View
50
Download
0
Category
Preview:
DESCRIPTION
Commissioning Status of the Drift Chamber for a Di-Muon Spectrometer at the E906/ SeaQuest Experiment at Fermilab. Florian Sanftl , 柴田研究室. 2011 年 10 月 24 日 , GCOE コロキウム @ 東工大. Outline. Physics Motivation & Introduction E906/ SeaQuest : Physics Goal Muon Pair Spectrometer - PowerPoint PPT Presentation
Citation preview
Commissioning Status of the Drift Chamber for a Di-Muon Spectrometer at the E906/SeaQuest
Experiment at Fermilab
2011 年 10 月 24 日 , GCOE コロキウム @ 東工大
Florian Sanftl, 柴田研究室
2
Outline
1) Physics Motivation & Introduction2) E906/SeaQuest: Physics Goal3) Muon Pair Spectrometer4) Design and Commissioning of Drift Chamber built by
Japanese Group5) Track Reconstruction Algorithm / XT curve / position
resolution of charged particles6) Conclusion & Outlook
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
3
Photon
e+
e-
1) Physics Introduction & Motivation
Proton Three “Valence” quarks 2 “up” quarks (q = +⅔) 1 “down” quark (q = -⅓)
Bound together by gluons Gluons can split into quark-
antiquark pairs (similar to the photon splitting into a electron-positron pair)
The Proton “Sea” is formed ofquarks and antiquarks
What is the Proton?
Gluons
Sea-quarks
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
4
Purpose of our Study
Is ū = đ valid in the Proton?
Is there a Flavor Asymmetry of Anti-quarks in the Proton?
đ - ū ≠ 0?
đ/ū ≠ 1?
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
5
How can we measure Sea-Quarks?
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
Deep Inelastic Scattering (DIS) Drell-Yan Process
Electron beam scatters off a proton Electromagnetic interaction
between electron and quark Comparing electron before and
after interaction reveals information about the proton structure
Proton beam scatters off a proton Quark and anti-quarks annihilate
into virtual photon Virtual photon decays into two
muons Anti-quarks can be selected
Proton / Target
Proton / Beam
Proton
90° Rotation
6
Importance of ‘Bjorken-x’ xB and Q2
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
Q2:4-momentum transferred squared (“virtuality of photon”)Q2 = -q2 = 2EeE’e(1+cosθl)
Alternative way for Q2:Q2 also represents spatial resolution where proton is probedr = hc/Q = 0.2fm/Q[GeV]typically Q2 > 1GeV2, r < 0.2*10-15 m
Bjorken-x:xB = fractional momentum carried by the struck quarkxB = pQUARK / pPROTON
0 ≤ xB ≤ 1 q(xB,Q2):
probability to hit a quark with flavour q, xB and Q2
7
Experimental Results
2011 年 10 月 24 日
Unknown effects
apparently dilutes meson cloud effects
at large-x
NMC (Gottfried Sum Rule)
NA51 (Drell-Yan)
E866/NuSea (Drell-Yan)
ū ≠ đ
đ - ū đ / ū
GCOE コロキウム @ 東工大
8
2) The E906/SeaQuest Experiment
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
Old Experiment:Fermilab E866/NuSea
1H, 2H, and nuclear targets 800 GeV proton beam
New Experiment:Fermilab E906/SeaQuest
1H, 2H, and nuclear targets 120 GeV proton Beam
Higher Cross section and Less Background
50x statistics!!Fixed Target
Beam lines
Tevatron 800 GeV
Main Injector 120 GeV
9
Physics Goal
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
E906/Drell-Yan will extend old measurements toxB values > 0.3 and reduce statistical uncertainty.
25m
Solid Iron
Focusing Magnet,
Hadron absorber
and beam dump
4.9m
Mom. Meas.
(KTeV Magnet)
Hadron Absorber
(Iron Wall)
Station 1:
Hodoscope array
MWPC tracking
Station 4:
Hodoscope array
Prop tube tracking
Liquid H2, d2, and
solid targets
Station 2 and 3:
Hodoscope array
Drift Chamber tracking
Drawing: T. O’Connor and K. Bailey
Station 3: NEW from Tokyo Tech
2011 年 10 月 24 日 GCOE コロキウム @ 東工大 10
3) Muon Pair Spectrometer
• St. 4 Prop Tubes: Homeland Security via Los Alamos• St. 3 & 4 Hodo PMT’s: E-866, HERMES, KTeV• St. 1 & 2 Hodoscopes: HERMES• St. 2 & 3Minus- tracking: E-866• St. 3: NEW from Japanese Collaborators• St. 2 Support Structure: KTeV• Target Flasks: E-866• Cables: KTeV
• 2nd Magnet: KTeV Analysis Magnet• Hadron Absorber: Fermilab Rail Head???
• Solid Fe Magnet Coils: E-866 SM3 Magnet• Shielding blocks: old beamline (Fermilab Today)
• Solid Fe Magnet Flux Return Iron: E-866 SM12 Magnet
Expect to start collecting data this autumn!
