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From the nucleus to the quarks
Roy J. Holt
Achievements and Future Directions in Subatomic Physics:A Workshop in honor of Tony Thomas’ 60th birthday
Adelaide15-19 February 2010
Argonne National Laboratory
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Nucleon-Nucleon Models
Hadronic Probes
Neutron Target
Subnucleonic Effects
Standard Model
The Deuteron has an Extraordinary Role in Nuclear Physics
Argonne National Laboratory
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Tony’s 1977 letter on pion-deuteron scattering
“It [t20] is a very interesting quantity to measure …”
Argonne National Laboratory
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Scattering from aligned Deuterons
MS=1, -1
MS=0
Spin 1 nucleus:
MS = 1
MS = 0
MS =-1
Argonne National Laboratory
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Los Alamos Meson Physics Facility (LAMPF)
Series of three pion-deuteron scattering experiments at LAMPF
•Exp. 388 (LEP)
•Exp. 483 (LEP)
•Exp. 673 (P3)
Argonne National Laboratory
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Issues in Pion-Deuteron Elastic Scattering (ca. 1982)
Pion Absorption
Dibaryon Resonances??
Exact three-body calculations– Afnan, Thomas,…
Relativistic Include absorption
– Rinat, Thomas et al.– Giraud et al– Blankleider and Afnan– Betz and Lee– Lee and Matsuyama– Garcilazo
d
d
1D2 , 3F3 , …
Argonne National Laboratory
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Polarization in Pion-Deuteron Elastic Scattering
R. J. Holt et al, PRL 43 (1979) 1229R. J. Holt et al, PRL 47 (1981) 472E. Ungricht et al, PRL 52 (1984) 333
The LAMPF Experiments
First polarization experiments in pion-deuteron scattering
Argonne National Laboratory
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Pion-Deuteron Scattering Puzzle
E. Ungricht et al, PRC 31 (1985) 934
Calculations that don’t include pion absorption agree best with the data!!
Betz & Lee
Blankleider & Afnan
Fayard et al
Rinat et al
Garcilazo
Confirmed by TRIUMF data: G. Smith et al, PRC 38 (1988) 251.
Jennings & Rinat, NP A (1988)
Argonne National Laboratory
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Elastic Scattering from the Deuteron
Cross section depends on three electromagnetic form factors:
e’
e q=pe-pe’
d d’
Electron-deuteron scattering Measure another quantity:Scatter from aligned deuterons
MS=1, -1
MS=0
Argonne National Laboratory
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Issues in Electron-Deuteron Elastic Scattering Meson-Exchange Models
– Wiringa, Schiavilla, et al.– Chung, Coester, Polyzou, Hummel, Tjon,
Phillips, Wallace, Gross, van Orden, et al.
QCD Inspired Models– Reduced Nuclear Amplitudes
• Brodsky, Chertok, Hiller, Ji– Constituent Counting Rule
• Brodsky, Farrar, LePage, Matveev et al
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First t20 Experiment in Electron-Deuteron Scattering
M. E. Schulze et al., PRL 52 (1984)
First experiment in the South Hall at MIT-Bates
Argonne National Laboratory
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Polarized Deuterium Gas Target in the VEPP-3 Electron Storage RingArgonne-Novosibirsk Collaboration
R. Gilman et al., PRL 65 (1990) 1733
• First use of a storage cell for polarized gas targets in a storage ring• Proof of principle for HERMES: DESY PRC
2 GeV200 mA
Argonne National Laboratory
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Polarized Deuterium Gas Target in VEPP-3
D. Nikolenko et al, PRL 90 (2003)
Last published T20 measurement in e-d scattering!
