Antiproton Physics Antiproton Physics Experiments Experiments Keith Gollwitzer -- Fermilab •Antiproton Sources •Accumulator Antiproton Physics Experiments –Precision measurements •Method •Charmonium •XYZ States •Antiproton Physics Experiments Beyond the Accumulator XYZ p p p p D D p p c c p p e e p p p p q q c c p p nMesons p p e H Z p
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–Precision measurements•Method•Charmonium•XYZ States
•Antiproton Physics Experiments Beyond the Accumulator
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Fermilab and CERN have/had the only Antiproton Sources.Currently, the operating Antiproton Sources are used for the Tevatron low energy/trapping programs, respectively. Schedules beyond 2010 do not exist for either Antiproton Source.
GSI (Darmstadt, Germany) is to construct an Antiproton Source as part of the Facility for Antiproton and Ion Research project. At the design peak production rate, FAIR will make <1014 antiprotons/year starting ~2016.
Fermilab has the best Antiproton Source now and the future
SummarySummary• The world’s most productive Antiproton
Source is here at Fermilab and could continue to be for the next decades
• The Fermilab Accumulator has hosted successful experiments
• The Fermilab Accumulator can be ready to perform experiments ~6months after Run II
• Many different measurements can be made• First physics results could be in 2011• New rings could exploit the Fermilab
Antiproton Source capabilities.
Extra Slides
Charmonium Masses and Widths11
F i g u r e1 . 7 :Thecharmoniums pectrumbe l ow t h eopencharmt h r e s h o l dwitht h e1P1
l oc a t e da tt h es p i nwe i g ht e dave r a g eo ft h et r i p l e tP wave s t a t e s .Thick s o l i dl i n e s
d e n o t et h es t a t e swhich a r ed i r e c t l yp r oducedby e+e# a n n i h i l a t i o n ;s t a t e swhichwe r e
unseeno rneededt obe ve r i f i e dbe f o r et h i sexperiment a r er e p r e s e nt e dby t h i ckbrokenl i n e s .Theknown andexpe c t e dh a d r o n i cande l e c t r o m a g n e t i ct r a n s i t i o n sanddecay st h a tE760cand e t e c ta r es h own.
E760/E835 main purposes were to do precision measurements of the
Charmonium spectrum as well as the
discovery/confirmation of 1P1 and ηc
/
TechniqueThe Accumulator is the Spectrometer
Annihilation of pbar p to form each state
All quantum numbers can be formed
Detector is a big scalar
Scan beam energy to map out resonance
“Clean” electron/positron Signals
/ J/ X e+e- X
/ e+e- Threshold CernekovShower shape
1-- State Scans (1990-1)
PRECISION
PRECISION
PRECISION
PRECISION 1 & 2 Scans
0 Scan
Could be more precise with more integrated luminosity
Interference will be shown later
pbarp 0 0
0
Two Photon Final States
Takes work to understand the feed-
down from multi-photon final states
CCAL threshold of 5/20MeV
These data are from the c peak
pbarp 0 & 2 In
terfe
renc
e ne
xt s
lide
Interference can be your friend
The continuum “amplifies” the resonance
E835 example in 4 photonspbarp c0 0 0 , , /
Should expand interference analyses to
more channels; in particular pbarp at 90o
in the center of mass system
Search using inclusive J/
c/ s
earc
h fo
r pos
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e hi
nder
ed
M1
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ition
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umul
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rist P
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The States
J PC
1 - -
2 + +
1 + +
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/0 12
c c/hc
pbarp +
pbarp two neutral mesons
00 0
Scaling Rule?
pbarp two neutral particles
Proton Magnetic Form Factor
pbarp 6
Steering Group Report• P19 Precision Physics – muons: “An intense 8 GeV beam and the
Accumulator and Debuncher rings, …, would make this LFV search possible.”
• P20 Precision Physics – Charm and hyperon physics with antiprotons (1 paragraph sub-section)
• P24 SNuMI: “SNuMI uses antiproton facilities….”• P25 Project X: “…compatible with reconfigurations of the Debuncher
ring and the Tevatron to support slow spill programs….”• P25 Existing Rings: Debuncher Slow Extraction (1 paragraph sub-
section)• P27 Summary paragraph: “The SNuMI project is based on reusing
existing antiproton rings for proton accumulation.”• P44 Appendix G Facilities Considered: table entry of Antiproton
Facility with Performance Parameters of “Incompatible with SNuMI. Minor hit on proton availability from Project X”
• Most overview presentations of the Steering Group Report and Project X spend time discussing reusing the Antiproton Source rings (sometimes even emphasizing existing accelerator) with little or no mention of Antiproton Physics