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Neutrinos:. To the Terascale…. …and Beyond!. Extreme Beam Lecture Series Janet Conrad, May 28. The story begins with a unique accelerator:. If there remains good physics that we can get out, we should go for it…. We need to maximally exploit our existing resources. Question:. What new - PowerPoint PPT Presentation
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To the Terascale……and Beyond!
Neutrinos:
Extreme BeamLecture SeriesJanet Conrad, May 28
The story begins with a unique accelerator:
If there remains good physics that we can get out,we should go for it….
We need to maximally exploit our existing resources.
What newfixed targetprogramscould weput out here?
Question:
Answer :
Over 100 peoplesigned up to follow
this“FutureTev Study”
$15M/year to run(less with optimizations)
NEW
The take-away: if we build a new Fixed Target facility, there will be lots of good physics to do! and plenty of users to do it
This paper focused on Beyond Standard Model Searchesand featured:
* A Charm program* Neutrissimo Searches* A new experiment* NuSOnG
We did not have the chance to cover…* A hyperon program (under development)* A major QCD program (about to be published)
There is surely a lot of fixed target physics that can be done, but…
I
(And Charm will be covered by an Extreme Beamlecture by Ikaros Bigi in Sept!)
A 1-TeV-proton-based Neutrino Program
A suite of interesting experiments:
• NuSOnG • A new experiment • A small dedicated search for neutrissimos
(moderately-heavy neutral heavy leptons)
The Tevatron can yield very high event rates…
e
Past Sample Tev-program
~500k events 6M events~20M events 600M events
~10 events 1000 or more events
Far and away the least explored sector!Many theories argue for new physics
appearing in the 3rd generation.
This offers a neutrino physics program which…
Is complementary to LHC,
Is complementary to the existing neutrino program,
… and it offers a lot of physics topics/experiment
& Moves neutrino technology forward
NuSOnG: Neutrino Scattering On Glass
http://www-nusong.fnal.gov
Outline for the remainder of this talk:
1) Neutrinos, in a nutshell2) The NuSOnG Design (including a new LArTPC option)3) The Electroweak Physics Reach4) The Connection to the QCD & Direct Searches
Neutrinos in a Nutshell…
Z
W
-
The charged current (CC)
interaction
The neutral current (NC)
interaction
W
-
The CC interactionconnects the isospin doublets
e
e CC
u c t
d s bCC
Leptons
Quarks
Z
The neutral current (NC)
interaction
Hello?
NuSOnG focuseson new physics “speaking up” viathe NC interaction
Is where we will look for new physics
The Weak Mixing Angle
sin2 W
= 1(MW
/MZ)2
A fundamental parameter accessible in all processes with Z-exchange
SU(3) SU(2) U(1)
wea
k is
ospi
n
weak hypercharge
elec
tric
char
ge
WParameterizes the mixing between
ZSU(2) and U(1) in the electroweak theory
We look for new physics by cross comparing measurementsbetween experiments…
& = NC coupling/CC coupling
You are used to hearing about 0.1-10 GeV neutrino interactions
1 TeV protons produce neutrinos at ~100 GeV and higher
At these energies, if the target has constituents,there is a high probability it will be blown up!
MiniB.T2K NOvA MINOS
We areHere!
Energy
We will still have low-multiplicity interactions,But they will be a small fraction of the event rate
n p
- e
n p
e-
&
“Quasielastic Scattering”
Magnetic field
You can produce the neutrinos in 2 ways…
1 TeV pDump
Neutrinos andantineutrinos out.
A good design if you want to enhance the fractionof neutrinos from shorter-lived mesons, like Ds
1 TeV ptarget
Long decay pipe,for both s and Ks
Dump
Nu OR nubarout.
A good design to maximize flux and to have sign selection
The general goals and designof NuSOnG
A NuTeV-style FluxUniquely high energy, and low background,
NuSOnG will have a decay length 3 times longer than NuTeV
Why Glass?
• Silicon is the highest A isoscalar (p=n) target• It is relatively inexpensive to obtain• It is relatively easy to handle• You can instrument it if you like…
With this said…
We are looking at an alternative LArTPC design(to be discussed later…)
NUTEV CHARM II
1.5E20 POT in , 0.5E20 POT in
High energy, very pure beam
(20 POT)
Fine-grained, massive detector
(6 mass)
This design comes from past history…
5 1019 POT/year
3 the number of protons per fill,
1.5 faster cycle time66% uptime per year
Two useful publicly-available memos:
http://beamdocs.fnal.gov/AD-public/DocDB/ShowDocument?docid=2222http://beamdocs.fnal.gov/AD-public/DocDB/ShowDocument?docid=2849
Can the Tevatron Deliver the rate?
NuSOnG Eventsrare event & high precision studies
Process Rate Physics+ e- - + e [IMD]
+ e- - +e
700k
0
normalization, “WSIMD”, non-standard interactions
+ e- + e- [ES]
+ e- + e-
75k
7k
new “heavy” physics (Z’, mixing with heavy singlets), new “light” physics, modified couplings, sin2w, , R-parity, extended Higgs
+ q + X [DIS]
+ q + X
+ q -+ X
+ q + + X
190M
12M
600M
33M
-q non-standard interactions, sin2w, xF3, F2, isospin violation, heavy quarks, nuclear effects
decays in low density decay regions
60?? new long-lived heavy neutral particles
100x NuTeV
30x NuTeV
20x CHARM II
40x CHARM II
As many thesis topics as I can type in 5 minutes…
1. The weak mixing angle measure from neutrino-electron scattering2. The weak mixing angle measured from neutrino-quark scattering3. New physics limits probed through coupling to the Z4. New physics limits from the inverse muon decay cross section5. Cross section measurement of neutrino and antineutrino electron scattering6. A search for N decay in the 5 GeV mass range7. Searches for light mass neutrissimos8. disappearance at very high m
9. A search for evidence of nonunitarity of the 3 neutrino matrix10. A search for neutral heavy leptons in the 5 GeV mass range11. Constraints on muonic photons12. Measurement of the CCQE cross section at high energy13. Measurement of the NC0 cross section at high energy14. A study of the transition from single pion to DIS production at high energy15. Measurement of F2 and xF3 at very high statistics16. Comparisons of F2 on nuclear targets from low to high x17. High precision measurement of R from neutrino scattering18. Constraint on isospin violation from xF3
19. Charm production in the emulsion target and a measure of Bc
20. Measurement of the strange sea and s from dimuon production21. Measurement of the charm sea from wrong-sign single muon production in DIS22. Neutrino vs antineutrino nuclear effects
Electro
weak!
Sear
ches
!
QCD!
We have published a paper on our electroweak physics case:
14 institutions: 2 International, 3 National Laboratories, 7 Universities, 2 Colleges
Int.J.Mod.Phys.A24:671-717,2009.arXiv:0803.0354
In one year on the web this paper has received 17 citations…3) Multi-parameter approach to R-parity violating SUSY couplings.
E.M. Sessolo, F. Tahir, D.W. McKay, arXiv:0903.0118 [hep-ph]
7) Fake Dark Matter at Colliders. Spencer Chang, Andre de Gouvea, arXiv:0901.4796
8) Unparticle physics and neutrino phenomenology.J. Barranco, A. Bolanos, O.G. Miranda, C.A. Moura, T.I. Rashba, arXiv:0901.2099 10) Neutral current neutrino-nucleus interactions at high energies.M.B. Gay Ducati, M.M. Machado M.V.T. Machado, arXiv:0812.4273
12) Charged current reactions in the NuSOnG and a test of neutrino-W couplings.A.B. Balantekin, I. Sahin, J.Phys.G36:025010,2009, arXiv:0810.4318
15) Tests of flavor universality for neutrino-Z couplings in future neutrino experiments.A.B. Balantekin, I. Sahin, B. Sahin Phys.Rev.D78:073003,2008, arXiv:0807.3385
16) Model Independent Explorations of Majorana Neutrino Mass Origins.James Jenkins . e-Print: arXiv:0805.0303
17) Effects of new leptons in Electroweak Precision Data.F. del Aguila, J. de Blas, M. Perez-Victoria, Phys.Rev.D78:013010,2008. arXiv:0803.4008]
Many introducephysics
opportunitiesbeyond
our paper
A very special data set…
A unique opportunity for these channels!
e-
Z
e-
e-
W
e
-
Purely leptonic
e-
Z
e-
e-
We
-
NuTeV-style“Paschos-Wolfenstein”
qZ
q
qZ
q
qW
q’
-
qW
q’
+
New!NuSOnG will work with ratios….