2011 年 10 月 24 日 GCOE コロキウム @ 東工大 11
Motivation: Re-do, Re-use & Re-cylce
12
Spectrometer Top View
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
25 m
μ+
U U’V
XV’
X’
Cell Structure• Cell width & height 20 mm• Wire spacing 10 mm• Diameter sense wire (Au-W) 30 μm,
others (Au-CuBe) 80 μmPerformance Parameters• Gas-gain ~4.0E5• Drift velocity 3-6 cm / μsec (Ar:CO2)
2011 年 10 月 24 日 GCOE コロキウム @ 東工大 13
General Performance requirements• Detection Area:
1.6 m (vertical) x 2.2 m (horizontal)• 6 Active layers:
U/U’ (+14°), X/X’ (0°), V/V’ (-14°)• Position resolution: < 400 μm per planeGas Selection:• For now: Argon:CO2 (80:20)
4) Design of the New Drift Chamberμ+ / μ-
14
June, 2009
January, 2010
March, 2010
July, 2010
Now
STATUS of Station 3+ DC
Tests at RIKEN
Tests at Fermilab
Installation & Setup in
Spectrometer
Design completed
Fabrication completed
Transport to RIKEN
Transport to Fermilab
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
Commissioning Timeline
Measure time difference between trigger and Signal
from Chamber
Convert time to distance by
simulation(GARFIELD)
ReconstructTrack
(5 layer based)
2-dim distribution
Time vs. Distance
Project distance distributions and fit
for position resolution
Extract new time to distance relation
We are measuring:• Coincidence between
bottom and top scintillator caused by cosmic rays
• Time difference between coincidence and signal from chamber
Accepted Hits
Projected distance
2011 年 10 月 24 日 GCOE コロキウム @ 東工大 15
5) Track Reconstruction AlgorithmReconstructed track
Scintillator
Iteration
ScintillatorCosmic Ray
XT extraction:• 1st Iteration• Extracted curve agrees well with input
curve within uncertainties• Still too little statistics from the edge of
cell
2011 年 10 月 24 日 GCOE コロキウム @ 東工大 16
Deviation simulation between measurement:• Green bands is width of the projections• Those are constant over a wide T range• Band corresponds to position resolution
of 500μm• Tilting behavior due to statistical effects
Results and Discussion
2011 年 10 月 24 日 GCOE コロキウム @ 東工大 17
• E906/SeaQuest is a Drell-Yan experiment• It measures the asymmetry of anti-quarks in the proton• Tokyo Tech group designed and built and a new drift chamber• We prepared a Track Reconstruction Algorithm• Algorithm is working well• We already achieved a position resolution of 500μm which is very
close to the design value of 400μm• Improvement by more iterations• We are ready for the first beam in November 2011!!!
6) Conclusion and Outlook
18
The E906 Collaboration
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
Abilene Christian UniversityObiageli AkinbuleBrandon BowenMandi CrowderTyler HagueDonald IsenhowerBen MillerRusty TowellMarissa WalkerShon WatsonRyan Wright
Academia SinicaWen-Chen ChangYen-Chu ChenShiu Shiuan-HalDa-Shung Su
Argonne National LaboratoryJohn ArringtonDon Geesaman*Kawtar HafidiRoy HoltHarold JacksonDavid PotterveldPaul E. Reimer*Josh Rubin
University of ColoradoJoshua BravermanEd KinneyPo-Ju LinColin West
Fermi National Accelerator LaboratoryChuck BrownDavid Christian
University of IllinoisBryan DannowitzDan JumperBryan KernsNaomi C.R MakinsJen-Chieh Peng
KEKShin'ya Sawada
Ling-Tung UniversityTing-Hua Chang
Los Alamos National LaboratoryGerry GarveyMike LeitchHan LiuMing Xiong LiuPat McGaughey
University of MarylandPrabin AdhikariBetsy BeiseKaz Nakahara
University of MichiganBrian BallWolfgang LorenzonRichard Raymond
National Kaohsiung Normal UniversityRurngsheng GuoSu-Yin Wang
RIKENYuji GotoAtsushi TaketaniYoshinori FukaoManabu Togawa
Rutgers UniversityLamiaa El FassiRon GilmanRon RansomeElaine SchulteBrian TiceRyan ThorpeYawei Zhang
Texas A & M UniversityCarl GagliardiRobert Tribble
Thomas Jefferson National Accelerator FacilityDave GaskellPatricia Solvignon
Tokyo Institute of TechnologyToshi-Aki ShibataKenichi Nakano
Florian SanftlShintaro TakeuchiShou Miyasaka
Yamagata UniversityYoshiyuki Miyachi
19
Flavor Asymmetry: Models
2011 年 10 月 24 日 GCOE コロキウム @ 東工大
LA-LP-
98-56
Chiral Quark models—effective Lagrangians
Meson Cloud in the nucleon—Sullivan process in DIS
Instantons
Statistical Parton Distributions
Antiquarks in spin 0 object → No net spin
Pauli Blocking:Excess of up-quarks permits creation of up-anti-up-pairs
Recommended