Flavor Physics and the Triviality Bound on the Higgs Mass

The triviality of the scalar sector of the standard one-doublet Higgs model implies that this model is only an effective low-energy theory valid below some cut-off scale $\Lambda$. The underlying high-energy theory must include flavor dynamics at a scale of order $\Lambda$ or greater in order to give rise to the different Yukawa couplings of the Higgs to ordinary fermions. This flavor dynamics will generically produce flavor-changing neutral currents and non-universal corrections to Z -> b b-bar. We show that the experimental constraints on the neutral D-meson mass difference imply that $\Lambda$ must be greater than of order 21 TeV. We also discuss bounds on $\Lambda$ from the constraints on extra contributions to the K_L - K_S mass difference and to the coupling of the Z boson to b-quarks. For theories defined about the infrared-stable Gaussian fixed-point, we estimate that this lower bound on $\Lambda$ yields an upper bound of approximately 460 GeV on the Higgs boson's mass, independent of the regulator chosen to define the theory.Comment: 11 pages, 2 embedded figures, LaTeX; references and discussion of CP violation adde

Population control of 2s-2p transitions in hydrogen

We consider the time evolution of the occupation probabilities for the 2s-2p transition in a hydrogen atom interacting with an external field, V(t). A two-state model and a dipole approximation are used. In the case of degenerate energy levels an analytical solution of the time-dependent Shroedinger equation for the probability amplitudes exists. The form of the solution allows one to choose the ratio of the field amplitude to its frequency that leads to temporal trapping of electrons in specific states. The analytic solution is valid when the separation of the energy levels is small compared to the energy of the interacting radiation.Comment: 6 pages, 3 figure

Electromagnetic contributions to pseudoscalar masses

We report on the calculation by the MILC Collaboration of the electromagnetic effects on kaon and pion masses. These masses are computed in QCD with dynamical (asqtad staggered) quarks plus quenched photons at three lattice spacings varying from 0.12 to 0.06 fm. The masses are fit to staggered chiral perturbation theory with NLO electromagnetic terms, as well as analytic terms at higher order. We extrapolate the results to physical light-quark masses and to the continuum limit. At the current stage of the analysis, most, but not all, of the systematic errors have been estimated. The main goal is the comparison of kaon electromagnetic splittings to those of the pion, i.e., an evaluation of the corrections to “Dashen’s theorem.” This in turn will allow us to significantly reduce the systematic errors in our determination of m<sub>u</sub>/m<sub>d</sub>

Complications Associated With Anesthesia Services in Endoscopic Procedures Among Patients With Cirrhosis

Background and Aims: Anesthesia services for endoscopic procedures have proliferated with the promise of increased comfort and safety. Cirrhosis patients are higher risk for sedation, yet limited data are available describing anesthesia complications in this population. Approach and Results: This cross-sectional study utilized the National Anesthesia Clinical Outcomes Registry, a multicenter quality-improvement database from 2010 to 2015. Patients with cirrhosis undergoing an endoscopy were identified by International Classification of Diseases, Ninth Revision (ICD-9)/Current Procedures Terminology (CPT) codes. The outcome of interest was serious anesthesia-related complication defined as cardiovascular, respiratory, neurological, drug related, patient injury, death, or unexpected admission. A mixed-effects multivariate logistic regression model determined odds ratios (ORs) between variables and serious complications, adjusting for potential confounders. In total, 9,007 endoscopic procedures were performed among patients with cirrhosis; 92% were esophagogastroduodenoscopies. The majority (81%) were American Society of Anesthesiologists (ASA) class ≥3, and 72% had a history of hepatic encephalopathy, ascites, varices, hepatorenal syndrome, or spontaneous bacterial peritonitis identified by ICD-9/CPT codes. In total, 87 complications were reported, 33 of which were serious. Frequency of serious complications was 0.4% or 378.6 per 100,000 procedures (95% confidence interval [CI], 260.8, 531.3). The majority of serious complications were cardiovascular (21 of 33), including 15 cardiac arrests. Serious complications were significantly associated with ASA 4/5 (OR, 3.84; 95% CI, 1.09, 13.57) and general anesthesia (OR, 4.71; 95% CI, 1.20, 18.50), adjusting for age, sex, ASA class, anesthesia type, inpatient status, portal hypertension history, and variable complication reporting practices. Conclusions: Anesthesia complications among endoscopic procedures in cirrhosis are rare overall. Serious complications were predominantly cardiac and associated with sicker patients undergoing general anesthesia. The complexity of end-stage liver disease may warrant more intensive care during endoscopic procedures, including anesthesia monitoring

Evidence for SU(3) symmetry breaking from hyperon production

We examine the SU(3) symmetry breaking in hyperon semileptonic decays (HSD) by considering two typical sets of quark contributions to the spin content of the octet baryons: Set-1 with SU(3) flavor symmetry and Set-2 with SU(3) flavor symmetry breaking in HSD. The quark distributions of the octet baryons are calculated with a successful statistical model. Using an approximate relation between the quark fragmentation functions and the quark distributions, we predict polarizations of the octet baryons produced in $e^+e^-$ annihilation and semi-inclusive deeply lepton-nucleon scattering in order to reveal the SU(3) symmetry breaking effect on the spin structure of the octet baryons. We find that the SU(3) symmetry breaking significantly affects the hyperon polarization. The available experimental data on the $\Lambda$ polarization seem to favor the theoretical predictions with SU(3) symmetry breaking. We conclude that there is a possibility to get a collateral evidence for SU(3) symmetry breaking from hyperon production. The theoretical errors for our predictions are discussed.Comment: 3 tables, 14 figure

Cultural orientations and preference for HRM policies and practices:the case of Oman

This study empirically examines the influence of cultural orientations on employee preferences of human resource management (HRM) policies and practices in Oman. Data were collected from 712 employees working in six large Omani organizations. The findings indicate that there is a number of differences among Omani employees regarding value orientations due especially to age, education and work experience. The findings show a strong orientation towards mastery, harmony, thinking and doing, and a weak orientation towards hierarchy, collectivism, subjugation and human nature-as-evil. The results demonstrate a clear link between value orientations and preferences for particular HRM policies and practices. Group-oriented HRM practices are preferred by those who scored high on collectivism and being orientations, and those who scored low on thinking and doing orientations. Hierarchy-oriented HRM practices are preferred by those scoring high on hierarchy, subjugation and human nature-as-bad orientations, and those scoring low on thinking and mastery orientations. Finally, preference for loose and informal HRM practices was positively associated with being, and negatively associated with thinking, doing and harmony orientations. The theoretical and practical implications of these findings are discussed in detail

Electromagnetic contributions to pseudoscalar masses

We report on the calculation by the MILC Collaboration of the electromagnetic effects on kaon and pion masses. These masses are computed in QCD with dynamical (asqtad staggered) quarks plus quenched photons at three lattice spacings varying from 0.12 to 0.06 fm. The masses are fit to staggered chiral perturbation theory with NLO electromagnetic terms, as well as analytic terms at higher order. We extrapolate the results to physical light-quark masses and to the continuum limit. At the current stage of the analysis, most, but not all, of the systematic errors have been estimated. The main goal is the comparison of kaon electromagnetic splittings to those of the pion, i.e., an evaluation of the corrections to “Dashen’s theorem.” This in turn will allow us to significantly reduce the systematic errors in our determination of m<sub>u</sub>/m<sub>d</sub>

Collinear helium under periodic driving: stabilization of the asymmetric stretch orbit

The collinear eZe configuration of helium, with the electrons on opposite sides of the nucleus, is studied in the presence of an external electromagnetic (laser or microwave) field. We show that the classically unstable "asymmetric stretch" orbit, on which doubly excited intrashell states of helium with maximum interelectronic angle are anchored, can be stabilized by means of a resonant driving where the frequency of the electromagnetic field equals the frequency of Kepler-like oscillations along the orbit. A static magnetic field, oriented parallel to the oscillating electric field of the driving, can be used to enforce the stability of the configuration with respect to deviations from collinearity. Quantum Floquet calculations within a collinear model of the driven two-electron atom reveal the existence of nondispersive wave packets localized on the stabilized asymmetric stretch orbit, for double excitations corresponding to principal quantum numbers of the order of N > 10.Comment: 13 pages, 12 figure