Polyatomic molecules have been identified as sensitive probes of chargeparity violating and parity violating physics beyond the Standard Model (BSM). For example, many linear triatomic molecules are both lasercoolable and have parity doublets in the ground electronic
We study the ringdown signal of black holes formed in promptcollapse binary neutron star mergers. We analyze data from 47 numerical relativity simulations. We show that the
 NSFPAR ID:
 10517344
 Publisher / Repository:
 IOP Publishing
 Date Published:
 Journal Name:
 Classical and Quantum Gravity
 Volume:
 41
 Issue:
 14
 ISSN:
 02649381
 Format(s):
 Medium: X Size: Article No. 145006
 Size(s):
 Article No. 145006
 Sponsoring Org:
 National Science Foundation
More Like this

Abstract state arising from the bending vibration, both features that can greatly aid BSM searches. Understanding the $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ state is a crucial prerequisite to precision measurements with linear polyatomic molecules. Here, we characterize the fundamental bending vibration of $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ YbOH using highresolution optical spectroscopy on the nominally forbidden ${}^{174}$ $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ transition at 588 nm. We assign 39 transitions originating from the lowest rotational levels of the $\to \tilde{A}{}^{2}{\mathrm{\Pi}}_{1/2}(000)$ state, and accurately model the state’s structure with an effective Hamiltonian using bestfit parameters. Additionally, we perform Stark and Zeeman spectroscopy on the $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ state and fit the moleculeframe dipole moment to $\tilde{X}{}^{2}{\mathrm{\Sigma}}^{+}(010)$ ${D}_{\mathrm{m}\mathrm{o}\mathrm{l}}=2.16(1)$D and the effective electrong factor to . Further, we use an empirical model to explain observed anomalous line intensities in terms of interference from spin–orbit and vibronic perturbations in the excited ${g}_{S}=2.07(2)$ state. Our work is an essential step toward searches for BSM physics in YbOH and other linear polyatomic molecules. $\tilde{A}{}^{2}{\mathrm{\Pi}}_{1/2}(000)$ 
Abstract Spinflip (SF) methods applied to excitedstate approaches like the Bethe–Salpeter equation allow access to the excitation energies of openshell systems, such as molecules and defects in solids. The eigenstates of these solutions, however, are generally not eigenstates of the spin operator
. Even for simple cases where the excitation vector is expected to be, for example, a triplet state, the value of ${\hat{S}}^{2}$ may be found to differ from 2.00; this difference is called ‘spin contamination’. The expectation values $\u27e8{\hat{S}}^{2}\u27e9$ must be computed for each excitation vector, to assist with the characterization of the particular excitation and to determine the amount of spin contamination of the state. Our aim is to provide for the first time in the SF methods literature a comprehensive resource on the derivation of the formulas for $\u27e8{\hat{S}}^{2}\u27e9$ as well as its computational implementation. After a brief discussion of the theory of the SF Bethe–Salpeter equation (BSE) and some examples further illustrating the need for calculating $\u27e8{\hat{S}}^{2}\u27e9$ , we present the derivation for the general equation for computing $\u27e8{\hat{S}}^{2}\u27e9$ with the eigenvectors from an SFBSE calculation, how it is implemented in a Python script, and timing information on how this calculation scales with the size of the SFBSE Hamiltonian. $\u27e8{\hat{S}}^{2}\u27e9$ 
Abstract A test of lepton flavor universality in
and ${\text{B}}^{\pm}\to {\text{K}}^{\pm}{\mu}^{+}{\mu}^{}$ decays, as well as a measurement of differential and integrated branching fractions of a nonresonant ${\text{B}}^{\pm}\to {\text{K}}^{\pm}{\text{e}}^{+}{\text{e}}^{}$ decay are presented. The analysis is made possible by a dedicated data set of protonproton collisions at ${\text{B}}^{\pm}\to {\text{K}}^{\pm}{\mu}^{+}{\mu}^{}$ recorded in 2018, by the CMS experiment at the LHC, using a special highrate data stream designed for collecting about 10 billion unbiased b hadron decays. The ratio of the branching fractions $\sqrt{s}=13{\textstyle}\text{TeV}$ to $B({\text{B}}^{\pm}\to {\text{K}}^{\pm}{\mu}^{+}{\mu}^{})$ is determined from the measured double ratio $B({\text{B}}^{\pm}\to {\text{K}}^{\pm}{\text{e}}^{+}{\text{e}}^{})$ of these decays to the respective branching fractions of the $R(\text{K})$ with ${\text{B}}^{\pm}\to \text{J}/\text{\psi}{\text{K}}^{\pm}$ and $\text{J}/\text{\psi}\to {\mu}^{+}{\mu}^{}$ decays, which allow for significant cancellation of systematic uncertainties. The ratio ${\text{e}}^{+}{\text{e}}^{}$ is measured in the range $R(\text{K})$ , where $1.1<{q}^{2}<6.0{\textstyle}{\text{GeV}}^{2}$q is the invariant mass of the lepton pair, and is found to be , in agreement with the standard model expectation $R(\text{K})={0.78}_{0.23}^{+0.47}$ . This measurement is limited by the statistical precision of the electron channel. The integrated branching fraction in the same $R(\text{K})\approx 1$q ^{2}range, , is consistent with the present worldaverage value and has a comparable precision. $B({\text{B}}^{\pm}\to {\text{K}}^{\pm}{\mu}^{+}{\mu}^{})=(12.42\pm 0.68)\times {10}^{8}$ 
Abstract We present a new class of AI models for the detection of quasicircular, spinning, nonprecessing binary black hole mergers whose waveforms include the higher order gravitational wave modes
, and mode mixing effects in the $(\ell ,m)=\{(2,2),(2,1),(3,3),(3,2),(4,4)\}$ harmonics. These AI models combine hybrid dilated convolution neural networks to accurately model both short and longrange temporal sequential information of gravitational waves; and graph neural networks to capture spatial correlations among gravitational wave observatories to consistently describe and identify the presence of a signal in a three detector network encompassing the Advanced LIGO and Virgo detectors. We first trained these spatiotemporalgraph AI models using synthetic noise, using 1.2 million modeled waveforms to densely sample this signal manifold, within 1.7 h using 256 NVIDIA A100 GPUs in the Polaris supercomputer at the Argonne Leadership Computing Facility. This distributed training approach exhibited optimal classification performance, and strong scaling up to 512 NVIDIA A100 GPUs. With these AI ensembles we processed data from a three detector network, and found that an ensemble of 4 AI models achieves stateoftheart performance for signal detection, and reports two misclassifications for every decade of searched data. We distributed AI inference over 128 GPUs in the Polaris supercomputer and 128 nodes in the Theta supercomputer, and completed the processing of a decade of gravitational wave data from a three detector network within 3.5 h. Finally, we finetuned these AI ensembles to process the entire month of February 2020, which is part of the O3b LIGO/Virgo observation run, and found 6 gravitational waves, concurrently identified in Advanced LIGO and Advanced Virgo data, and zero false positives. This analysis was completed in one hour using one NVIDIA A100 GPU. $\ell =3,m=2$ 
Abstract Entanglement is an intrinsic property of quantum mechanics and is predicted to be exhibited in the particles produced at the Large Hadron Collider. A measurement of the extent of entanglement in top quarkantiquark (
) events produced in proton–proton collisions at a centerofmass energy of 13 TeV is performed with the data recorded by the CMS experiment at the CERN LHC in 2016, and corresponding to an integrated luminosity of 36.3 fb^{−1}. The events are selected based on the presence of two leptons with opposite charges and high transverse momentum. An entanglementsensitive observable $\mathrm{t}\overline{\mathrm{t}}$D is derived from the top quark spindependent parts of the production density matrix and measured in the region of the $\mathrm{t}\overline{\mathrm{t}}$ production threshold. Values of $\mathrm{t}\overline{\mathrm{t}}$ are evidence of entanglement and $D<1/3$D is observed (expected) to be ( ${0.480}_{0.029}^{+0.026}$ ) at the parton level. With an observed significance of 5.1 standard deviations with respect to the nonentangled hypothesis, this provides observation of quantum mechanical entanglement within ${0.467}_{0.029}^{+0.026}$ pairs in this phase space. This measurement provides a new probe of quantum mechanics at the highest energies ever produced. $\mathrm{t}\overline{\mathrm{t}}$