Muonium – Muonium – Physics of a Most Fundamental AtomPhysics of a Most Fundamental Atom
Klaus Jungmann Kernfysisch Versneller Instituut & Rijksuniversiteit Groningen
Simple Atomic SystemSimple Atomic SystemAtomic TheoryAtomic Theory
Fundamental ConstantsFundamental ConstantsFundamental SymmetriesFundamental SymmetriesSearch for New PhysicsSearch for New Physics
Atomic Physics at AcceleratorsAtomic Physics at AcceleratorsPrecision MeasurementsPrecision Measurements
……Condensed Matter PhysicsCondensed Matter Physics
ChemistryChemistryLow energy Muon Beams Low energy Muon Beams
Muonium (M)Muonium (M)
What is it ?What is it ?
What is it good for ?What is it good for ?• test of electromagnetic bound state theorytest of electromagnetic bound state theory• fundamental constantsfundamental constants• tests of fundamental symmetriestests of fundamental symmetries• search for New Physicssearch for New Physics• tool for condensed matter researchtool for condensed matter research• …… ……
““Muonium is the bound state of a Muonium is the bound state of a positive Muon and an Electron”positive Muon and an Electron”• ““point-like” particlespoint-like” particles• no (severe) strong interaction effectsno (severe) strong interaction effects• calculable to required accuracycalculable to required accuracyMuonium (M)Muonium (M)
hydrogen-like atom hydrogen-like atom but no strong but no strong
interactioninteraction
Past of Muonium (Ground State Hyperfine Structure)Past of Muonium (Ground State Hyperfine Structure)
Discovery of Muonium 1960Discovery of Muonium 1960
Hyperfine Structure addressedHyperfine Structure addressedas an Important Quantityas an Important Quantity
From: V. Telegdi, in: “A Festschrift for Vernon W. Hughes”, 1990
There was stimulating There was stimulating competitioncompetition
...
Theorists are confident that muonium HFS
Theorists are confident that muonium HFS
Can be calculated to 10 Hz, if needed
Can be calculated to 10 Hz, if needed (Eides, Pachucki,(Eides, Pachucki,
…)…)
magnetic moment magnetic moment , ,
The worlds most intense quasi continuous muon source - the
LLos AAlamos MMeson PPhysics FFacility
Muonium Hyperfine Structure
Solenoid
ein
S GatedDetector
MW-Resonator/Kr target
Yale - Heidelberg - Los Alamos
pulsedpulsed beambeam essentialessential
old Muoniumold Muonium
freq. scanfreq. scanB scanB scan
Results from LAMPF Muonium HFS ExperimentResults from LAMPF Muonium HFS Experiment
measured:
• 12 = 1 897 539 800(35) Hz ( 18 ppb)• 34 = 2 565 762 965(43) Hz ( 17 ppb)
from Breit-Rabi equation:
12 • exp = 4 463 302 765(53) Hz ( 12 ppb)• theo = 4 463 302 563(520)(34)(<100) Hz (<120 ppb)12 • p = 3.183 345 24(37) (120 ppb)
alternatively derived:
• mme = 206.768 277(24) (120 ppb)• ppb)
-1= 137.035 999 9 (5)
-1= 137.035 99X X (1)
CODATA 2002
muonium and hydrogen hfs → proton structure
?
1810m
mmr
0
00
K
KK||
K
12102avga
|e
ae
a|3101.2
avgg
|e
ge
g|
er
CPTbreakb,a μμ Invariance LorentzbreakH,d,c,b,a μνμνμνμμ
?
CPT and Lorentz Non-Invariant Models
CPT tests
Are they comparable - Which one is appropriate
Use common ground, e.g. energies
Leptons in External Magnetic Field
Bluhm , Kostelecky, Russell, Phys. Rev. D 57,3932 (1998)
For g-2 Experiments :
Dehmelt, Mittleman,Van Dyck, Schwinberg, hep-ph/9906262
μμ qAiiD
0Dμγ5γμνidνDμγμνicμνσμνH21μγ5γμbμγμamμDμ(iγ
equation DIRAC violating Lorentz and CPT generic
ψ)
2clmaΔω
lupspinE
|ldownspinEl
upspinE|lr
l34bl
aωlaωaΔω
avg
ll2
l
cl a
|aa|cm
ωr
24103.5μr21101.2er :: muonelectron
CPTCPT – ViolationLorentz Invariance ViolationWhat is best CPT test ?
