One of the current goals of neutrino experiments is to precisely determine standard unknown oscillation parameters such as the leptonic $CP$ phase and mass hierarchy. Lorentz invariance violation represents a potential physics factor that could influence the experiment’s ability to achieve these precise determinations. This study investigates the influence of Lorentz invariance violation on oscillation dynamics, particularly through nonisotropic $CPT$-violating ($a_{e\mu }^X$, $a_{e\tau }^X$, $a_{\mu \tau }^X$) and $CPT$-conserving ($c_{e\mu }^{XY}$, $c_{e\tau }^{XY}$, $c_{\mu \tau }^{XY}$) parameters within the Deep Underground Neutrino Experiment. We analyze the impact of these parameters on the mass hierarchy (MH) and Dirac $CP$ phase sensitivity measurements. Our findings indicate that while MH sensitivity remains relatively unaffected, only the presence of $c_{\mu \tau }^{XY}$ significantly deteriorates MH sensitivity, albeit remaining above the $5\sigma$ threshold. Additionally, we observe a substantial compromise in $CP$ sensitivity due to the $c_{e\mu }^{XY}$ and $c_{e\tau }^{XY}$ parameters.

In this work we analyze the scenario where a MeV scale $L_{\mu }-L_{\tau }$ gauge boson can explain the deficit in the diffuse ultrahigh-energy (UHE) astrophysical neutrino spectrum observed in IceCube, as well as the discrepancy between experimental and $e^{+}{e}^{-}$ scattering data-driven Standard Model calculations of the muon anomalous magnetic moment. We map the parameter space of the model where the elastic resonant s-channel scattering of UHE neutrinos with the cosmic neutrino background, mediated by the new $Z^{\prime }$, can improve the description of the observed cascade and track spectra over the no-scattering hypothesis. Comparing to recent NA64-$\mu$ results, we find that some part of the parameter space remains unexplored, but at a data volume of ${10}^{11}$ muons on target NA64-$\mu$ will completely probe this region.

We discuss the future prospects of a minimally five-dimensional version of the well-motivated scenario for addressing the discrepancy in the muon anomalous magnetic moment, the $U{(1)}_{L_{\mu }-L_{\tau }}$ extension of the standard model gauge symmetry. Here, multiple associated massive gauge bosons appear thanks to the five-dimensional $U{(1)}_{L_{\mu }-L_{\tau }}$ gauge symmetry, and they contribute to the muon ($g-2$) and also other processes. We focus on the powerful probe of elastic neutrino-electron scatterings since the upcoming DUNE experiment will explore MeV-scale uncharted regions by previous experiments (e.g., CHARM-II and Borexino) in the near future. We found that even with small kinetic mixing parameters, much of the parameter space, including those satisfying the muon ($g-2$) process, can be probed using several years of data from the DUNE experiment, focusing on the near detector. In our scenario, interference effects between intermediate-state gauge bosons play an important role. Our results include comparisons between flat and warped extra dimensions.

Fixed-target proton-beam experiments produce a multitude of charged pions that rescatter in the beam dump. These charged pion scattering events can be an additional irreducible source of exotic particles which couple to photons or hadrons. We analyze the sensitivity of the DUNE near detector complex to millicharged particles (MCPs) and heavy axionlike particles (ALPs) with low-energy couplings to gluons. Using the framework of chiral perturbation theory, we demonstrate regimes of parameter space where the charged pion production channel dominates over previously considered production mechanisms for both MCPs and ALPs, thereby improving the sensitivity of DUNE to these new particles compared to previous studies.

The $DDK$ system has gained increasing attention in recent research due to its potential to contain a three-hadron bound state. This paper utilizes an extension of the nonrelativistic effective field theory and the finite volume particle-dimer framework to derive Lorentz invariant quantization conditions for the $DDK$ three-body system. Using current model input conditions, the finite volume energy spectrum of the $DDK$ three-body system was calculated. This new calculation incorporates relativistic kinematics, allowing it to be applicable across a broader energy range starting from the threshold. In this work, we present a comprehensive $O(p^2)$ calculation. The spurious pole is effectively subtracted within the framework of relativistic kinematics. The spectra in the moving frame are also obtained. These analyses provide a broader testing ground for future lattice simulations. Based on this framework, it is expected to reveal more detailed properties of the $DDK$ system and other three-hadron systems, if various higher-order effects, such as the isospin $I=1$ $DK$ interactions and the coupled-channel effects are introduced.

