Download or read book Parity Violating Electron Scattering Measurements of Neutron Densities written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Parity violating electron scattering allows model independent measurements of neutron densities that are free from most strong interaction uncertainties. In this paper we present statistical error estimates for a variety of experiments. The neutron radius $R_n$ can be measured in several nuclei, as long as the nuclear excited states are not too low in energy. We present error estimates for $R_n$ measurements in $^{40}$Ca, $^{48}$Ca, $^$Sn, $^$Sn, $^$Sn, and $^$Pb. In general, we find that the smaller the nucleus, the easier the measurement. This is because smaller nuclei can be measured at higher momentum transfers where the parity violating asymmetry $A_{pv}$ is larger. Also in general, the more neutron rich the isotope, the easier the measurement, because neutron rich isotopes have larger weak charges and larger $A_{pv}$. Measuring $R_n$ in $^{48}$Ca appears very promising because it has a higher figure of merit than $^$Pb. In addition, $R_n(^{48}$Ca) may be more easily related to two nucleon and three nucleon interactions, including very interesting three neutron forces, than $R_n(^$Pb). After measuring $R_n$, one can constrain the surface thickness of the neutron density $a_n$ with a second measurement at somewhat higher momentum transfers. We present statistical error estimates for measuring $a_n$ in $^{48}$Ca, $^$Sn, and $^$Pb. Again, we find that $a_n$ is easier to measure in smaller nuclei.

Download or read book Measurement of the Neutron Radius of 208Pb Through Parity Violation in Electron Scattering written by and published by . This book was released on 2013 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: In contrast to the nuclear charge densities, which have been accurately measured with electron scattering, the knowledge of neutron densities still lack precision. Previous model-dependent hadron experiments suggest the difference between the neutron radius, Rn, of a heavy nucleus and the proton radius, Rp, to be in the order of several percent. To accurately obtain the difference, Rn-Rp, which is essentially a neutron skin, the Jefferson Lab Lead (208Pb) Radius Experiment (PREX) measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 208Pb at an energy of 1.06 GeV and a scattering angle of 5° . Since Z0 boson couples mainly to neutrons, this asymmetry provides a clean measurement of Rn with respect to Rp. PREX was conducted at the Jefferson lab experimental Hall A, from March to June 2010. The experiment collected a final data sample of 2x 107 helicity-window quadruplets. The measured parity-violating electroweak asymmetry APV = 0.656 ± 0.060 (stat) ± 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions, Rn-Rp = 0.33+0.16-0.18 fm and provides the first electroweak observation of the neutron skin as expected in a heavy, neutron-rich nucleus. The value of the neutron radius of 208Pb has important implications for models of nuclear structure and their application in atomic physics and astrophysics such as atomic parity non-conservation (PNC) and neutron stars.

Download or read book Parity Violation In Atoms And In Polarized Electron Scattering written by Marie-anne Bouchiat and published by World Scientific. This book was released on 1999-07-13 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last few years there has been considerable progress in improving the accuracy of parity violation experiments in electron scattering at high energy and in atomic physics. Recent results are a challenge to the standard electroweak theory and our understanding of hadron structure. This book is an extensive review of the advances in this field. The theoretical framework is presented at a pedagogical level, experiments and future projects are reviewed, and the results and their interpretation are discussed in depth.

Download or read book Electroweak Measurements of Neutron Densities in PREX and CREX at JLab USA written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurement of the parity-violating electron scattering asymmetry from ${}^$Pb has demonstrated a new opportunity at Jefferson Lab to measure the weak charge distribution and hence pin down the neutron radius in nuclei in a relatively clean and model-independent way. This is because the Z boson of the weak interaction couples primarily to neutrons. We will describe the PREX and CREX experiments on ${}^$Pb and ${}^{48}$Ca respectively. PREX-I ran in 2010, and CREX and a second run of PREX are currently in preparation.

Download or read book Parity Violation In Electron Scattering Proceedings Of The Workshop written by E J Beise and published by World Scientific. This book was released on 1990-08-23 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings cover the recent progress and future directions of parity violation in electron scattering. Both experimental and theoretical issues are discussed, such as those of hadronic structure, radiative corrections, and tests of the standard model. There are three sessions, the first of which serves as a general overview of theory and experiment. The second session deals with the technical aspects of making a measurement of the parity violating asymmetry in electron scattering, including not only detector design but polarized electron beams and beam polarimeters.. The remaining session covers the corrections to lowest order parity violating cross sections.

Download or read book Using Parity violating Weak Interaction to Measure Neutron Matter Density and Search for New Physics written by Sakib Rahman and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The weak interaction is the only fundamental interaction in nature that violates parity symmetry. Parity-violation produces asymmetric outcomes in mirror image experiments. The high-precision asymmetry measurements, using electrons with rapidly flipping polarization as probes, have extraordinary scientific reach across various subfields. PREX-2 and MOLLER are two such experiments that can only be conducted at the state-of-the-art Thomas Jefferson National Accelerator Facility. The asymmetries (A_PV) measured at PREX-2 and MOLLER kinematics (Q^2), can help to estimate the density distributions in neutron-rich matter and search for Physics Beyond the Standard Model respectively. PREX-2 was conducted by scattering a longitudinally polarized 953 MeV electron beam elastically from 208Pb at a ~ 5 degree scattering angle. The measured asymmetry was A_PV = 550±16 [stat.]±8 [sys.] ppb at average Q^2 = 0.00616 GeV^2. Together with PREX-1, it imposes robust constraints on the interior baryon density (0.1480±0.0036 [exp.]±0.0013 [theo.] fm^−3) and the neutron skin (0.283±0.071 fm) of 208Pb. Model correlations between the neutron skin and the nuclear symmetry pressure indicate a stiff symmetry energy near the nuclear saturation density. Together with neutron star observations, it enhances the understanding of exotic matter states. In contrast to PREX-2, MOLLER will operate with an 11 GeV longitudinally polarized electron beam as the flagship experiment utilizing the 12 GeV upgrade at Jefferson Lab. The electrons will be scattered from atomic electrons in a liquid hydrogen target and the scattered electrons will be guided by a novel spectrometer with full azimuthal coverage to an array of quartz Cerenkov detectors. The asymmetry and consequently the weak charge of the electron will be measured to a precision of 2.4% at average Q^2 = 0.0056 GeV^2. The value of the electroweak mixing angle derived from the above measurement can be compared to the Standard Model prediction in search of a deviation. MOLLER is sensitive to new physics in the MeV to multi-TeV range. This dissertation details the PREX-2 measurement and the current design status of MOLLER, highlighting my contributions towards PREX-2 data analysis and optimization of MOLLER experimental subsystems.

Download or read book Measurements of the Strangeness Content of the Proton Through Parity Violating Electron Scattering at JLAB written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured the parity violating asymmetry in the cross section for elastic scattering of longitudinally polarized electrons from protons at 3.36 GeV incident energy and 0.48 GeV/c[sup 2] momentum transfer at Jefferson Lab. This asymmetry is[minus]14.5[+-] 2.3 ppm, consistent with the Standard Model with no contribution from strange quarks. They extract the combination of strange form factors G[sub E][sup s]+ 0.39G[sub M][sup s]= 0.023[+-] 0.034(stat)[+-] 0.022(syst)[+-] 0.026[delta]G[sub E][sup n], where the last error arises from the neutron electric form factor.

Download or read book Electroweak Measurements of Neutron Densities in CREX and PREX at JLab USA written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurement of the parity-violating electron scattering asymmetry is an established technique at Jefferson Lab and provides a new opportunity to measure the weak charge distribution and hence pin down the neutron radius in nuclei in a relatively clean and model-independent way. This is because the Z boson of the weak interaction couples primarily to neutrons. We will describe the PREX and CREX experiments on ${}{̂u00D0}$Pb and ${}{̂48}$Ca respectively; these are both doubly-magic nuclei whose first excited state can be discriminated by the high resolution spectrometers at JLab. The heavier lead nucleus, with a neutron excess, provides an interpretation of the neutron skin thickness in terms of properties of bulk neutron matter. For the lighter ${}{̂48}$Ca nucleus, which is also rich in neutrons, microscopic nuclear theory calculations are feasible and are sensitive to poorly constrained 3-neutron forces.

Download or read book Measurement of the Parity Violating Asymmetry in Elastic Electron Scattering Off 208Pb written by and published by . This book was released on 2014 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lead Radius Experiment (PREX) was carried out in order to provide a model-independent measurement of the RMS radius sqrt(r-2/n) of the neutron distribution in the 208Pb nucleus. The parity-violating scattering asymmetry for longitudinally polarized 1.06 GeV electrons from an unpolarized 208Pb target was measured at Q2 = 0.00880 GeV2. This measurement was performed by the PREX collaboration in Hall A at Jefferson Laboratory in Newport News, VA, between March and June, 2010. The electron detectors used in this measurement were designed and fabricated by University of Massachusetts-Amherst and Smith College. The resulting parity-violating asymmetry was measured as APV = 656±60(stat.)±14(sys.) ppb. This asymmetry extrapolates to a difference in radii between the nuclear neutron and proton distributions of sqrt(r-2/n)-sqrt(r-2/p)=0.33^+0.16/-0.18 fm.

Download or read book A Clean Measurement of the Neutron Skin of 208Pb Through Parity Violating Electron Scattering written by Riad Suleiman and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The difference between the neutron radius Rn of a heavy nucleus and the proton radius Rp is believed to be on the order of several percent. This qualitative feature of nuclei, which is essentially a neutron skin, has proven to be elusive to pin down experimentally in a rigorous fashion. A new Jefferson Lab experiment will measure the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 208Pb. Since the Z-boson couples mainly to neutrons, this asymmetry provides a measure of the size of Rn that can be interpreted with as much confidence as the traditional electron scattering data. The projected experimental precision corresponds to a 1% determination of Rn, which will have a big impact on nuclear theory and its application to neutron rich matter such as neutron stars.

Download or read book Proceedings of the International Symposium Electromagnetic Interactions in Nuclear and Hadron Physics written by Mamoru Fujiwara and published by World Scientific. This book was released on 2002 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the following topics: (1) meson and hadron production by real and virtual photon interaction with nucleons and nuclei; (2) astrophysical studies via photoreactions and hadron reactions; (3) new technologies for the electromagnetic probes and detector development; (4) nuclear structure studies with electromagnetic probes; (5) fundamental symmetries with electromagnetic probes and related problems.The proceedings have been selected for coverage in: ? Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)

Download or read book Parity Violation in Electron Scattering written by E. J. Beise and published by World Scientific Publishing Company. This book was released on 1990 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings cover the recent progress and future directions of parity violation in electron scattering. Both experimental and theoretical issues are discussed, such as those of hadronic structure, radiative corrections, and tests of the standard model. There are three sessions, the first of which serves as a general overview of theory and experiment. The second session deals with the technical aspects of making a measurement of the parity violating asymmetry in electron scattering, including not only detector design but polarized electron beams and beam polarimeters.. The remaining session covers the corrections to lowest order parity violating cross sections.