New Ansatz (Kostelecky)• K0 10-18 GeV/c2
• n 10-30 GeV/c2
• p 10-24 GeV/c2
• e- 10-27 GeV/c2• Future: Anti hydrogen 10-18 GeV/c2
often quoted:
• K0- K0 mass difference (10-18)
• e- - e+ g- factors (2* 10-12)
• We need an interaction with a finite strength !
What about Second Generation Leptons?What about Second Generation Leptons?
CPT and Lorentz Invariance from Muon ExperimentsCPT and Lorentz Invariance from Muon Experiments
Muonium:
new interaction below 2* 10-23 GeV
Muon g-2:
new interaction below 4* 10-22 GeV (CERN) 15 times better expected from BNL
V.W. Hughes et al., Phys.Rev. Lett. 87, 111804 (2001)
Present Status of Muonium Ground State Hyperfine Present Status of Muonium Ground State Hyperfine StructureStructure
• No Experimental Activities known at this timeNo Experimental Activities known at this time
• Refinement of Theory going onRefinement of Theory going one.g.e.g. Eides, Grotch, “Three-Loop Radiative-Recoil Corrections to Hyerfine Splitting Eides, Grotch, “Three-Loop Radiative-Recoil Corrections to Hyerfine Splitting in Muonium”, Phys.Rev.D67, 113003 (2003) and hep-ph/0412372 (2005)in Muonium”, Phys.Rev.D67, 113003 (2003) and hep-ph/0412372 (2005) Marciano, “Muonium Lifetime and Heavy Quark Decays”, hep-ph/0403071 Marciano, “Muonium Lifetime and Heavy Quark Decays”, hep-ph/0403071 (2004)(2004) . . .. . .
• Exploitation of the Atom in Condensed Matter ScienceExploitation of the Atom in Condensed Matter Sciencee.g.e.g. Ivanter et al. “On the anomalous muonium hyperfine structure in silicon”Ivanter et al. “On the anomalous muonium hyperfine structure in silicon” J.Phys.: Condens. Matter 15, 7419 (2003) J.Phys.: Condens. Matter 15, 7419 (2003) … …..
NEVISCHICAGO-SRELLAMPFLAMPF latest experiment
Quo
ted
Unc
erta
inty
[kH
z]
Year
History of Muonium Ground StateHyperfine Splitting Measurements
Future Possibilities for Muonium Ground State Future Possibilities for Muonium Ground State Hyperfine StructureHyperfine Structure
LAMPF Experiment limited byLAMPF Experiment limited by STATISTICSSTATISTICS more more MUONS MUONS needed needed factor > 100 over LAMPF – pulsed > 5*10factor > 100 over LAMPF – pulsed > 5*1088++/s /s below 28 MeV/c below 28 MeV/c
newnew ACCELERATORS ACCELERATORS J-PARC ?J-PARC ? Neutrino Factory ?Neutrino Factory ? Eurisol ?Eurisol ? GSI ?GSI ? FNALFNAL…………....
What other experiments besides the What other experiments besides the Ground State Hyperfine StructureGround State Hyperfine Structure
are possible ?are possible ?
• Gas StopGas Stop
Yields up to 100% foreign gas effectsPolarization up to 50% (B=0) 100% (B>>1T)
++e
+Kr, Ar
• Beam FoilBeam Foil
Muonium in Vacuo keV energyn=2 state populatedfast muonium
+ 50%
+e 1%
+ee0.01%
+
• SiOSiO22 Powder Powder
thermal Muonium in Vacuo M(2s) /M(1s) < 10-4
Yields up to 12%Polarization 39(9)% velocity 1.5 cm/
+ M
Methods of Muonium ProductionMethods of Muonium Production
Completed Experiments on Muonium 1s-2s IntervalCompleted Experiments on Muonium 1s-2s Interval
Pioneering effort at Pioneering effort at KEKKEK ((Chu,Mills,Nagamine et al.)Chu,Mills,Nagamine et al.)
