Short-distance constraints for the longitudinal component of the hadronic light-by-light amplitude: an update.

We reassess the impact of short-distance constraints for the longitudinal component of the hadronic light-by-light amplitude on the anomalous magnetic moment of the muon, a µ = ( g - 2 ) µ / 2 , by comparing different solutions that have recently appeared in the literature. In particular, we analyze the relevance of the exact axial anomaly and its impact on a µ and conclude that it remains rather limited. We show that all recently proposed solutions agree well within uncertainties on the numerical estimate of the impact of short-distance constraints on a µ , despite differences in the concrete implementation. We also take into account the recently calculated perturbative corrections to the massless quark loop to update our estimate and outline the path towards future improvements.

Review of lattice results concerning low-energy particle physics: Flavour Lattice Averaging Group (FLAG).

We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor [Formula: see text], arising in the semileptonic [Formula: see text] transition at zero momentum transfer, as well as the decay constant ratio [Formula: see text] and its consequences for the CKM matrix elements [Formula: see text] and [Formula: see text]. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of [Formula: see text] and [Formula: see text] Chiral Perturbation Theory. We review the determination of the [Formula: see text] parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for [Formula: see text] and [Formula: see text] (also new compared to the previous review), as well as those for D- and B-meson-decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant [Formula: see text].

Entanglement-Enhanced Phase Estimation without Prior Phase Information.

We study the generation of planar quantum squeezed (PQS) states by quantum nondemolition (QND) measurement of an ensemble of ^{87}Rb atoms with a Poisson distributed atom number. Precise calibration of the QND measurement allows us to infer the conditional covariance matrix describing the F_{y} and F_{z} components of the PQS states, revealing the dual squeezing characteristic of PQS states. PQS states have been proposed for single-shot phase estimation without prior knowledge of the likely values of the phase. We show that for an arbitrary phase, the generated PQS states can give a metrological advantage of at least 3.1 dB relative to classical states. The PQS state also beats, for most phase angles, single-component-squeezed states generated by QND measurement with the same resources and atom number statistics. Using spin squeezing inequalities, we show that spin-spin entanglement is responsible for the metrological advantage.

Entanglement-Enhanced Radio-Frequency Field Detection and Waveform Sensing.

We demonstrate a new technique for detecting the amplitude of arbitrarily chosen components of radio-frequency waveforms based on stroboscopic backaction evading measurements. We combine quantum nondemolition measurements and stroboscopic probing to detect waveform components with magnetic sensitivity beyond the standard quantum limit. Using an ensemble of 1.5×10^{6} cold rubidium atoms, we demonstrate entanglement-enhanced sensing of sinusoidal and linearly chirped waveforms, with 1.0(2) and 0.8(3) dB metrologically relevant noise reduction, respectively. We achieve volume-adjusted sensitivity of δBsqrt[V]≈3.96 fTsqrt[cm^{3}/Hz], comparable to the best rf magnetometers.

Real-time shot-noise-limited differential photodetection for atomic quantum control.

We demonstrate high-efficiency, shot-noise-limited differential photodetection with real-time signal conditioning, suitable for feedback-based quantum control of atomic systems. The detector system has quantum efficiency of 0.92, is shot-noise-limited from 7.4×105 to 3.7×108 photons per pulse, and provides real-time voltage-encoded output at up to 2.3 M pulses per second.

Quantum Nondemolition Measurement Enables Macroscopic Leggett-Garg Tests.

We show how a test of macroscopic realism based on Leggett-Garg inequalities (LGIs) can be performed in a macroscopic system. Using a continuous-variable approach, we consider quantum nondemolition (QND) measurements applied to atomic ensembles undergoing magnetically driven coherent oscillation. We identify measurement schemes requiring only Gaussian states as inputs and giving a significant LGI violation with realistic experimental parameters and imperfections. The predicted violation is shown to be due to true quantum effects rather than to a classical invasivity of the measurement. Using QND measurements to tighten the "clumsiness loophole" forces the stubborn macrorealist to recreate quantum backaction in his or her account of measurement.

