Transcript Jefferson Lab Science Bob McKeown June 4, 2015 Outline • Recent Highlights • PAC • Experimental equipment - SBS - Enhancements beyond 12 GeV project • MOLLER, SoLID status • MEIC April 2015

Jefferson Lab Science
Bob McKeown
June 4, 2015
Outline
•
Recent Highlights
•
PAC
•
Experimental equipment
- SBS
- Enhancements beyond 12 GeV project
•
MOLLER, SoLID status
•
MEIC
April 2015
2
Momentum Sharing in Imbalanced Fermi Systems
O. Hen et al., Science 346 (2014) 614, doi:10.1126/science.1256785
The Jefferson Lab CLAS Collaboration
Selected for Science Express (16 October 2014)
• At momentum greater than the Fermi momentum (kf), the fraction
of proton-neutron pairs dominates in atomic nuclei. It was recently
found that even in neutron-rich heavy nuclei proton-neutron pairs
dominate over proton-proton and by inference neutron-neutron
pairs [1].
CEBAF Large Acceptance Spectrometer (CLAS)
• The implication of this pairing is that, even if there are far more
neutrons than protons in nuclei, the proton momentum above kf is
near-identical to that of the neutron – the momentum is shared.
• This is confirmed in nuclear theory calculations for light nuclei [2],
and results in an on average higher proton than neutron
momentum, as suggested for neutron-rich nuclei [3].
This is completely unlike the effects for non-interacting Fermions in a
mean field, and has implications for the equations of state of neutron
stars and atomic interactions in ultra-cold atomic gases.
April 2015
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[1] The data were analyzed by the CLAS Data Mining Initiative.
[2] R. Wiringa et al., Phys. Rev. C 89, 024305 (2014)
[3] M. Sargsian, arXiv:1210.3280 (2012); PRC 89, 034305 (2014)
Exploring Proton Structure with Electrons and Positrons
•
The proton electric form factor GEp, describes the proton
charge distribution.
•
There is a discrepancy between GEp measurements with
polarized and unpolarized electrons.
•
A mixed electron and positron beam was produced in
Jefferson Lab’s Hall B. Complementary experiments at VEPP-3
at Novosibirsk and OLYMPUS at DESY used sequential beams.
•
The scattered electron or positron and struck proton were
detected in the CEBAF Large Acceptance Spectrometer.
Unpolarized
Measurements
Polarized
Measurements
The e+p and e−p cross section ratio versus
virtual photon polarization ε at Q2 = 1.5 GeV2.
•
This big discrepancy is possibly due to two photon
exchange, which can’t be calculated exactly.
•
Comparing electron and positron scattering off protons
directly measures the two photon exchange correction.
•
The positron to electron (e+p/e−p) ratios agree with hadronic two
photon exchange calculations, which would resolve the proton
form factor discrepancy up to Q2 ~2.5 GeV2. This also has
relevance for the proton radius extraction.
