279 research outputs found
Resummation of threshold logarithms in deeply-virtual Compton scattering
I derive an all-order resummation formula for the logarithmically enhanced
contributions proportional to in the coefficient function of deeply-virtual-Compton scattering
and the pion-photon transition form factor in momentum space. The resummation
is performed at the next-to-next-to-leading logarithmic accuracy. The key
observation is that the non-singlet coefficient function itself factorizes in
the limit, which allows for a resummation using
renormalization group equations
Two-loop coefficient functions in deeply virtual Compton scattering: flavor-singlet axial-vector and transversity case
We calculate the two-loop flavor-singlet axial-vector and gluon transversity
coefficient functions for deeply virtual Compton scattering in QCD. We observe
interesting properties regarding the transcendentality of the transversity
coefficient function. Our results complete the calculation of the full
next-to-next-to-leading order coefficient function in deeply virtual Compton
scattering. Numerically, the two-loop corrections in the axial-vector and
transversity channel are comparable to their vector counterpart at moderate
skewness parameter {\xi} and hence indispensable for analyzing the upcoming
high-precision data from the Electron-Ion Collider.Comment: 22 pages, 6 figures, 1 ancillary file "axial_and_transversity_CF.m'
Best Practices and Biblical Worldview for Technology Integration
This research focused on a study conducted across three different teacher education programs, focusing on equipping teacher candidates with strategies for technology integration while encouraging them to examine how to best glorify God with appropriate technology use in the classroom. Students were instructed using common research-based practices and assignments. These included instruction on the SAMR model, exploration of a variety of technology tools, and a reflection on what it means to glorify God through teaching with technology. Pre- and post-survey data was collected to measure the effectiveness of both the instruction and changes in students\u27 attitudes and perceptions of technology use in teaching. Pre-service teachers read and discussed research addressing Christian wisdom on technology, pursuing excellence in Christian education, technology and computational thinking in the classroom, and digital citizenship as they engaged in these assignments. This article includes main themes, preliminary findings, and implications for future research based on results across all three institutions
Deeply-virtual Compton scattering at the next-to-next-to-leading order
Deeply-virtual Compton scattering gives access to the generalized parton
distributions that encode the information on the transverse position of quarks
and gluons in the proton in dependence in their longitudinal momentum. In
anticipation of the high-precision experimental data in a broad kinematic range
from the Electron-Ion Collider, we have calculated the two-loop,
next-to-next-to-leading (NNLO) DVCS coefficient functions associated with the
dominant Compton form factors and at large energies.
The NNLO correction to the imaginary part of appears to be rather
large, up to factor two at the input scale GeV for simple GPD
models, due to a cancellation between quark and gluon contributions.Comment: 9 pages, 3 figure
Breakdown of collinear factorization in the exclusive photoproduction of a pair with large invariant mass
We study the exclusive photoproduction of a pair with
large invariant mass , which is sensitive to the exchange
of either two quarks or two gluons in the -channel. In this letter, we
show that the process involving two-gluon exchanges does not factorize in the
Bjorken limit at the leading twist. This can be explicitly demonstrated by the
fact that there exist diagrams, which contribute at the leading twist, for
which Glauber gluons remain trapped, due to the pinching of the contour
integrations of both the plus and minus component of the Glauber gluon
momentum. For the same reason, -nucleon scattering to two photons also
suffers from the same issue. On the other hand, we stress that there are no
issues with respect to collinear factorization for the quark channels. By
considering an analysis of all potential reduced diagrams of leading pinch
surfaces, we argue that the quark channel is safe from Glauber pinches, and
therefore, a collinear factorization in that case follows through without any
problems. This means that processes where gluon exchanges are forbidden, such
as the exclusive photoproduction of and , are unaffected by the factorization breaking effects we point out in
this letter.Comment: 11 pages, 4 figure
Cooking Turkey in Aluminum Foil
Roasting a good-sized turkey by the traditional method always has called for some expert maneuvering on the part of the homemaker. Does the [unknown] of aluminum foil make turkey roasting easier? Some Iowa State College food researchers discuss the advantages and disadvantages of this method
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Using Interpretive Signs and Theory-based Messaging to Protect the Western Snowy Plover (Charadrius alexandrinus nivosus)
Although the human health and social benefits from outdoor recreation are numerous, there is mounting evidence that outdoor recreation can negatively impact wildlife. Shorebirds are known to be especially sensitive to recreation-related disturbance because they nest and forage directly on beaches that are often used for recreation. Many studies have documented negative effects of outdoor recreation on shorebirds, and some have specifically related to the federally threatened western snowy plover (WSPL) (Charadrius alexandrinus nivosus). The Oregon Dunes National Recreation Area (ODNRA) is a popular location for beach recreation that provides critical habitat for the WSPL. ODNRA managers struggle to keep visitors from recreating inside sensitive WSPL nesting and foraging habitat in dunes and open sand. Due to limited personnel, the ODNRA uses rope fencing and signs to communicate rules about WSPL nesting habitat.
In an effort to improve compliance and influence attitudes, this study tested signs based on two communication theories: the Focus Theory of Normative Conduct (i.e., normative) and the Extended Elaboration Likelihood Model (i.e., narrative). This thesis contains one standalone article that examines how narrative and normative messaging: (a) relates to visitor attention to signs at the ODNRA, (b) impacts visitor attitudes related to the WSPL and their management at the ODNRA, and (c) impacts compliance with WSPL restrictions at the ODNRA.
In the summer of 2018, direct observation and questionnaires were used at a popular ODNRA beach to compare the normative and narrative signs against an existing interpretive sign on the following variables: attention capture and holding, impact on attitudes about the WSPL, and impact on beach use. A total of 440 completed questionnaires were collected with a response rate of 74%. Results showed that visitors were more likely to read the treatment signs than the existing interpretive sign, although many visitors ignored the signs altogether. The narrative sign was the most effective in encouraging visitors to stay out of WSPL nesting habitat. However, the impact of the treatment signs on attitudes was minimal compared to the existing interpretive sign. This thesis suggests changes in the design of interpretive signs at the ODNRA and recommends using a narrative format to encourage visitors to perform wildlife friendly behaviors. However, because many visitors still recreated inside WSPL nesting habitat after being exposed to signs, these signs should not be used as a primary management tool at the ODNRA. Rather, signs should be used to supplement strategies such as fencing or personal contact
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