1. Drell-Yan実験 - Fermilab-E906/SeaQuest実験 - 偏極Drell-Yan実験の計画
放射線研PHENIXミーティング
2011年1月21日(金)
後藤雄二

2. Fermilab-E906/SeaQuest実験
Drell-Yan過程からのdimuonの測定
物理ランは今春開始
物理の結果はまだない
建設と設置が進行中
3月からビームを用いた調整
Fixed Target Beam lines
Tevatron 800 GeV
Main Injector 120 GeV
January 21, 2011

3. 実験の目標 Drell-Yan過程 核子構造 核物質 ハドロン同士の反応において最も単純な過程 ターゲットのsea-quark分布を選択
QCD終状態効果がない
ターゲットのsea-quark分布を選択
核子構造
水素および重水素標的
Sea-quark分布のフレーバー非対称性
Boer-Mulders分布関数
核子スピン構造との関連
核物質
原子核標的
パートンのエネルギー損失
EMC効果
January 21, 2011

4. Sea-quark分布のフレーバー非対称性
Fermilab E866/NuSea
Sea-quark分布のフレーバー非対称性
Ebeam = 800 GeV
x = 0.01 – 0.35 (valence region)
Fermilab E906/SeaQuest
Ebeam = 120 GeV
x = 0.1 – 0.45
競合する説明
摂動論的QCD
グルーオンの解離
非摂動論的QCDからの寄与
中間子雲模型
カイラルクォーク模型
January 21, 2011 4

5. EMC効果 1983年、EMC (European Muon Collaboration) がミューオンDIS実験において発見
原子核中のパートン分布が核子中の分布に対して修正を受ける
仮想中間子の交換が原子核中のパートン分布に修正を与える
現在あるDrell-Yan過程のデータには、この修正がないことが示唆される
Shadowing
Anti-Shadowing
EMC Effect
January 21, 2011

6. Fermilab E906/SeaQuest Collaboration
Abilene Christian University Obiageli Akinbule Brandon Bowen Mandi Crowder Tyler Hague Donald Isenhower Ben Miller Rusty Towell Marissa Walker Shon Watson Ryan Wright Academia Sinica Wen-Chen Chang Yen-Chu Chen Shiu Shiuan-Hal Da-Shung Su Argonne National Laboratory John Arrington Don Geesaman* Kawtar Hafidi Roy Holt Harold Jackson David Potterveld Paul E. Reimer* Josh Rubin University of Colorado Joshua Braverman Ed Kinney Po-Ju Lin Colin West
Fermi National Accelerator Laboratory
Chuck Brown David Christian
University of Illinois
Bryan Dannowitz Dan Jumper Bryan Kerns Naomi C.R Makins Jen-Chieh Peng
KEK
Shin'ya Sawada
Ling-Tung University
Ting-Hua Chang
Los Alamos National Laboratory
Gerry Garvey Mike Leitch Han Liu Ming Xiong Liu Pat McGaughey
University of Maryland
Prabin Adhikari Betsy Beise Kaz Nakahara
University of Michigan
Brian Ball Wolfgang Lorenzon Richard Raymond
National Kaohsiung Normal University
Rurngsheng Guo Su-Yin Wang
RIKEN
Yuji Goto Atsushi Taketani Yoshinori Fukao
Rutgers University
Lamiaa El Fassi Ron Gilman Ron Ransome Elaine Schulte Brian Tice Ryan Thorpe Yawei Zhang
Texas A & M University
Carl Gagliardi Robert Tribble
Thomas Jefferson National Accelerator Facility
Dave Gaskell Patricia Solvignon
Tokyo Institute of Technology
Toshi-Aki Shibata
Ken-ichi Nakano
Florian Sanftl
S. Miyasaka
S. Takeuchi
Yamagata University
Yoshiyuki Miyachi
*Co-Spokespersons
January 21, 2011

7. スケジュール http://www.fnal.gov/directorate/program_planning/schedule/
January 21, 2011

8. Fermilab E906/SeaQuest timeline
2001年: Fermilab PACにより採択
2007年: DOE nuclear physicsから資金を得る
2008年-2009年: Fermilab所長によるステージ２採択およびFermilabとE906 collaborationの間でMoU (Memorandum of Understanding)が交わされる
2009年-2010年: 実験装置の建設および設置
2011年3月: ビームを用いた実験調整開始
2011年-2013年: 物理データ集積
2009
2008
2011
Publications
Expt. Funded
2010
Magnet Design Experiment
and Construction Construction
Proposed
Jan. 2007
Experiment
Runs
2012
January 21, 2011

