Download or read book Role of the Strange Quark in the Nucleon Electromagnetic Structure The First Outcomes of the G0 Experience Contribution Du Quark trange la Structure lectromag etique Du Nuc eon written by and published by . This book was released on 2005 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the framework of the Quantum Chromodynamics (QCD), the nucleon is described as being composed of three valence quarks surrounded by a sea of virtual quark-antiquark pairs and gluons. If the role of this virtual sea in the nucleon properties is inferred to be important, this contribution is still poorly understood. In this context, we study the role of the strange quarks in the nucleon since this is the lightest quark flavor of the sea with no valence contribution. We are determining its contribution to the charge and magnetization distributions in the nucleon via parity violation experiments. The measurement is performed by elastically scattering polarized electrons from nucleon target. A world wide program in which the G0 experiment takes place is being performed since a decade. The G0 experiment and the analysis of the results from its forward angles phase are the topics of this thesis. This document presents the physics case of the strangeness content of the nucleon (mass, spin, impulsion). It describes also the formalism related to the electroweak probe and the form factors, and then the principle of parity violating asymmetry measurement. The G0 experimental setup, which was built and installed in the Hall C of the Jefferson Laboratory (Newport-News, USA), is detailed. This set-up was designed for the measurement of asymmetries of the order of 10-6 with an overall relative uncertainty better than 10 %, over a momentum transfer range 0.1-1 (GeV/c)2. The various steps of the data analysis are exposed. They allow to start from measured counting rates to reach parity violating physics asymmetries. This required a careful treatment of the various sources of systematical errors which is discussed extensively. Finally the results from the G0 forward angle measurement, its comparison with others experiments and with theoretical models, are presented. They support a non null strange quark contribution.
Download or read book Measurement of the Strange Quark Contribution to the Vector Structure of the Proton written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of the G0 experiment is to determine the contribution of the strange quarks in the quark-antiquark sea to the structure of the nucleon. To this end, the experiment measured parityviolating asymmetries from elastic electron-proton scattering from 0.12 ≤ Q2 ≤ 1.0 (GeV/c)2 at Thomas Jefferson National Accelerator Facility. These asymmetries come from the interference of the electromagnetic and neutral weak interactions, and are sensitive to the strange quark contributions in the proton. The results from the forward-angle measurement, the linear combination of the strange electric and magnetic form factors GsE +[eta]GsM, suggest possible non-zero, Q2 dependent, strange quark contributions and provide new information to understand the magnitude of the contributions. This dissertation presents the analysis and results of the forward-angle measurement. In addition, the G0 experiment measured the beam-normal single-spin asymmetry in the elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2 = 0.15, 0.25 (GeV/c)2 as part of the forward-angle measurement. The transverse asymmetry provides a direct probe of the imaginary component of the two-photon exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments. The results of the measurement indicate that calculations using solely the elastic nucleon intermediate state are insufficient and generally agree with calculations that include significant inelastic hadronic intermediate state contributions. This dissertation presents the analysis and results of this measurement.
Download or read book International Workshop on Strange Quarks in Hadrons Nuclei and Nuclear Matter written by Kenneth Harrison Hicks and published by World Scientific. This book was released on 2000 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume brings together the contributions of experts from different fields within the nuclear physics community. Topics such as rare kaon decays, astrophysics, relativistic heavy ion collisions, and few-GeV electromagnetic probes are covered. The strange quark plays a vital role in understanding such diverse phenomena as CP violation (article by Lincoln Wolfenstein), the ?spin crisis? (article by Brad Filipone), and supernova explosions (article by Chris Fryer). Additional topics of interest are parity violation experiments, strangeness content of the proton, and enhanced strangeness production at CERN and RHIC. This unique blend of recent results, with a focus on the role of the strange quark, shows the prominence of strangeness in nuclear physics over the past 50 years.
