Constituent and current quark masses at low chiral energies

Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the Quark-Level Linear $\sigma$ Model, and infrared QCD. This allows to define effective nonstrange and strange current quark masses which reproduce the experimental pion and kaon masses very accurately, by simple additivity. Moreover, the masses of the light scalar mesons $\sigma(600)$ and $\kappa(800)$ can be obtained straightforwardly from the constituent quark masses. In contrast, the usual nonstrange and strange current quark masses employed by Chiral Perturbation Theory do not allow a simple quantitative explanation of the pion and kaon masses.Comment: 5 pages, EPL style, accepted for publication in Europhys. Let

Pion and Kaon Masses and Pion Form Factors from Dynamical Chiral-Symmetry Breaking with Light Constituent Quarks

Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the quark-level linear sigma model, and infrared QCD. This allows to define effective nonstrange and strange current quark masses, which reproduce the experimental pion and kaon masses very accurately, by simple additivity. In contrast, the usual nonstrange and strange current quarks employed by the Particle Data Group and Chiral Perturbation Theory do not allow a straightforward quantitative explanation of the pion and kaon masses.Comment: 4 pages, AIP style, contribution to conference ``Quark Confinement and the Hadron Spectrum VII'', Azores, Portugal, 2-7 September 200

Why the f(0)(980) is mostly ssbar

We exploit the W-emission process to study the measured weak decay of the D(s,+)(1.9686) meson into f(0)(980) and a positively charged pion. We conclude that the scalar f(0)(980) meson contains mostly strange-antistrange flavors, which is supported by different model studies.Comment: 5 pages, plain LaTeX, minor changes, acknowledgment

Mach 5 inlet CFD and experimental results

An experimental research program was conducted in the NASA Lewis Research Center 10 x 10 ft supersonic wind tunnel. The 2-D inlet model was designed to study the Mach 3.0 to 5.0 speed range for an over-under turbojet plus ramjet propulsion system. The model was extensively instrumented to provide both analytical code validation data as well as inlet performance information. Support studies for the program include flow field predictions with both 3-D parabolized Navier-Stokes (PNS) and 3-D full Navier-Stokes (FNS) analytical codes. Analytical predictions and experimental results are compared

Comment on "Two-photon decay of the sigma meson"

We comment on a recent paper by Giacosa, Gutsche, and Lyobovitskij, in which it is argued that a quarkonium interpretation of the $\sigma$ meson should give rise to a much smaller two-photon decay width than commonly assumed. The reason for this claimed discrepancy is a term in the transition amplitude, necessary for gauge invariance, which allegedly is often omitted in the literature, including the work of the present authors. Here we show their claims to be incorrect by demonstrating, in the context of the Quark-Level Linear $\sigma$ Model, that the recently extracted experimental value $\Gamma_{\sigma\to2\gamma}=(4.1\pm0.3)$ keV is compatible with a $q\bar{q}$ assignment for the $\sigma$, provided that meson loops are taken into account as well.Comment: RevTeX, 4 pages, Comment on Phys. Rev. D 77 (2008) 034007 [0710.3403 [hep-ph]

First-Year Students\u27 Perception of Vocation at a Private Faith-Based Liberal Arts Institution

The current study surveyed 100 first-year students in order to answer the research question, “What are the perceptions of vocation of first-year students at a private faith-based liberal arts institution?” The study ultimate aimed to use the findings to assist career development professionals in planning programs that foster students’ discovery of their career aspirations and life purpose. A review of the literature revealed a gap regarding the perceptions of vocation among first-year students and how a private faith-based liberal arts institution can better support students’ vocational aspirations. The study utilized a modified grounded research theory qualitative design, which enabled the identification of themes through the analysis of student responses. The researcher selected the methods to achieve a more accurate theoretical sampling of the first-year students’ understanding of vocation by allowing their voices to drive the results. The participants received twenty-five minutes to respond to the following questions: “How would you describe your understanding of the idea of vocation?” and “How do you believe attending this university will impact your sense of vocation, calling, and/or life’s purpose?” The researcher read, analyzed, and categorized the essays into themes that emerged from the participants’ responses. Seven themes emerged from each question. The primary finding of question one indicated that 90% of the participants viewed vocation as “a calling.” In response to question two, the predominant theme showed that students desired encouragement from their university community to develop their self-awareness and career path. The results of this study reflected the critical role of career development professionals—as well as the high expectations that students have of their institutions—to offer students support in discovering their career aspirations and life purpose. Future research could include the development of a survey instrument and quantitative analysis in order to gain a more precise understanding of students understanding of vocation