Exploring the Antiquark Structure of Matter with Drell-Yan Scattering: Fermilab E-906/SeaQuest

Document #:

Projects-doc-675-v1

Document type:

Conference Presentation

Submitted by:

Paul E. Reimer

Updated by:

Paul E. Reimer

Document Created:

13 Aug 2009, 17:08

Contents Revised:

13 Aug 2009, 17:08

DB Info Revised:

20 Aug 2009, 17:05

Abstract:

Deep inelastic scattering (DIS) is an excellent tool for probing the quark structure of
hadrons. It has been used to determine precisely the distributions of quarks and to
determine the spin they carry. DIS is only sensitive to the charge-squared weight sum
of all (valence and sea) quark and cannot easily probe just the sea quark distributions.
The Drell-Yan mechanism provides a complementary approach that can select only the
antiquark distributions in the target. A remarkable asymmetry has been observed in
the difference of anti-down to anti-up quarks in the proton, which cannot simply be
generated through perturbative QCD, but rather indicates an underlying and fundamental
antiquark component in the proton. The Fermilab E-906 Drell-Yan experiment
will extend earlier measurements of this difference to larger values of xBj and increase
statistical precision at lower xBj . Using the same technique, E-906/SeaQuest will investigate
the differences between the antiquark distributions of a free and bound proton.
Nuclear binding should modify the quark distributions and DIS data has shown that
the overall quark distributions are different (the EMC effect). Surprisingly, present
data suggests that the antiquark distributions are not modified. To accomplish these
goals, the experiment will use a 120 GeV proton beam extracted from the Fermilab
Main Injector. The lower beam energy requires several upgrades and configuration
changes to the spectrometer which are underway. The collaboration expects to begin
data collection summer, 2010.

Files in Document:

• Reimer_Fermilab_DY.pdf (149.8 kB)

Topics:

• E906:Public Documents:Conference Preceedings

Authors:

• Paul E. Reimer

Notes and Changes:

Contribution to DIS 2009 in Madrid