763 research outputs found
Enhanced nonperturbative effects in jet distributions
We consider the triple differential distribution
d\Gamma/(dE_J)(dm_J^2)(d\Omega_J) for two-jet events at center of mass energy
M, smeared over the endpoint region m_J^2 << M^2, |2 E_J -M| ~ \Delta, \lqcd <<
\Delta << M. The leading nonperturbative correction, suppressed by
\lqcd/\Delta, is given by the matrix element of a single operator. A similar
analysis is performed for three jet events, and the generalization to any
number of jets is discussed. At order \lqcd/\Delta, non-perturbative effects in
four or more jet events are completely determined in terms of two matrix
elements which can be measured in two and three jet events.Comment: Significant changes made. The first moment does not vanish--the paper
has been modified to reflect this. Relations between different numbers of
jets still hol
An operator expansion for the elastic limit
A leading twist expansion in terms of bi-local operators is proposed for the
structure functions of deeply inelastic scattering near the elastic limit , which is also applicable to a range of other processes. Operators of
increasing dimensions contribute to logarithmically enhanced terms which are
supressed by corresponding powers of . For the longitudinal structure
function, in moment () space, all the logarithmic contributions of order
are shown to be resummable in terms of the anomalous dimension of
the leading operator in the expansion.Comment: 9 pages, 1 figure, uses REVTEX 3.1 and axodra
Dijet Event Shapes as Diagnostic Tools
Event shapes have long been used to extract information about hadronic final
states and the properties of QCD, such as particle spin and the running
coupling. Recently, a family of event shapes, the angularities, has been
introduced that depends on a continuous parameter. This additional
parameter-dependence further extends the versatility of event shapes. It
provides a handle on nonperturbative power corrections, on non-global
logarithms, and on the flow of color in the final state.Comment: 18 pages, 3 figure
Summary: Working Group on QCD and Strong Interactions
In this summary of the considerations of the QCD working group at Snowmass
2001, the roles of quantum chromodynamics in the Standard Model and in the
search for new physics are reviewed, with empahsis on frontier areas in the
field. We discuss the importance of, and prospects for, precision QCD in
perturbative and lattice calculations. We describe new ideas in the analysis of
parton distribution functions and jet structure, and review progress in
small- and in polarization.Comment: Snowmass 2001. Revtex4, 34 pages, 4 figures, revised to include
additional references on jets and lattice QC
The Perturbative Pole Mass in QCD
It is widely believed that the pole mass of a quark is infrared-finite and
gauge-independent to all orders in perturbation theory. This seems not to have
been proved in the literature. A proof is provided here.Comment: 12 pages REVTeX with 2 figures; archiving published version with note
and references added. If you thought this was proven long ago see
http://www-theory.fnal.gov/people/ask/TeX/mPole
Exclusive Hadronic Processes and Color Transparency
We review the current status of high energy exclusive processes and color
transparency.Comment: 17 pages, 8 figures, based on talk given at International Symposium
on Nuclear Physics, Mumbai, Dec 18-22, 200
Large distance behaviour of light cone operator product in perturbative and nonperturbative QCD regimes
We evaluate the coordinate space dependence of the matrix elements of the
commutator of the electromagnetic and gluon currents in the vicinity of the
light-cone but at large distances within the parton model, DGLAP, the
resummation approaches to the small x behaviour of DIS processes, and for the
Unitarity Bound. We find that an increase of the commutator with relative
distance as is the generic property of QCD
at small but fixed space-time interval in perturbative and
nonperturbative QCD regimes. We explain that the factor follows within the
dipole model (QCD factorization theorem) from the properties of Lorents
transformation. The increase of disappeares at central impact parameters
if cross section of DIS may achieve the Unitarity Limit. We argue that such
long range forces are hardly consistent with thermodynamic equilibrium while a
Unitarity Limit may signal equilibration. Possible implications of this new
long range interaction are briefly discussed.Comment: 23 page
Two-Loop Calculations with Vertex Corrections in the Walecka Model
Two-loop corrections with scalar and vector form factors are calculated for
nuclear matter in the Walecka model. The on-shell form factors are derived from
vertex corrections within the framework of the model and are highly damped at
large spacelike momenta. The two-loop corrections are evaluated first by using
the one-loop parameters and mean fields and then by refitting the total
energy/baryon to empirical nuclear matter saturation properties. The modified
two-loop corrections are significantly smaller than those computed with bare
vertices. Contributions from the anomalous isoscalar form factor of the nucleon
are included for the first time. The effects of the implicit density dependence
of the form factors, which arise from the shift in the baryon mass, are also
considered. Finally, necessary extensions of these calculations are discussed.Comment: 29 pages in REVTeX, 18 figures, preprint IU/NTC 94-02 //OSU--94-11
A Modeling Framework to Assess Strategies Alignment based on Collaborative Network Emotions