9. Dimuon spectrometer KMAG FMAG Momentum analysis Focusing magnet
Hadron absorber
Beam dump
Momentum
analysis
FMAG
KMAG
January 21, 2011

10. NM4 hall (ex KTeV hall) & magnets
FMAG
KMAG
January 21, 2011

11. 水素/重水素標的 Cryocooler compressor Cryocooler coolhead Condenser
Vacuum vessel
Target test flask
January 21, 2011

12. Station 3 ドリフトチェンバー 日本で建設 航空便で日本からFermilabへ輸送 2010.7.2 RIKEN
January 21, 2011

13. 飛跡検出器、エレキ Station 4 proportional tubes Hodoscopes for dimuon trigger
Latch
/TDC
ASDQ card
PAD card
Readout electronics
January 21, 2011

14. ここまでのまとめ Fermilab-E906/SeaQuest実験 立ち上げの現状 Drell-Yan過程からのdimuon測定
核子構造
Sea-quark分布のフレーバー非対称性
Boer-Mulders分布関数
核物質
EMC効果
パートンのエネルギー損失
立ち上げの現状
建設と設置が進行中
ビームライン、電磁石、飛跡検出器、ガス、エレキ、トリガー、ＤＡＱ
Station 3 ドリフトチェンバーを日本で建設、2010年7月に航空便でFermilabへ輸送
2011年3月からビームを用いた調整
ビームの理解、検出器ゲイン・タイミング、トリガータイミング・レート・マトリクス、位置合わせ、ＤＡＱ、データ解析
今春物理データ収集を開始、2013年まで2年間集積
January 21, 2011

15. Introduction Transverse-spin asymmetry measurement
Theoretical development to understand the transverse structure of the nucleon
Sivers effect, Collins effect, higher-twist effect, …
Relation to orbital angular momentum inside the nucleon
FNAL-E704 s = 20 GeV
RHIC-STAR s = 200 GeV
There are measurement of the transverse-spin asymmetries.
Large asymmetries in the forward region were shown in FNAL-E704 experiment, and also at RHIC, though the energy scale is 10-times different.
In order to explain these and many other transverse-spin asymmetry data, there have been many theoretical developments to understand the transverse structure of the nucleon, for instance by Sivers effect, Collins effect, and higher-twist effect, and these are expected to have relation to orbital angular momentum inside the nucleon.
January 21, 2011 15

16. Introduction Transverse structure of the proton
Transversity distribution function
Correlation between nucleon transverse spin and parton transverse spin
TMD distribution functions
Sivers function
Correlation between nucleon transverse spin and parton transverse momentum (kT)
Boer-Mulders function
Correlation between parton transverse spin and parton transverse momentum (kT)
To investigate the transverse structure of the proton, one important extension of the parton distribution function is a transverse-momentum dependent (TMD) distribution functions shown in this table.
Three important functions are transversity distribution functions, Sivers function, and Boer-Mulders function. These are shown in the table of leading-twist transverse-momentum dependent distribution functions.
The transversity distribution shows …, Sivers function shows …, and Boer-Mulders function shows ….
Leading-twist transverse momentum dependent (TMD) distribution functions
January 21, 2011 16

17. Sivers function Single-spin asymmetry (SSA) measurement
M. Anselmino, et al.
EPJA 39, 89 (2009)
Single-spin asymmetry (SSA) measurement
< 1% level multi-points measurements have been done for SSA of DIS process
Valence quark region: x = – 0.3
(more sensitive in lower-x region)
Sivers function
u-quark
d-quark
Because one of the most important goal of the experiment is the measurement and determination of the Sivers function, I show one more slide for the Sivers function.
It is measured and determined by the single-spin asymmetry measurement.
In the DIS, or deep-inelastic scattering experiment, it has already been measured less than 1% level multi-point measurement whose x-region x = to 0.3 covers the valence quark region around x around 0.2.
These are HERMES result and COMPASS result of the SSA measurement of semi-inclusive DIS with pi0, pi+ and pi- measurement.
Using these data, this is the global-fitting result of the Sivers function of u-quark and d-quark by Anselmino’s group.
January 21, 2011 17

