E906/SeaQuest Drell-Yan Experiment - Brookhaven National ...
E906/SeaQuest Drell-Yan Experiment - Brookhaven National ...
E906/SeaQuest Drell-Yan Experiment - Brookhaven National ...
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<strong>E906</strong>/<strong>SeaQuest</strong><br />
<strong>Drell</strong>-<strong>Yan</strong> <strong>Experiment</strong><br />
Kazutaka Nakahara<br />
University of Maryland College Park<br />
for the<br />
<strong>E906</strong> Collaboration<br />
June 8 th , RHIC/AGS User’s Meeting
Nucleon Structure<br />
• Light sea quark<br />
• Gottfried Sum Rule:<br />
S G = 1/3 if u = d<br />
S<br />
=<br />
1<br />
1<br />
3<br />
1<br />
3<br />
[ ]<br />
p n<br />
−<br />
G 2 2<br />
x<br />
Charge Symmetry<br />
0<br />
=<br />
=<br />
∫<br />
F<br />
+<br />
1<br />
∫<br />
0<br />
2<br />
3<br />
F<br />
dx<br />
[ u − d ]<br />
dx<br />
u =<br />
d
NMC Measurement<br />
0.004 < x < 0.8<br />
S G = 0.235 +/- 0.026<br />
New Muon Collaboration<br />
(NMC), Phys. Rev. D50<br />
(1994) R1<br />
Extrapolate results<br />
over all x (0 < x < 1)<br />
Nuclear shadowing (double scattering of virtual photon from both<br />
nucleons in deuteron) ~ 4-10% effect on Gottfried sum �<br />
disagreement with naive calculation of GSR remains
Reconciling the Disconnect<br />
Three assumptions:<br />
NMC:<br />
1. Extrapolation of NMC measurement to<br />
lower x?<br />
GSR:<br />
1. Charge symmetry?<br />
2. u = d ?<br />
E665 experiment measured to<br />
lower x<br />
No signs of charge symmetry<br />
breaking<br />
Directly measure through <strong>Drell</strong>-<strong>Yan</strong><br />
Knowledge is data-driven
Target<br />
Beam x1, q<br />
σ<br />
2σ<br />
pd<br />
pp<br />
|<br />
x<br />
1<br />
>><br />
x<br />
2<br />
First Direct Measurement<br />
≈<br />
x2, q<br />
⎛ 1<br />
⎜1+<br />
1 ⎝ 4<br />
2 ⎛ 1<br />
⎜<br />
1+<br />
d<br />
⎝ 4 u<br />
d<br />
1 ⎛ d(<br />
⎞<br />
⎜<br />
x2)<br />
≈<br />
⎟<br />
⎜<br />
1+<br />
2 ⎟<br />
⎝ u(<br />
x2)<br />
⎠<br />
γ*<br />
( )<br />
u ( x1)<br />
( x1)<br />
d(<br />
( ) u(<br />
x<br />
1<br />
x<br />
1<br />
µ -<br />
µ +<br />
⎞<br />
⎟<br />
⎠ ⎛ d(<br />
⎞<br />
⎜<br />
x2)<br />
⎟<br />
⎜<br />
1+<br />
⎞ ⎟<br />
x2)<br />
⎟ ⎝ u(<br />
x2)<br />
⎠<br />
) ⎟<br />
x2<br />
⎠<br />
• NA51 (<strong>Drell</strong>-<strong>Yan</strong>)<br />
shows u < d
Target<br />
x2, q<br />
Beam x1, q<br />
σ<br />
2σ<br />
pd<br />
pp<br />
|<br />
x<br />
1<br />
>><br />
x<br />
2<br />
≈<br />
≈<br />
E866 <strong>Drell</strong>-<strong>Yan</strong><br />
γ*<br />
⎛ 1<br />
⎜1+<br />
1 ⎝ 4<br />
2 ⎛ 1<br />
⎜<br />
1+<br />
d<br />
⎝ 4 u<br />
1 ⎛ d(<br />
⎜<br />
x<br />
⎜<br />
1+<br />
2 ⎝ u(<br />
x<br />
2<br />
2<br />
d<br />
µ -<br />
µ +<br />
( )<br />
u ( x1)<br />
( x1)<br />
d(<br />
( ) u(<br />
x<br />
1<br />
) ⎞<br />
⎟<br />
) ⎟<br />
⎠<br />
x<br />
1<br />
⎞<br />
⎟<br />
⎠ ⎛ d(<br />
⎜<br />
x<br />
⎜<br />
1+<br />
x ⎞ 2)<br />
⎟ ⎝ u(<br />
x<br />
) ⎟<br />
x2<br />
⎠<br />
2<br />
2<br />
) ⎞<br />
⎟<br />
) ⎟<br />
⎠
• Fermilab Meson East Building<br />
• 800 GeV proton beam<br />
• 0.04 < x < 0.35<br />
• Uncertainties dominated by<br />
