Decay channels and charmonium mass-shifts

The discovery in the last few years of the $X, Y$ and $Z$ states of the extended charmonium family has highlighted the importance of the closeness of decay channels to an understanding of these mesons. We aid this debate by illustrating a simple calculational procedure for including the effect of open and nearby closed channels.Comment: 4 pages, 2 figures Revised version: (1) corrected 2 typos in Table II, (2) additional text in penultimate paragraph to clarify the calculation of mass-shifts for $\eta_c'$ and $\eta_c"$. We thank colleagues for pointing out confusing wording of previous tex

Visual Communications on the Road in Arkansas: Analysis of Secondary Students Videos

In the summer of 2010, the Visual Communications on the Road in Arkansas: Creative Photo and Video Projects to Promote Agriculture program was initiated. The program consisted of a two-week agricultural communications curriculum that would be taught by agricultural science teachers in Arkansas. The curriculum was composed of lessons about photography, writing, and videography, and the program introduced students to digital photography and videography equipment and the proper uses of equipment. Once the curriculum was taught in secondary schools, a mobile classroom unit—consisting of a travel trailer, photography and videography equipment, and laptop computers equipped with editing software—would visit the school to assist students with the creation of short promotional videos about agriculture. The student-created videos were used as a hands-on extension of the curriculum learned in the classroom. Completed videos were posted to YouTube and then analyzed to assess student application of competencies taught in the curriculum. The researchers created a coding sheet to systematically assess all posted videos and inter- and intrarater reliability was maintained. An analysis of data gathered from the video assessment showed that secondary students were able to effectively apply many of the techniques taught in the curriculum through the agricultural videos created. Additional findings and recommendations for application and future research are presented

Cross-Disciplinary Collaboration and Learning

Complex environmental problem solving depends on cross-disciplinary collaboration among scientists. Collaborative research must be preceded by an exploratory phase of collective thinking that creates shared conceptual frameworks. Collective thinking, in a cross-disciplinary setting, depends on the facility with which collaborators are able to learn and understand each others’ perspectives. This paper applies three perspectives on learning to the problem of enabling cross-disciplinary collaboration: Maslow’s hierarchy of needs, constructivism, and organizational learning. Application of learning frameworks to collaboration provides insights regarding receptive environments for collaboration, and processes that facilitate cross-disciplinary interactions. These environments and interactions need time to develop and require a long phase of idea generation preceding any focused research effort. The findings highlight that collaboration is itself a complex system of people, scientific theory, and tools that must be intentionally managed. Effective management of the system requires leaders who are facilitators and are capable of orchestrating effective environments and interactions

The Relationship of Stress Levels to Wellness Practices Among U.S. Radiologic Technology Program Directors

The purpose of this modified replication study is to examine the relationship between the stress levels and the wellness practices of U.S. radiologic technology program directors and to determine if correlations exist between wellness practices and stress levels of the group. Additionally, relaxation activities and the feelings, characteristics, and symptoms associated with stress were considered. The design of the study was ex post facto correlational. The population of the study was U.S. radiologic technology program directors working in JRCERT accredited programs. The electronic instrument was distributed to 635 program directors through e-mail, with 424 (66.7%) usable returns. Significant associations were found between the management of stress and the balance of wellness practices for the RT program directors. It was concluded that while program directors showed significant control in stressful events and issues, continued efforts are needed to promote wellness practices into their busy lives

Structure of the lightest scalar meson from the 1/Nc expansion of Unitarized Chiral Perturbation Theory and Regge Theory

One-loop unitarized Chiral Perturbation Theory (UChPT) calculations, suggest a different Nc behaviour for the sigma or f_0(600) and rho(770) mesons: while the rho meson becomes narrower with Nc, as is expected for a q-qbar meson, the sigma becomes broader, and its contribution to the total cross section is less and less important. On the other hand, local duality requires a cancellation between the sigma and rho amplitudes, but if there is a different Nc behaviour for them, there is a possible contradiction between the Inverse Amplitude Method (IAM) and local duality for large Nc. However, next to next to leading order UChPT calculations suggested a subdominant q-qbar component for the sigma with a mass around 1.2 GeV. In this work, we show that this subdominant q-qbar component is indeed needed to ensure local duality.Comment: To appear in the Proceedings of the Hadron09 International Conference. 29th Nov-4th Dec. 2009. Tallahassee, FL, USA. 5 page

Historic Seismicity in and Around the Texas Panhandle

At least twenty earthquakes have occurred in the Texas Panhandle north of 34°N since 1907. The largest earthquakes had magnitudes up to 4.8, and the intensities throughout the Panhandle have ranged from IV to VI (Modified Mercalli), corresponding to accelerations from 6.8 cm/s² to over 31.6 cm/s². The record of seismicity in the Texas Panhandle dates back to 1907 when the first reported event occurred near Amarillo. Since then, numerous events have been reported or instrumentally recorded from the Panhandle. In the most complete survey of seismicity in the Panhandle (north of 34° latitude) to be undertaken, 20 earthquakes were identified from 1907 through July 1982. Slightly more than half of the events have locations determined from felt reports, and the others from instrumental locations. During the process of identifying earthquakes, contemporary newspaper accounts, weather bulletins, seismological reports, and other sources were reviewed. Several reported events were found to be in error. Specifically, the published locations of some events are erroneous by tens or hundreds of kilometers, one event was, in fact, a sonic boom, and one "event" near the Panhandle resulted from spurious data reported from seismological observatories nearby. The largest earthquakes in the Texas Panhandle had magnitudes of 4.7 to 4.8 (determined by maximum intensity and felt areas); there were five such events between 1917 and 1951. Since instrumental recording became widespread in about 1962, only two events of magnitude greater than 4.0 have occurred. Although some of the earthquakes reported have been assigned magnitudes of 3.0 or less, the detection threshold is probably considerably higher. As evidence, it is noted that a magnitude 3.4 event in 1983 would have been undetected by conventional procedures, had there not been a specific interest in modern seismicity. Since this interest did not exist until recently, it is probable that many earthquakes of magnitude up to 3.5 have gone unrecognized, and it is likely that some larger events have been missed as well.Bureau of Economic Geolog

QCD Green functions in a gluon field

We formulate a dressed perturbative expansion of QCD, where the standard diagrams are evaluated in the presence of a constant external gluon field whose magnitude is gaussian distributed. The approach is Poincar{\'e} and gauge invariant, and modifies the usual results for hard processes only by power suppressed contributions. Long distance propagation of quarks and gluons turns out to be inhibited due to a branch point singularity instead of a pole at $p^2=0$ in the quark and gluon propagators. The dressing keeps the (massless) quarks in q qbar fluctuations of the photon at a finite distance from each other.Comment: 21 pages, 7 figures. Minor modifications in text. Version to be published in JHE