18. Single transverse-spin asymmetry
Sivers function
Correlation between nucleon transverse spin and parton transverse momentum (Sivers distribution function)
Related to the orbital angular momentum in the proton (and the shape of the proton)
“Non-universality” of Sivers function
Sign of Sivers function determined by SSA measurement of DIS and Drell-Yan processes should be opposite each other
final-state interaction with remnant partons in DIS process
Initial-state interaction with remnant partons in Drell-Yan process
Fundamental QCD prediction
One of the next milestones for the field of hadron physics
Our important goal is a measurement of the Sivers function, which describe “correlation between …” and related to the orbital angular momentum
The reason of the importance is its “non-universality” which has already discussed by many speakers in this workshop.
“Sign of Sivers function …” because there is final-state interaction with remnant partons in DIS process, and there is initial-state interaction with remnant partons in Drell-Yan process.
This is a fundamental QCD prediction, and one of the next milestones for the field of hadron physics.
January 21, 2011 18

19. Future polarized Drell-Yan experiments
particles
energy
x1 or x2
luminosity
COMPASS
+ p
160 GeV
s = 17.4 GeV
x2 = 0.2 – 0.3
2 × 1033 cm-2s-1
(low mass)
x2 ~ 0.05
PAX
p + pbar
collider
s = 14 GeV
x1 = 0.1 – 0.9
2 × 1030 cm-2s-1
PANDA
pbar + p
15 GeV
s = 5.5 GeV
x2 = 0.2 – 0.4
2 × 1032 cm-2s-1
J-PARC
p + p
50 GeV
s = 10 GeV
x1 = 0.5 – 0.9
1035 cm-2s-1
NICA
s = 20 GeV
x1 = 0.1 – 0.8
1030 cm-2s-1
RHIC PHENIX
Muon
s = 500 GeV
x1 = 0.05 – 0.1
RHIC Internal
Target phase-1
250 GeV
s = 22 GeV
x1 = 0.2 – 0.5
Target phase-2
3 × 1034 cm-2s-1
This is a table of proposed polarized Drell-Yan experiments in the world.
In Europe, there are plans at COMPASS and GSI/FAIR.
At COMPASS, it is a pion-induced experiment, and at GSI/FAIR, it is proton + antiproton experiments.
In my talk, I will discuss plans at RHIC and J-PARC.
Both are proton + proton Drell-Yan experiments.
January 21, 2011 19

20. Polarized Drell-Yan experiments at RHIC
“Transverse-Spin Drell-Yan Physics at RHIC”
Les Bland, et al., May 1, 2007
s = 200 GeV
PHENIX muon arm
STAR FMS (Forward Muon Spectrometer)
Discussions at PHENIX and STAR underway in their decadal plan discussion with their upgrade plan
Two new Letter-of-Intent submitted to BNL PAC
Collider experiment dedicated to the polarized Drell-Yan experiment
“Feasibility Test of Large Rapidity Drell-Yan Production at RHIC”
Fixed-target experiment
“Measurement of Dimuons from Drell-Yan Process with Polarized Proton Beams and an Internal Target at RHIC”
For the polarized Drell-Yan experiements, there was one proposal made in 2007 by Les Bland, et al. which showed sensitivity with 200 GeV collisions with existing PHENIX muon arm and STAR FMS.
The figure shows the sensitivity of both PHENIX and STAR compared with theory calculation.
Recently discussions at PHENIX and STAR are underway in their decadal plan discussion with their upgrade plan.
In addition to these, there are two new letter-of-intent submitted to BNL PAC this year.
One is a collider experiment…
Another is a fixed target expriment…
January 21, 2011 20

21. Collider experiment LoI
I just show two pages from the collider experiment LoI whose title is “Feasibility Test of Large Rapidity Drell-Yan Production at RHIC”.
They want to start with a test experiment.
This is the first page which show the authors from institutes from USA and Russia.
January 21, 2011 21

22. Collider experiment LoI
And this is their proposed final form of the experiment which identifies e+e- pair from the polarized proton-proton collision at here, interaction point.
Detector consists of magnets, fiber trackers, MWPC, and EM & Hadron calorimeters.
January 21, 2011 22