Staggered fermion shift symmetries correspond to translations of the fermion field within the unit cell of a hypercubic lattice. They satisfy an algebra and in four Euclidean dimensions can be related to a discrete subgroup of an $SU(4)$ flavor symmetry which plays a crucial role in showing that staggered fermions lead to a theory of four degenerate Dirac fermions in the continuum limit. They are associated with the appearance of certain $Z_2$ valued global parameters. We propose a strategy to try to partially gauge these translation symmetries by allowing these parameters to vary locally in the lattice. To maintain invariance of the action requires the addition of $Z_2$ valued higher form lattice gauge fields. An analogous procedure can be carried out for reduced staggered fermions where the shifts correspond to a discrete subgroup of an $SO(4)$ flavor symmetry.

The effective potential of the $O(N)$ model at large $N$ limit is reinvestigated with varying pion mass and temperature. For large pion masses and high temperatures, we find the phenomenologically favored vacuum, located on the upper branch of the double-branched effective potential for physical $m_{\pi }$, moves to the lower branch and becomes no longer a local minimum but a saddle point. The existence and running of the tachyon pole are also discussed. These phenomena indicate that the applicable energy range of the $O(N)$ model is more and more limited as $m_{\pi }$ becomes larger and the temperature goes higher. With the effective coupling constant defined from the effective potential, the possible correspondence between the two branches of the effective potential and the two phases of the theory (distinguished by positive or negative coupling) is verified even with nonzero explicit symmetry breaking and at finite temperature. Also, we generalize the $N/D$ modified $O(N)$ model to study the thermal trajectory of the $\sigma$ pole with the cross-channel contributions considered and find the thermal $\sigma$ pole trajectory resembles its counterpart with varying pion masses at zero temperature.

We discuss the effect of rigid rotation on the critical temperatures of deconfinement and chiral transitions in the linear sigma model coupled to quarks and the Polyakov loop. We point out the essential role of the causality condition, which requires that any point of the system should rotate slower than the velocity of light. We show that imposing this physical requirement leads to inhibition of the splitting between the chiral and confining transitions, which becomes negligibly small ($\mathrm{\Delta }T\sim 1\mathrm{MeV}$ or less) for experimentally relevant, slow angular velocities $\mathrm{\Omega }\sim 10\mathrm{MeV}$ of a (5–10) fm-sized systems. Moreover, the boundedness of the system has a much bigger effect on temperature splitting than the rotation itself: the splitting reaches 10 MeV in a small, one-fermi-sized nonrotating system. The temperature splitting may, however, become enhanced in an academic limit of ultrarelativistic regimes when the boundary of the system rotates at near-to-light velocities.

The internal structure of the light scalar meson $a_0(980)$ is explored in the three-body $D$ decays of $D\to a_0(980)P\to P_1{P}_{2}P$ through the intermediate state $a_0(980)$, where $P$ denotes a pseudoscalar meson. The quasi-two-body $D\to a_0(980{)}^{+}P$ decays are governed by the external $W$-emission diagram in which $a_0(980{)}^{+}$ is emitted. The predicted branching fractions in the $q\overline{q}$ model of $a_0(980)$ are too small by one to two orders of magnitude compared to the experiment as the amplitude is suppressed by the smallness of the $a_0(980{)}^{+}$ decay constant, while those for $D^{+}\to a_0(980{)}^{0}P$ and $D^0\to a_0(980{)}^{-}P$ are usually too large. These discrepancies can be resolved, provided that $a_0(980)$ is a tetraquark state. In this case, there exist two additional $T$-like topological amplitudes, denoted by $\overline{T}$ and $\tilde{T}$, which readily account for the discrepancies. An important implication of the tetraquark model is that the $D_s^{+}\to a_0(980{)}^{+}{\pi }^0+a_0(980{)}^0{\pi }^{+}$ decay is not a purely $W$-annihilation process as in the $q\overline{q}$ model of $a_0(980)$; it receives dominant contributions from $\overline{T}$ newly noticed in this work. Therefore, measurements of $(D,D_s^{+})\to a_0(980)P$ decays lend strong support to the tetraquark picture of $a_0(980)$.