Precision measurement at Precision measurement at RALRAL ((HHeidelberg – eidelberg – OOxford – xford – RRutherford – utherford – SStrathclyde – trathclyde – SSiberia –iberia –YYaleale Collaboration)Collaboration)
The most intense pulsed muon source – ISIS at the
RRutherford AAppleton LLaboratory
Muonium 1S-2S Experiment
-.25 R
1S
2S244 nm
244 nm
Ener
gy
-R
0
ekin
Laser
Diagnostics
Detection
in
e
Target
Mirror
Heidelberg - Oxford - Rutherford - Sussex - Siberia - Yale
MuoniumMuonium1s-2s 1s-2s
At RALAt RAL1987 -20001987 -2000
Results:Results:1s-2s = 2455 528 941.0(9.1)(3.7) MHz
1s-2s = 2455 528 935.4(1.4) MHz
mm= 206.768 38 (17) m= 206.768 38 (17) me e (0.8ppm)(0.8ppm)
qq= [ -1 -1.1 (2.1) 10= [ -1 -1.1 (2.1) 10-9 -9 ] q] qe-e-(2.2 ppb)(2.2 ppb)
exp
theo
Future Possibilities for Muonium 1s-2s IntervalFuture Possibilities for Muonium 1s-2s Interval
• No Precision Experiment Activities known at No Precision Experiment Activities known at this timethis time
• Exploitation of Laser Spectroscopy to obtainExploitation of Laser Spectroscopy to obtain
““Slow Muons” Condensed Matter ScienceSlow Muons” Condensed Matter Science(K. Nagamine et al. @RAL)(K. Nagamine et al. @RAL)
Y Matsuda Y Matsuda et alet al J. Phys. G: Nucl. Part. Phys.J. Phys. G: Nucl. Part. Phys. 29,29, 2039 (2003) 2039 (2003)
Future Possibilities for Muonium 1s-2s IntervalFuture Possibilities for Muonium 1s-2s Interval
RAL Experiment limited byRAL Experiment limited by STATISTICSSTATISTICS more more MUONS MUONS needed needed
factor > 1000 over RAL – pulsed > 5*10factor > 1000 over RAL – pulsed > 5*1088++/s/s below 28 MeV/c below 28 MeV/c would enable cw laser spectroscopy ! (precision !)would enable cw laser spectroscopy ! (precision !)
newnew ACCELERATORS ACCELERATORS J-PARC ?J-PARC ? Neutrino Factory ?Neutrino Factory ? Eurisol ?Eurisol ? GSI ?GSI ? . . . . .. . . . .
QEDm
QEDm
QED
, , g
+e-
HFS, n=1QED correctionsweak contribution
+e-
1S-2S
m
QED corrections
ge hm c2
g-2
hadronic contributionweak contributionNew Physics
a = a m c
e B= a pa p
p-
Experiment:
Fundamental Constants of Interest to g-2
Theory: weakhadronicAAAa
...483624
21
* need for muon ! * hadronic and weak corrections* various experimental sources ofbetter 100ppb>need constants at very moderate * no concern for (g-2) even with recent corrections accuracy
* a and B (p) measured in (g-2) experiment <better 0.35 and 0.1 ppm>* c is a defined quantity <“infinite” accuracy>* m () is measured in muonium spectroscopy (hfs) <better 120 ppb> NEW 2000* eis measured in muonium spectroscopy (1s -2s) <better 1.2 ppb> NEW 1999* p in water known >> probe shape dependence << <better 26 ppb>* 3He to p in water >> gas has no shape effect << <better 4.5 ppb> being improved
Any New Effort to improve significantly onAny New Effort to improve significantly onthe the Muon Magnetic AnomalyMuon Magnetic Anomaly will need better will need better
constants !constants !
Where should they come from, if not fromWhere should they come from, if not fromMuonium Spectroscopy Muonium Spectroscopy ??
