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Polarized SeaQuest

Fermilab Drell-Yan E1039

    The Experiment

    • Spokesmen: A. Klein (LANL) and D. Keller (UVA)
    • Configuration: Transversely-Vertical Pointing Polarized Target
    • Group: Fermilab SeaQuest Collaboration

    Importance of Polarized Drell-Yan

    The importance of studying transverse momentum dependent parton distributions (TMDs) and advancing the related theory of the nucleon spin is well summarized by the goals of the nuclear theory TMD Collaboration. The details of which can be found in the Proposal for a topical collaboration in nuclear theory for the coordinated theoretical approach to transverse momentum dependent hadron structure in QCD. Nucleons are the fundamental building blocks of atomic nuclei and make up essentially all the visible matter in the universe. Our modern understanding of the strong interaction is based on Quantum Chromodynamics (QCD), in which the nucleon arises as a strongly interacting, relativistic bound state of quarks and gluons (referred to as partons). The nucleon is not static, but has complex internal structure, full of features that emerge from QCD dynamics and that are only now beginning to be revealed in modern experiments. Explaining the origin, the evolution, and the structure of the visible world is a central goal of nuclear physics. In order to do this, it is vital to understand the internal structure of the nucleon in terms of its partonic constituents. Over the last 50 years, since the first deep inelastic scattering experiments, there have been many advances in our understanding of the partonic structure of the nucleon, including its momentum and spin structure. The most significant progress has been in understanding the (one-dimensional) longitudinal momentum distributions of quarks and gluons encoded in the standard unpolarized collinear parton distribution functions (PDFs) in terms of the longitudinal momentum fraction of the nucleon carried by the parton and the resolution momentum scale of the external probe. However, there are still unknown and important aspects of the nucleon structure to be further explored, especially the ones related to the transverse momentum distribution of partons and its full 3-dimensional landscape. Several recent experiments have helped to uncover the first layers of transverse partonic structure of the proton but there is still essential helicity dependent information missing that requires polarized nucleon reaction so that the full picture of QCD dynamics and nucleon structure. Transverse momentum dependence in the parton distributions of the nucleon allows for the appearance of unsuppressed single spin azimuthal asymmetries, such as Sivers and Collins asymmetries. The measured spin azimuthal asymmetries will enable us to extract the TMD parton distributions through a global analysis of the experimental data, from which we can obtain an image of the nucleon in transverse, as well as in longitudinal momentum space.

expected results

    Here we show the expected results for E1039 after two years of combined running on NH3 and ND3 targets. The red error bars are statistical only. The absolute systematic uncertainty is estimated to be around 1%, and the relative is estimated to be about 4.0%. The theory model predictions are for the proton.

    Drell-Yan Polarized Target System

    The polarized target system to be used in E1039 is a high cooling power fridge connected to a large pump stack (14,000 m3/hour) and a microwave generator used to dynamically polarize the nucleons in the target. The magnet has a 5 T field with a homogeneous region of 8 cm and will be used to polarize protons and neutrons in the sample.


    Here the target system is shown our polarized target lab where the system is setup of testing and optimization. Solid polarized target experiments and demanding and require of team of well trained polarized target expert in order for the experiment to run smoothly.

    Main Pages and Important Links

    E1039 Polarized Target Wiki

    UVA Collab Utilities

    Fermilab E906/E1039 docdb

    Fermilab E906/E1039 software

    Fermilab MCR logbook

    Fermilab Machine logbooks

    Fermilab External Beams logbook

    Drell-Yan Work Dir

    Drell-Yan Meetings

    At this time have the following working group meetings for E1039 (All US Eastern Time):

    • Polarized Target meeting (biweekly on Tuesday at 3PM)
    • Engineering meeting (weekly on Tuesday 4PM)
    • Labview meeting (biweekly on Tuesday 5PM)
    • General biweekly meeting (Tuesday 6PM)
    • Software\Simulations meeting (biweekly Thursday 7PM)

    Join from PC, Mac, Linux, iOS or Android
    Target Meetings
    Meeting ID: 438821341

    LabView Meetings
    Meeting ID: 705516494

    US: (646)558-8656 or (669)900-6833 (US West) (US East) (China) (India) (EMEA) (Australia) (Hong Kong) (Brazil)

    Contact Information

    Dustin Keller:

    Andi Klien:

    Kun Liu: