1,961 research outputs found
Threshold Hadronic Event Shapes with Effective Field Theory
Hadronic event shapes, that is, event shapes at hadron colliders, could
provide a great way to test both standard and non-standard theoretical models.
However, they are significantly more complicated than event shapes at e+e-
colliders, involving multiple hard directions, multiple channels and multiple
color structures. In this paper, hadronic event shapes are examined with
Soft-Collinear Effective Theory (SCET) by expanding around the dijet limit. A
simple event shape, threshold thrust, is defined. This observable is global and
has no free parameters, making it ideal for clarifying how resummation of
hadronic event shapes can be done in SCET. Threshold thrust is calculated at
next-to-leading fixed order (NLO) in SCET and resummed to
next-to-next-to-leading logarithmic accuracy (NNLL). The scale-dependent parts
of the soft function are shown to agree with what is expected from general
observations, and the factorization formula is explicitly shown to be
renormalization group invariant to 1-loop. Although threshold thrust is not
itself expected to be phenomenologically interesting, it can be modified into a
related observable which allows the jet pT distribution to be calculated and
resummed to NNLL+NLO accuracy. As in other processes, one expects resummation
to be important even for moderate jet momenta due to dynamical threshold
enhancement. A general discussion of threshold enhancement and non-global logs
in hadronic event shapes is also included.Comment: 38 pages, 2 figures; small typos corrected in v
1-loop matching and NNLL resummation for all partonic 2 to 2 processes in QCD
The Wilson Coefficients for all 4-parton operators which arise in matching
QCD to Soft-Collinear Effective Theory (SCET) are computed at 1-loop. Any dijet
observable calculated in SCET beyond leading order will require these results.
The Wilson coefficients are separated by spin and color, although most
applications will involve only the spin-averaged hard functions. The anomalous
dimensions for the Wilson coefficients are given to 2-loop order, and the
renormalization group equations are solved explicitly. This will allow for
analytical resummation of dijet observables to next-to-next-to-leading
logarithmic accuracy. For each channel, there is a natural basis in which the
evolution is diagonal in color space. The same basis also diagonalizes the
color evolution for the soft function. Even though soft functions required for
SCET calculations are observable dependent, it is shown that their
renormalization group evolution is almost completely determined by a universal
structure. With these results, it will be possible to calculate hadronic event
shapes or other dijet observables to next-to-leading order with
next-to-next-to-leading log resummation.Comment: 28 pages, 5 tables; v2: typo corrected in Eq. (56
The Body of Ideas: Nietzsche, Embodiment, and the Genealogical Method
How are we to understand Nietzsche’s ubiquitous use of physiological language and imagery in On the Genealogy of Morality? I claim that Nietzsche’s use of physiological language is a crucial element of the method of historical investigation he develops (“genealogy”). If Nietzsche’s genealogy attends to the practices of moral concepts, then the physiological undergoing of those practices will be important data for the genealogist. In other words, in Nietzsche’s critical-historical investigation of morality, accounts of physiological experience will be crucial for having an accurate picture of the practices under investigation. This improved mode of historical investigation sees morality not simply as set of beliefs, but as a lived practice
Leading Wnt down a PCP Path: Cthrc1 Acts as a Coreceptor in the Wnt-PCP Pathway
Wnt signaling regulates many aspects of development through canonical and PCP signaling pathways. A paper by Yamamoto et al. in this issue of Developmental Cell identifies collagen triple helix repeat containing 1 as a Wnt-binding cofactor that specifically activates the Wnt-PCP pathway
Acoustic absement in detail: Quantifying acoustic differences across time-series representations of speech data
The speech signal is a consummate example of time-series data. The acoustics
of the signal change over time, sometimes dramatically. Yet, the most common
type of comparison we perform in phonetics is between instantaneous acoustic
measurements, such as formant values. In the present paper, I discuss the
concept of absement as a quantification of differences between two time-series.
I then provide an experimental example of absement applied to phonetic analysis
for human and/or computer speech recognition. The experiment is a
template-based speech recognition task, using dynamic time warping to compare
the acoustics between recordings of isolated words. A recognition accuracy of
57.9% was achieved. The results of the experiment are discussed in terms of
using absement as a tool, as well as the implications of using acoustics-only
models of spoken word recognition with the word as the smallest discrete
linguistic unit.Comment: 5 pages, 1 figure, accepted for ICPhS 202
Privatization in Higher Education: Contracting for Services at Public Colleges and Universities
During the Reagan presidency, a wide variety of privatization alternatives were examined. Among these was contracting for services, an alternative already in use for many years at the state and local level. Contracting for services has also been used by colleges and universities throughout this country, and remains a major focus for facilities managers at these institutions. Survey data from colleges and universities through this country were examined to determine if: 1) the amount of contracting varied by institution size; 2) the amount of contracting varied by region of the country; and 3) the amount of contracting varied with the relative degree of unionization. The results of the analysis indicate that 1) large institutions contract to a lesser extent than do small and medium institutions; 2) the extent of contracting does vary by region, with the Midwest region contracting to a greater extent than the Southwestern, Central, Rocky Mountain and Pacific Coast regions; 3) the differences in the extent of contracting for services between institutions with non-union, mixed, or union workforces was not statistically significant.Master of Public AdministrationPublic AdministrationUniversity of Michigan-Flinthttps://deepblue.lib.umich.edu/bitstream/2027.42/143458/1/Kelley.pd
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