1,901 research outputs found
A model of non-perturbative gluon emission in an initial state parton shower
We consider a model of transverse momentum production in which
non-perturbative smearing takes place throughout the perturbative evolution, by
a simple modification to an initial state parton shower algorithm. Using this
as the important non-perturbative ingredient, we get a good fit to data over a
wide range of energy. Combining it with the non-perturbative masses and cutoffs
that are a feature of conventional parton showers also leads to a reasonable
fit. We discuss the extrapolation to the LHC.Comment: 14 pages, 6 figures; version accepted by JHE
The Hot Bang state of massless fermions
In 2002, a method has been proposed by Buchholz et al. in the context of
Local Quantum Physics, to characterize states that are locally in thermodynamic
equilibrium. It could be shown for the model of massless bosons that these
states exhibit quite interesting properties. The mean phase-space density
satisfies a transport equation, and many of these states break time reversal
symmetry. Moreover, an explicit example of such a state, called the Hot Bang
state, could be found, which models the future of a temperature singularity.
However, although the general results carry over to the fermionic case easily,
the proof of existence of an analogue of the Hot Bang state is not quite that
straightforward. The proof will be given in this paper. Moreover, we will
discuss some of the mathematical subtleties which arise in the fermionic case.Comment: 17 page
RESPON PAKAN SILASE KOMBINASI JERAMI JAGUNG DAN KACANG TANAH SEBAGAI PAKAN SAPI BALI
Penelitian ini bertujuan mengkaji pengaruh pemberian silase kombinasi limbah jagung dan
limbah kacang tanah terhadap konsumsi ransum, pertambahan berat badan dan konversi ransum sapi
potong. Penelitian dilaksanakan di PT. Tata Hidup Cemerlang (THC) Desa Lengkese Kecamatan
Mangara Bombang (Marbo) Kabupaten Takalar Sulawesi Selatan selama 4 bulan mulai dari bulan Juni
2009 sampai dengan September 2009, menggunakan limbah jagung dan limbah kacang tanah (batang
dan daun) untuk pembuatan silase dan sapi bali jantan umur 2 2,5 tahun dengan berat badan 200 -
250 kg sebanyak 12 ekor, chopper, silo, kandang, tempat pakan, tempat minum, sapu, sikat, selang air,
sekop, cikrak/trisula, arit, tambang pengikat, timbangan digital ternak. Introduksi pakan yang diberikan
adalah dengan pemanfaatan limbah jagung dan limbah kacang tanah yang disilase dan konsentrat
komersial hasil produksi PT. Tata Hidup Cemerlang yang menggunakan rancangan acak lengkap
(RAL) yang terdiri dari empat perlakuan dan tiga kali ulangan. Pemberian pakan silase dan air minum
adlibitum sedangkan konsentrat diberikan sebanyak 2 kg/ekor/hari. Hasil penelitian menunjukkan
bahwa perlakuan ransum kombinasi limbah jagung dan limbah kacang tanah (50 % : 50 %)
memperlihatkan respon yang lebih baik dibanding ransum lainnya terhadap konsumsi ransum,
pertambahan berat badan dan konversi ransum sehingga perlu penelitian lebih lanjut dengan
menggunakan teknologi pakan silase (kombinasi limbah jagung dan kacang tanah berkualitas) dan
pakan suplemen UMB berbasis sumber daya local (local knowledge) untuk peningkatan bobot badan
sapi bali
Extrapolation of Multiplicity distribution in p+p(\bar(p)) collisions to LHC energies
The multiplicity (N_ch) and pseudorapidity distribution (dN_ch/d\eta) of
primary charged particles in p+p collisions at Large Hadron Collider (LHC)
energies of \sqrt(s) = 10 and 14 TeV are obtained from extrapolation of
existing measurements at lower \sqrt(s). These distributions are then compared
to calculations from PYTHIA and PHOJET models. The existing \sqrt(s)
measurements are unable to distinguish between a logarithmic and power law
dependence of the average charged particle multiplicity () on \sqrt(s),
and their extrapolation to energies accessible at LHC give very different
values. Assuming a reasonably good description of inclusive charged particle
multiplicity distributions by Negative Binomial Distributions (NBD) at lower
\sqrt(s) to hold for LHC energies, we observe that the logarithmic \sqrt(s)
dependence of are favored by the models at midrapidity. The dN_ch/d\eta
versus \eta for the existing measurements are found to be reasonably well
described by a function with three parameters which accounts for the basic
features of the distribution, height at midrapidity, central rapidity plateau
and the higher rapidity fall-off. Extrapolation of these parameters as a
function of \sqrt(s) is used to predict the pseudorapidity distributions of
charged particles at LHC energies. dN_ch/d\eta calculations from PYTHIA and
PHOJET models are found to be lower compared to those obtained from the
extrapolated dN_ch/d\eta versus \eta distributions for a broad \eta range.Comment: 11 pages and 13 figures. Substantially revised and accepted for
publication in Journal of Physics
Higher levels of CO2 during late incubation alter the hatch time of chicken embryos
status: publishe
Radiotherapy optimAl Design: An Academic Radiotherapy Treatment Design System
Optimally designing radiotherapy and radiosurgery treatments to increase the likelihood of a successful recovery from cancer is an important application of operations research. Researchers have been hindered by the lack of academic software that supports head-to-head comparisons of different techniques, and this article addresses the inherent difficulties of designing and implementing an academic treatment planning system. In particular, this article details the algorithms and the software design of Radiotherapy optimAl Design (RAD)
Effect of species-specific sound stimulation on the development and hatching of broiler chicks
Improving LADCP velocity with external heading, pitch, and roll
Data collected with acoustic Doppler current profilers installed on CTD rosettes and lowered through the water column [lowered ADCP (LADCP) systems] are routinely used to derive full-depth profiles of ocean velocity. In addition to the uncertainties arising from random noise in the along-beam velocity measurements, LADCP-derived velocities are commonly contaminated by bias errors due to imperfectly measured instrument attitude (heading, pitch, and roll). Of particular concern are the heading measurements, because it is not usually feasible to calibrate the internal ADCP compasses with the instruments installed on a CTD rosette, away from the magnetic disturbances of the ship. Heading data from dual-headed LADCP systems, which consist of upward- and downward-pointing ADCPs installed on the same rosette, commonly indicate heading-dependent compass errors with amplitudes exceeding 10°. In an attempt to reduce LADCP velocity errors, several dozen profiles of simultaneous LADCP and magnetometer/accelerometer data were collected in the Gulf of Mexico. Agreement between the LADCP profiles and simultaneous shipboard velocity measurements improves significantly when the former are processed with external attitude measurements. Another set of LADCP profiles with external attitude data was collected in a region of the Arctic Ocean where the horizontal geomagnetic field is too weak for the ADCP compasses to work reliably. Good agreement between shipboard velocity measurements and Arctic LADCP profiles collected at magnetic dip angles exceeding and processed with external attitude measurements indicate that high-quality velocity profiles can be obtained close to the magnetic poles
- …