Engineering topics

Weygand, Dennis

Publications and source records attributed to Weygand, Dennis.

4 records

DOE OSTI2014

Light Vector Meson Photoproduction off of 1H at Jefferson Lab and p-w Interference in the Leptonic Decay Channel

Although the phenomena of r – w interference has been studied at great length in pionic decay channel over the past 50 years, a study of the interference in a purely electromagnetic production and decay channel has never been performed on an elementary proton target until now. The only published photo-production data of the r - w leptonic decay channel was obtained in the early seventies on C and Be. An investigation of the r - w interference on a Hydrogen was recently completed at Jefferson Lab with the CLAS detector. The di-lepton spectra was fit with two inter- fering relativistic Breit-Wigner functions, and the interference phase was extracted. Preliminary results will be compared to the previous experimental studies in nuclei.

Djalali, Chaden↗

DOE OSTI2013

Photoproduction of scalar mesons at CLAS

A single gluon, which carries color charge, cannot exist independently outside a hadron. Lattice QCD calculations in pure SU(3), however, predict the existence of glueballs which are bound states of two or more gluons. In the real world, the challenge to identify glueballs experimentally is the fact they mix with meson states. The f0(1500) is one of several candidates for the lightest glueball, with JPC=0++. We investigate the presence of this particle in photoproduction by analyzing the reaction ?p?fJp?K0SK0Sp?2(?+??)p. This reaction was studied using data from the g12 experiment performed using the CLAS detector at Jefferson Lab. A preliminary partial wave analysis, performed on the K0SK0S invariant mass spectrum, will be presented. These results update those presented for this reaction channel at previous conferences.

Weygand, Dennis↗

DOE OSTI2013

Dalitz Decay of Pseudoscalar Mesons from Photoproduction on Hydrogen Target with CLAS

Experimental results on the Dalitz decay of pseudoscalar mesons P(pi0,n,n') --> e+e-y produced in the photoproduction reaction y + p --> P(n0,n,n') + p on a Hydrogen target, with CLAS setup at Thomas Jefferson National Accelerator Facility (TJNAF), are presented. The total statistics collected for pi0,n Dalitz decay exceeds the world's published statistics by an order of magnitude, while the Dalitz decay of n' --> e+e-y is observed and measured for the first time. The data obtained will allow for measurements of transition form factors that are encoded in the mass spectrum of the e+e- system. The current status of analysis of the pi0,n transition form factors and the search for the heavy photon from the e+e- mass system will be discussed.

Kunkel, Michael↗

DOE OSTI2013

Applicability of Parallel Computing to Partial Wave Analysis

Bound states of Quantum Chromodynamics (QCD) give insights into the nature of confinement, a key element of the strong interaction. States may be identified from weak signals extracted from the analysis of high statistics data from reactions with many final state particles. One of the best tools for the analysis of these reactions is Partial Wave Analysis (PWA). PWA transforms an ensemble of experimental data from a large acceptance detector from free particle eigenstates to angular momentum eigenstates. The PWA program must be fast enough to deal with the large amounts of data available currently, as processing time scales with the number of events. The scope of this research is to study the applicability and scalability of Intel's Xeon Phi using the Many Integrated Core (MIC) architecture when applied to the existing PWA code at Jefferson Laboratory. An algorithm was developed for the Xeon Phi and scaled across 240 available threads, giving parallel functionality to the PWA which was originally written serially. This scaling can make the fitting process fifteen times faster.

Ruger, Justin↗