this regard a modified universal function is constructed, which provides a test for SRC in (neutrino)-nucleus scattering. In fact we can show that the modification of the structure function of nucleons bound in atomic nuclei [known as the European Muon Collaboration (EMC effect)] are consistently accounted for within the framework of a universal modification of nucleons in SRC pairs. In this article, based on the strategy that was introduced in Schmookler et al. [Nature (London) 566, 354 (2019).], we are investigating to find the universality behavior for the ratio of nonsinglet $x{F}_3^A$ nuclear structure function. The numerical calculations performed within the CTEQ framework confirm the universality feature of the concerned ratio, as has been established for the ratio of the structure function $F_2^A$ in Schmookler et al. [Nature (London) 566, 354 (2019).]. Following that we reformulate the $R_{\mathrm{EMC}}$ nuclear weight function, which relates the free and bound structure function in terms of modified universal function. It makes us a possibility to achieve $R_{\mathrm{EMC}}$ and finally $x{F}_3^A$ nuclear structure function for each nucleus only by considering the specified feature of nucleus. The results are compared with the nuclear $x{F}_3$ structure function, which are computing from bound PDFs, based on some parametrization models. The findings, considering the SRC effect, demonstrate qualitative agreement with nCTEQ15 and EPPS21 parametrization models and also the available experimental data.

Under chiral effective field theory, we study the $S$-wave $D{D}^{*}$ interactions up to second chiral order at one-loop level, which contain full contact, one-pion-exchange (OPE) and two-pion-exchange (TPE) contributions. Here, we adopt a new subtraction scheme of the two-particle-reducible contributions and attempt different regularization schemes uniquely for the TPE contributions since they are highly divergent on the momentum transfer. Under these schemes, we conclude that, in the $I=0$ channel, the TPE contribution is repulsive, then the competition between this powerful repulsing TPE and the other two (contact and OPE) results in a quite weak attraction. This explains why $T_{cc}$ has an extremely small binding energy if treated as the $I=0$ $D{D}^{*}$ bound state. This feature resembles that of hidden charm $D{\overline{D}}^{*}$ as we investigated in previous work [Phys. Rev. D 105, 034013 (2022)], which also interpreted the extremely near-threshold phenomenon of $X(3872)$. In addition, we also solve the Bethe-Salpeter equation with the chiral interactions for a consistency check.

Charged-current neutrino interactions with final states containing zero mesons and at least one proton are of high interest for current and future accelerator-based neutrino oscillation experiments. Using the Booster Neutrino Beam and the MicroBooNE detector at Fermi National Accelerator Laboratory, we have obtained the first double-differential cross-section measurements of this channel for muon neutrino scattering on an argon target with a leading proton momentum threshold of $0.25\mathrm{GeV}/c$. We also report a flux-averaged total cross section of $\sigma =(11.8\pm 1.2)\times {10}^{-38}{\mathrm{cm}}^2/\mathrm{Ar}$ and several single-differential measurements which extend and improve upon previous results. Statistical and systematic uncertainties are quantified with a full treatment of correlations across 359 kinematic bins, including correlations between distributions describing different observables. The resulting dataset provides the most detailed information obtained to date for testing models of mesonless neutrino-argon scattering.

Conformal field theory (CFT) can be placed on disparate space-time manifolds to facilitate investigations of their properties. For ($2+1$)-dimensional [$(2+1)\mathrm{D}$] theories, one useful choice is the real projective space ${\mathbb{RP}}^3$ obtained by identifying antipodal points on the boundary sphere of a three-dimensional ball. One-point functions of scalar primary fields on this manifold generally do not vanish and encode the so-called crosscap coefficients. These coefficients also manifest on the sphere as the overlaps between certain crosscap states and CFT primary states. Taking the $(2+1)\mathrm{D}$ Ising CFT as a concrete example, we demonstrate that crosscap coefficients can be extracted from microscopic models. We construct crosscap states in both lattice models defined on polyhedrons and continuum models in Landau levels, where the degrees of freedom at antipodal points are entangled in Bell-type states. By computing their overlaps with the eigenstates of many-body Hamiltonians, we obtain results consistent with those from conformal bootstrap. Importantly, our approach directly reveals the absolute values of crosscap overlaps, whereas bootstrap calculations typically yield only their ratios. Furthermore, we investigate the finite-size scaling of these overlaps and their evolution under perturbations away from criticality.