In this paper, we try to reveal the structure of the $Y(4660)$ from the light-quark perspective. We study the dipion invariant mass spectrum and the helicity angular distributions of the $e^{+}{e}^{-}\to Y(4660)\to \psi (2S){\pi }^{+}{\pi }^{-}$ process. In particular, we consider the effects of different light-quark SU(3) eigenstates inside the $Y(4660)$. The strong pion-pion final-state interactions as well as the $K\overline{K}$ coupled channel in the $S$-wave are taken into account model independently by using dispersion theory. We find that the light-quark SU(3) octet state plays a significant role in this transition, implying that the $Y(4660)$ contains a large light-quark component and thus might not be a pure conventional charmonium state. In the fit scheme considering both the SU(3) singlet and SU(3) octet states, two solutions are found, and both solutions reproduce the $\pi \pi$ invariant-mass spectra well. New measurement data with higher statistics in the future will be helpful to better distinguish these two solutions.

We present a phenomenological study of photon–initiated (PI) lepton production at the LHC, as implemented in the structure function (SF) approach. We provide detailed predictions for multidifferential lepton pair production, and show that the impact on observables sensitive to the weak mixing angle, ${\sin }^2{\theta }_W$, and $W$ boson mass, $M_W$, as well as PDFs can be non-negligible, in particular given the high precision being aimed for. The SF calculation can provide percent level precision in the corresponding production cross sections, and is therefore well positioned to account for LHC precision requirements. In addition to the pure $\gamma \gamma$ channel, we include initial-state $Z$ as well as mixed $\gamma /Z+q$ contributions, and assess their impact. We also consider photon-initiated lepton-lepton scattering, and again find the SF approach can provide high precision predictions for this process in way that can straightforwardly account for any fiducial cuts imposed. Finally, we provide a publicly available Monte Carlo generator, SFGen, for PI lepton pair production and lepton-lepton scattering within the SF approach, for use by the community.

We study the processes $\gamma \gamma \to {\eta }_c\to {\eta }^{\prime }{K}^{+}{K}^{-}$, ${\eta }^{\prime }{\pi }^{+}{\pi }^{-}$, and $\eta {\pi }^{+}{\pi }^{-}$ using a data sample of $519{\mathrm{fb}}^{-1}$ recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy $e^{+}{e}^{-}$ collider at center-of-mass energies at and near the $\mathrm{\Upsilon }(nS)$ ($n=2$, 3, 4) resonances. This is the first observation of the decay ${\eta }_c\to {\eta }^{\prime }{K}^{+}{K}^{-}$ and we measure the branching fraction $\mathrm{\Gamma }({\eta }_c\to {\eta }^{\prime }{K}^{+}{K}^{-})/(\mathrm{\Gamma }({\eta }_c\to {\eta }^{\prime }{\pi }^{+}{\pi }^{-})=0.644\pm 0.039_{\mathrm{stat}}\pm 0.032_{\mathrm{sys}}$. Significant interference is observed between $\gamma \gamma \to {\eta }_c\to \eta {\pi }^{+}{\pi }^{-}$ and the nonresonant two-photon process $\gamma \gamma \to \eta {\pi }^{+}{\pi }^{-}$. A Dalitz plot analysis is performed of ${\eta }_c$ decays to ${\eta }^{\prime }{K}^{+}{K}^{-}$, ${\eta }^{\prime }{\pi }^{+}{\pi }^{-}$, and $\eta {\pi }^{+}{\pi }^{-}$. Combined with our previous analysis of ${\eta }_c\to K\overline{K}\pi$, we measure the $K_0^{*}(1430)$ parameters and the ratio between its ${\eta }^{\prime }K$ and $\pi K$ couplings. The decay ${\eta }_c\to {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$ is dominated by the $f_0(2100)$ resonance, also observed in $J/\psi$ radiative decays. A new $a_0(1700)\to \eta \pi$ resonance is observed in the ${\eta }_c\to \eta {\pi }^{+}{\pi }^{-}$ channel. We also compare ${\eta }_c$ decays to $\eta$ and ${\eta }^{\prime }$ final states in association with scalar mesons as they relate to the identification of the scalar glueball.

