Transcript Muon Physics Overview (A Muon Collider Roadmap) William J. Marciano July 23, 2009 Chicago, ILL.

Muon Physics Overview
(A Muon Collider Roadmap)
William J. Marciano
July 23, 2009
Chicago, ILL
OUTLINE
1. Great Muon Expectations
2. Recent Muon Results (PSI)
i) Muon Lifetime G=1.166367(5)x10-5 GeV-2
S Parameter: New Heavy Chiral Doublets?
Extra Dimensions?
ii) Muon-H Capture gP=7.71.2 (Agrees with PT)
3. Muon Anomalous Magnetic Moment (BNL E821)
aexp-aSM=307(63)exp(53)SMx10-11 3.7sigma (SUSY?)
4. LFV: e PSI (10-13)
2e Fermilab/JPARC (2x10-17)
5. Muon Collider(2TeV)/Neutrino Factory
6. Outlook/Vision
Apologies For Incompleteness
Not enough time to discuss TRIUMF (TWIST),
Muon Cooling, -EDM, JPARC plans…
1. Great Muon Expectations
• Muons are very special: ≈2.2x10-6sec!
m=105.66MeV ( heavy electron,  light proton)
• Decay: ee()
100%Polarized-P.V. Decay Ang. Dist. Tracks Pol.
SR (condensed matter), Muon g-2 (Garwin et al.)
Copious Production: 1p(8GeV)+N1
Intense Muon Source 1013-1014/sec possible!
(Currently 108+/sec, 107-/sec at PSI)
Muon Collider , Neutrino Factory, Nanoscience…
CF? DTHe(4MeV)+n(14MeV)+ (1020p/s!!)
Muon Collider: Produce 1013/sec, Collect, Cool,
Accelerate, Store, Collide  at s≥mZ, …2TeV!
Challenging! Neutrino Radiation Problem?
(Plan B Muon SR-Neutrino Factory +e+e)
Muon Technology Needs To Be Nurtured!
(Pursue Fundamental Muon Physics Aggressively!)
Build Muon Community
2. Recent Muon Results (PSI)
Standard Model Natural Relations:
e02/g02=sin20W=1-(m0W/m0Z)2
Radiative Corrections (Loops) Finite & Calculable
mt prediction160-180GeV, mH160GeV (95%CL)!
(Relatively light Higgs suggests Supersymmetry)
Deviation”New Physics”: SUSY, Technicolor, W*…
LIFETIME PARTICULARLY IMPORTANT G
eg. G(1-r(mZ)MS)=/2mW2sin2W(mZ)MS
r(mZ)MS=0.0696+0.0085S + (1)(mW/mW*)2+ …
S=ND/6, ND= No. of new heavy doublets
eg. (4th generation), 12 (mirror fermions), Technifermions…
W* excited W (extra dimensions, compositeness…)
* MUON
i) Muon () Lifetime
MuLAN & FAST experiments at PSI:
World Ave. =2.197035(17)x10-6sec
(Further factor ~10 improvement expected in 2010)
Already Confirms (improves) Previous World Average by error/2.
-1= (+e+e())=G2m5f(me2/m2)[1+RC]/1923
RC =/2(25/4-2)(1+/[2/3ln(m/me)-3.7)…] Fermi Th.
Other SM and “New Physics” radiative corrections absorbed
into G. Eg. Top Mass, Higgs Mass, Technicolor, Susy,W*…
G=1.166367(5)x10-5GeV-2 precise & important
S Parameter
Use , G, mW, and sin2W(mZ)MSS (Counts ND) & mW*
S/120+(mW/mW*)2=[(G-1.166367x10-5GeV-2)/1.166367x10-5GeV-2
+(-1-137.035999084)/137.035999084
+2(mW-80.351GeV)/80.351GeV
+(sin2W(mZ)MS-0.23132)/0.23132]
-0.085X+0.019X2,
X=ln(mH/115GeV)
mW=80.398(25)GeV

sin2W(mZ)MS= 0.23125(16) Ave
S=0.10(11) & MW*>2-3TeV
No Sign of “New Physics”!
