6,583 research outputs found
An Overview of Transverse Momentum Dependent Factorization and Evolution
I review TMD factorization and evolution theorems, with an emphasis on the
treatment by Collins and originating in the Collins-Soper-Sterman (CSS)
formalism. I summarize basic results while attempting to trace their
development over that past several decades.Comment: 14 pages, 1 figure, Submission to EPJ A topical issue on "3D
Structure of the Nucleon
FED CATTLE SPATIAL TRANSACTIONS PRICE RELATIONSHIPS
Delineation of geographic markets for fed cattle is essential in monitoring price behavior and determining geographic markets. This study uses transactions data from 28 U.S. fed cattle slaughter plants to determine the extent of the geographic market for fed cattle. Results indicate a national market for fed cattle with prices across most plants cointegrated. In addition, price discovery originates predominantly at plants located in Nebraska, and typically one-third of the total price adjustment to spatial integration occurs in one day.Cointegration, Relevant market, Spatial prices, Demand and Price Analysis, Livestock Production/Industries,
Connecting Different TMD Factorization Formalisms in QCD
In the original Collins-Soper-Sterman (CSS) presentation of the results of
transverse-momentum-dependent (TMD) factorization for the Drell-Yan process,
results for perturbative coefficients can be obtained from calculations for
collinear factorization. Here we show how to use these results, plus known
results for the quark form factor, to obtain coefficients for TMD factorization
in more recent formulations, e.g., that due to Collins, and apply them to known
results at order and . We also show that the
"non-perturbative" functions as obtained from fits to data are equal in the two
schemes. We compile the higher-order perturbative inputs needed for the updated
CSS scheme by appealing to results obtained in a variety of different
formalisms. In addition, we derive the connection between both versions of the
CSS formalism and several formalisms based in soft-collinear effective theory
(SCET). Our work uses some important new results for factorization for the
quark form factor, which we derive.Comment: 30 pages, 2 Figures; Fixed typos including missing term in Eq.(60
DETERMINANTS OF FEEDER CATTLE PRICE-WEIGHT SLIDES
Feeder cattle price-weight slides are analyzed using transactions data on 46,123 pens of feeder cattle over a 10-year period. Fed cattle futures prices and corn prices are important determinants of price-weight slides. Cattle producers can use this information when making sell timing decision, purchase decisions, and managing production.Livestock Production/Industries,
Universality and Evolution of TMDs
In this talk, we summarize how QCD evolution can be exploited to improve the
treatment of transverse momentum dependent (TMD) parton distribution and
fragmentation functions. The methods allow existing non-perturbative fits to be
turned into fully evolved TMDs that are consistent with a complete
TMD-factorization formalism over the full range of kT. We argue that evolution
is essential to the predictive power of calculations that utilize TMD parton
distribution and fragmentation functions, especially TMD observables that are
sensitive to transverse spin.Comment: To appear in the proceedings of the Third International Workshop on
Transverse Polarization Phenomena in Hard Scattering (Transversity 2011), in
Veli Losinj, Croatia, 29 August - 2 September 2011. 5 pages, 1 figur
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