A sensitive test for whether a black hole is a wormhole, using astronomical observations, would be to look for perturbations in the orbit of a pulsar around the black hole, caused by a perturbing object on the other side of the wormhole. By observing a pulsar in an orbit like that of S2 around the supermassive black hole at Sgr A* at the center of our Galaxy, the attainable mass limit on the perturber would be approximately ${10}^4$ times better than derived from current observations of S2. For a nominal stellar-mass black hole–pulsar binary, observing for 1 year could set a mass limit on a perturber more than 6 orders of magnitude better than for a pulsar orbiting Sgr A*. Observations of a star in a stellar-mass binary containing a black hole could set limits similar to the case of a pulsar orbiting Sgr A*.

In this paper, we study the bulk local states in the $\mathrm{AdS}/\mathrm{CFT}$ correspondence in the large $N$ limit using the formula explicitly relating the bulk local operators and the conformal field theory (CFT) local operators. We identify the bulk local state in terms of CFT local states and find that the bulk local state corresponds to a CFT state supported in the whole space, which means a version of the subregion duality is not valid. On the other hand, CFT states supported in a space region are expressed in terms of the bulk states supported in a certain region. We find that the quantum error correction proposal is not realized although the puzzles of the radial locality which motivated the proposal are resolved in our analysis. For the understating of the bulk local states, an explicit realization of an analog of the Reeh-Schlieder theorem plays an important role.

Laser frequency noise (LFN) is the dominant source of noise expected in the Laser Interferometer Space Antenna (LISA) mission, at approximately 7 orders of magnitude greater than the typical signal expected from gravitational waves (GWs). Time-delay interferometry (TDI) suppresses LFN to an acceptable level by linearly combining measurements from individual spacecraft delayed by durations that correspond to their relative separations. Knowledge of the delay durations is crucial for TDI effectiveness. The work reported here extends upon previous studies using data-driven methods for inferring the delays during the postprocessing of raw phase meter data, also known as TDI ranging (TDIR). Our TDIR analysis uses Bayesian methods designed to ultimately be included in the LISA data model as part of a “Global Fit” analysis pipeline. Including TDIR as part of the Global Fit produces GW inferences which are marginalized over uncertainty in the spacecraft separations and allows for independent estimation of the spacecraft orbits. We demonstrate Markov chain Monte Carlo (MCMC) inferences of the six time-independent delays required in the rigidly rotating approximation of the spacecraft configuration (TDI 1.5) using simulated data. The MCMC uses fractional delay interpolation to digitally delay the raw phase meter data, and we study the sensitivity of the analysis to the filter length. Varying levels of complexity in the noise covariance matrix are also examined. Delay estimations are found to result in LFN suppression well below the level of secondary noises and constraints on the arm lengths to $\mathcal{O}(30)\mathrm{cm}$ over the approximately $2.5\times {10}^9\mathrm{m}$ baseline.

The Rényi and Tsallis entropies are discussed as possible alternatives to the Bekenstein-Hawking area-law entropy. It is pointed out how replacing the entropy notion, but not the Hawking temperature and the thermodynamical energy may render the whole black hole thermodynamics inconsistent. The possibility to relate the Rényi and Tsallis entropies with the quantum gravity corrected Bekenstein-Hawking entropy is discussed.

One class of competitive candidates for dark matter is ultralight bosons. If they exist, these bosons may form long-lived bosonic clouds surrounding rotating black holes via superradiant instabilities, acting as sources of gravity and affecting the propagation of gravitational waves around the host black hole. During extreme-mass-ratio inspirals, the bosonic clouds will survive the inspiral phase and can affect the quasinormal-mode frequencies of the perturbed black-hole–bosonic-cloud system. In this work, we compute the shifts of gravitational quasinormal-mode frequencies of a rotating black hole due to the presence of a surrounding bosonic cloud. We then perform a mock analysis on simulated Laser Interferometer Space Antenna observational data containing injected ringdown signals from supermassive black holes with and without a bosonic cloud. We find that with less than an hour of observational data of the ringdown phase of nearby supermassive black holes such as Sagittarius A* and M32, we can rule out or confirm the existence of cloud-forming ultralight bosons of mass $\sim {10}^{-17}\mathrm{eV}$.

