We explore the potential for detecting rotational instabilities in the postmerger phase of binary neutron star mergers using different network configurations of upgraded and next-generation gravitational wave detectors. Our study employs numerically generated postmerger waveforms, which reveal the reexcitation of the $l=m=2$ $f$-mode at a time of $O(10)\mathrm{ms}$ after merger. We evaluate the detectability of these signals by injecting them into colored Gaussian noise and performing a reconstruction as a sum of wavelets using Bayesian inference. Computing the overlap between the reconstructed and injected signal, restricted to the instability part of the postmerger phase, we find that one could infer the presence of rotational instabilities with a network of planned third-generation detectors, depending on the total mass and distance to the source. For a recently suggested high-frequency detector design, we find that the instability part would be detectable even at 200 Mpc, significantly increasing the anticipated detection rate. For a network consisting of the existing HLV detectors, but upgraded to twice the $\mathrm{A}+$ sensitivity, we confirm that the peak frequency of the whole postmerger gravitational wave emission could be detectable with a network signal-to-noise ratio of 8 at a distance of 40 Mpc.

Gravitational-wave (GW) observations provide unique information about compact objects. As detector sensitivity increases, new astrophysical sources of GWs could emerge. Close hyperbolic encounters are one such source class: Scattering of stellar mass compact objects is expected to manifest as GW burst signals in the frequency band of current detectors. We present the search for GWs from hyperbolic encounters in the second half of the third Advanced LIGO-Virgo observing run (O3b). We perform a model-informed search with a machine-learning enhanced Coherent WaveBurst algorithm. No significant event has been identified in addition to known detections of compact binary coalescences. We inject in the O3b data nonspinning third post-Newtonian order accurate hyperbolic encounter model with component masses between $[2,100]M_{\odot }$, impact parameter in $[60,100]GM/c^2$, and eccentricity in [1.05, 1.6]. We further discuss the properties of the simulation recovered. For the first time, we report the sensitivity volume achieved for such sources, which for O3b data reaches up to $3.9\pm 1.4\times {10}^5{\mathrm{Mpc}}^3\mathrm{yr}$ for compact objects with masses in the range $[20,40]M_{\odot }$, corresponding to a rate density upper limit of $0.589\pm 0.094\times {10}^{-5}{\mathrm{Mpc}}^{-3}{\mathrm{yr}}^{-1}$. Finally, we present a projected sensitive volume for the next observing runs of current detectors, namely, O4 and O5.

Thermal behavior of effective, chiral condensate-dependent $U_A(1)$ anomaly couplings is investigated using the functional renormalization group approach in the $N_f=3$ flavor meson model. We derive flow equations for anomaly couplings that arise from instantons of higher topological charge, dependent also on the chiral condensate. These flow equations are solved numerically for the $|Q|=1$, 2 topological sectors at finite temperature. Assuming that the anomaly couplings at the ultraviolet scale may also exhibit explicit temperature dependence, we calculate the thermal behavior of the effective potential. In accordance with our earlier study, [G. Fejos and A. Patkos, Phys. Rev. D 105, 096007 (2022)], we find that for increasing temperatures, the anomalous breaking of chiral symmetry tends to strengthen toward the pseudocritical temperature ($T_C$) of chiral symmetry breaking. It is revealed that below $T_C$, around $\sim 10\%$ of the $U_A(1)$ breaking arises from the $|Q|=2$ topological sector. Correspondingly, a detailed analysis on the thermal behavior of the mass spectrum is also presented.

This study delves into the contribution of the strange quark within the proton, which influences several fundamental proton properties. By establishing a robust relationship between the proton’s quantum anomalous energy and the sigma term, we successfully extract the contribution of the strangeness sigma term in the proton, obtaining it from parametrized fits of the differential cross section using exponential and dipole forms. The extracted sigma term values are estimated to be $455.62\pm 64.60\mathrm{MeV}$ (exponential fit) and $337.74\pm 106.79\mathrm{MeV}$ (dipole fit). Additionally, we present novel results for the proton trace anomalous energy, observing values of $0.13\pm 0.02$ (exponential fit) and $0.15\pm 0.03$ (dipole fit). Our analysis integrates the novel data from the $J/\psi -007$ and GlueX Collaborations, to some extent providing an experimental phenomenological window into the nonzero strange quark content inside proton, with the statistical significances $7.1\sigma$ (exponential fit) and $3.2\sigma$ (dipole fit), respectively. Furthermore, we discuss the possibility of scheme independence in the extraction results and examine the uniformity of sigma terms obtained from the datasets provided by the two collaborations. Our analysis may reveals compatibility between the extracted results of the respective experiments.

