49,249 research outputs found
Hadroproduction of electroweak gauge boson plus jets and TMD parton density functions
If studies of electroweak gauge boson final states at the Large Hadron
Collider, for Standard Model physics and beyond, are sensitive to effects of
the initial state's transverse momentum distribution, appropriate
generalizations of QCD shower evolution are required. We propose a method to do
this based on QCD transverse momentum dependent (TMD) factorization at high
energy. The method incorporates experimental information from the
high-precision deep inelastic scattering (DIS) measurements, and includes
experimental and theoretical uncertainties on TMD parton density functions. We
illustrate the approach presenting results for production of W-boson + n jets
at the LHC, including azimuthal correlations and subleading jet distributions.Comment: 9 pages, 4 figures. v2: comments and references added, typos
corrected; results unchange
The CCFM uPDF evolution uPDFevolv
uPDFevolv is an evolution code for TMD parton densities using the CCFM
evolution equation. A description of the underlying theoretical model and
technical realization is given together with a detailed program description,
with emphasis on parameters the user may want to changeComment: Code and description on https://updfevolv.hepforge.org Version to be
published in EPJ
Third-order Intermodulation Reduction in Mobile Power Amplifiers by the First Stage Bias Control
In this paper, the third order intermodulation distortion (IMD3) of three-stage power amplifier (PA) is analyzed using the Volterra series. The analysis explains how the total IMD3 of the three-stage power amplifier can be reduced by the first-stage bias condition. The three-stage PA, which is fabricated using InGaP/GaAs hetero-junction bipolar transistor (HBT), operates with an optimized first driver stage bias for higher P1dB and good gain flatness. The power amplifier has been designed for 1626.5 MHz~1660.5 MHz satellite mobile communications. With π/4 DQPSK modulation signals, this PA can deliver a highly linear output power of 33 dBm from 3.6V supply voltage. At 33 dBm output power, it shows a gain of 31.9 dB, a power-added efficiency (PAE) of 39.8%, an adjacent channel power ratio (ACPR) of -28.2 dBc at a 31.25 KHz offset frequency
A phenomenological interpretation of open charm production at HERA in terms of the semi-hard approach
In the framework of the semi-hard (k_t-factorization) approach, we analyze
the various charm production processes in the kinematic region covered by the
HERA experiments.Comment: DESY 02-017, LUNFD6/(NFFL--7209) 200
- …