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Hadrons and Cold Nuclear Matter Rapporteur Presentation. Donald Geesaman JLAB PAC 36 24 August 2010. A person appointed by a deliberative body to investigate an issue or a situation and report to that body. History – as started by Mont in his ascent to Nuclear Physics.
JLAB PAC 36
24 August 2010
A person appointed by a deliberative
body to investigate an issue or a situation
and report to that body
1983- EMC - Ratio of iron to deuterium
Note systematic errors are large and don’t show up on
1984-EMC- virtual photon energy dependence of leading hadron multiplicities
The Essence of Confinement
One of my criteria for a successful theoretical description is multiple phenomena should be described, both at the hadronic and parton levels.
Most models have limited x
interference or other hadrons
Either f(y) peaks below 1
or F2N modified in nucleus
As x-> 2 ratio goes to ~6
L ~ 2ν/Q2 ~ 1/x >2 fm
or gluon recombination
SLAC fit to heavy nuclei
(scaled to 3He)
Black points 3He
Benhar and Pandharipande 3He
Calculations by Pandharipande and Benhar for 3He and 4He
Magenta points 4He
I don’t like presenting
Isoscalar corrected ratio
Benhar and Pandharipande 4He
Kulagin and Petti (ArXiv:1004.3062v1) find in their model NMC d/p and JLab 3He/D give different F2n/F2p ratios. They advocate a 5% renormalization (~3 times published systematic error) of JLab data. I advocate reexamining isovector dependence of EMC effect.
If one understands parton propagation in nuclei, semi-inclusive DIS and flavor tagging could give insight into flavor dependence of EMC effect as it has for spin.HERMES has a new slant on the strange quark sea distributions. A. Airapetian et al Phys. Lett. B 666, 446 (2008)
Usually s(x)+sbar(x) ~ κ (ubar+ dbar) with κ~ 0.5
Best handle has been considered to be multi-muon events in neutrino scattering.
HERMES looks at DIS on deuterium and compares inclusive with semi-inclusive kaon multiplicities
A. Airapetian et al Phys. Lett. B 666, 446 (2008) Q2=2.5 GeV2
NUTEV, PRD 64 112006(2001)
CTEQ, JHEP 42, 89 (2007) Q2=1.69
vs 0.25 *HERMES
Based on the HERMES result and assuming the strange quark distribution represents the gluon-splitting induced distribution, the shape of the non-perturbative
is similar to
The primary question is can this precision be achieved.
Double ratios reduce systematics for measurements in two different spectrometers
Q2 < 1at JLab12 in shadowing region.
Kulagin and Petti
(1004.3062) take difference between NMC and HERMES as evidence of Q2 dependence from vector dominance description of shadowing
Stolen from John Arrington
emphasize/mimimize FSI and MEC?
d(,p) scales at E>1 GeV
pp(,p) may scale at E>2.5 GeV
Oscillation signal rescattering picture
Does not require 12 GeV
Using secondary interactions in a nuclear target to study cross sections for short lived objects to interact with nucleons and to determine time scales in strong interaction dynamics
Mostly taken from Accardi et al. RIVISTA DEL NUOVO CIMENTO 32, 439-553 (2009)
Overlap of target and projectile fragmentation regions at low z
Jlab has the luminosity to slice and dice this:CLAS12: 12-06-117Likely not have the ν range to reach non-interacting limit to separate energy loss from attenuation?
small size q-qbar pair with small color dipole
to measure formation length/transparency
both Q2 and range of formation and coherence
In non-diffractive channels, compact size of elementary interaction is still an issue.Many consider it a necessary condition for GPD applicability
No clear effect so far
Extend to Q2=16 GeV2 at 12 GeV
I am betting on no effect to higher Q2,
but it has to be measured.
First hint in non-diffractive production
Extend to Q2~9 GeV2
past the exploratory phase and
into a production phase for this
to realize its promise, i.e. not study
one or two levels but many.
Q2 = (k-k’)2 = mass2 of the virtual boson
x= Q2/(2m) is the fractional momentum nucleon carried by the parton
muon and electron scattering~
charge current scattering ~
anti- c. c. scattering~
parity violating scattering, F3~
parity violating anti- scattering~
The high statistics experiments are all done on nuclear targets
Schienbein et al.
Charged lepton Fe/D
F2(Fe from neutrinos)/F2(D determined w/o neutrino data)