23. Fixed-target experiment LoI
Measurement of Dimuons from Drell-Yan Process with Polarized Proton Beams and an Internal Target at RHIC
Academia Sinica (Taiwan): W.C. Chang
ANL (USA): D.F. Geesaman, P.E. Reimer, J. Rubin
UC Riverside (USA): K.N. Barish
UIUC (USA): M. Groose Perdekamp, J.-C. Peng
KEK (Japan): N. Saito, S. Sawada
LANL (USA): M.L. Brooks, X. Jiang, G.L. Kunde, M.J. Leitch, M.X. Liu, P.L. McGaughey
RIKEN/RBRC (Japan/USA): Y. Fukao, Y. Goto, I. Nakagawa, K. Okada, R. Seidl, A. Taketani
Seoul National Univ. (Korea): K. Tanida
Stony Brook Univ. (USA): A. Deshpande
Tokyo Tech. (Japan): K. Nakano, T.-A. Shibata
Yamagata Univ. (Japan): N. Doshita, T. Iwata, K. Kondo, Y. Miyachi
I will mainly discuss the fixed-target experiment LoI whose title is “Measurement of Dimuons from Drell-Yan Process with Polarized Proton Beams and an Internal Target at RHIC”
This is the author list of the Letter-of-Intent, which consists of institutes from Taiwan, USA, Japan and Korea.
It involve collaborators from Fermilab-E906/SeaQuest, Academia Sinica and Argonne, and from COMPASS, Yamagata Univ.
January 21, 2011 23

24. IP2 (overplotted on BRAHMS)
Internal target position
St.4
MuID
St.1
St.2
St.3
F MAG3.9 m
Mom.kick
2.1 GeV/c
KMAG 2.4 m
Mom.kick
0.55 GeV/c
The IP of the IP2 is at the center of this figure. Internal target is assumed to be located at here. 14 meter is available for detector apparatus.
The assumption of the momentum kick by the first magnet is 2.1 GeV/c and that by the second magnet is 0.55 GeV/c.
These red and green lines show simulated tracks of mu+ and mu- of 100 fast simulation events.
14 m
18 m
January 21, 2011 24

25. Experimental sensitivities
PYTHIA simulation
s = 22 GeV (Elab = 250 GeV)
luminosity assumption 10,000 pb-1
Phase-1 (parasitic operation) 10,000 pb-1
Phase-2 (dedicated operation) 30,000 pb-1
4.5 GeV < M < 8 GeV
acceptance for Drell-Yan dimuon signal is studied
all generated
dumuon from
Drell-Yan
accepted by
all detectors
To estimate the experimental sensitivities, we performed a PYTHIA simulation under conditions of E_beam = 250 GeV, or sqrt(s) = 22 GeV and luminosity assumption 10,000 pb^-1.’
For the internal-target experiment, about 10 times larger luminosity is necessary than that of the collider experiments because of about 10 times smaller cross section x acceptance in the same mass region.
We investigate dimuon mass region from 4.5 GeV to 8 GeV.
The black histogram shows all generated dimuons from Drell-Yan process and the blue histogram shows accepted by the detectors.
January 21, 2011 25

26. Experimental sensitivities
About 50K events for 10,000pb-1 luminosity
x-coverage: 0.2 < x < 0.5
Mass
(GeV/c2)
Total
Rapidity
45 – 50
50 – 60
60 – 80
45 – 80
-0.4 – 0
3.1 K
1.4 K
7.6 K
0 – 0.4
6.2 K
6.1 K
3.0 K
15.3 K
0.4 – 0.8
6.4 K
2.3 K
16.3 K
0.8 – 1.2
4.4 K
2.5 K
0.4 K
7.3 K
x1: x of beam proton (polarized)
x2: x of target proton
About 50K events are detected in the detector acceptance for 10,000 pb^-1 luminosity.
The table shows number of events for each rapidity and dimuon mass bins.
This figure show x1 vs x2, where x1 is x of polarized beam proton and x2 is x of target proton.
This is a projection to x1 which show expected x-coverage 0.2 < x < 0.5.
January 21, 2011 26