Generation of macroscopic singlet states in a cold atomic ensemble.

We report the generation of a macroscopic singlet state in a cold atomic sample via quantum nondemolition measurement-induced spin squeezing. We observe 3 dB of spin squeezing and detect entanglement with 5σ statistical significance using a generalized spin-squeezing inequality. The degree of squeezing implies at least 50% of the atoms have formed singlets.

Review of lattice results concerning low-energy particle physics.

We review lattice results related to pion, kaon, [Formula: see text]- and [Formula: see text]-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor [Formula: see text], arising in semileptonic [Formula: see text] transition at zero momentum transfer, as well as the decay-constant ratio [Formula: see text] of decay constants and its consequences for the CKM matrix elements [Formula: see text] and [Formula: see text]. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of [Formula: see text] and [Formula: see text] Chiral Perturbation Theory and review the determination of the [Formula: see text] parameter of neutral kaon mixing. The inclusion of heavy-quark quantities significantly expands the FLAG scope with respect to the previous review. Therefore, we focus here on [Formula: see text]- and [Formula: see text]-meson decay constants, form factors, and mixing parameters, since these are most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. In addition we review the status of lattice determinations of the strong coupling constant [Formula: see text].

Feedback cooling of an atomic spin ensemble.

We apply entropy removal by measurement and feedback to a cold atomic spin ensemble. Using quantum nondemolition probing by Faraday rotation measurement, and feedback by weak optical pumping, we drive the initially random collective spin variable F toward the origin F=0. We use input-output relations and ensemble quantum noise models to describe this quantum control process and identify an optimal two-round control procedure. We observe 12 dB of spin noise reduction, or a factor-of-63 reduction in phase-space volume. The method offers a nonthermal route to generation of exotic entangled states in ultracold gases, including macroscopic singlet states and strongly correlated states of quantum lattice gases.

Mass and width of the lowest resonance in QCD.

We demonstrate that near the threshold, the pi pi scattering amplitude contains a pole with the quantum numbers of the vacuum--commonly referred to as the sigma--and determine its mass and width within small uncertainties. Our derivation does not involve models or parametrizations but relies on a straightforward calculation based on the Roy equation for the isoscalar S wave.

The quark condensate from K(e(4)) decays.

We show that, independently of the size of the quark condensate, chiral symmetry correlates the two S-wave pipi scattering lengths. In view of this constraint, the new precision data on K(e(4)) decay allow a remarkably accurate determination of these quantities. The result confirms the hypothesis that the quark condensate is the leading order parameter.

Linking postdoctoral general dentistry programs with managed care programs and settings.

This report presents the results of a small workgroup convened by the American Association of Dental Schools to examine experiences related to postdoctoral general dentistry programs linked with managed care systems and clinical settings. The workgroup was a component of an Association effort to identify and promote innovative and nontraditional methods by which the number of postdoctoral general dentistry (PGD) positions can be increased to meet current demand for PGD education. The participants identified factors and conditions that they believed to be critical to the planning, development, and conduct of PGD programs with substantial linkages with managed care systems and settings. The information should be helpful to others as they consider opportunities to establish PGD programs or increase their number of PGD training positions.

Chronic hypercapnia in obstructive sleep apnea-hypopnea syndrome.