Expected errors0.7% conservative, 0.4% conservative0.4% best case 0.2% best case
Our case is based on the conservative estimates
Why do we not focus on:
e-
e-
e-
e-
Like past experiments?
Theory-based reason: Sensitivity to new physics arises from = NC/CC coupling -- which cancels in this ratio
Experimental reason: and fluxes are never identical,
so one cannot do a precision (<1%) measurement
Practical reason:Equal statistics in running takes 3 the proton on target!
Why do we need a Tev-based beam?
e-
We
-
Want flux above ~ 30 GeVNeed no flux below!
The strong cutoff at low energy is dueto the energy-angle correlation in decay
Bottom line:
A 120 GeV program cannot do this physicsbecause it does not have ability to normalize via
e-
We
-
The physics presented hererequires a Tevatron-based beam.
One issue that we face…In a glass detector, some of this….
e- e
-
Gets confused with this….
n p
-in cases where the pis absorbed in the glass
All results I show here include a systematic for how well we understand this background.
&
e-
e-
e
n p
e-
&
But we are also looking a new detector concept using ~3 ktons of LAr
e event at 60 GeV The most perniciousbackground: e CCQE
WOW!See that proton
NuSOnGNeutrino Scattering On Glass
may become
NuSONGNeutrino Scattering On (liquid) Noble Gas
But for this discussion we stick withthe glass detector.
The Electroweak Physics Program of NuSOnG
At the energies ~1 TeV,we expect rich new phenomena to appear.
But since this is terra incognita,We are faced with the conundrum…
>
The Standard ModelThe Standard Model
The Terascale
RSUSY
Which monster shall we discuss?
Leptoquark
Z’B-L Z’q-xu
Neutrissimo
model
Following the structure of our paper (arXiv:0803.0354 )
1) Reach within general classes of New Physics
2) Reach within specific models and scenarios
What we show:There are cases where we have overlapping reach with LHC
or other experimentsThere are cases where our reach is unique.
We provide valuable information beyondthe present program in both cases
From our paper:
5 general classes of new physics searches…
… “generic ways” that new physics might show up
Oblique CorrectionsNeutrino-lepton NSIsNeutrino-quark NSIs
Nonuniversal couplingsRight-handed coupling to the Z
Take all of the world’s past measurements of sin2 W and and map them to
S = weak isospin conserving parameter
T = weak isospin violating parameter
New physics through “oblique corrections”
This would be affected by, e.g., adding a new weak isospin doublet with
degenerate masses
This is affected by anything which makes one isospin partner significantly different from the other
t
b
S = weak isospin conserving T = weak isospin violating
S
Textra families
extra Z’s
Heavier Higgs
very roughly:
So if we plot experiment in S vs T:
S = weak isospin conserving T = weak isospin violating
S
Textra families
extra Z’s
mt=172 GeV,mH=115 GeV.
Heavier Higgs
Cheat sheet:
Now plot the world’s data: LEP wins!It has the highest precisionNC measurements,so it defines the center(S,T)=(0,0)
DIS
What’s this experiment way over here?
NuTeV is the previous generation neutrino experiment,and it is 3 from the “Standard Model”
DIS
“Standard Model”?
It’s clearer when expressedjust as sin2W
New Physics,e.g. nonuniversality?
or
qZ
q
qZ
q
qW
q’
-
qW
q’
+
Recall the method…
“Standard Model”?