statistics (~1% systematic<br />
uncertainties in cross section<br />
ratio)<br />
σ<br />
2σ<br />
pd<br />
pp<br />
|<br />
x<br />
1<br />
>><br />
x<br />
2<br />
≈<br />
≈<br />
E866 <strong>Drell</strong>-<strong>Yan</strong><br />
⎛ 1<br />
⎜1+<br />
d<br />
1 ⎝ 4<br />
2 ⎛ 1<br />
⎜<br />
1+<br />
d<br />
⎝ 4 u x<br />
1 ⎛ d(<br />
) ⎞<br />
⎜<br />
x2<br />
⎟<br />
⎜<br />
1+<br />
2 ⎟<br />
⎝ u(<br />
x2)<br />
⎠<br />
( )<br />
u ( x1)<br />
( x1)<br />
d(<br />
( ) u(<br />
1<br />
x<br />
1<br />
⎞<br />
⎟<br />
⎠ ⎛ d(<br />
⎜<br />
x<br />
⎜<br />
1+<br />
x ⎞ 2)<br />
⎟ ⎝ u(<br />
x<br />
) ⎟<br />
x2<br />
⎠<br />
2<br />
2<br />
) ⎞<br />
⎟<br />
) ⎟<br />
⎠
Main Injector 120 GeV<br />
Tevatron 800 GeV
Abilene Christian University<br />
Obiageli Akinbule<br />
Brandon Bowen<br />
Mandi Crowder<br />
Tyler Hague<br />
Donald Isenhower<br />
Ben Miller<br />
Rusty Towell<br />
Marissa Walker<br />
Shon Watson<br />
Ryan Wright<br />
Academia Sinica<br />
Wen-Chen Chang<br />
Yen-Chu Chen<br />
Shiu Shiuan-Hal<br />
Da-Shung Su<br />
Argonne <strong>National</strong> Laboratory<br />
John Arrington<br />
Don Geesaman*<br />
Kawtar Hafidi<br />
Roy Holt<br />
Harold Jackson<br />
David Potterveld<br />
Paul E. Reimer*<br />
Josh Rubin<br />
University of Colorado<br />
Joshua Braverman<br />
Ed Kinney<br />
Po-Ju Lin<br />
Colin West<br />
E-906/<strong>SeaQuest</strong> Collaboration<br />
Fermi <strong>National</strong> Accelerator Laboratory<br />
Chuck Brown<br />
David Christian<br />
University of Illinois<br />
Bryan Dannowitz<br />
Dan Jumper<br />
Bryan Kerns<br />
Naomi C.R Makins<br />
Jen-Chieh Peng<br />
KEK<br />
Shin'ya Sawada<br />
Kyoto University<br />
KenIchi Imai<br />
Tomo Nagae<br />
Ling-Tung University<br />
Ting-Hua Chang<br />
Los Alamos <strong>National</strong> Laboratory<br />
Gerry Garvey<br />
Mike Leitch<br />
Han Liu<br />
Ming Xiong Liu<br />
Pat McGaughey<br />
University of Maryland<br />
Betsy Beise<br />
Kaz Nakahara<br />
University of Michigan<br />
Chiranjib Dutta<br />
Wolfgang Lorenzon<br />
Richard Raymond<br />
<strong>National</strong> Kaohsiung Normal University<br />
Rurngsheng Guo<br />
Su-Yin Wang<br />
University of New Mexico<br />
Imran Younus<br />
RIKEN<br />
Yuji Goto<br />
Atsushi Taketani<br />
Yoshinori Fukao<br />
Manabu Togawa<br />
Rutgers University<br />
Lamiaa El Fassi<br />
Ron Gilman<br />
Ron Ransome<br />
Elaine Schulte<br />
Brian Tice<br />
Ryan Thorpe<br />
Yawei Zhang<br />
Texas A & M University<br />
Carl Gagliardi<br />
Robert Tribble<br />
Thomas Jefferson <strong>National</strong> Accelerator Facility<br />
Dave Gaskell<br />
Patricia Solvignon<br />
Tokyo Institute of Technology<br />
Toshi-Aki Shibata<br />
Ken-ichi Nakano<br />
Yamagata University<br />
Yoshiyuki Miyachi<br />
*Co-Spokespersons
• 120 GeV proton beam<br />
(E866: 800 GeV)<br />
– cross section scales as 1/s:<br />
7x statistics<br />
– background scales as s:<br />
7x luminosity<br />
�50x statistics<br />
• Systematic uncertainties<br />
~1%<br />
<strong>E906</strong> <strong>Drell</strong>-<strong>Yan</strong><br />
What happens at high x?
