Isospin breaking in pion-nucleon scattering at threshold by radiative processes

We investigate the dispersive contribution by radiative processes such as (pi- proton to neutron gamma) and (pi- proton to Delta gamma) to the pion-nucleon scattering lengths of charged pions in the heavy baryon limit. They give a large isospin violating contribution in the corresponding isoscalar scattering length, but only a small violation in the isovector one. These terms contribute 6.3(3)% to the 1s level shift of pionic hydrogen and give a chiral constant F_pi^2f_1=-25.8(8) MeV.Comment: 9 pages with 1 figur

Precision determination of the pi-N scattering lengths and the charged pi-NN coupling constant

We critically evaluate the isovector GMO sumrule for the charged $\pi N N$ coupling constant using recent precision data from $\pi ^-$p and $\pi^-$d atoms and with careful attention to systematic errors. From the $\pi ^-$d scattering length we deduce the pion-proton scattering lengths ${1/2}(a_{\pi ^-p}+a_{\pi ^-n})=(-20\pm 6$(statistic)$\pm 10$ (systematic))~$\cdot 10^{-4}m_{\pi_c}^{-1}$ and ${1/2}(a_{\pi ^-p}-a_{\pi ^-n})=(903 \pm 14)\cdot 10^{-4}m_{\pi_c}^{-1}$. From this a direct evaluation gives $g^2_c(GMO)/4\pi =14.20\pm 0.07$(statistic)$\pm 0.13$(systematic) or $f^2_c/4\pi= 0.0786\pm 0.0008$.Comment: 4 pages, 1 figure, latex and postscript; invited talk at PANIC99; to appear in Nucl. Phys. A; changed notation: g^2 and f^2 replaced by conventional g^2/4\pi and f^2/4\p

Chiral Dynamics of Deeply Bound Pionic Atoms

We present and discuss a systematic calculation, based on two-loop chiral perturbation theory, of the pion-nuclear s-wave optical potential. A proper treatment of the explicit energy dependence of the off-shell pion self-energy together with (electromagnetic) gauge invariance of the Klein-Gordon equation turns out to be crucial. Accurate data for the binding energies and widths of the 1s and 2p levels in pionic ^{205}Pb and ^{207}Pb are well reproduced, and the notorious "missing repulsion" in the pion-nuclear s-wave optical potential is accounted for. The connection with the in-medium change of the pion decay constant is clarified.Comment: preprint ECT*-02-16, 4 pages, 3 figure

Impulse approximation in the n p --> d pi^0 reaction reexamined

The impulse approximation (one-body operator) in the n p --> d pi^0 reaction is reexamined with emphasis on the issues of reducibility and recoil corrections. An inconsistency when one pion exchange is included in the production operator is demonstrated and then resolved via the introduction of "wave function corrections" which nearly vanish for static nucleon propagators. Inclusion of the recoil corrections to the nucleon propagators is found to change the magnitude and sign of the impulse production amplitude, worsening agreement with the experimental cross section by approximately 30%. A cutoff is used to account for the phenomenological nature of the external wave functions, and is found to have a significant impact up to approximately 2.5 GeV.Comment: Published versio

Isospin breaking of the narrow charmonium state of Belle at 3872 MeV as a deuson

The narrow charmonium state near 3872 MeV reported by the Belle collaboration and confirmedby CDF lies almost exactly at the neutral D anti-D* threshold. As was predicted many years ago it can be a deuteronlike meson-meson state called a deuson. If so, it should be an axial, or possibily a pseudoscalar state with C=0, and isospin predominantly 0. Large isospin breaking is expected because of the isospin mass splitting between the neutral and charged D (D*) mesons. Because of this large isospin breaking the decay X(3872) to J/psi rho would be allowed, while J/psi sigma would be forbidden by C-parity, as indicated by the present data.Comment: 7 latex pages 5 figures. This report supercedes the unpublished reminder hep-ph/0308277. Version 2 to appear in Physics Letters B, one reference added and minor improvement

Some Preliminary Observations On The Acoustic Behavior Of Semi-Domestic Reindeer (Rangifer Tarandus Tarandus) With Emphasis On Intraspecific Communication And The Mother-Calf Relationship

Thesis (M.S.) University of Alaska Fairbanks, 197

Ground state energy fluctuations in nuclear matter II

Improvements are performed on a recently proposed statistical theory of the mean field of a many-fermion system. The dependence of the predictions of the theory upon its two basic ingredients, namely the Hartree-Fock energy and the average energy of the two particle-two hole excitations, is explored.Comment: 16 pages, 1 figure, revte

Subjective Bayesian Models in Sampling Finite Populations

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146905/1/rssb00782.pd

Implementation of a Wellness Program for Nurse Leaders

Background: The setting for this study is the implementation of a wellness program for nurse leaders at Hospital A, a healthcare organization servicing the South Sacramento area in California. Healthcare is a challenging and high-demand profession, and the COVID-19 pandemic has exacerbated an issue of burnout and unwavering job-related stress for physicians and employees. This remains true for nurse leader professionals who take on the responsibility to ensure safety and quality always remains at ideal measures for any facility. Problem: During the past several years of the pandemic, the nurse leader role has had to endure several unknowns, placing significant stress on many, causing some to exit their role. In Hospital A, the facility has lost an average of three nurse leaders each year during the pandemic. Aside from having to deal with a once in a lifetime public health emergency, another contributing factor could well be the lack of a wellness program to aide in dealing with the strenuous work associated with being a nurse leader. Intervention: The goal of implementing a wellness program for nurse leaders is to improve their overall wellness as measured by a survey pre and post implementation. The survey consists of questions pertaining to five elements of employee health and wellness: emotional, environmental, occupational, physical health, and social well-being. Specific Plan-Do-Study-Act (PDSA) cycles will be created based on the measures of the survey. Outcome Measure: The outcome measure for this quality improvement project was an improvement in wellness scores by 20% from pre and post implementation surveys. The process measure for this project was a 5% increase from baseline for the specific elements of wellness addressed by the PDSA cycles: occupational well-being and physical health. Results: A total of 40 nurse leaders took the wellness survey pre-implementation on May 1, 2023. After two and a half months of the wellness program, which included several PDSA cycles, the wellness scores remained unchanged from a baseline score of 3.83/5.00 rating to a 3.80/5.00. The process measures around occupational well-being and physical health had a 7.9% and 5.5% increase, respectively, within the project time period. Conclusion: The implementation of a wellness program shows benefits to nurse leaders in certain aspects of their workplace wellness. As Hospital A continues to transition out of the pandemic back into normal operations, sustainability of the program must remain a focus to ensure nurse leader wellness remains a top priority for organizational goals