The detection of high-energy astrophysical neutrinos and ultra-high-energy cosmic rays (UHECRs) provides a new way to explore sources of cosmic rays. One of the highest energy neutrino events detected by IceCube, tagged as IC35, is close to the UHECR anisotropy region detected by Pierre Auger Observatory. The nearby starburst (SB) galaxy, NGC 4945, is close to this anisotropic region and inside the mean angular error of the IC35 event. Considering the hypernovae contribution located in the SB region of NGC 4945, which can accelerate protons up to $\sim {10}^{17}\mathrm{eV}$ and inject them into the interstellar medium, we investigate the origin of this event around this starburst galaxy. We show that the interaction of these protons with the SB region’s gas density could explain Fermi-LAT gamma-ray and radio observations if the magnetic field’s strength in the SB region is the order of $\sim \mathrm{mG}$. Our estimated PeV neutrino events, in ten years, for this source is approximately 0.01 ($4\times {10}^{-4}$) if a proton spectral index of 2.4 (2.7) is considered, which would demonstrate that IC35 is not produced in the central region of this SB galaxy. Additionally, we consider the superwind region of NGC 4945 and show that protons can hardly be accelerated in it up to UHECRs.

The latest AMS-02 data on cosmic-ray electrons show a break in the energy spectrum around 40 GeV, with a change in the slope of about 0.1. We perform a combined fit to the newest AMS-02 positron and electron flux data above 10 GeV using a semianalytical diffusion model where sources include production of pairs from pulsar wind nebulae (PWNe), electrons from supernova remnants (SNRs), and both species from spallation of hadronic cosmic rays with interstellar medium atoms. We demonstrate that within our setup the change in the slope in the AMS-02 electron data is well explained by the interplay between the flux contributions from SNRs and PWNe. In fact, the relative contribution to the data of these two populations changes by a factor of about 13 from 10 to 1000 GeV. The PWN contribution has a significance of at least $4\sigma$, depending on the model used for the propagation, interstellar radiation field, and energy losses. We check the stability of this result against low-energy effects by numerically solving the transport equation. as well as adding possible breaks in the injection spectrum of SNRs. The effect of the energy losses alone, when the inverse Compton scattering is properly computed within a fully numerical treatment of the Klein-Nishina cross section, cannot explain the break in the $e^{-}$ flux data, as recently proposed in the literature.

Starting from the one-loop divergences we obtained previously, we work out the renormalization of the Higgs-electroweak chiral Lagrangian explicitly and in detail. This includes the renormalization of the lowest-order Lagrangian, as well as the decomposition of the remaining divergences into a complete basis of next-to-leading-order counterterms. We provide the list of the corresponding beta functions. We show how our results match the one-loop renormalization of some of the dimension-6 operators in SMEFT. We further point out differences with related work in the literature and discuss them. As an application of the obtained results, we evaluate the divergences of the vacuum expectation value of the Higgs field at one loop and show that they can be appropriately removed by the corresponding renormalization. We also work out the finite renormalization required to keep the no-tadpole condition on the Higgs field at one loop.

We reexamine the shapes of the strange quark parton distribution functions (PDFs) of the proton by means of QCD analysis of HERA $\mathrm{I}+\text{II}$ $e^{\pm }p$ deep inelastic scattering cross section measurement at DESY and inclusive gauge boson production and $W$ boson production associated with a charm quark from the LHC at CERN. We find that there is an overall agreement on the strange quark distributions obtained from CMS $W+\mathrm{charm}$ and ATLAS $W/Z$ data at the parton momentum fraction range $x\lesssim {10}^{-2}$. Meanwhile, there is also a strong tension between these data toward large $x$. We find that this tension fades away if the ATLAS measurement of $W/Z$ production is analyzed together with the ATLAS $W+\mathrm{charm}$ data. The $W/Z$ and $W+\mathrm{charm}$ data both from ATLAS and CMS experiments agree that the proton strangeness is enhanced toward small momentum fraction $x$ and is smoothly suppressed at large $x$. Furthermore, a strong $x$ dependence of the strange-to-nonstrange parton ratio $R_s(x,Q^2)$ is observed.