D. Adikaram et al. (Jefferson Lab CLAS Collaboration), Phys. Rev. Lett. 114 062003 (2015).
DOI: http://dx.doi.org/10.1103/PhysRevLett.114.062003
April 2015
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Theory and Computation Highlight
New Technology + Innovative Techniques
Lattice QCD Advance:
First scattering calculation of
Inelastic channels
p
p ,h
K
K
Now published in PRL
0+
ppK
K
d
published
d
hK
2
0
Ecm
pK
hK
MeV
h
2+
Ecm
h
MeV
Work on leadership GPU systems
such as DOE Titan (ORNL) and
Large ASCR Computing Challenge Award
NSF Blue Waters (NCSA - University of Illinois)
in May 2014: 250M core hours
April 2015
5
Polarized ρ Production with the Hall D Photon Beam
April 2015
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Heavy Photon Search
HPS tracked
pairs
•
•
Engineering run in Hall B
CE from DOE-HEP
April 2015
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7
12 GeV Approved Experiments by Physics Topics
Topic
Hall A Hall B Hall C Hall D Other
The Hadron spectra as probes of QCD
(GluEx and heavy baryon and meson spectroscopy)
1
Total
3
4
1
11
The transverse structure of the hadrons
(Elastic and transition Form Factors)
5
3
2
The longitudinal structure of the hadrons
(Unpolarized and polarized parton distribution functions)
2
3
6
11
The 3D structure of the hadrons
(Generalized Parton Distributions and Transverse
Momentum Distributions)
5
9
7
21
Hadrons and cold nuclear matter
(Medium modification of the nucleons, quark hadronization,
N-N correlations, hypernuclear spectroscopy, few-body
experiments)
6
3
7
Low-energy tests of the Standard Model and Fundamental
Symmetries
3
1
21
20
TOTAL
April 2015
8
22
1
17
1
1
6
5
2
70
12 GeV Approved Experiments by PAC Days
Topic
Hall A Hall B Hall C Hall D Other
The Hadron spectra as probes of QCD
(GluEx and heavy baryon and meson spectroscopy)
119
The transverse structure of the hadrons
(Elastic and transition Form Factors)
Total
540
659
25
357.5
145.5
85
102
65
230
165
460
The 3D structure of the hadrons
(Generalized Parton Distributions and Transverse Momentum
Distributions)
409
872
212
1493
Hadrons and cold nuclear matter
(Medium modification of the nucleons, quark hadronization,
N-N correlations, hypernuclear spectroscopy, few-body
experiments)
180
175
201
Low-energy tests of the Standard Model and Fundamental
Symmetries
547
205
1346.5
1686
The longitudinal structure of the hadrons
(Unpolarized and polarized parton distribution functions)
TOTAL
April 2015
9
79
680
644
14
570
60
891
74 4430.5
PAC Membership
•
Retired last year:
– N. Makins
– M. Vanderhaegen
– J. Ahrends
– B. Sherrill
•
New members starting this year:
– R. Fatemi
– F. Maas
– D. Dean
– W. Vogelsang
•
New PAC Chair: J. Napolitano
April 2015
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PAC43
Scheduled for week of July 6
Proposals due 8AM EDT Monday, May 18, 2015
Charge:
8 new proposals
2 run group additions
7 LOI’s
Review new proposals, previously conditionally approved proposals, and letters of
intent for experiments that will utilize the 12 GeV upgrade of CEBAF and provide
advice on their scientific merit, technical feasibility and resource requirements.
Identify proposals with high-quality physics that, represent high quality physics
within the range of scientific importance represented by the previously approved
12 GeV proposals and recommend for approval.
Also provide a recommendation on scientific rating and beam time allocation for
proposals newly recommended for approval.
Identify other proposals with physics that have the potential for falling into this
category pending clarification of scientific and/or technical issues and recommend
for conditional approval. Provide comments on technical and scientific issues that
should be addressed by the proponents prior to review at a future PAC.
April 2015
11
Super Bigbite Spectrometer (SBS)
New spectrometer to support three form factor
experiments (GEP high impact), and one SIDIS
experiment in Hall A.
 Magnet and infrastructure (JLab)
 2400 channel scintillator hodoscope (ISU)
 40 GEM modules ( each area = 50x60cm2) for rear
tracker (UVa)
 Other equipment: Hadron calorimeter (CMU),
Cerenkov (W&M), Front Tracker GEMs (INFN),
Electron Calorimeter (SBU & JLab) and polarized
helium target (UVa)
Magnet tested
at JLab
CAD drawing of
SBS magnet and
infrastructure
Power supply tested at JLab
April 2015
11/6/2015
12
12
Super Bigbite Spectrometer (SBS)
R&D on polarized 3He target at UVa
to reach 60cm length and sustain
60uA beam
• UVa is in full GEM module production mode.
• 12 of the 40 GEMs have been constructed and passed
Q&A tests
Clean room for GEM construction
Postdoc and grad student
constructed a GEM
Hadron calorimeter module at
CMU. Production started in April.