Precision Parameters (status):
Quantity
2006 Value
2009 Value
Comment
-1
137.035999710(96) 137.035999084(51)
ge-2
G
1.16637(1)x10-5GeV-2 1.166367(5)x10-5GeV-2 PSI
mZ
91 .1875(21)GeV
91.1875(21)GeV
*mt
171.4(2.1)GeV
 173.1(1.2)GeV
FNAL
mW
80.410(32)GeV
 80.398(25)GeV LEP2/FNAL
sin2W(mZ)
0.23125(16)
0.23125(16)
Ave.
sin2W(mZ)
sin2W(mZ)
0.23070(26)
0.23070(26)
0.23193(29)
0.23193(29)
(3 sigma difference?)
ALR
AFB(bb)
sin2W(mZ)MS
S
Average
0.23125(16)
-0.04(8)
ALR
AFB(bb)
0.23070(26)
0.23193(29)
-0.32(13)
+0.32(15)
S
+0.10(11)
-0.19(15)
+0.45(17)
ND
2(2)
(SUSY)
9(3)!
If ALR had never been measured: sin2W(mZ)MS=0.23158(20)
That would imply S=+0.28(12)ND~62.4!!) (Heavy Higgs!
4th Generation, mW*1.6TeV…)
We would be waiting for 4th Generation, Technicolor, Extra Dim.
We missed our chance to nail sin2W(mZ)MS at the Z pole!
Future sin2W(mZ)MS Precision: Z Factory?
ii) Hydrogen Muon Capture:
• Muonic Atom (-NN’): <V>=-Z22m, =Z
 +(1 + Z22/2 - Capture BR(~Z3/1000))
(capture)=1/-1/ (after time dilation correction)
For N=H, theory clean but high precision lifetimes
needed.
nd(1- 5)up=gV(q2)np +igM(q2)/2mNnqp
-gA(q2)n5p-gP(q2)q/mn5p
Chiral Pert. Th. Predicts: gP(-0.88m2)=8.20.2
Exp.(Pre 2007)gP=11-12(1) Off by 3-4 sigma
Muon-H Capture Result
(Including recent update with gA=1.275(1))
(capture)=1/-1/ (after time dilation correction)
For atomic 1S singlet
(-pn)exp=725(17)sec-1 MuCap
(-pn)SM=717(3)(1-0.0108(gP-8.2))2sec-1
Implies: gP=7.7(1.2)
gpPT8.2(0.2) Good Agreement!
Additional datafurther factor 3 improvement
Push as far as possible! Improve Theory
3. Muon Anomalous Magnetic Moment
Final Experimental Result: E821 at BNL
aexp  (g-2)/2 =116592080(54)stat(33)sysx10-11
=116592080(63)x10-11
Factor of 14 improvement over CERN results
(Proposing Factor 4 Upgrade at FNAL - Up The
Calumet Canal) ) D. Hertzog & B. Lee Roberts
Also, JPAC low energy muon R&D
BNL Muon g-2 Experiment
N(t) = N0 e-t/ [1+Acos(wat + f)]
Standard Model Prediction
aSM = aQED+aEW+aHadronic
QED Contributions:
• aQED=0.5(/)+0.765857410(27)(/)2+
24.05050964(43)(/)3+
130.8055(80)(/)4+
663(20)(/)5+… (5 loops)
-1=137.035999084(51) From ae (new)
aQED=116584718.1(2)x10-11 Very Precise!
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Electroweak Loop Effects
aEW(1 loop)=194.8x10-11 goal of E821
2 loop EW corrections are large -21%
aEW(2 loop)=-40.7(1.0)(1.8)x10-11
3 loop EW leading logs very small O(10-12)
• aEW=154(2)x10-11 Non Controversial
• Hadronic Contributions
(some controversey)
e+e-hadrons vs hadrons+(isospin)
Novosibirsk, KLOE vs BaBar (e+e-+-)
KEY REGION
From e+e-hadrons data + dispersion relation
aHad(V.P.)LO=6894(42)(18)x10-11 (Hagiwara et al)
3 loop=aHad(V.P.)NLO+aHad(LBL)
aHad(V.P.)NLO = -98(1)x10-11
aHad(LBL) = 105(26)x10-11 (Consensus)
aHad=6901(42)(18)(26)x10-11
aSM=116591773(2)(46)(26)x10-11
a=aexp-aSM=307(63)(53)x10-11 (3.7!)