Argonne National Laboratory
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Technology led to worldwide programs
Neutron andDeuteronPolarimeters
Storage Cells in Storage Rings
Laser-Driven Target
NovosibirskHERMES at DESY
MIT-Bates
IUCF Cooler
LAMPF
SIN/PSI
TRIUMFJefferson Lab
NIKHEF
Argonne
Argonne National Laboratory
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Two photon exchange in e-p elastic scattering
P. G. Blunden et al, PRC 72 (2005) 034612A.V. Afanasev et al, PRD 72 (2005) 013008J. Arrington et al, PRC 76 (2007) 035205J. Carlson, M. Vanderhaeghen, Annu. Rev. Nucl. Part. Sci. 57 (2007) 171
Golden mode: positron and electron elastic scattering from the proton
Rosenbluth data
Polarization transfer data
Courtesy of W. Melnitchouk
Three new experiments:
• BINP Novosibirsk – internal target
• JLab Hall B – LH2 target, CLAS
• DESY (OLYMPUS) - internal target
Argonne National Laboratory
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Very preliminary Novosibirsk datae+-p/e-- p cross section ratio
J. Arrington, L. M. Barkov, V. F. Dmitriev, V. V. Gauzshtajn, R. A Golovin, A. V. Gramolinv,R. J. Holt, V. V. Kaminsky, B. A. Lazarenko, S. I . Mishnev, N. Yu. Muchnoi, D. M. Nikolenko,A. V. Osipov, I. A. Rachek, R. Sh. Sadykov, Yu. V. Shestakov, V. N. Stibunov, H. de Vries,S. A. Zevakov, V. N. Zhilich ----- ANL, BINP, INP TPU, NIKHEF
Argonne National Laboratory
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Deep Inelastic Scattering and Structure Functions
Proton structure function:
Neutron structure function (isospin symmetry):
Ratio:
Nachtmann inequality:
Focus on high x:
leptonic hadronic
Parton model:
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The Neutron Structure Function at high x
SU(6) symmetry
pQCD
Scalar di-quark
Reviews: N. Isgur, PRD 59 (1999), S Brodsky et al NP B441 (1995),W. Melnitchouk and A. Thomas PL B377 (1996) 11.
Argonne National Laboratory
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Extractions with modern deuteron wave functions
Courtesy of J. Arrington
J. Arrington et al, J. Phys. G 36 (2009)
The ratio at high x has a strong dependence on deuteron structure.
• Lorentz invariant convolution relation
• Light front with null plane kinematics
Argonne National Laboratory
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Nuclear Physicists’ Approach to F2n
Problems:– The proton experiments are difficult and costly. – The deuteron experiments present extraction
complications.
Nuclear physicists’ solution: Add another nucleon.
I. Afnan et al, PRC 68 (2003)
Argonne National Laboratory
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Ratio of 3He, 3H JLab E12-06-118 Measure F2’s and form ratios:
Form “super-ratio”, r, then
where
Theoretically,
I. Afnan et al, PRC 68 (2003)
Argonne National Laboratory
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E12-06-118 Projected Results
• JLab E12-06-118, G. Petratos, J. Gomez, R. J. Holt, R. Ransome et al
Argonne National Laboratory
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Tritium target design must pass safety hurdle at JLab
Tritium Target Task Force
E. J. Beise (U. of Maryland) B. Brajuskovic (Argonne)
R. J. Holt (Argonne)W. Korsch (U. of Kentucky)
D. Meekins (JLab)T. O’Connor (Argonne)
G. G. Petratos (Kent State U.) R. Ransome (Rutgers U.)
P. Solvignon (JLab) B. Wojtsekhowski (JLab)
Review: June 2010
Argonne National Laboratory
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Tritium Targets at Electron Accelerators
Lab Year Quantity(kCi)
Thickness(g/cm2)
Current(A)
Current x thickness
(A-g/cm2)
Safe FOM(A-g/
cm2/kCi)
StanfordHEPL
1963 25 0.8 1 0.8 0.03
MIT-Bates 1982 180 0.3 20 6.0 0.03
Saclay 1985 10 1.1 15 16.0 1.6
JLab 201? 1.6 0.13 30 3.9 2.4
JLab also has a huge spectrometer acceptance advantage, eg. SBS
Argonne National Laboratory
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Summary
Tony and colleagues have had a profound influence on experimental nuclear physics.
Pion- and electron-deuteron scattering drove polarization technology. Development of the polarization technology has been extraordinarily fruitful
– HERMES, MIT-Bates, Novosibirsk, NIKHEF, JLab, ... Latest internal target experiment: best evidence for 2-photon exchange Scientific stage being set at JLab for d/u ratio measurement using
polarization in isospin space: 3H/3He
Happy Birthday Tony!