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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Tony’s perspective (ca. 1977)

Courtesy of J. Carlson

Happy Birthday!

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Nucleon-Nucleon Models

Hadronic Probes

Neutron Target

Subnucleonic Effects

Standard Model

The Deuteron has an Extraordinary Role in Nuclear Physics

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Tony’s 1977 letter on pion-deuteron scattering

“It [t20] is a very interesting quantity to measure …”

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Scattering from aligned Deuterons

MS=1, -1

MS=0

Spin 1 nucleus:

MS = 1

MS = 0

MS =-1

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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)

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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 , …

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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

91983

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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)

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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

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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

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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

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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!

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World’s Data for Electron-Deuteron Scattering

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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

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Fast forward – Jefferson Lab

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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.

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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

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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)

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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)

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E12-06-118 Projected Results

• JLab E12-06-118, G. Petratos, J. Gomez, R. J. Holt, R. Ransome et al

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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

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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!