[DE] The Collaborative Networks (CN) discipline has been largely studied in last decades, addressing different problems and proposing solutions for the robust establishment of collaborative processes, within the enterprises willing to collaborate. The main aim of CN research is, therefore, to generate approaches that enable creating effective relationships in the long term, to achieve stable and agile alliances. The concept of alignment among the CN partners has been considered since the beginning of CN research. Nevertheless, novel perspectives of study in CN, such as the consideration of collaborative emotional states, within the CN, have been introduced in recent years. This paper connects the research area of strategies alignment and the CN emotion models. Accordingly, a modelling framework to assess strategies alignment considering the emotional environment within the CN is proposed. The modelling framework allows representing how the enterprises emotions affect in the selection and alignment of formulated enterprises¿ strategiesAndres, B.; Ferrada, F.; Poler, R.; Camarinha-Matos, L. (2018). A Modeling Framework to Assess Strategies Alignment based on Collaborative Network Emotions. IFIP Advances in Information and Communication Technology. 534:349-361. https://doi.org/10.1007/978-3-319-99127-6_30S349361534Camarinha-Matos, L.M.: Collaborative networks in industry and the role of PRO-VE. Int. J. Prod. Manag. Eng. 2(2), 53–57 (2014)Andres, B., Poler, R.: Models, guidelines and tools for the integration of collaborative processes in non-hierarchical manufacturing networks: a review. Int. J. Comput. Integr. Manuf. 2(29), 166–201 (2016)Bititci, U., Martinez, V., Albores, P., Parung, J.: Creating and managing value in collaborative networks. Int. J. Phys. Distrib. Logist. Manag. 34(3/4), 251–268 (2004)Carbo, B.: Align the organization for improved supply chain performance. ASCET Proj. 2, 244–447 (2002)Macedo, P., Camarinha-Matos, L.: Value systems alignment analysis in collaborative networked organizations management. Appl. Sci. 7(12), 123 (2017)Andres, B., Poler, R.: A decision support system for the collaborative selection of strategies in enterprise networks. Decis. Support Syst. 91, 113–123 (2016)Andres, B., Macedo, P., Camarinha-Matos, L.M., Poler, R.: Achieving coherence between strategies and value systems in collaborative networks. In: Camarinha-Matos, L.M., Afsarmanesh, H. (eds.) PRO-VE 2014. IFIP AICT, vol. 434, pp. 261–272. Springer, Heidelberg (2014). https://doi.org/10.1007/978-3-662-44745-1_26Ferrada, F., Camarinha-Matos, L.M.: A system dynamics and agent-based approach to model emotions in collaborative networks. In: Camarinha-Matos, L.M., Parreira-Rocha, M., Ramezani, J. (eds.) DoCEIS 2017. IFIP AICT, vol. 499, pp. 29–43. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-56077-9_3Campuzano, F., Mula, J.: Supply Chain Simulation. A System Dynamics Approach for Improving Performance. Springer, London (2011). https://doi.org/10.1007/978-0-85729-719-8Camarinha-Matos, L.M., Afsarmanesh, H.: Collaborative networks: a new scientific discipline. J. Intell. Manuf. 16(4–5), 439–452 (2005)Vicsek, T.: Complexity: the bigger picture. Nature 418(6894), 131 (2002)Sterman, J., Richardson, G., Davidsen, P.: Modelling the estimation of petroleum resources in the United States. Technol. Forecast. Soc. Chang. 33(3), 219–249 (1998)Vlachos, D., Georgiadis, P., Iakovou, E.: A system dynamics model for dynamic capacity planning of remanufacturing in closed-loop supply chains. Comput. Oper. Res. 34(2), 367–394 (2007)Campuzano-Bolarín, F., Mula, J., Peidro, D.: An extension to fuzzy estimations and system dynamics for improving supply chains. Int. J. Prod. Res. 51(10), 3156–3166 (2013)Barton, P., Bryan, S., Robinson, S.: Modelling in the economic evaluation of health care: selecting the appropriate approach. J. Heal. Serv. Res. Policy 9(2), 110–118 (2004)Eldabi, T., Paul, R.J., Young, T.: Simulation modelling in healthcare: reviewing legacies and investigating futures. J. Oper. Res. Soc. Spec. Issue Oper. Res. Heal. 58(2), 262–270 (2007)Andres, B., Poler, R., Camarinha-Matos, L.M., Afsarmanesh, H.: A simulation approach to assess partners selected for a collaborative network. Int. J. Simul. Model. 16(3), 399–411 (2017)Gohari, A., Mirchi, A., Madan, K.: System dynamics evaluation of climate change adaptation strategies for water resources management in central Iran. Water Resour. Manag. 31(5), 1413–1434 (2007)Fishera, D., Norvell, J., Sonka, S., Nelson, M.J.: Understanding technology adoption through system dynamics modeling: implications for agribusiness management. Int. Food Agribus. Manag. Rev. 3, 281–296 (2000)Lyneisa, J.M.: System dynamics for market forecasting and structural analysis. Syst. Dyn. Rev. 16(1), 3–25 (2000)Borshchev, A., Filippov, A.: From system dynamics and discrete event to practical agent based modeling: reasons, techniques, tools. In: The 22nd International Conference of the System Dynamics Society (2004)Ferrada, F.: C-EMO: A Modeling Framework for Collaborative Network Emotions Doctoral dissertation, Nova University of Lisbon, Portugal (2017). https://run.unl.pt/handle/10362/26857Scherer, K.R.: Emotions are emergent processes: they require a dynamic computational architecture. Rev. Philos. Trans. R. Soc. Biol. Sci. 364(1535), 3459–3474 (2009
Scaling Rule for Nonperturbative Radiation in a Class of Event Shapes
We discuss nonperturbative radiation for a recently introduced class of
infrared safe event shape weights, which describe the narrow-jet limit.
Starting from next-to-leading logarithmic (NLL) resummation, we derive an
approximate scaling rule that relates the nonperturbative shape functions for
these weights to the shape function for the thrust. We argue that the scaling
reflects the boost invariance implicit in NLL resummation, and discuss its
limitations. In the absence of data analysis for the new event shapes, we
compare these predictions to the output of the event generator PYTHIA.Comment: 23 pages, 3 figures, uses JHEP3.cls (included); v2 - version to
appear in JHE
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