In order to determine the relationship between chronic hypercapnia and anthropomorphic data, pulmonary function tests and slopes of ventilatory responses to hypercapnia (HVCR) and hypoxia (HVR), we studied 55 patients with sleep apnea-hypopna syndrome (SAHS). Patients were divided into hypercapnic, PaCO2 > or = 45 mm Hg (Group I, n = 23, PaO2 = 61 +/- 10 and PaCO2 = 50 +/- 5 mm Hg, and [HCO3-] = 30 +/- 4 mEq/l [means +/- SD]) and normocapnic (or eucapnic), PaCO2 < 45 mm Hg (Group II, n = 32, PaO2 = 76 +/- 10 and PaCO2 = 39 +/- 4 mm Hg and [HCO3-] = 25 +/- 3 mEq/l [means +/- SD]) groups. When compared to the normocapnic group, hypercapnic patients were significantly heavier (with greater body surface area) and had significantly more severe restrictive and obstructive defects and impaired HVR and HCVR. The means (+/- SD) of some of the data follow (* indicates p < 0.05 when Group I is compared to Group II): [table: see text] When subgroups of hypercapnic and eucapnic patients with similar lung functions were compared, the subgroups differed significantly in their weights; conversely, in subgroups with comparable weights, lung function tests differed significantly. These data suggest that the mechanisms of chronic hypercapnia are multifactorial, and we hypothesize that, in the face of repetitive apneas and hypopneas, increased weight and abnormal lung function tests interact and contribute to the generation and maintenance of hypercapnia.

The relationship between first presentation and subsequent observations in heavy calculus formers.

There are few studies that provide information on the natural history of calculus formation. The purpose of this study is to evaluate the relationship between pre-scaling baseline calculus scores, the time since the last prophylaxis before baseline, and scores 8 weeks after scaling in a group of presumed heavy calculus formers. Scaling and polishing were completed on 203 subjects with Volpe-Manhold Index (VMI) calculus scores of 7 or higher, and the date of the last prophylaxis was noted. All were re-examined after 3 weeks. The group included 45.8% males and 54.2% females; the mean age was 41.74 (range = 24 to 72). Racial mix was 57.6% African-American, 39.9% white, and 2.5% other. The mean baseline VMI score was 24.07 (SD = 15.38, range = 7-97). The VMI scores were directly related (P = < .001) to the date of the last scaling and were highest in subjects whose last scaling was more than 2 years earlier (33.67) and least in subjects whose last scaling was less than 6 months previous (15.12). At 8 weeks the mean VMI score was 9.96 (SD = 7.30; range = 0-41). The VMI scores at this time were inversely related (P = < .05) to the date of the last scaling before baseline and were lowest in subjects whose last scaling was more than 2 years earlier (9.07) and highest in subjects with the last scaling less than 6 months previous to baseline (13.07).(ABSTRACT TRUNCATED AT 250 WORDS)

Familial respiratory chemosensitivity does not predict hypercapnia of patients with sleep apnea-hypopnea syndrome.

The mechanisms of hypercapnia observed in some patients with sleep apnea-hypopnea syndrome (SAHS) are not known. In chronic obstructive lung disease (COLD), hypercapnic and hypoxic ventilatory responses (HCVR/HVR) are decreased in normal family members of hypercapnic patients compared with those of non-hypercapnic patients. This suggests a familial (presumably genetic) diminished chemosensitivity predisposing to hypercapnia. In this study we investigated the possibility of a similar mechanism in SAHS. Based on PaCO2, 29 patients with polysomnographic evidence of SAHS were divided into those with chronic hypercapnia (PaCO2 greater than or equal to 45 mm Hg, n = 13) and those with normocapnia (PaCO2 less than 45 mm Hg, n = 16). We studied healthy adult (greater than or equal to 17 yr) immediate family members of these patients. Family members were required to have normal spirometry and be on no medications. In Group I, there were 32 family members of hypercapnic patients and in Group II, 26 family members of normocapnic patients. In Group I, the mean (+/- SD) of age (yr) was 36 +/- 12, weight (kg) 82 +/- 22, FEV1 (L) 3.1 +/- 0.8, VCO2 (ml/min) 228 +/- 63, slope (L/min) of HCVR 2.0 +/- 0.8, and slope (L/min/1% saturation) of HVR -1.20 +/- 0.82. Respective values in Group II were 34 +/- 14, 83 +/- 16, 3.2 +/- 0.8, 233 +/- 63, 2.0 +/- 1.0, and -1.34 +/- 1.20. There were no statistically significant differences in measured variables between the two groups. Furthermore, there were no significant correlations between PaCO2 of patients and slopes of HCVR or HVR of their family members.(ABSTRACT TRUNCATED AT 250 WORDS)