We investigate the dilepton production rates from annihilation processes of charged pion pairs with modified pion dispersion relations in the inhomogeneous chiral condensed phase. We assume a dual chiral density wave as an inhomogeneous chiral condensate, and obtain the dispersion relations of the Nambu-Goldstone modes in the inhomogeneous chiral condensed phase. We use a low energy effective Lagrangian based on the $O(4)$ symmetry which is expanded by the order parameter up to the sixth order. The obtained dispersion relations are anisotropic and quadratic for the momentum. We evaluate the electron-positron production rates by charged pion-pair annihilations as functions of an invariant mass using the obtained dispersion relations. Basically, the production rate in the inhomogeneous chiral condensed phase has a steeper overall slope with respect to an invariant mass than that in the homogeneous chiral condensed phase. Therefore, the production rate may be enhanced when the invariant mass is around twice the pion mass.

In this work, we systematically study the heavy baryonium and heavy dibaryon systems using the Bethe-Salpeter equation in the ladder and instantaneous approximations for the kernel. Our results indicate that all the heavy baryonium systems, specifically ${\mathrm{\Lambda }}_Q{\overline{\mathrm{\Lambda }}}_Q$, ${\mathrm{\Xi }}_Q{\overline{\mathrm{\Xi }}}_Q$, ${\mathrm{\Sigma }}_Q{\overline{\mathrm{\Sigma }}}_Q$, ${\mathrm{\Xi }}_Q^{\prime }{\overline{\mathrm{\Xi }}}_Q^{\prime }$, and ${\mathrm{\Omega }}_Q{\overline{\mathrm{\Omega }}}_Q$ ($Q=c$, $b$), can form bound states. Among the heavy dibaryon systems, only the ${\mathrm{\Xi }}_Q{\mathrm{\Xi }}_Q$ system with $I=0$ and the ${\mathrm{\Sigma }}_Q{\mathrm{\Sigma }}_Q$ systems with $I=0$ and $I=1$ can exist as bound states. Additionally, the ${\mathrm{\Sigma }}_Q{\overline{\mathrm{\Sigma }}}_Q$ system with $I=2$ and the ${\mathrm{\Sigma }}_Q{\mathrm{\Sigma }}_Q$ system with $I=1$ are not deeply bound.

In this work we make use of the Nambu–Jona-Lasinio model to investigate thermodynamic properties of magnetized three-flavor quark matter. The nonequilibrium Tsallis distribution is characterized by a dimensionless nonextensive parameter $q$. We find that the system always undergoes a crossover transition for all given $q$ values and the pseudocritical temperature decreases with the increasing nonextensive parameter. We show the variation of the pressure and its anisotropy in parallel and perpendicular directions. However, the diamagnetic nature appears within a certain temperature range at zero chemical potential. Moreover, strong magnetic fields can affect the property of a nonextensive system by changing the magnetization significantly. At high temperatures, the paramagnetic nature always occurs no matter how strong the magnetic field is. Finally, we study the effects of nonextensive parameter $q$ on the trace anomaly and the speed of sound of the system.

We calculate the form factors $F_V(q^2,q^{\prime 2})$ and $F_{TV}(q^2,q^{\prime 2})$ describing the $B_s\to {\gamma }^{*}$ transition induced by the vector and tensor weak currents in a broad range of values of $q^2$ and $q^{\prime 2}$ far below the quark thresholds in both $q^2$ and $q^{\prime 2}$ channels. These form factors are calculated via the distribution amplitudes of the $B_s$-meson. We then interpolate the obtained results by a formula that contains pole at $q^{\prime 2}=M_{\varphi }^2$ and extract the residue which gives the $B_s\to \varphi$ transition form factors $V(q^2)$ and $T_1(q^2)$. In this way we obtain theoretical predictions for these form factors without invoking quark-hadron duality and QCD sum rules. Furthermore, we calculate the relationship between $V(0)$ and $T_1(0)$ and the parameter ${\lambda }_{B_s}(\mu )$, the inverse moment of the $B_s$-meson distribution amplitude. Using the available predictions for $V(0)$ and $T_1(0)$ coming from approaches not referring to the $B_s$-meson distribution amplitudes, we obtain the estimate ${\lambda }_{B_s}(\mu \simeq m_b)=(0.62\pm 0.10)\mathrm{GeV}$.

