skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Measuring nucleon TMD spin-momentum correlations via Drell-Yan at Fermilab E906/E1039 SeaQuest Experiment

  1. Los Alamos National Laboratory
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: Baryons 2016 International Conference on the Structure of Baryons ; 2016-05-16 - 2016-05-20 ; Talahassee, Florida, United States
Country of Publication:
United States
Atomic and Nuclear Physics

Citation Formats

Kleinjan, David William. Measuring nucleon TMD spin-momentum correlations via Drell-Yan at Fermilab E906/E1039 SeaQuest Experiment. United States: N. p., 2016. Web.
Kleinjan, David William. Measuring nucleon TMD spin-momentum correlations via Drell-Yan at Fermilab E906/E1039 SeaQuest Experiment. United States.
Kleinjan, David William. 2016. "Measuring nucleon TMD spin-momentum correlations via Drell-Yan at Fermilab E906/E1039 SeaQuest Experiment". United States. doi:.
title = {Measuring nucleon TMD spin-momentum correlations via Drell-Yan at Fermilab E906/E1039 SeaQuest Experiment},
author = {Kleinjan, David William},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 7

Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • The E906/SeaQuest experiment will use the 120 GeV proton beam extracted from the Fermilab Main Injector to measure the Drell-Yan cross section in p-p, p-d, and p-A scattering. Data from liquid hydrogen and deuterium targets will be sensitive to the light anti-quark asymmetry, d-bar/u-bar, over a range of parton momentum fraction 0.04<x<0.45. Previous measurements from the E866/NuSea experiment have shown that while there were clear signs of flavor asymmetry at moderate x, the quark sea became flavor symmetric at higher x, suggesting a possible shift in the underlying mechanism generating the sea. Measurements from solid nuclear targets (carbon, calcium, andmore » tungsten) will determine the modification of antiquark distributions in the nucleus. The results, in addition to being complementary to similar measurements performed through deep inelastic scattering, will also be valuable in providing the nuclear corrections necessary to extract nucleon parton distribution functions from neutrino data. The experiment will start in 2011, and will run for two years.« less
  • A measurement of the flavor asymmetry of the antiquarks (more » $$\bar{d}$$ and $$\bar{u}$$) in the proton is described in this thesis. The proton consists of three valence quarks, sea quarks, and gluons. Antiquarks in the proton are sea quarks. They are generated from the gluon splitting: g → q + $$\bar{q}$$. According to QCD (Quantum Chromodynamics), the gluon splitting is independent of quark flavor. It suggests that the amounts of $$\bar{d}$$ and $$\bar{u}$$ should be the same in the proton. However, the NMC experiment at CERN found that the amount of $$\bar{d}$$ is larger than that of $$\bar{u}$$ in the proton using the deep inelastic scattering in 1991. This result is obtained for $$\bar{d}$$ and $$\bar{u}$$ integrated over Bjorken x. Bjorken x is the fraction of the momentum of the parton to that of the proton. The NA51 experiment (x ~ 0.2) at CERN and E866/NuSea experiment (0.015 < x < 0.35) at Fermilab measured the flavor asymmetry of the antiquarks ($$\bar{d}$$/$$\bar{u}$$) in the proton as a function of x using Drell–Yan process. The experiments reported that the flavor symmetry is broken over all measured x values. Understanding the flavor asymmetry of the antiquarks in the proton is a challenge of the QCD. The theo- retical investigation from the first principle of QCD such as lattice QCD calculation is important. In addition, the QCD effective models and hadron models such as the meson cloud model can also be tested with the flavor asymmetry of antiquarks. From the experimental side, it is important to measure with higher accuracy and in a wider x range. The SeaQuest (E906) experiment measures $$\bar{d}$$/$$\bar{u}$$ at large x (0.15 < x < 0.45) accurately to understand its behavior. The SeaQuest experiment is a Drell–Yan experiment at Fermi National Accelerator Laboratory (Fermilab). In the Drell–Yan process of proton-proton reaction, an antiquark in a proton and a quark in another proton annihilate and create a virtual photon, which then decays into a muon pair (q$$\bar{q}$$ → γ* → µ +µ -). The SeaQuest experiment uses a 120 GeV proton beam extracted from Fermilab’s Main Injector. The proton beam interacts with hydrogen and deuterium targets. The SeaQuest spectrometer detects the muon pairs from the Drell–Yan process. The $$\bar{d}$$/$$\bar{u}$$ ratio at 0.1 < x < 0.58 is extracted from the number of detected Drell–Yan muon pairs. After the detector construction, commissioning run and detector upgrade, the SeaQuest experiment started the physics data acquisition from 2013. We finished so far three periods of physics data acquisition. The fourth period is in progress. The detector construction, detector performance evaluation, data taking and data analysis for the flavor asymmetry of the antiquarks $$\bar{d}$$/$$\bar{u}$$ in the proton are my contribution to SeaQuest. The cross section ratio of Drell–Yan process in p- p and p-d reactions is obtained from dimuon yields. In the experiment with high beam intensity, it is important to control the tracking efficiency of charged particles through the magnetic spectrometer. The tracking efficiency depends on the chamber occupancy, and the appropriate method for the correction is important. The chamber occupancy is the number of hits in drift chambers. A new method of the correction for the tracking efficiency is developed based on the occupancy, and applied to the data. This method reflects the real response of the drift chambers. Therefore, the systematic error is well controlled by this method. The flavor asymmetry of antiquarks is obtained at 0.1 < x < 0.58. At 0.1 < x < 0.45, the result is $$\bar{d}$$/$$\bar{u}$$ > 1. The result at 0.1 < x < 0.24 agrees with the E866 result. The result at x > 0.24, however, disagrees with the E866 result. The result at 0.45 < x < 0 the statistical errors. u¯ results extracted from experiments are used to investigate the validity of the theoretical models. The present experimental result provides the data points in wide x region. It is useful for understanding the proton structure in the light of QCD and effective hadron models. The present result has a practical application as well. Antiquark distributions are important as inputs to simulations of hadron reactions such as W± production in various experiments. The new knowledge on antiquark distributions helps to improve the precision of the simulations.« less