591 research outputs found
Jets and produced particles in pp collisions from SPS to RHIC energies for nuclear applications
Higher-order pQCD corrections play an important role in the reproduction of
data at high transverse momenta in the energy range 20 GeV GeV. Recent calculations of photon and pion production in collisions
yield detailed information on the next-to-leading order contributions. However,
the application of these results in proton-nucleus and nucleus-nucleus
collisions is not straightforward. The study of nuclear effects requires a
simplified understanding of the output of these computations. Here we summarize
our analysis of recent calculations, aimed at handling the NLO results by
introducing process and energy-dependent factors.Comment: 4 pages with 5 eps figures include
Recommended from our members
Digital Machines, Space, And Time: Towards A Behavioral Perspective Of Flexible Manufacturing
Recently, the diffusion of digital machines has further enhanced firmsâ manufacturing flexibility, but also opened questions on potential challenges and implications in the production process. To respond to these timely issues, we adopt a behavioral perspective and comparatively explore how four different types of digital machinesâcharacterized by increasing degrees of manufacturing flexibilityâaffect the perception and use of space and time for routines within the production plant. We qualitatively observe and compare 45 digital manufacturing machines, sampled across 14 firms in the British and Italian motorsport industry. A model emerges where four key mechanisms reshape the âspace-machineâ and âtime-machineâ routines. Such mechanisms mediate the relationship between manufacturing flexibility and firm performance. Further, we show how increasing digitalization in the manufacturing process enhances the establishment of new routines as flexible machines get introduced in the production. Finally, we discuss the theoretical and practical implications related to fostering a behavioral perspective in innovation and operations management studies
Single-Inclusive Jet Production in Polarized pp Collisions at O(alpha_s^3)
We present a next-to-leading order QCD calculation for single-inclusive
high-p_T jet production in longitudinally polarized pp collisions within the
``small-cone'' approximation. The fully analytical expressions obtained for the
underlying partonic hard-scattering cross sections greatly facilitate the
analysis of upcoming BNL-RHIC data on the double-spin asymmetry A_{LL}^{jet}
for this process in terms of the unknown polarization of gluons in the nucleon.
We simultaneously rederive the corresponding QCD corrections to unpolarized
scattering and confirm the results existing in the literature. We also
numerically compare to results obtained with Monte-Carlo methods and assess the
range of validity of the ``small-cone'' approximation for the kinematics
relevant at BNL-RHIC.Comment: 23 pages, 8 eps-figure
Very Large Array And Atca Search For Natal Star Clusters In Nearby Star-Forming Galaxies
In order to investigate the relationship between the local environment and the properties of natal star clusters, we obtained radio observations of 25 star-forming galaxies within 20 Mpc using the Very Large Array and the Australia Telescope Compact Array. Natal star-forming regions can be identified by their characteristic thermal radio emission, which is manifest in their spectral index at centimeter wavelengths. The host galaxies in our sample were selected based upon their likelihood of harboring young star formation. In star-forming regions, the ionizing flux of massive embedded stars powers the dominant thermal free-free emission of those sources, resulting in a spectral index of {alpha} {approx}\u3e -0.2 (where S{sub {nu}} {proportional_to} {nu}{sup {alpha}}), which we compute. With the current sensitivity, we find that of the 25 galaxies in this sample only 5 have radio sources with spectral indices that are only consistent with a thermal origin, 4 have radio sources that are only consistent with a non-thermal origin, 6 have radio sources whose nature is ambiguous due to uncertainties in the spectral index, and 16 have no detected radio sources. For those sources that appear to be dominated by thermal emission, we infer the ionizing flux of the star clusters andmore » the number of equivalent O7.5 V stars that are required to produce the observed radio flux densities. The most radio-luminous clusters that we detect have an equivalent of {approx}7 x 10{sup 3} O7.5 V stars, and the smallest only have an equivalent of {approx}10{sup 2} O7.5 V stars; thus these star-forming regions span the range of large OB associations to moderate \u27super star clusters\u27. With the current detection limits, we also place upper limits on the masses of clusters that could have recently formed; for a number of galaxies we can conclusively rule out the presence of natal clusters significantly more massive than the Galactic star-forming region W49A ({approx}5 x 10{sup 4} M{sub sun}). The dearth of current massive cluster formation in these galaxies suggests that either their current star formation intensities have fallen to near or below that of the Milky Way and/or the evolutionary state that gives rise to thermal radio emission is short-lived.« les