• New Physics? Nearly 2xStandard Model!
Most Natural Explanation: SUSY Loops
Generic 1 loop SUSY Conribution:
aSUSY= (sgn)130x10-11(100GeV/msusy)2tan
tan3-40, msusy100-500GeV Natural Explanation
Other Explanations: Hadronic?  +isospin data
BaBar e+e-+- rad. return
(a=~150x10-11 (1.9)
Other New Physics ~ 2TeV
eg Extra Dimensions
SUSY 1 loop a Corrections
• SUSY Loops are like EW, but depend on:
• 2 spin 1/2 - (charginos)
• 4 spin 1/2 0 (neutralinos) including dark matter!
• 3 spin 0 sneutrinos and sleptons with mixing
Enhancement tan=f2/f1~3-40
Implications: sgn0 (dark matter searches easier)
SUSY at LHC very likely
bs, e, edms… Good Bets
“The deviation in a could be to Supersymmetry
what the anomalous precession of the perihelion
of Mercury was for General Relativity”
J. Marburger
Presidential Science Advisor
(Former BNL Director)
• “The g-2 experiment makes me proud to
be a physicist”
Bill Foster
Local Congressman
4. Charged Lepton Flavor Violation
• 1947 Muon established as independent elementary
lepton: No e+ implies  not excited electron
• 1958 Feinberg loop calculation of e+
B(e)<10-4~10-5 implies second neutrino!
1959 Feinberg and Weinberg Study -Ne-N
Coherent Ee105MeV Very Clean-Distinct
Stop - in material (10-10sec)N(1S) atom
i) e
Rate0.5x106/sec
ii) NN’
w(N=Al)0.7x106/sec
w(N=Ti)2.6x106/sec
grows  Z4 (very roughly)
• iii) R(N)w(NeN)/w(NN’)Z (for low Z)
R(Au)<7x10-13 SindrumII at PSI
R(Ti)<7x10-13 Unpublished
Conversion can take very high rate-No Accidentals
Every Muon We Can Produce
mu2e would stop 1011/sec!
Needs Clean Beam & Good Ee Resolution
+e++ Accidentals a problem (for B(e)<10-14)
MEG at PSI (DC  Beam)
Ongoing Goal 2x10-13 2x10-14 (upgrade)
2e Fermilab/JPARC R(AleAl)2x10-17!
• Coherent -e Conversion in Nuclei (NeN)
Stop  in material, ~10-10sec, N (1S) atom forms
i) (e-) = 0.5x106/sec
ii) w(NN’) = 0.7x106/sec (N=Al)
= 2.6x106/sec (N=Ti)
iii) Ne-N
R(Tie-Ti)<7x10-13 (Prelim.)
*Signature: m-BE=105 MeV monoenergetic electron
single particleno accidentalshigh rate capability!
It can take every muon we can provide!
Stop 1011/sec!
wait ~0.6x10-6sec (reject prompt background)
Requires ~300keV resolution & Clean beam between pulses
potential sources of fake backgrounds specify much
of the design of the beam and experimental
apparatus.
Prompt background
Expected
signal
Experimental signature is105 MeV eoriginating in a thin stopping target.
Cosmic ray
background
Charged Lepton Number Violating Processes
Reaction
BR(e)
BR(eee)
R(TieTi)
Bound
In Progress Proposed Possible
1.2x10-11 2x10-13SES 2x10-14SES ?
1x10-12
10-15
4x10-12
2x10-17SES 10-18
(7x10-13)
BR(e)
7.2x10-11
BR(KLe)
4.7x10-12
10-13
BR()
5.9x10-8
10-9
BR()
<2.0x10-8
10-10
BR(Ze)
<1.7x10-6 (10-13 from TieTi!)
(From Marciano, Mori and Roney Annual Reviews)
Muon Conversion Experiment
Straw Tracker
Muon Stopping
Target
Muon Beam
Stop
Superconducting
Transport Solenoid
(2.5 T – 2.1 T)
Crystal
Calorimeter
Superconducting
Production Solenoid
(5.0 T – 2.5 T)
Superconducting
Detector Solenoid
(2.0 T – 1.0 T)
Collimators
Some Theory Considerations:
If transition dipole operator (chiral changing) dominates
BR(e)=389R(AleAl)=238R(TieTi)
But conversion exp. can be more sensitive by 103-104!