We investigate the nonmonotonic behavior observed in the timelike nucleon electromagnetic form factors. Using a phenomenological extending vector meson dominance model, where the ground states $\rho$ and $\omega$ and their excited states $\rho (2D)$, $\omega (3D)$, and $\omega (5S)$ are taken into account, we have successfully reproduced the cross sections of $e^{+}{e}^{-}\to p\overline{p}$ and $e^{+}{e}^{-}\to n\overline{n}$ reactions. Furthermore, we have derived the nucleon electromagnetic form factors in the timelike region, and it is found that the so-called periodic behavior of the nucleon effective form factors is not confirmed. However, there are indeed nonmonotonic structures in the line shape of nucleon effective form factors, which can be naturally reproduced by considering the contributions from the low-lying excited vector states.

We perform a new global analysis of spin-dependent parton distribution functions with the inclusion of Ioffe time pseudodistributions computed in lattice QCD (LQCD), which are directly sensitive to the gluon helicity distribution, $\mathrm{\Delta }g$. These lattice data have an analogous relationship to parton distributions as do experimental cross sections, and can be readily included in global analyses. We focus in particular on the constraining capability of current LQCD data on the sign of $\mathrm{\Delta }g$ at intermediate parton momentum fractions $x$, which was recently brought into question by analysis of data in the absence of parton positivity constraints. We find that present LQCD data cannot discriminate between positive and negative $\mathrm{\Delta }g$ solutions, although significant changes in the solutions for both the gluon and quark sectors are observed.

The creation of polarized electron-positron pairs by the nonlinear Breit-Wheeler process in short laser pulses is investigated using the Baier-Katkov semiclassical method beyond local-constant-field approximation (LCFA), which allows for identifying the interferences effects in the positron polarization. When the laser intensity is in the intermediate regime, the interferences of pair production in different formation lengths induce an enhancement of pair production probability for spin-down positrons, which significantly affects the polarization of created positrons. The polarization features are distinct from that obtained with LCFA, revealing the invalidity of LCFA in this regime. Meanwhile, the angular distribution for different spin states varies, resulting in an angular-dependent polarization of positrons. The average polarization of positrons at beam center is highly sensitive to the laser’s carrier-envelope phase (CEP), which provides a potential alternative way of determining the CEP of strong lasers. The verification of the observed interference phenomenon is possible for the upcoming experiments.

We consider the contribution of the Odderon to diffractive $pp$ and $p\overline{p}$ elastic scattering at large center of mass energy. We identify the Odderon and Pomeron with the Reggeized $1^{\pm -}$ and $2^{++}$ glueballs in the bulk, respectively. We use for the gravity dual description the repulsive wall model, to account for the proper Gribov diffusion for off-forward scattering. The eikonalized and unitarized amplitudes exhibit a vanishingly small rho-parameter, and a slope parameter fixed by twice the closed string slope. The results for the differential and total cross sections are compared to the empirical results reported recently by the TOTEM collaboration.

We investigate the pair production of right-handed neutrinos mediated by a $Z^{\prime }$ mainly from the meson decays at the FASER detector of the HL-LHC. The $Z^{\prime }$ can be the additional gauge boson in either the $U(1{)}_{B-L}$ or sterile $\nu$-specific $U(1{)}_s$ model. Taking the gauge coupling or the kinetic mixing at the current limits, we analyze the sensitivity to the masses of the heavy neutrinos, $M_N$, and active-sterile mixing, $|V_{lN}{|}^2$, of FASER2. In a background-free scenario, for the $U(1{)}_{B-L}$ case, FASER2 is able to probe $|V_{lN}{|}^2\approx {10}^{-8}$ when $M_N\sim 0.3\mathrm{GeV}$, which is comparable to the current limits from the beam dump experiments. When comes to the $U(1{)}_s$ model, FASER2 can probe $|V_{lN}{|}^2\approx {10}^{-10}$, which is better than the current limits for at least one magnitude, in all three flavors. A proposed long-lived particle detector, FACET, is also studied, but no significant difference from FASER2 is derived.