INCLUSIVE PARTICLE PRODUCTION IN \pbp COLLISIONS
We calculate the inclusive production of charged hadrons in \pbp collisions
to next-to-leading order (NLO) in the QCD improved parton model using a new set
of NLO fragmentation functions for charged pions and kaons. We predict
transverse-momentum distributions and compare them with experimental data from
the CERN S\pbpS Collider and the Fermilab Tevatron.Comment: the file containing the figures has been replaced: we correct a
mistake in the uuencoding procedure and we give the real Fig 4 instead of the
spurious one which was accidentally included in the previous file. the text
is unchanged
Positive Impact of Physical Exercise for Managing Stereotypies in Dogs
Stereotypies in dogs are repetitive behavioral patterns that occur always in the same sequence but do not play any role. This altered behavior may thus take over the animalâs life, changing its sleep patterns and eating habits. The drive to adopt the specific behavior becomes increasingly stronger, to the extent that the animal may sometimes even mutilate parts of its own body, such as the tail and limbs. The overall approach to the problem through retraining of owners, environmental modification and enrichment and proper use of psychotropics proved necessary for restoring the patientsâ balance. However, it was also necessary to introduce a physical exercise routine with a canine motorized treadmill and/or daily walks. Although exercise itself may contribute to increased anxiety in the animal, the potential benefits justify considering its introduction for managing dogs with stereotypies.Fil: Ostrovsky, G.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Alvarez, F.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Risso, Analia Lorena. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico CONICET- La Plata. Instituto de GenĂ©tica Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de GenĂ©tica Veterinaria; ArgentinaFil: Pellegrino, Francisco Javier. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Marchionni, M.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Aversa, D.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Corrada, Yanina Alejandra. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Glassy amorphous metal injection molded induced morphological defects
Melt rheology in injection molded metastable supercooled liquid metal of Zr44-Ti11-Cu10-Ni10-Be25 alloy may induce selective crystallizations. High mobility Be, Cu and Ni atoms have been observed to differently crystallize in bulk metal glassy supercooled liquids. Here, we analyze the result of morphological microscopic observation conduct on Bulk Metallic Glass (BMG) with composition of a commercial liquid metal alloy (LM001B). The injection molded plate has been supplied by âLiquid Metals Technologies Inc, Ca USAâ and manufactured using an Engel injection molding machine operating at 1050-1100°C; the observed sample then has been cut by water jet. FEI Scios Dual-Beam has carried out the microscopic observation. Particularly, through a cross section, we observe the presence of crystalline phases on the short-range order. We investigate the presence of short-range order clusters, their distribution and the effect that they could cause on the alloysâ behaviors and properties
Effects of Higher-Order Threshold Corrections in High-E_T Jet Production
Results for higher-order threshold enhancements in high-E_T jet production in
hadron-hadron collisions are presented. Expressions are given for the
next-to-next-to-leading order (NNLO) threshold corrections to the single-jet
inclusive cross section at next-to-leading logarithmic (NLL) accuracy. The
corrections are found to be small for the specific choice of E_T/2 for the
factorization and renormalization scales, and the corrected cross section shows
a substantial reduction of the scale dependence. A comparison to experimental
results from the Tevatron is presented.Comment: 24 pages LaTeX, 5 figure
Examination of direct-photon and pion production in proton-nucleon collisions
We present a study of inclusive direct-photon and pion production in hadronic
interactions, focusing on a comparison of the ratio of gamma/pi0 yields with
expectations from next-to-leading order perturbative QCD (NLO pQCD). We also
examine the impact of a phenomenological model involving k_T smearing (which
approximates effects of additional soft-gluon emission) on absolute predictions
for photon and pion production and their ratio.Comment: 20 pages, 12 figures. Minor changes in wording and in figure
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