Download or read book Quarks and Nuclei written by W. Weise and published by World Scientific. This book was released on 1984 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: http://www.worldscientific.com/worldscibooks/10.1142/0102
Download or read book Strange Quarks In Hadrons Nuclei And Nuclear Matter Proceedings Of The International Workshop written by Kenneth H Hicks and published by World Scientific. This book was released on 2001-02-28 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume brings together the contributions of experts from different fields within the nuclear physics community. Topics such as rare kaon decays, astrophysics, relativistic heavy ion collisions, and few-GeV electromagnetic probes are covered. The strange quark plays a vital role in understanding such diverse phenomena as CP violation (article by Lincoln Wolfenstein), the “spin crisis” (article by Brad Filipone), and supernova explosions (article by Chris Fryer). Additional topics of interest are parity violation experiments, strangeness content of the proton, and enhanced strangeness production at CERN and RHIC. This unique blend of recent results, with a focus on the role of the strange quark, shows the prominence of strangeness in nuclear physics over the past 50 years.
Download or read book Measurement of the Strange Quark Contribution to Nucleon Structure Through Parity Violating Electron Scattering written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The G0 backward angle experiment, completed in Hall C of the Thomas Jefferson National Accelerator Facility (TJNAF), measured parity-violating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at Q2 = 0.22 and 0.63 (GeV/c)2. The asymmetries are sensitive to strange quark contributions to currents in the nucleon and the nucleon axial-vector current. The results indicate strange quark contributions of lte 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. This was also the first measurement of the anapole moment effects in the axial-vector current at these four-momentum transfers.
Download or read book The Heart of the Matter from Nuclear Interactions to Quark Gluon Dymanics sic written by J.-F. Mathiot and published by Atlantica Séguier Frontières. This book was released on 1995 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Polarization of Strange Quark in the Nucleon and Determination of Quark Fragmentation Functions Into Hadrons written by Nour Makke and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the nucleon structure is currently one of the main challenges encountered in nuclear physics. The present work represents a contribution to the study of the nucleon structure and deals, in particular, with the study of the role of strange quarks in the nucleon. The latter can be investigated by determing the strange quark distribution in the nucleon as well as the contribution of the spins of strange quarks to the nucleon spin (∆s). This work first presents a measurement of ∆s performed via Deeply Inelastic Scattering of a muon beam off polarized proton and deuterium targets. The result is found to be strongly dependent on the quark fragmentation functions into hadrons (FFs), which define the probability that a quark of a given flavour fragments into a final state hadron. The FFs are poorly known, in particular, the FF of strange quark into kaons, which play an important role in the determination of ∆s. In deep inelastic scattering process, the access to the FFs is provided by the hadron multiplicities which, in turn, define the average number of hadrons produced per DIS event. Pion and kaon multiplicities have been extracted versus different kinematic variables, using DIS data collected by deeply inelastic scattering of a 160 GeV muons off a deuterium target. A first LO extraction of the fragmentation functions has then been performed using the measured pion and kaon multiplicities.
Download or read book Measurement of the Strange Quark Contribution to Nucleon Structure Through Parity violating Electron Scattering written by Colleen L. Ellis and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of the Strange Quark Contributions to the Electromagnetic Form Factors of the Nucleon written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: G0 is a parity violating electron scattering program at the Thomas Jefferson National Accelerator Facility, and its forward angle measurement is reported in this thesis. In this experiment, parity violating asymmetries of elastic electron-proton scattering were measured over a range of four-momentum transfer from 0.12 to 1.0 (GeV/c)2. From the asymmetries, linear combinations of the strange electric and magnetic form factors of the nucleon, G$s\atop{E}$ + [eta]G$s\atop{M}$, are extracted over the same kinematic range. These results, combined with existing data from other experiments, indicate that both G$s\atop{E}$ and [eta]G$s\atop{M}$ are non-zero and dependent on the four-momentum transfer, with imply non-trivial strange quark contributions to the low energy electromagnetic properties of the nucleon.
Download or read book Quark Matter written by Helmut Satz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the Editors Preface: "Quark Matter 1987 was attended by about 250 scientists, representing 75 research institutions around the world - the scientific community engaged in experimental and theoretical studies of high energy nuclear collisions. The central theme of the meeting was the possibility of achieving extreme energy densities in extended systems of strongly interacting matter - with the ultimate aim of creating in the laboratory a deconfined state of matter, a state in which quarks and gluons attain the active degrees of freedom. High energy accelerator beams and cosmic radiation projectiles provide the experimental tools for this endeavour; on the theoretical side, it is intimately connected to recent developments in the non-perturbative study of quantum chromodynamics. Phase transitions between hadronic matter and quark-gluon plasma are of basic interest also for our understanding of the dynamics of the early universe ... A very special feature of this Sixth Quark Matter Conference was the advent of the first experimental results from dedicated accelerator studies. These were conducted during 1986/87 at the AGS of Brookhaven National Laboratory ... and at the CERN SPS ... An intense discussion of these data formed the main activity of the meeting.