The Top Yukawa coupling profoundly influences several core mysteries linked to the electroweak scale and the Higgs boson. We study the feasibility of measuring the Top Yukawa coupling at high energy muon colliders by examining the high energy dynamics of the weak boson fusion to top quark pair processes. A deviation of the Top Yukawa coupling from the Standard Model would lead to a modified $VV\to t\overline{t}$ process, violating unitarity at high energy. Our analysis reveals that utilizing a muon collider with a center-of-mass energy of 10 TeV and an integrated luminosity of $10{\mathrm{ab}}^{-1}$ allows us to investigate the Top Yukawa coupling with a precision surpassing 1.5%, more than one order of magnitude better than the precision from $t\overline{t}h$ channel at muon colliders. This precision represents a notable enhancement compared to the anticipated sensitivities of the High-Luminosity LHC (3.4%) and those at muon colliders derived from the $t\overline{t}H$ process.

In this article, we elucidate the structure and properties of a class of anomalous high-energy states of matter-free $U(1)$ quantum link gauge theory Hamiltonians using numerical and analytical methods. Such anomalous states, known as quantum many-body scars in the literature, have generated a lot of interest due to their athermal nature. Our starting Hamiltonian is $H={\mathcal{O}}_{\mathrm{kin}}+\lambda {\mathcal{O}}_{\mathrm{pot}}$, where $\lambda$ is a real-valued coupling, and ${\mathcal{O}}_{\mathrm{kin}}$ (${\mathcal{O}}_{\mathrm{pot}}$) are summed local off-diagonal (diagonal) operators in the electric flux basis acting on the elementary plaquette $\square$. The spectrum of the model in its spin-$\frac{1}{2}$ representation on $L_x\times L_y$ lattices reveal the existence of sublattice scars, $|{\psi }_s⟩$, which satisfy ${\mathcal{O}}_{\mathrm{pot},\square }|{\psi }_s⟩=|{\psi }_s⟩$ for all elementary plaquettes on one sublattice and ${\mathcal{O}}_{\mathrm{pot},\square }|{\psi }_s⟩=0$ on the other, while being simultaneous zero modes or nonzero integer-valued eigenstates of ${\mathcal{O}}_{\mathrm{kin}}$. We demonstrate a “triangle relation” connecting the sublattice scars with nonzero integer eigenvalues of ${\mathcal{O}}_{\mathrm{kin}}$ to particular sublattice scars with ${\mathcal{O}}_{\mathrm{kin}}=0$ eigenvalues. A fraction of the sublattice scars have a simple description in terms of emergent short singlets, on which we place analytic bounds. We further construct a long-ranged parent Hamiltonian for which all sublattice scars in the null space of ${\mathcal{O}}_{\mathrm{kin}}$ become unique ground states and elucidate some of the properties of its spectrum. In particular, zero energy states of this parent Hamiltonian turn out to be exact scars of another $U(1)$ quantum link model with a staggered short-ranged diagonal term.

The leading-order chiral Lagrangian for the baryon octet and decuplet states coupled to Goldstone bosons and external sources contains six low-energy constants. Five of them are fairly well-known from phenomenology, but the sixth one is practically unknown. This coupling constant provides the strength of the (p-wave) coupling of Goldstone bosons to decuplet states. Its size and even sign are under debate. Quark models and quantum chromodynamics (QCD) for a large number of colors provide predictions, but some recent phenomenological analyses even suggest an opposite sign for the Delta-pion coupling. The Goldberger-Treiman relation connects this coupling constant to the axial charge of the Delta baryon. This suggests a Wu-type experiment to determine the unknown low-energy constant. While this is not feasible in the Delta sector because of the large hadronic width of the Delta, there is a flavor symmetry related process that is accessible; the weak semileptonic decay of the Omega baryon to a spin $3/2$ cascade baryon. A broad research program is suggested that can pin down at least the rough size and the sign of the last unknown low-energy constant of the leading-order Lagrangian. It encompasses experimental measurements, in particular the forward-backward asymmetry of the semileptonic decay, together with a determination of the quark-mass dependences using lattice QCD for the narrow decuplet states and chiral perturbation theory to extrapolate to the Delta sector. Besides discussing the strategy of the research program, the present work provides a feasibility check based on a simple leading-order calculation.