It’s clearer when expressedjust as sin2W
New Physics,e.g. nonuniversality?
or
qZ
q
qZ
q
dv
Wq’
-
uv
Wq’
+
Recall the method…
Most viable SM explanation: nuclear isospin violation?
Surely at some level!• u and d quarks have different masses
(biggest effect in “bag model”)• Difference in the virtual meson (pion) cloud• QED corrections (different because u is +2/3, d is -1/3)
0 ?
0 ?
no model fully explains it…
up ≠dn
Sources of information on nuclear isospin violation:
Past experiments used as constraints:F2 in charged lepton vs neutrino scattering
(comparison will be improved by NuSOnG, which will extend to lower x due to higher stats and less dense target)
W lepton charge asymmetry from the TeVatronDrell-Yan 866
Proposed Experiments:NuSOnG (We can directly measure this... I’ll return to this!)Drell-Yan: E906 -- approved! -- run date 2010
Possible Experiments (suggested in hep-ph/0507029)±D scatteringSemi-inclusive deep inelastic scattering
Returning to the Terascale Physics…
NuSOnG makes 4 measurements…
These twoare the“strongest”
A strength of NuSOnG is ability to play thesemeasurements off each other to identify physics
DIS
DIS
qZ
q
e-
Z
e-
The(,e) and gL2
measurements are the strongestwith the initialrun-plan
Going back to my S&T plot and assuming onlyStandard Model Physics….
Present status
If NuSOnGagrees withthe SM
NuSOnG improves the result by ~25%
But of course the more interesting case is…disagreement with SM!
A “realistic” possibility: NuSOnG agrees with NuTeV
a 6 deviation from the SM in gL
2 ( DIS) only
(This particular case, where all other measurements agree with the SM, is a triplet Leptoquark)
Non-standard interactions (NSIs):
Neutrino-lepton NSI
e-
e-
New physics is characterized by • The mass scale of the new physics ()• The probability of left vs. right-handed coupling to the e,
described by a mixing angle (cos ) • The flavor of the outgoing neutrino (“”flavor)
i.e. “pseudo-elastic” neutrino scattering
Look for this new physics via:• change in cross section• angular dependence of outgoing electron
NSI reach for neutrino-lepton scattering
e-
e-
mass scale
outgoingflavor
Relative mixture of handedness
95% CL sensitivity
if = muon flavor~4.5 TeV
if ≠ muon flavor~1.25 TeV
The sensitivity to this term comes from the combination of this diagram… and this diagram….
e-
e-
e-
Z
e-
You will have an interference term if the final state is identical (
But not for
Why is the mass-scale sensitivity lower for compared to
The larger the interference, the higher the sensitivity!
But we might see a signal!
Assume =3.5 TeV, =2/3, … this is the 2contour from NuSOnG
Assume =1 TeV, =4/3, … these are the 2contours from NuSOnG
Conclusions on the general discussion of NuSOnG’s Terascale reach…
• Mass reach: 1 to 7 TeV • Unique information on the couplings• Many ways to probe for new physics with high sensitivity.
Onward to somespecific models!
We have been conservative in our assumed sensitivity.It is likely that we can do better than this.
Through NuSOnG’s measurements, we can help identify the new physics
By the time NuSOnG runs,chances are something new will have been seen…
One Example Scenario:A Chiral 4th Generation Family
(Four Generations and Higgs Physics, hep-ph/0706.3718G. D. Kribs, Y. Plehn, M. Spannowsky, T.M.P. Tait)
LHC:
• Highly enhanced H ZZ • The Higgs mass,
lets say 300 GeV• complex decay modes
(e.g. 6W’s and 2 b’s)
• Measure mass of new quarks• Observe new charged leptons
(off mass shell Drell-Yan produced)• Reconstruct the decay modes fully
And what it doesn’t…
NuSOnG:
A Chiral 4th generation (S=0.2)with isospin violation (T=0.2)
QCD explanation for NuTeV is found, allowing NuTeV to be corrected
NuTeV &NuSOnGConverge
(0.2,0.2)
Pick your favorite LHC BSM model, I’ll show how we help…
LHC sees a standard model Higgs and no signs of new physics
The “God-forbid” Scenario
There is new physics in the neutrino sector!