The rising adoption of machine learning in high-energy physics and lattice field theory necessitates the reevaluation of common methods that are widely used in computer vision, which, when applied to problems in physics, can lead to significant drawbacks in terms of performance and generalizability. One particular example for this is the use of neural network architectures that do not reflect the underlying symmetries of the given physical problem. In this work, we focus on complex scalar field theory on a two-dimensional lattice and investigate the benefits of using group equivariant convolutional neural network architectures based on the translation group. For a meaningful comparison, we conduct a systematic search for equivariant and nonequivariant neural network architectures and apply them to various regression and classification tasks. We demonstrate that in most of these tasks our best equivariant architectures can perform and generalize significantly better than their nonequivariant counterparts, which applies not only to physical parameters beyond those represented in the training set, but also to different lattice sizes.

In this paper, we generalize Jordan-Lee-Preskill, an algorithm for simulating flat-space quantum field theories, to $3+1$ dimensional inflationary spacetime. The generalized algorithm contains the encoding treatment, the initial state preparation, the inflation process, and the quantum measurement of cosmological observables at late time. The algorithm is helpful for obtaining predictions of cosmic non-Gaussianities, serving as useful benchmark problems for quantum devices, and checking assumptions made about interacting vacuum in the inflationary perturbation theory. Components of our work also include a detailed discussion about the lattice regularization of the cosmic perturbation theory, a detailed discussion about the in-in formalism, a discussion about encoding using the Hamilton-Kabat-Lifschytz-Lowe-type formula that might apply for both dS and AdS spacetimes, a discussion about bounding curvature perturbations, a description of the three-party Trotter simulation algorithm for time-dependent Hamiltonians, a ground state projection algorithm for simulating gapless theories, a discussion about the quantum-extended Church-Turing thesis, and a discussion about simulating cosmic reheating in quantum devices.

In a perturbative approach Einstein-Hilbert gravity is quantized about a flat background. In order to render the model power counting renormalizable, higher order curvature terms are added to the action. They serve as Pauli-Villars type regulators and require an expansion in the number of fields in addition to the standard expansion in the number of loops. Renormalization is then performed within the Bogoliubov-Parasiuk-Hepp-Zimmermann-Lowenstein scheme, which provides the action principle to construct the Slavnov-Taylor identity and invariant differential operators. The final physical state space of the Einstein-Hilbert theory is realized via the quartet mechanism of Kugo and Ojima. Renormalization group and Callan-Symanzik’s equation are derived for Green’s functions and, formally, also for the $S$-matrix.

We study D-brane actions in nonrelativistic string theory. We consider single D-brane and analyze its properties under $T$ duality. We also derive an action for $N$ D8-branes and also for lower dimensional D-branes through $T$ duality transformations.

We perform a covariant (Lagrangian) quantization of perturbative gravity in the background of a Schwarzschild black hole. The key tool is a decomposition of the field into spherical harmonics. We fix Regge-Wheeler gauge for modes with angular momentum quantum number $l\ge 2$, while for low-multipole modes with $l=0$ or 1—for which Regge-Wheeler gauge is inapplicable—we propose a set of gauge-fixing conditions which are 2D background covariant and perturbatively well defined. We find that the corresponding Faddeev-Popov ghosts are nonpropagating for the $l\ge 2$ modes, but are in general nontrivial for the low-multipole modes with $l=0$, 1. However, in Schwarzschild coordinates, all time derivatives acting on the ghosts drop from the action and the low-multipole ghosts have instantaneous propagators. Up to possible subtleties related to quantizing gravity in a space with a horizon, Faddeev’s theorem suggests the possibility of an underlying canonical (Hamiltonian) quantization with a manifestly ghost-free Hilbert space.

We investigate gauge anomalies in the context of orbifold conformal field theories. Such anomalies manifest as failures of modular invariance in the constituents of the orbifold partition function. We review how this irregularity is classified by cohomology and how extending the orbifold group can remove it. Working with such extensions requires an understanding of the consistent ways in which extending groups can act on the twisted states of the original symmetry, which leads us to a discrete torsionlike choice that exists in orbifolds with trivially acting subgroups. We review a general method for constructing such extensions and investigate its application to orbifolds. Through numerous explicit examples we test the conjecture that consistent extensions should be equivalent to (in general multiple copies of) orbifolds by nonanomalous subgroups.