Cosmic ray test stand for Q&A
April 2015
11/6/2015
13
13
Future Projects
• MOLLER experiment
(Possible MIE – FY17-20)
– Standard Model Test
– DOE science review (September 2014) – strong endorsement
- Technical, cost & schedule reviews?
• SoLID
– Chinese collaboration
– CLEO Solenoid 
– Director’s review (Feb. 2015)
 lots of good feedback
April 2015
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EIC at Jefferson Lab
JLab MEIC Figure 8 Concept
Initial configuration:
• 3-10 GeV on 20-100 GeV ep/eA collider
• Optimized for high ion beam polarization:
 polarized deuterons
• Luminosity:
 up to few x 1034 e-nucleons cm-2 s-1
Low technical risk
Upgradable to higher energies
250 GeV protons + 20 GeV electrons
Flexible timeframe for Construction
consistent w/running 12 GeV CEBAF
Thorough cost estimate completed
presented to NSAC EIC Review
Cost effective operations
 Fulfills White Paper Requirements
Current Activities
Site evaluation (VA funds)
Accelerator, detector R&D
Design optimization
Cost reduction
April 2015
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15
MEIC Baseline Design
Features:
• Collider ring circumference: ~2100 m
• Electron collider ring and transfer lines : PEP-II magnets, RF
(476 MHz) and vacuum chambers
• Ion collider ring: super-ferric magnets
• Booster ring: super-ferric magnets
• SRF ion linac
April 2015
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NSAC EIC Cost Review – Jan 26-28
From the Charge:
Understanding that a detailed conceptual design has not been completed,
the Subcommittee is asked to provide NSAC with its best current estimate
of the costs of the projects, including R&D, construction, pre-operating and
operating costs. NSAC is aware that there are uncertainties regarding
siting and other issues that limit the precision of such an estimate at this
time. Nevertheless, the advice of the Subcommittee will be of great value
to NSAC as it evaluates the relative merit of this and other initiatives. Since
the charge to NSAC for the long range plan explicitly discusses resources
in terms of the 2015 President’s Budget Request, we ask that the results of
this review be presented in FY2015 dollars. If the laboratories choose to
present staging options to incrementally reach the science goals, please
consider these as well.
The subcommittee is asked to provide a written report to NSAC by the end
of February 2015. I expect it will be considered by NSAC in a meeting in
late March 2015.
April 2015
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Level 2 Cost Estimate
(k$, FY15, w/OH)
Scope
1.1.
CDR
1.2.
Contingency
4,656
1,629
Accelerator
692,285
271,740
1.4.
Conv. Facilities
210,349
42,070
1.5.
Integrated comm.
37,327
13,064
1.6.
Management -Project
13,411
4,694
Total
1.3.
1,291,255
Exp. Systems
126,639
61,418
188,056
L. Harwood – NSAC Cost Review
April 2015
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Cost Review Presentation to NSAC
April 2015
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MEIC Life Cycle Cost (FY15$)
•
TPC without detector = $1.29B
•
TPC with large acceptance detector = $1.48B
•
Ops = $0.117B/year x 15 years = $1.76B
•
MEIC Total (w/detector): construction + ops (15 years) = $3.24B
•
20% of the anticipated NP budget over a 25 year (construction+operation)
period
– presently CEBAF operations is 16%
– presently RHIC operations is 28%
•
CEBAF (6 GeV): construction + ops (1996-2014) = $2.98B
→ NP community can manage this scale.
April 2015
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Future EIC activities
• POETIC VI - Sept. 7-11, Palaiseau, France
• MEIC Collaboration meeting in October
• EIC User meeting (joint with eRHIC) late 2015
• User workshops to advance science case?
April 2015
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Summary and Outlook
•
Physics Output from 6 GeV is healthy
•
Experiments on the floor are doing well
•
SBS making good progress
•
Trying to move MOLLER and SoLID along
•
EIC science and designs are making good progress
•
Awaiting results from NSAC Long Range Plan
April 2015
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