Other Physics to be Probed with <strong>Drell</strong>-<strong>Yan</strong><br />
Partonic energy loss in nuclei<br />
• Beam quark lose energy as it penetrates nucleus<br />
� shift in observed parton momentum fraction<br />
�measure energy loss by using different size nuclei<br />
� establish a baseline for energy loss expected in heavy<br />
ion collision
<strong>Drell</strong>-<strong>Yan</strong> Spectrometer for E-906<br />
Liquid H 2, d 2, and<br />
solid targets<br />
Hadron Absorber
• Statistics are better, but some issues to keep in mind:<br />
• Lower particle energy � increased muonic decay of hadronic<br />
background<br />
• Lower energy muons multiple scatter more readily in the hadron<br />
absorber
Magnet Installation<br />
• Focusing magnet (FMAG) installed<br />
• Momentum measuring magnet (KMAG) installed<br />
• Hadron absorber<br />
• Beam dump (watch muons from J/ψ)
<strong>E906</strong> Beam<br />
• 53 MHz beam repetition frequency (18.9ns)<br />
• 5 seconds every minute: 2 ×10 12 protons/sec<br />
(4 kW beam, 5 W deposited on target,1 ×10 13 protons/min)<br />
• at least 5.2 ×10 18 total protons for experiment<br />
18.9 ns RF buckets<br />
6 trains of 81 RF buckets<br />
5 seconds<br />
. . .
<strong>E906</strong> Target<br />
• 2 liter LH 2 and LD 2 target flasks<br />
• Empty target for target systematics<br />
• Solid targets (C, W, Ca, ??)<br />
• Targets on movable table: change<br />
targets between pulses (each min)<br />
• Closed circuit GM cryocoolers cools a<br />
condenser<br />
• H 2/D 2 liquifies in condenser � drips<br />
(fills) into target flask
Detectors<br />
• Station 1: MWPC (Multi-Wire Proportional Chamber)<br />
• Station 2: E866 Station 2<br />
• Station 3: Two halves<br />
– Lower half: E866 Drift Chamber<br />
– Upper half: Newly designed and constructed<br />
• Station 4: Muon Prop. Tubes<br />
• Hodoscope scintillators to trigger info. For all four stations
Schedule<br />
• First commissioning beam in July (?) 2010 depending on<br />
machine schedule.<br />
• <strong>Experiment</strong> with H2/D2 to begin late 2010.<br />
• Run with full beam ~2 years<br />
• Prospects for further <strong>Drell</strong>-<strong>Yan</strong> experiments at J-PARC (50<br />
GeV) or Fermilab Main Injector (60 GeV)<br />
Proposed<br />
Jan. 2007<br />
Expt.<br />
Funded<br />
Magnet Design <strong>Experiment</strong><br />
And construction Construction<br />
2008<br />
2009<br />
2010<br />
<strong>Experiment</strong><br />
Runs<br />
2011<br />
2012<br />
J-PARC<br />
Publications
• <strong>E906</strong> experiment will extend the measurement of light antiquark<br />
asymmetries<br />
– to higher x<br />
– with greater statistics<br />
• Absolute pp, pd cross sections<br />
• Partonic energy loss<br />
• Structure of nucleonic matter<br />
• Commissioning to start in July<br />
• Data-taking to start late 2010
20<br />
u =<br />
Is in the proton?<br />
Gottfried Sum Rule<br />
1<br />
S = [( F ( x) − F ( x)) / x] dx<br />
G<br />
d<br />
∫<br />
0<br />
=<br />
p n<br />
2 2<br />
1 2 1<br />
= + ∫ ( u ( ) ( ))<br />
3 3 0<br />
p x − dp<br />
x dx<br />
1<br />
= ( ifup<br />
= dp)<br />
3
<strong>Drell</strong>-<strong>Yan</strong> fixed target experiments at Fermilab<br />
• What is the structure of the<br />
nucleon?<br />
➡ What is d / u?<br />
➡ What is the origin of the<br />
sea quarks?<br />
➡ What is the high x<br />
structure of the proton?<br />
• What is the structure of nucleonic matter?<br />
➡ Where are the nuclear pions?<br />
➡ Is anti-shadowing a valence effect?<br />
• Do colored partons lose energy in cold nuclear<br />
matter?<br />
• <strong>SeaQuest</strong>: 2010 - 2012<br />
➡ significant increase in physics reach<br />
• Beyond <strong>SeaQuest</strong><br />
➡ Polarized <strong>Drell</strong>-<strong>Yan</strong><br />
21 ➡ Pionic <strong>Drell</strong>-<strong>Yan</strong>
Other Physics to be Probed with <strong>Drell</strong>-<strong>Yan</strong><br />
• EMC effect<br />
� parton distributions of bound vs free nucleons<br />
• What can the sea parton distributions tell us about nuclear<br />
binding?<br />
• <strong>E906</strong>: Measure nuclear effects precisely
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