Eg. Popular SUSY Models (may be related to a)
Neutrino Mass & Mixing EffectsLepton Flavor Violation
BR(e)~3/32[m32-m22]2/mW4(s13c13s23)2  10-54
R(NeN)~100BR(e)~10-52 still tiny, but enhanced by
Chiral conserving amplitudes.
(Lesson) Conversion better for Heavy Neutrino Mixing
In General: 1/200BR(e)/R(NeN)200
Physics scale ~3000TeV Probed!
Muon g-2 and LFV
• If SUSY or any other New Physics is
responsible for a, it will also induce LFV
via mixing effects. (Chiral Changing)
DL,R=1622ae/GFm2 e<4.5x10-5
Large Slepton Mixing(M2-M1)/M1<4.5x10-5!
Very Near Degeneracy (R Symmetry?)
MEG(e) at 2x10-13 may see an effect
or e<6x10-6!  M2-M1O(1MeV)
Sensitivity to Different Muon Conversion
Mechanisms
Supersymmetry
Predictions at 10-15
Heavy Neutrinos
Leptoquarks
Compositeness
ΛC = 3000
TeV
Second Higgs
doublet
Heavy Z’,
Anomalous Z
coupling
5. Muon Collider(+-)/Neutrino Factory
i) Need Copious Source of Protons
Fast cycling 8-16GeV Accelerator or Linac
Power~4MW >1014 +-/sec
ii) Collect and Cool + & - Beams
iii) Accelerate  High Energy
iv) Large Storage Ring (~1000 revolutions)
v) Luminosity ~ 1034-1035 desirable (at 2TeV)
Energy: 91GeV Z Factory (sin2W, bb,…)
114-150GeV Higgs Pole Resonance(s)
161GeV W+W- (mW)
350GeV tt (mt), HZ…
SUSY Pairs
2TeV +-“New Physics”,-- p…
Neutrino Factory SR
Intense Muon Beam: +e+e; -e-e
Leads to clean source of neutrinos
StatisticsE3 Go to 20GeV Very Good 13
e, but osc length ~500km x E(GeV)
Not optimized for CP Violation  Long Distances!
Very Good for small 13, New Physics
Currently: All Neutrino Data (including MINOS2009)
sin2213=0.080.04 (relatively large!)
Fogli et al. Hep-ph0905.3549 (2009)
6. Outlook/Vision
PSI Exps. MuLAN, FAST and MuCAP interesting and timely.
Expect Improvement in  and gP to continue (2010 results)
No definitive sin2W(mZ)MS in sight (LHC? AFB(Z))
Perhaps aexp improvement (x4) at Fermilab (JPARC?)
BaBar and Belle doing e+e-hadrons + as well as
+hadrons with high statistics. Factor 2 a(V.P.)
improvement? (Novosibirsk factor 3)
MEG at PSI: BR(e)~2x10-13 (running!) (future 2x10-14)
2e at Fermilab/JPARC aim for AleAl with 2x10-17 SES!
Sensitive to “New Physics” up to 3000TeV (Robust)
If MEG (e) sees several (5) events
it will be a major discovery. 2e should
then see between 100-10,000 events from AleAl.
If MEG sees nothing, 2e could still see 10,000 events!
2e promises to be a flagship experiment.
With upgrade eg. (project X) it could be extended to
10-18. No better way to push muon technology
while doing forefront physics!
2e must do experiment (fast track)
LHC
• Many Discoveries Anticipated:
Higgs, SUSY, Extra Dimensions, Z’, Strong
Dynamics etc.
So far, no evidence for New Physics except
perhaps g-2 (Hope Deviation is Correct)
Can Mainland USA get back to Collider HEP?
Project X at Fermilab
• 2MW proton Linac with 8GeV protons
muon, kaon, neutrino physics (motivation)
(Upgradeable to 4MW)
Front end of a muon collider (Real Motivation?)
Z Factory, Higgs,… Neutrino Factory… p,
2 TeV +- Collider at Fermilab
The Future of US Collider HEP is the Muon!