We perform a comprehensive study within quantum chromodynamics (QCD) of dihadron observables in electron-positron annihilation, semi-inclusive deep-inelastic scattering, and proton-proton collisions, including recent cross section data from Belle and azimuthal asymmetries from STAR. We extract simultaneously for the first time ${\pi }^{+}{\pi }^{-}$ dihadron fragmentation functions (DiFFs) and the nucleon transversity distributions for up and down quarks as well as antiquarks. For the transversity distributions we impose their small-$x$ asymptotic behavior and the Soffer bound. In addition, we utilize a new definition of DiFFs that has a number density interpretation to then calculate expectation values for the dihadron invariant mass and momentum fraction. Furthermore, we investigate the compatibility of our transversity results with those from single-hadron fragmentation (from a transverse momentum dependent/collinear twist-3 framework) and the nucleon tensor charges computed in lattice QCD. We find a universal nature to all of this available information. Future measurements of dihadron production can significantly further this research, especially, as we show, those that are sensitive to the region of large parton momentum fractions.

The Forward Physics Facility (FPF) plans to use neutrinos produced at the Large Hadron Collider to make a variety of measurements at previously unexplored TeV energies. Its primary goals include precision measurements of the neutrino cross section and using the measured neutrino flux both to uncover information about far-forward hadron production and to search for various beyond standard model scenarios. However, these goals have the potential to conflict: Extracting information about the flux or cross section relies upon an assumption about the other. In this paper, we demonstrate that the FPF can use the low-$\nu$ method—a technique for constraining the flux shape by isolating neutrino interactions with low energy transfer to the nucleus—to break this degeneracy. We show that the low-$\nu$ method is effective for extracting the ${\nu }_{\mu }$ flux shape, in a model-independent way. We discuss its application for extracting the ${\overline{\nu }}_{\mu }$ flux shape but find that this is significantly more model dependent. Finally, we explore the precision to which the ${\nu }_{\mu }$ flux shape could be constrained at the FPF for a variety of proposed detector options. We find that the precision would be sufficient to discriminate between various realistic flux models.

Based on $7.33{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, the experimental studies of the doubly Cabibbo-suppressed decays $D_s^{+}\to K^{+}{K}^{+}{\pi }^{-}$ and $D_s^{+}\to K^{+}{K}^{+}{\pi }^{-}{\pi }^0$ are reported. We determine the absolute branching fraction of $D_s^{+}\to K^{+}{K}^{+}{\pi }^{-}$ to be ($1.24_{-0.26}^{+0.28}(\mathrm{stat})\pm 0.06(\mathrm{syst}))\times {10}^{-4}$. No significant signal of $D_s^{+}\to K^{+}{K}^{+}{\pi }^{-}{\pi }^0$ is observed and the upper limit on its decay branching fraction at 90% confidence level is set to be $1.7\times {10}^{-4}$.

A search for quantum black holes in $\mathrm{electron}+\text{jet}$ and $\mathrm{muon}+\text{jet}$ invariant mass spectra is performed with $140{\mathrm{fb}}^{-1}$ of data collected by the ATLAS detector in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$ at the Large Hadron Collider. The observed invariant mass spectrum of $\mathrm{lepton}+\text{jet}$ pairs is consistent with Standard Model expectations. Upper limits are set at 95% confidence level on the production cross section times branching fractions for quantum black holes decaying into a lepton and a quark in a search region with invariant mass above 2.0 TeV. The resulting quantum black hole lower mass threshold limit is 9.2 TeV in the Arkani-Hamed-Dimopoulos-Dvali model, and 6.8 TeV in the Randall-Sundrum model.

A number of arguments at the interplay of general relativity and quantum theory suggest an operational limit to spatial resolution, conventionally modeled as a generalized uncertainty principle (GUP). Recently, it has been demonstrated that the dynamics postulated as a part of these models are only loosely related to the existence of the minimal-length scale. In this paper, we intend to make a more informed choice on the Hamiltonian by demanding, among other properties, that the model be invariant under (possibly) deformed Galilean transformations in one dimension. In this vein, we study a two-particle system with general interaction potential under the condition that the addition of two wave numbers as well as the action of Galilean boosts on wave numbers be nonlinearly deformed so as to comply with the cutoff. We find that the customary GUP Hamiltonian does not allow for invariance under (any kind of) generalized Galilean transformations. Those Hamiltonians which allow for a deformed relativity principle have to be related to the ordinary Galilean ones by virtue of a momentum-space diffeomorphism, i.e., a canonical transformation. Far from being trivial, the resulting dynamics is deformed, as we show at the example of the harmonic interaction.

The stochastic effective theory approach, often called stochastic inflation, is widely used in cosmology to describe scalar field dynamics during inflation. The existing formulations are, however, more qualitative than quantitative because the connection to the underlying quantum field theory (QFT) has not been properly established. A concrete sign of this is that the QFT parameters depend on the renormalization scale, and therefore the relation between the QFT and stochastic theory must have explicit scale dependence that cancels it. In this paper we achieve that by determining the parameters of the second-order stochastic effective theory of light scalar fields in de Sitter to linear order in the self-coupling constant $\lambda$. This is done by computing equal-time 2-point correlators to one-loop order both in QFT using dimensional regularization and the $\overline{\mathrm{MS}}$ renormalization scheme and the equal-time 4-point correlator to leading order in both theories, and demanding that the results obtained in the two theories agree. With these parameters, the effective theory is valid when $m\lesssim H$ and ${\lambda }^2\ll m^4/H^4$, and therefore it is applicable in cases where neither perturbation theory nor any previously proposed stochastic effective theories are.

We propose herein an extension of truncated spectrum methodologies, a nonperturbative numerical approach able to elucidate the low energy properties of quantum field theories. TSMs, in their various flavors, involve a division of a computational Hilbert space, $\mathcal{H}$, into two parts, one part, ${\mathcal{H}}_1$ that is “kept” for the numerical computations, and one part, ${\mathcal{H}}_2$, that is discarded or “truncated.” Even though ${\mathcal{H}}_2$ is discarded, truncated spectrum methodologies will often try to incorporate the effects of ${\mathcal{H}}_2$ in some effective way. In these terms, we propose to keep the dimension of ${\mathcal{H}}_1$ small. We pair this choice of ${\mathcal{H}}_1$ with a Krylov subspace iterative approach able to take into account the effects of ${\mathcal{H}}_2$. This iterative approach can be taken to arbitrarily high order and so offers the ability to compute quantities to arbitrary precision. In many cases it also offers the advantage of not needing an explicit UV cutoff. To compute the matrix elements that arise in the Krylov iterations, we employ a Feynman diagrammatic representation that is then evaluated with Monte Carlo techniques. Each order of the Krylov iteration is variational and is guaranteed to improve upon the previous iteration. The first Krylov iteration is akin to the next-to-leading order approach of Elias-Miró et al. [NLO renormalization in the Hamiltonian truncation, Phys. Rev. D 96, 065024 (2017)]. To demonstrate this approach, we focus on the ($1+1d$)-dimensional ${\varphi }^4$ model and compute the bulk energy and mass gaps in both the ${\mathbb{Z}}_2$-broken and unbroken sectors. We estimate the critical ${\varphi }^4$ coupling in the broken phase to be $g_c=0.2645\pm 0.002$.

Matched-filtering gravitational-wave search pipelines identify gravitational-wave signals by computing correlations, i.e., signal-to-noise ratios, between gravitational-wave detector data and gravitational-wave template waveforms. Intrinsic parameters, the component masses and spins, of the gravitational-wave waveforms are often stored in “template banks,” and the construction of a densely populated template bank is essential for some gravitational-wave search pipelines. This paper presents a template bank that is currently being used by the GstLAL-based compact binary search pipeline in the fourth observing run of the LIGO, Virgo, and KAGRA collaboration, and was generated with a new binary tree approach of placing templates, manifold. The template bank contains $1.8\times {10}^6$ sets of template parameters covering plausible neutron star and black hole systems up to a total mass of $400M_{\odot }$ with component masses between $1–200M_{\odot }$ and mass ratios between 1 and 20 under the assumption that each component object’s angular momentum is aligned with the orbital angular momentum. We validate the template bank generated with our new method, manifold, by comparing it with a template bank generated with the previously used stochastic template placement method. We show that both template banks have similar effectualness. The GstLAL search pipeline performs singular value decomposition (SVD) on the template banks to reduce the number of filters used. We describe a new grouping of waveforms that improves the computational efficiency of SVD by nearly 5 times as compared to previously reported SVD sorting schemes.