antiproton physics experiments
DESCRIPTION
Antiproton Physics Experiments. Antiproton Sources Accumulator Antiproton Physics Experiments Precision measurements Method Charmonium XYZ States Antiproton Physics Experiments Beyond the Accumulator. Keith Gollwitzer -- Fermilab. Antiproton Sources. - PowerPoint PPT PresentationTRANSCRIPT
Antiproton Physics Antiproton Physics ExperimentsExperiments
Keith Gollwitzer -- Fermilab
•Antiproton Sources•Accumulator Antiproton Physics Experiments
–Precision measurements•Method•Charmonium•XYZ States
•Antiproton Physics Experiments Beyond the Accumulator
XYZpp
ppDDpp ccpp
eepp
pp qqccpp
nMesonspp
eHZp
Yearly Production
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Ant
ipro
tons
CERN FNAL
Antiproton SourcesAntiproton Sourcese1
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ear
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ipro
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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
Accumulator Antiproton Accumulator Antiproton PhysicsPhysics
• Precision measurements of Charmonium
• Precision measurements of XYZ States
• Measurements of continuum processes– Associated production of
Charmonium– Proton Form Factor– Multi-meson final states
• Searches/confirmations – Excited Charmonium
states, – Exotics/hybrids – Glueballs
• Partial Rate Asymmetries of Hyperon Decays– CP violation
• Rare Hyperon Decays– Dimuon resonance search
• Relativistic Antihydrogen– Lamb Shift
• Open Charm– D-mixing; CP violation
• Charmonium produced in different nuclear targets
• Polarized hydrogen target – Electric and magnetic
contributions to the Proton Time-like Form Factor
Beam Profiles
Breit-Wigner line shape
Beam Scan of ψ(2S)
Most precise measurement of the ψ(2S) width despite
much smaller statistics than e+e- experiments
Precision Measurement Method
Convolution results in the
observed cross section
The precision of the mass and width of the c needs to be improved
E760 & E835 only reported pbarp
Need to observe c in more channels
1P1 or hc JPC = 1+-
The hc mass is important to understanding hyperfine splitting.
The hc width has not been measured. Need more channels.
pbarp hc c ()
E760: pbarp hc J/ 0 (e+e-) ()
Searched for pbarp ηc/
PDGM = 3637 ± 4 MeVГ = 14 ± 7 MeV
Need more channels.
Also in March 2008 CERN Courier
Study in pbarp in the A
ccumulator?
X(3872) has been seen to decay via Charmonium and Charm Mesons
resulting in different masses. 1 or 2 states? Only upper limit on width.
Accumulator could scan this resonance(s)
Charmonium ReactionsCharmonium Reactions
0/ Jpp
pppp // Jpp c
eeψJpp /
/Jpp /0 Jpp c
/cpp
pppp c /
/cpp
0cpp
0cpp
pphpp c
pppp c 0
2cpp 2cpp
0/Jhpp c
/Jpp
/1 Jpp c
pppp c 2
pppp c 2
ppJpp /
ccpp /
/cpp
/Jhpp c
cpp 0cpp 2cpp
eeψpp
/2 Jpp c
pppp c
cpp
cpp
2cpp
0cppcchpp
0/Jhpp c
XYZ ReactionsXYZ Reactions
pp X(3872) D0D00
pp X(3872) D0D*0
pp Z(3930) D Dpp X(3940) D*Dpp X(4160) D*D*
pp X(3872) J/ pp X(3872) J/ pp X(3872) J/ pp Y(3940) J/ ωpp Y(4008) J/ pp Y(4260) J/ pp Y(4260) J/ KK
pp J/ 0
pp J/ ωpp c 0
pp c ωpp c0 0
pp c1 0
pp c2 0
pp / 0
pp c/ 0
pp 0pp
pp J/ pp J/ /
pp c pp c /
pp c0 pp c1 pp c2 pp / pp c
/ pp pp ω
pp J/ pp J/ pp c pp c pp c0 pp c1 pp c2 pp / pp c
/
pp 0ωpp /ω
pp 0pp 0/
pp 00
pp /
pp /
pp //
pp ωpp ωω
pp φφpp KK
pp
eeppContinuum ProcessesContinuum Processes
Facilities Beyond the Facilities Beyond the AccumulatorAccumulator• Low Energy Ring/Stopping
– Decelerate in MI and extract to new ring capable of further deceleration and cooling
• Slow Antiprotons and Trapping• Antihydrogen and Antiprotonic Atoms
• Medium Energy Ring– Accumulator freed from experiment to stack full
time– Extend energy reach of experiment; electron
cooling?• Bottomonium
– Precision Measurements– Small collider (asymmetric?) – Internal jet target (50-70GeV/c)
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
sibl
e hi
nder
ed
M1
trans
ition
to J
/
Max
imum
Acc
umul
ator
Ene
rgy
Favo
rite
Theo
rist P
oint
of
the
mom
ent
The States
J PC
1 - -
2 + +
1 + +
? ? ?
/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