Based on the factorization framework of nonrelativistic quantum chromodynamics, we study the associated $J/\psi +c+\overline{c}$ photoproduction process at next-to-leading order (NLO) in ${\alpha }_s$ and leading order (LO) in the velocity expansion. The NLO (LO) total cross section for HERA is ${\sigma }_{\mathrm{tot}}^{\mathrm{HERA}}=0.118(0.074)\mathrm{nb}$ and for EIC is ${\sigma }_{\mathrm{tot}}^{\mathrm{EIC}}=0.046(0.027)\mathrm{nb}$. The differential cross sections in $p_T^2$, $W$, and $z$ are presented. The results indicate that the next-to-leading order corrections are substantial, and testable in experiment.

In this work, we embark on the thermodynamic investigation concerning a family of primary charged black holes within the context of shift and parity symmetric Beyond Horndeski gravity. Employing the Euclidean approach, we derive the functional expression for the free energy and derive the first thermodynamic law, offering a methodology to address the challenge of extracting the thermal quantities in shift-symmetric scalar tensor theories characterized by linear time dependence in the scalar field. Following the formal analysis, we provide some illustrative examples focusing on the thermal evaporation of these objects.

We use partial wave unitarity to constrain various bespoke four-point amplitudes. We start by constructing bespoke generalizations of the type-I superstring amplitude, which we show satisfy dual resonance and have suitable high-energy limits. By analyzing the behavior of partial wave coefficients for highly massive states, we strictly rule out all bespoke amplitudes with asymptotically nonlinear Regge trajectories and place constraints on the first few nontrivial parameters in asymptotically linear cases. Finally, we argue that while a large class of unitary bespoke amplitudes fails to satisfy Regge sum rules, there exists a smaller subclass with a vanishing mass gap that is superpolynomially bounded.

We demonstrate a tree-level equivalence between four distinct infrared objects in ($d+2$)-dimensional Abelian gauge theories. These are (i) the large gauge charge $Q_{ϵ}$ where the function $ϵ$ on the sphere parametrizing large gauge transformations is identified with the Goldstone mode $\theta$ of spontaneously broken large gauge symmetry; (ii) the soft effective action that captures the dynamics of the soft and Goldstone modes; (iii) the edge mode action with Neumann boundary conditions; and (iv) the Wilson line dressing of a scattering amplitude, including a novel dressing for soft photons, which have local charge distributions despite having vanishing global charge. The promotion of the large gauge parameter to the dynamical Goldstone and the novel dressing of soft gauge particles give rise to intriguing possibilities for the future study of infrared dynamics of gauge theories and gravity.

We investigate the effects of the presence of conserved charges on the momentum-space entanglement of quantum field theories. We show that if a given model has superselection sectors, then it allows for different notions of momentum modes, each associated with a complete set of commuting observables. Applying this idea to investigate the entanglement of momentum degrees of freedom on both sides of the Abelian bosonization duality, we find that different tensor product partitions are mapped into each other and give explicit examples to sustain our findings. The conditions on which our conclusions may be generalized to other duality transformations, which require the introduction of a notion stricter than the most general possible, are laid and directions for further work are given.

We show that particle detectors coupled to a massless quantum field through its derivative can genuinely harvest entanglement form the field even when they are in causal contact in flat spacetime. This is particularly relevant since the derivative coupling model captures some interesting experimentally realizable systems and since the harvested entanglement peaks at full light contact.

The generalized SU(2) Proca theory is a vector-tensor modified gravity theory characterized by an action that remains invariant under both diffeomorphisms and global internal transformations of the SU(2) group. This study aims to further explore the physical properties of the theory within astrophysical contexts. Previous investigations have unveiled intriguing astrophysical solutions, including particlelike configurations and black holes. The purpose of this work is to constrain the theory’s free parameters by modeling realistic neutron stars. To that end, we have assumed solutions that are static, spherically symmetric, and have adopted the ’t Hooft-Polyakov magnetic monopole configuration for the vector fields. Employing both analytical techniques, such as asymptotic expansions, and numerical methods involving solving boundary value problems, we have obtained neutron star solutions whose baryonic matter is described by realistic equations of state for nuclear matter. Furthermore, we have constructed mass-radius relations which reveal that neutron stars exhibit greater compactness in comparison with general relativity predictions for most of the solutions we have found and for the employed equations of state. Finally, we have found out solutions where the mass of the star is greater than $\sim 2.5M_{\odot }$; this result poses an alternative in the exploration of the mass gap of compact stellar objects.