Download or read book The Quark Structure of Matter written by Société française de physique and published by World Scientific Publishing Company. This book was released on 1986 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quarks in Hadrons and Nuclei written by Amand Faessler and published by Pergamon. This book was released on 1996 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strange Quark Contribution to the Nucleon written by Dean Darnell and published by . This book was released on 2006 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The strangeness contribution to the electric and magnetic properties of the nucleon has been under investigation experimentally for many years. Lattice Quantum Chromodynamics (LQCD) gives theoretical predictions of these measurements by implementing the continuum gauge theory on a discrete, mathematical Euclidean space-time lattice which provides a cutoff removing the ultra-violet divergences. In this dissertation we will discuss effective methods using LQCD that will lead to a better determination of the strangeness contribution to the nucleon properties. Strangeness calculations are demanding technically and computationally. Sophisticated techniques are required to carry them to completion. In this thesis, new theoretical and computational methods for this calculation such as twisted mass fermions, perturbative subtraction, and General Minimal Residual (GMRES) techniques which have proven useful in the determination of these form factors will be investigated. Numerical results of the scalar form factor using these techniques are presented. These results give validation to these methods in future calculations of the strange quark contribution to the electric and magnetic form factors.
Download or read book Strange Quark Contributions to Nucleon Electric and Magnetic Form Factors from Parity violating Electron Scattering Asymmetries in the Backward Angle G0 Experiment written by Mathew O. Muether and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The G0 collaboration has measured parity-violating asymmetries in elastic electron-proton and quasi-elastic electron-deuteron scattering at Q^2 = 0.22, 0.63 GeV^2. These asymmetries are sensitive to strange quark contributions to electric and magnetic properties of the nucleon, as well as to the axial current of the nucleon. The measurements were made using the polarized beam at Jefferson Laboratory by detecting electrons scattered at ~110 degrees from liquid targets. Together with previous results from the G0 forward angle measurement, the form factors which characterize the strange electric, strange magnetic and axial contributions were found to be G^{s}_{E}(0.221 GeV^2)= -0.0142305 +/- 0.035562 +/- 0.0181952 +/-0.0176497 G^{s}_{M}(0.221 GeV^2)=0.0833777 +/- 0.18337 +/- 0.0854892 +/- 0.0780912 G^{e}_{A}(0.221 GeV^2)=-0.501236 +/- 0.317127 +/- 0.193005 +/- 0.0878386 G^{s}_{E}(0.628 GeV^2)=0.110227 +/-0.0488068 +/- 0.0296044 +/- 0.0236998 G^{s}_{M}(0.628 GeV^2)=-0.12354 +/- 0.10953 +/- 0.0614285 +/- 0.0316972 G^{e}_{A}(0.628 GeV^2)=-0.197329 +/- 0.425414 +/- 0.256755 +/- 0.0948741 with statistical, point-to-point systematic and global systematic uncertainties given respectively. These results indicate small (
Download or read book Proceedings of the Workshop on Future Directions in Quark Nuclear Physics 10 20 March 1998 Adelaide written by Anthony W. Thomas and published by World Scientific Publishing Company Incorporated. This book was released on 1999 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most fundamental questions in understanding strong interaction is whether or not quarks and gluons play a significant role in nuclear systems. At high densities we need to explore the existence and nature of a deconfinement phase transition. At lower densities we wish to study the changes in the properties of a hadron particle as mass and electroweak form factors, when it is immersed in nuclear matter. Finally, we may even ask whether the internal structure of the nucleon plays a role in the binding and properties of finite nuclei. On the theoretical side the issues raised here are of concern to a very broad community, from those working in traditional many-body physics, to those building effective field theories, to those working in lattice QCD. Experimentally, there are many accelerators, mature, new and planned, which can offer insight into this field -- from SLAC to HERA, COSY, CELSIUS and TJNAF. This workshop brought together key figures from all areas of theoretical and experimental physics concerned with this fundamental problem.
Download or read book The Quark Structure of Matter written by Maurice Jacob and published by World Scientific Publishing Company Incorporated. This book was released on 1986 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:
