The Weak Charge Of The Proton A Search For Physics Beyond The Standard Model PDF Download

Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download The Weak Charge Of The Proton A Search For Physics Beyond The Standard Model PDF full book. Access full book title The Weak Charge Of The Proton A Search For Physics Beyond The Standard Model.

The Weak Charge of the Proton

The Weak Charge of the Proton
Author:
Publisher:
Total Pages:
Release: 2015
Genre:
ISBN:

Download The Weak Charge of the Proton Book in PDF, ePub and Kindle

The Qweak experiment, which completed running in May of 2012 at Jefferson Laboratory, has measured the parity-violating asymmetry in elastic electron-proton scattering at four-momentum transfer Q^2=0.025 (GeV/c)^2 in order to provide the first direct measurement of the proton?s weak charge, Qpw. The Standard Model makes firm predictions for the weak charge; deviations from the predicted value would provide strong evidence of new physics beyond the Standard Model. Using an 89% polarized electron beam at 145 microA scattering from a 34.4 cm long liquid hydrogen target, scattered electrons were detected using an array of eight fused-silica detectors placed symmetric about the beam axis. The parity-violating asymmetry was then measured by reversing the helicity of the incoming electrons and measuring the normalized difference in rate seen in the detectors. The low Q^2 enables a theoretically clean measurement; the higher order hadronic corrections are constrained using previous parity-violating electron scattering world data. The experimental method will be discussed, with recent results constituting 4% of our total data and projections of our proposed uncertainties on the full data set.


The Weak Charge of the Proton

The Weak Charge of the Proton
Author: Scott James MacEwan
Publisher:
Total Pages: 0
Release: 2015
Genre:
ISBN:

Download The Weak Charge of the Proton Book in PDF, ePub and Kindle

The Qweak experiment will provide the most precise determination of the proton's weak charge Q^p_W by measuring the parity-violating asymmetry in elastic electron-proton scattering at low momentum transfer Q^2 = 0.0250 (GeV/c)^2. Qpw is related to the weak mixing angle sin^2\theta_W, a fundamental parameter of the standard model. A final measurement of the weak charge at the proposed 4% relative uncertainty is sensitive to certain types of new parity-violating physics beyond the standard model at the TeV mass-scale. Data were taken over a two year period beginning in 2010, using a custom apparatus installed in Hall-C at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. A 180 microamp beam of longitudinally polarized electrons was accelerated to 1.165 GeV and then scattered from unpolarized protons in a liquid hydrogen target. The scattered electrons were then collimated and steered using a magnetic spectrometer onto a set of azimuthally symmetric quartz bar Cherenkov detectors. The performance of this main detector subsystem will be described in detail in this dissertation. A blinded analysis of Run-II, roughly 2/3 of the entire Qweak data set, resulted in an elastic ep asymmetry of -235.6 +/- 8.7 (Stat) +/- 9.3 (Syst.) +/- 39.3 (Blind) ppb. Using this value, the proton's weak charge was calculated to be QpW = 0.0714 +/- 0.0093. This constitutes a 17% relative measurement, that will reduce to


Measuring the Weak Charge of the Proton at Jefferson Lab

Measuring the Weak Charge of the Proton at Jefferson Lab
Author:
Publisher:
Total Pages:
Release: 2008
Genre:
ISBN:

Download Measuring the Weak Charge of the Proton at Jefferson Lab Book in PDF, ePub and Kindle

The JLab Q weak Collaboration is designing and constructing an experiment to measure the protonâ s weak charge, Q W p, by measuring the parity violating asymmetry in elastic electron-proton scattering at very low momentum transfer. The standard model predicts Q W p = 1 - 4 sin2 theta w from the running of the weak mixing angle sin2 theta w, corresponding to a 10sigma effect in the experiment. The experiment will determine Q W p with 4% combined statistical and systematic uncertainties, which leads to 0.3% uncertainty in sin2 theta w . Installation of the experiment will begin in September 2009.


A Measurement of the Weak Charge of the Proton Through Parity Violating Electron Scattering Using the Qweak Apparatus

A Measurement of the Weak Charge of the Proton Through Parity Violating Electron Scattering Using the Qweak Apparatus
Author:
Publisher:
Total Pages: 251
Release: 2013
Genre:
ISBN:

Download A Measurement of the Weak Charge of the Proton Through Parity Violating Electron Scattering Using the Qweak Apparatus Book in PDF, ePub and Kindle

After a decade of preparations, the Qweak experiment at Jefferson Lab is making the first direct measurement of the weak charge of the proton, Qp̂_W. This quantity is suppressed in the Standard Model making a good candidate for search for new physics beyond the SM at the TeV scale. Operationally, we measure a small (about -0.200 ppm) parity-violating asymmetry in elastic electron-proton scattering in integrating mode while flipping the helicity of the electrons 1000 times per second. Commissioning took place Fall 2010, and we finished taking data in early summer 2012. This dissertation is based on the data taken on an initial two weeks period (Wien0). It will provide an overview of the Qweak apparatus, description of the data acquisition and analysis software systems, and final analysis and results from the Wien0 data set. The result is a 16% measurement of the parity violating electron-proton scattering asymmetry, A = -0.2788 +/- 0.0348 (stat.) +/- 0.0290 (syst.) ppm at Q2̂ = 0.0250 +/- 0.0006 (GeV)2̂. From this a 21% measurement of the weak charge of the proton, Q_wp̂(msr)= +0.0952 +/- 0.0155 (stat.) +/- 0.0131 (syst.) +/- 0.0015 (theory) is extracted. From this a 2% measurement of the weak mixing angle, sin2̂theta_W(msr)= +0.2328 +/- 0.0039 (stat.) +/- 0.0033 (syst.) +/- 0.0004 (theory) and improved constraints on isoscalar/isovector effective coupling constants of the weak neutral hadronic currents are extracted. These results deviate from the Standard Model by one standard deviation. The Wien0 results are a proof of principle of the Qweak data analysis and a highlight of the road ahead for obtaining full results.