27. Experimental sensitivities
Phase-1 (parasitic operation)
L = 2×1033 cm-2s-1
10,000 pb-1 with 5×106 s ~ 8 weeks, or 3 years (10 weeks×3) of beam time by considering efficiency and live time
Phase-2 (dedicated operation)
L = 3×1034 cm-2s-1
30,000 pb-1 with 106 s ~ 2 weeks, or 8 weeks of beam time by considering efficiency and live time
Theory calculation:
U. D’Alesio and S. Melis, private communication;
M. Anselmino, et al., Phys. Rev. D79, (2009)
Measure not only the sign of the Sivers function but also the shape of the funcion
From phase1 and phase1+phase2, our expected error bar of the single-spin asymmetry measurement is shown in this figure.
It is compared with theory calculation provided by Umberto D’Alesio and Stefano Melis based on the paper by Anselmino’s group.
By combining, we want to measure not only the sign of the Sivers function but also the shape of the function.
10,000 pb-1 (phase-1)
40,000 pb-1 (phase-1 + phase-2)
January 21, 2011 27

28. Summary Polarized Drell-Yan measurement
The simplest process in hadron-hadron reaction
But, not yet done because of technical difficulties so far
Sivers function measurement in the valence-quark region from the SSA of Drell-Yan process
Test of the QCD prediction “Sivers function in the Drell-Yan process has an opposite sign to that in the DIS process”
Milestone for the field of hadron physics
RHIC
Existing collider experiments (PHENIX/STAR)
Two new LoI’s – collider exp. and fixed-target exp.
Internal-target polarized Drell-Yan experiment at RHIC
250 GeV transversely polarized proton beam, s = 22 GeV
Dimuon spectrometer based on FNAL-E906 spectrometer
Measurement not only the sign of the Sivers function, but also the shape of the function feasible
This is the summary…
January 21, 2011 28

29. Backup slides

30. Shipping St.3+ Chamber from Japan to Fermilab
Concerns
Heat expansion of the metal parts
Requirement on the specification document: 10 deg. to 40 deg. in celcius.
The package was covered by “PROTECT SHEET” to prevent heat and humidity indide.
Gas expansion due to pressure drop in the air
May cause breaking of the window sheets.
Inner volume of the chamber can be ventilated through the gas inlets/outlets.
Shock
The chamber was laid down on a flat base with shock-absorbing forms.
“Shock wathch” and “Tilt watch” were on the surface of the package to warn workers to handle it carefully.
Threshhold of the “Shock watch” was 80G/50msec (Morimatsu L-47).
January 21, 2011

31. Shipping document (RIKEN, July 2, 2010)
January 21, 2011

32. Shipping document (Fermilab, July 20, 2010)
January 21, 2011

33. Shipping: Result ORD to Fermilab (truck) RIKEN to Narita (truck)
Narita to ORD (air freighter)
Stored near Narita with air conditioning
Stored near ORD without air conditioning
No wire breaking, no damage on the windows.
Temperature: stable, 19.6 (in aircraft) – 29.4 (near ORD) deg. (C)
Humidity: low around 20%. Spikes in the aircraft may be due to gas flows caused by pressure change.
Shocks: 4.080G on the way from RIKEN to Narita, 4.821G at Narita, 5.770G at O’Hare. Acceleration was detected mainly for the vertical direction.
January 21, 2011

34. Status Component Projected Ready Comments/Issues Beam Line
Early to Mid July ????
Target
When needed -Aug
Magnets
Mid June
Sta 1 DC
October
Hodo 1 and 2
1 July
Support Structure, Cabling, Electronics
Sta 2 DC
Ready
Cabling, Electronics
Absorber wall
Needed before Support Structure for 3 and 4
Sta 3 DC – Lower, New
Ready, Early July
Sta 3 and 4 Scin
Early July
Support Structure, Electronics
Prop Tubes
Gas System
Pre mix in July as fall back
Preamps
?????????
TDC’s
??????????
Latches
August
Trigger
Calibration triggers
Scalers
Not a major effort, but need organizing
DAQ
?????
January 21, 2011

35. Fermilab E906/SeaQuest timeline
Commissioning with beam from October 2010
Understand Beam
Check detector gains and thresholds with minimum ionizing particles
Set detector timing
Set trigger timing
Measure rates in a systematic way – multiple KMAG fields
Take data to align spectrometer – KMAG magnet on and magnet off
Take data to study trigger matrices
Exercise DAQ and analysis chain
Phsics run will start in 2010 for 2-year data collection until 2013
January 21, 2011