Muonium – Antimuonium Conversion Muonium – Antimuonium Conversion up to Nowup to Now
Did first Searchfor ConversionAmato et al.Phys.Rev.Lett. 21,1709 (1968)
PredictedM-M
Conversion1957-
NamedSystem
“Muonium” ?
The most intense continuos sourceof muons – the
Cyclotron Facilityat the
PPaul SScherrer IInstitut
Present Activities concerning Muonium – Present Activities concerning Muonium – Antimuonium ConversionAntimuonium Conversion
• No Experimental Activities known at this timeNo Experimental Activities known at this time
• Theory is proposing lots of modelsTheory is proposing lots of modelse.g.e.g. Clark, Love “Muonium-Antimuonium Oscillations and Massive Majorana Neutrinos”, Clark, Love “Muonium-Antimuonium Oscillations and Massive Majorana Neutrinos”, hep-ph/0307264 (2003)hep-ph/0307264 (2003) Gusso, Pires, Pires, Rodrigues da Silva “Minimal 3-3-1 Model, lepton Mixing and Gusso, Pires, Pires, Rodrigues da Silva “Minimal 3-3-1 Model, lepton Mixing and Muonium- Antimuonium Conversion”, hep-ph/0208062 (2002)Muonium- Antimuonium Conversion”, hep-ph/0208062 (2002) Cvetic,Dib, Kim, Kim, “Muonium-Antimuonium Conversion in models with heavy neutrinos”,Cvetic,Dib, Kim, Kim, “Muonium-Antimuonium Conversion in models with heavy neutrinos”, hep-ph/0504126 (2005)hep-ph/0504126 (2005) Applequist, Christensen, Piai, Schrock “ Flavour-Changing Processes in Extended Technicolor”,Applequist, Christensen, Piai, Schrock “ Flavour-Changing Processes in Extended Technicolor”, Phys. Rev.D70, 093919 (2004)Phys. Rev.D70, 093919 (2004)……..
Future Possibilities for Muonium – Antimuonium Future Possibilities for Muonium – Antimuonium SearchesSearches
PSI Experiment limited byPSI Experiment limited by STATISTICSSTATISTICS more more MUONS MUONS needed needed factor > 1000 over PSI – pulsed > 1*10factor > 1000 over PSI – pulsed > 1*1099++/s /s below 28 MeV/c below 28 MeV/c
newnew ACCELERATORS ACCELERATORS J-PARC ?J-PARC ? Neutrino Factory ?Neutrino Factory ? Eurisol ?Eurisol ? GSI ?GSI ? FNAL FNAL . . . . .. . . . .
Old Muonium for Muonium-Antimuonium Conversion ?Old Muonium for Muonium-Antimuonium Conversion ?
• P(M) sin2 [const * (GMM/GF)*t]*exp[-*t]
• Background exp(- n *t) ; n-fold coincidence detection
• For GMM << GF M gains over Background• P(M) / Background t2 * exp[+(n-1)* *t]
Pulsed ACCELERATORPulsed ACCELERATOR
There is not only Muonium SpectroscopyThere is not only Muonium Spectroscopywaiting for a push by Intense Muon Beamswaiting for a push by Intense Muon Beams
Muon Experiments Possible at a CERN Neutrino Factory -Expected Improvements
Muon Physics Possibilities at Muon Physics Possibilities at Any High Power Proton DriverAny High Power Proton Driver i.e. i.e. 4 MW 4 MW
<<<<
Muon Physics Possibilities at Muon Physics Possibilities at Any High Power Proton DriverAny High Power Proton Driver i.e. i.e. 4 MW 4 MW
K Jungmann 18-Apr-2001
J-PARCJ-PARCis one is one
PossibilityPossibility
There are othersThere are others as well:as well:• Neutrino Factory ?Neutrino Factory ?• Muon Collider ?Muon Collider ?• GSI ?GSI ?• … …..
Thank You Vernon for providing us theThank You Vernon for providing us the perhaps most perhaps most
Ideal AtomIdeal Atom
Muonium (M)Muonium (M)