Download or read book Nuclear Structure written by Giovanni Bonsignori and published by World Scientific. This book was released on 2001 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Conference OC Bologna 2000: Structure of the Nucleus at the Dawn of the CenturyOCO was devoted to a discipline which has seen a strong revival of research activities in the last decade. New experimental results and theoretical developments in nuclear physics will certainly make important contributions to our knowledge and understanding of Nature's fundamental building blocks. The interest aroused by the Conference among the scientific community was clearly reflected in the large number of participants. These represented the most important nuclear physics laboratories in the world. The Conference covered five major topics of modern nuclear physics: nuclear structure, nucleusOConucleus collisions, hadron dynamics, nuclear astrophysics, and transdisciplinary and peaceful applications of nuclear science. It reviewed recent progress in the field and provided a forum for the discussion of current and future research projects. Contents: Structure of Nuclei Far from the Valley of Beta-Stability; Nuclear Structure; Physics of High Spin States; Symmetries in Nuclear Structure; Collective Excitations; Nuclear Structure at Finite Temperature. Readership: Nuclear physicists."

Download or read book Time Reversal Invariance And Parity Violation In Neutron Reactions Proceedings Of The 2nd International Workshop written by Christopher R Gould and published by World Scientific. This book was released on 1994-01-28 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Workshop on Time Reversal Invariance and Parity Violation in Neutron Reactions focused on the study of parity violation (PV) and time reversal invariance (TRI) in neutron physics. Emphasis was placed on measurements with polarized neutron beams and polarized targets as well as on the implication of recent theoretical developments for the future progress of this rapidly developing and increasingly important field of research.

Download or read book Measurement of the Neutron Radius of 208Pb Through Parity Violation in Electron Scattering written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from 208Pb. APV is sensitive to the radius of the neutron distribution (Rn). The result APV = 0.656 " 0.060 (stat) " 0.013 (syst) corresponds to a difference between the radii of the neutron and proton distributions Rn-Rp = 0.33-0.18+0.16 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

Download or read book From Parity Violation to Hadronic Structure and more written by Serge Kox and published by Springer Science & Business Media. This book was released on 2007-06-07 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost 50 years after the proposal of Lee and Young in 1956 to test the hypothesis of parity violation in weak interactions and the subsequent experimental verification of parity violation by C. S. Wu, parity violation has today become a useful property of weak interactions. This is due to the fact that the focus nowadays has changed: parity violation in weak interactions is no more a topic of investigation but is used as a tool in many different fields ranging from nuclear physics to the search for the hidden extra dimensions requested by string theory. For our first workshop which took place June 5-8, 2002, at the Institut fiir Ke- physik of the Johannes Gutenberg-Universitat Mainz, we concentrated on the in vestigation of the strangeness contribution in the nucleon. This book contains the refereed and selected papers of the second workshop "From Parity Violation to Hadron Structure and more (Part II)", which took place June 8-11, in the Labo- toire de Physique Subatomique et de Cosmologie, in Grenoble. These papers appear in EPJAdirect, the electronic-only part of EPJA, and they are accessible without restrictions. They will also appear in printed form and can be ordered through Springer. The excellent presentations show the dramatic and steady progress in the accuracy of measured parity violating asymmetries over the last few years.

Download or read book Measurement of the Parity Violating Asymmetry in Elastic Electron Scattering Off 208Pb written by Jonathan William Wexler and published by . This book was released on 2014 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lead Radius Experiment (PREX) was carried out in order to provide a model independent measurement of the RMS radius square root r2 of the neutron distribution in the 208Pb nucleus. The parity-violating scattering asymmetry for longitudinally polarized 1.06 GeV electrons from an unpolarized 208Pb target was measured at Q2 = 0.00880 GeV2. This measurement was performed by the PREX collaboration in Hall A at Jefferson Laboratory in Newport News, VA, between March and June, 2010. The electron detectors used in this measurement were designed and fabricated by University of Massachusetts-Amherst and Smith College. The resulting parity-violating asymmetry was measured as APV = 656±60(stat.)±14(sys.) ppb. This asymmetry extrapolates to a difference in radii between the nuclear neutron and proton distributions of square root r2n - square root r2p =0.33 +0.16 -0.18 fm.