Regge Trajectories with Square-Root Branch Points and Their Regge Cuts

We discuss branch points in the complex angular momentum plane formed by two Regge poles on trajectories with square-root branch points at t=0. We find several new cuts which collide with the expected Mandelstam cuts at t=0. In the bootstrap of the Pomeranchon pole, the collection of cuts has the same effect as in the case of linear trajectories: The Pomeranchon can have α(0)=1 only if certain couplings vanish at t=0

Effective Field Theory and Unification in AdS Backgrounds

This work is an extension of our previous work, hep-th/0204160, which showed how to systematically calculate the high energy evolution of gauge couplings in compact AdS_5 backgrounds. We first directly compute the one-loop effects of massive charged scalar fields on the low energy couplings of a gauge theory propagating in the AdS background. It is found that scalar bulk mass scales (which generically are of order the Planck scale) enter only logarithmically in the corrections to the tree-level gauge couplings. As we pointed out previously, we show that the large logarithms that appear in the AdS one-loop calculation can be obtained within the confines of an effective field theory, by running the Planck brane correlator from a high UV matching scale down to the TeV scale. This result exactly reproduces our previous calculation, which was based on AdS/CFT duality. We also calculate the effects of scalar fields satisfying non-trivial boundary conditions (relevant for orbifold breaking of bulk symmetries) on the running of gauge couplings.Comment: LaTeX, 27 pages; minor typos fixed, comments adde

Galilean and Dynamical Invariance of Entanglement in Particle Scattering

Particle systems admit a variety of tensor product structures (TPSs) depending on the algebra of observables chosen for analysis. Global symmetry transformations and dynamical transformations may be resolved into local unitary operators with respect to certain TPSs and not with respect to others. Symmetry-invariant and dynamical-invariant TPSs are defined and various notions of entanglement are considered for scattering states.Comment: 4 pages, no figures; v.3 has typos corrected, a new reference, and a revised conclusio

Atrial fibrillation practice patterns among cardiac electrophysiologists and cardiologists

Background: Treatment paradigms for atrial fibrillation (AF) are highly variable. This study explores the management practices for AF between general cardiologists and electrophysiologists in an academic institution.Methods: One hundred and eighty eight patients with AF who had primary outpatient evaluation by either a cardiologist (n = 94) or electrophysiologist (n = 94) in 2008 were selected from the Northwestern electronic medical record and included in the study. Chart review was used to determine the type of therapy, methods of monitoring AF, antiarrhythmic drug use patterns and outcome.Results: Patients seen by cardiologists vs. electrophysiologists were older (70.3 ± 11.8 vs. 65.3 ± 10.3, p = 0.002) and had more diabetes (21.3% vs. 10.6%, p = 0.046), renal disease (29.0% vs. 9.2%, p = 0.001) and coronary artery disease (40.4% vs. 23.4%, p = 0.01). A rate control strategy was used more often (80.9% vs. 54.3%, p < 0.001), and antiarrhythmics were prescribed less (10.6% vs. 31.9%, p < 0.001) by cardiologists than electrophysiologists. Antiarrhythmic choices were amiodarone (33.3%), sotalol (20.0%), flecainide (13.3%), propafenone (13.3%), and dofetilide (23.3%) for electrophysiologists, and were limited to amiodarone (80%) and sotalol (20%) for cardiologists. After a mean follow-up of 14.0 ± 11.6 and 12.8 ± 11.1 months (p = 0.44) for patients managed by cardiologists and electrophysiologists, mortality was 13.8% and 6.4% (p = 0.09), respectively. Long-term ambulatory electrocardiogram monitoring was used more frequently by electrophysiologists (74.4%) than by cardiologists (55.6%, p = 0.15).Conclusions: Practice patterns for treatment of AF significantly differ between electrophysiologists and cardiologists. Understanding specialist treatment patterns will help optimize individualized therapy for treatment of AF

Efficacy and tolerability of dronedarone for patients with atrial fibrillation

Background: Dronedarone is a new antiarrhythmic drug used in the treatment of atrial fibrillation (AF). We investigate its efficacy and tolerability in clinical practice.Methods: We identified 208 patients treated with dronedarone for AF at the Northwestern outpatient practice. Charts were reviewed for clinical efficacy and reasons for discontinuation of the drug.Results: The average age was 65.2 ± 10.8 years, 37% females. Paroxysmal, persistent andpermanent AF were noted in 46.2%, 51.9%, and 1.9%, respectively. Average ejection fraction was 56.3 ± 9.1%, 12.8% had a history of congestive heart failure, and 10.3% had valvularheart disease. Dronedarone was discontinued in 25 patients after curative catheter or surgical ablation procedure. Of the remaining 183 patients, dronedarone was discontinued in 48.6% after a mean duration of 6.2 ± 6.3 months because of in efficacy (26.2%), side effects (6%), and other reasons (16.4%). For those remaining on dronedarone (n = 94), after a mean of 11.6 ± 6.6 months, clinical efficacy (resolution of or patient-reported improvement in symptoms) was noted in 45.4% patients. On dronedarone therapy, 57.4% had no AF on follow-up (overallefficacy of 29.5%). To evaluate efficacy, ECG only or long-term monitoring were performed in 62.7% and 37.3%, respectively, and found no AF in 69.2 and 48.4%, respectively. There were 3 deaths and 2 transient ischemic attacks (TIA) off dronedarone vs. 1 death, 1 TIA and 2 strokes on dronedarone.Conclusions: Dronedarone has a significant discontinuation rate due to both inefficacy and side effects in clinical practice. Nevertheless, it has moderate clinical efficacy and tolerability in an outpatient population of patients with AF

Systematics of Coupling Flows in AdS Backgrounds

We give an effective field theory derivation, based on the running of Planck brane gauge correlators, of the large logarithms that arise in the predictions for low energy gauge couplings in compactified AdS}_5 backgrounds, including the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast to the case of charged scalars coupled to Abelian gauge fields that has been considered previously in the literature, the one-loop corrections are not dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge field loops, the amplitudes can be reorganized into a leading logarithmic contribution that is identical to the running in 4D non-Abelian gauge theory, and a term which is not logarithmically enhanced and is analogous to a two-loop effect in 4D. In a warped GUT model broken by the Higgs mechanism in the bulk,we show that the matching scale that appears in the large logarithms induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV scale in the logarithmic contributions of scalars, which is simply the bulk mass m. Our results are summarized in a set of simple rules that can be applied to compute the leading logarithmic predictions for coupling constant relations within a given warped GUT model. We present results for both bulk Higgs and boundary breaking of the GUT gauge group.Comment: 22 pages, LaTeX, 3 figures. Comments and references adde

Subtractive renormalization of the NN scattering amplitude at leading order in chiral effective theory

The leading-order nucleon-nucleon (NN) potential derived from chiral perturbation theory consists of one-pion exchange plus a short-distance contact interaction. We show that in the 1S0 and 3S1-3D1 channels renormalization of the Lippmann-Schwinger equation for this potential can be achieved by performing one subtraction. This subtraction requires as its only input knowledge of the NN scattering lengths. This procedure leads to a set of integral equations for the partial-wave NN t-matrix which give cutoff-independent results for the corresponding NN phase shifts. This reformulation of the NN scattering equation offers practical advantages, because only observable quantities appear in the integral equation. The scattering equation may then be analytically continued to negative energies, where information on bound-state energies and wave functions can be extracted.Comment: 16 pages, 11 figure

Mapping of strongly correlated steady-state nonequilibrium to an effective equilibrium

By mapping steady-state nonequilibrium to an effective equilibrium, we formulate nonequilibrium problems within an equilibrium picture where we can apply existing equilibrium many-body techniques to steady-state electron transport problems. We study the analytic properties of many-body scattering states, reduce the boundary condition operator in a simple form and prove that this mapping is equivalent to the correct linear-response theory. In an example of infinite-U Anderson impurity model, we approximately solve for the scattering state creation operators, based on which we derive the bias operator Y to construct the nonequilibrium ensemble in the form of the Boltzmann factor exp(-beta(H-Y)). The resulting Hamiltonian is solved by the non-crossing approximation. We obtain the Kondo anomaly conductance at zero bias, inelastic transport via the charge excitation on the quantum dot and significant inelastic current background over a wide range of bias. Finally, we propose a self-consistent algorithm of mapping general steady-state nonequilibrium.Comment: 15 pages, 9 figure

Role of the N∗N^*(1535) in the J/ψ→pˉηpJ/\psi\to \bar{p}\eta p and J/ψ→pˉK+ΛJ/\psi\to \bar{p}K^+\Lambda reactions

We study the $J/\psi\to \bar{p}\eta p$ and $J/\psi\to \bar{p}K^+\Lambda$ reactions with a unitary chiral approach. We find that the unitary chiral approach, which generates the $N^*(1535)$ dynamically, can describe the data reasonably well, particularly the ratio of the integrated cross sections. This study provides further support for the unitary chiral description of the $N^*(1535)$. We also discuss some subtle differences between the coupling constants determined from the unitary chiral approach and those determined from phenomenological studies.Comment: version to appear in PRC; certain features of the approach clarifie

Localized Supersoft Supersymmetry Breaking

We consider supersymmetry breaking models in which the MSSM is extended to include an additional chiral adjoint field for each gauge group with which the the MSSM gauginos acquire Dirac masses. We investigate a framework in which the Standard Model gauge fields propagate in the bulk of a warped extra dimension while quarks and leptons are localized on the ultraviolet brane. The adjoint fields are localized on the infrared brane, where supersymmetry is broken in a hidden sector. This setup naturally suppresses potentially large flavor violating effects, while allowing perturbative gauge coupling unification under SU(5) to be realized. The Standard Model superpartner masses exhibit a supersoft spectrum. Since the soft scalar masses are generated at very low scales of order the gaugino masses these models are significantly less fine-tuned than other supersymmetric models. The LSP in this class of models is the gravitino, while the NLSP is the stau. We show that this theory has an approximate R symmetry under which the gauginos are charged. This symmetry allows several possibilities for experimentally distinguishing the Dirac nature of the gauginos.Comment: 23 pages, 2 figure