Q Weak

Q Weak
Author:
Publisher:
Total Pages:
Release: 2017
Genre:
ISBN:

Download Q Weak Book in PDF, ePub and Kindle

The Qweak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q2 = 0.025 (GeV/c)2. The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. Finally, the results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis.


Measurement of the Proton's Weak Charge at the Qweak Experiment

Measurement of the Proton's Weak Charge at the Qweak Experiment
Author:
Publisher:
Total Pages:
Release: 2011
Genre:
ISBN:

Download Measurement of the Proton's Weak Charge at the Qweak Experiment Book in PDF, ePub and Kindle

The Qweak experiment at Jefferson Laboratory measures the parity violating asymmetry of polarized electrons scattering from a proton target at very low momentum transfer. In the Standard Model, this asymmetry reveals the proton's coupling to the neutral vector current, the weak charge. This value, measured directly for the first time, will provide a precision test of the Standard Model and will constrain the possibility of relevant physics beyond the Standard Model. The planned precision will probe certain classes of new physics at the 2̃ TeV scale. In order to challenge the precise predictions, the asymmetry will be measured with a 2.5 percent accuracy. To achieve such a precision, great care has to be taken on many aspects of the experiment. The very low momentum transfer reduces the hadronic effects to the asymmetry and must be determined to half of a percent accuracy. Beam stability is controlled and monitored constantly and background events are carefully studied.


Physics Beyond the Standard Models of Particles, Cosmology and Astrophysics

Physics Beyond the Standard Models of Particles, Cosmology and Astrophysics
Author: Hans Volker Klapdor-Kleingrothaus
Publisher: World Scientific
Total Pages: 774
Release: 2011
Genre: Science
ISBN: 9814340855

Download Physics Beyond the Standard Models of Particles, Cosmology and Astrophysics Book in PDF, ePub and Kindle

This book contains the proceedings of the Fifth International Conference on Physics Beyond the Standard Models of Particle Physics, Cosmology and Astrophysics. It presents a brilliant overview of the status and future potential and trends in experimental and theoretical particle physics, cosmology and astrophysics, in the complimentary sectors of accelerator, non-accelerator and space physics.


The Standard Theory of Particle Physics

The Standard Theory of Particle Physics
Author: Luciano Maiani
Publisher: World Scientific Publishing Company
Total Pages: 483
Release: 2016-08-25
Genre: Science
ISBN: 9814733512

Download The Standard Theory of Particle Physics Book in PDF, ePub and Kindle

The book gives a quite complete and up-to-date picture of the Standard Theory with an historical perspective, with a collection of articles written by some of the protagonists of present particle physics. The theoretical developments are described together with the most up-to-date experimental tests, including the discovery of the Higgs Boson and the measurement of its mass as well as the most precise measurements of the top mass, giving the reader a complete description of our present understanding of particle physics.


Determination of the Proton's Weak Charge Via Parity Violating Electron Scattering

Determination of the Proton's Weak Charge Via Parity Violating Electron Scattering
Author:
Publisher:
Total Pages: 202
Release: 2015
Genre:
ISBN:

Download Determination of the Proton's Weak Charge Via Parity Violating Electron Scattering Book in PDF, ePub and Kindle

The Qweak experiment, which completed running in May of 2012 at Jefferson Laboratory, has measured the parity-violating asymmetry in elastic electron-proton scattering at four-momentum transfer Q2=0.025 (GeV/c)2 in order to provide the first direct measurement of the proton's weak charge, Qpw. The Standard Model makes firm predictions for the weak charge; deviations from the predicted value would provide strong evidence of new physics beyond the Standard Model. Using an 89% polarized electron beam at 145 microA scattering from a 34.4 cm long liquid hydrogen target, scattered electrons were detected using an array of eight fused-silica detectors placed symmetric about the beam axis. The parity-violating asymmetry was then measured by reversing the helicity of the incoming electrons and measuring the normalized difference in rate seen in the detectors. The low Q2 enables a theoretically clean measurement; the higher order hadronic corrections are constrained using previous parity-violating electron scattering world data. The experimental method will be discussed, with recent results constituting 4% of our total data and projections of our proposed uncertainties on the full data set.


Particle Physics Reference Library

Particle Physics Reference Library
Author: Herwig Schopper
Publisher: Springer Nature
Total Pages: 632
Release: 2020
Genre: Heavy ions
ISBN: 3030382079

Download Particle Physics Reference Library Book in PDF, ePub and Kindle

This first open access volume of the handbook series contains articles on the standard model of particle physics, both from the theoretical and experimental perspective. It also covers related topics, such as heavy-ion physics, neutrino physics and searches for new physics beyond the standard model. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access