But if NuSOnG sees this…
The Terascale Program and Other NuSOnG Physics Goals
Precision Electroweak
Measurements
QCD Studies
DirectSearches
NuSOnG has a rich physics program, with interlinked parts
The Terascale Goals provide nice examplesof how all these parts work together to lead to discovery…
Lets say that the “God Forbid” LHC Scenario comes true…
How do we sort out what neutrino physics causes this?
This is an effectonly seen inthe neutrino sector…
And NuSOnG sees…
Importance of the QCD measurements to the Terascale Studies
Precision Electroweak
Measurements
QCD Studies NuTeV-style
“Paschos-Wolfenstein”
qZ
q
qZ
q
qW
q’
-
qW
q’
+
The NuSOnG Structure Function Measurementscan rule out nuclear isospin violationas an explanation for the q result!
qW
q’
-
qW
q’
+
The question about NuTeV…
Is this:
being modeled correctly?
This is proportional to a “structure function” called
xF3
and this leads to a new story!
What does one do with
events???
Coming this week to an arXiv near you!
Deep Inelastic Scattering:
x = fractionof momentumcarried by struck quark
Q2 = negative squared 4-momentum exchanged
y = Energy transferred
Total beam energy
Probability for which parton is struck,is parameterized by the “structure functions”
3 for scattering & 3 for scattering
Three non-controversial theoretical assumptions...
1) the generic cross section formula:
2) F2 =F2, and 3) R = R
Fit in x, Q2 and y bins
extract F2, R, xF3 and xF3
fits include statistical and systematic errors
No inputs from any other experiment!
(xF3 = xF3
- xF3 )
Tremendous improvementover past experiments!
R=L/T
in x and Q2
WOW!
The NuSOnG measurements will have small errors,Crucial for the electroweak studies…
qW
q’
-
qW
q’
+
Returning to
~ xF3
Error
Conclusion about the QCD studies:
They are exciting in their own right!And they meet the needed precision
for the electroweak physics
Returning to our example…
What can cause the e and q to both sit low in T?
Precision Electroweak
Measurements
DirectSearches
Value of the additionaldirect searchesto the Terascale Studies
An example:Neutrissimos.
Not-so-heavy Neutral Heavy Leptons
The mixing modifies the couplings in a flavor dependent way
Say in our EW program we observe… both gL
2 and (e) are offset
This is a signal consistent with modified (i.e. nonuniversal) couplings.
Non-universal couplings may be due to mixing with ~100 GeV neutrissimos.
These neutrissimos may be very hard to see at LHC due to low production rates.
But,
nonuniversal couplings manifest as non-unitarityin the three neutrino mixing matrix
& the heavy neutrissimo may have a lighter partnerthat can be produced in meson decays
NuSOnG can search for both effects!
L/E dependent Not!
Appearance has same effect!
At L=0 there will be an instantaneous transitionbetween neutrino species!
Nonunitarity of the 3 neutrino mixing matrix
hep-ph/0705.0107
look for excess e
events here!
To see instantaneous e
look for an increase in e rate at E~350 GeV
• Look for excess e’s in a range not expected
• Look for “wrong sign” IMD
+e +e -- this should not occur! But if e , then e+e + … same signature!
Seeing bothwould be astriking signature!
Unique
Capability!
N
Vertex in helium
Also a direct search:Filling the 15 m region between subdetectors with heliumand looking for neutrissimo decays…
N ee … etc.
These are produced through mixing in meson decays:
meson xN
chgdlepton
Because of the Tev-based beam, NuSOnG search forproduction in B-decay… i.e. up to ~ 5 GeV!
This is one example of how, by putting all of the pieces together,we could decisively discover new Terascale physics
QCD Studies
DirectSearches
Neutrissimo
Precision Electroweak
Measurements
Returning to the larger neutrino
program…
* Complementary physics,* Shared detector technology,
* Able to be implemented at an existing accelerator
NuSOnG
Neutrissimos
To the Terascale…
…and Beyond!
LET’S GO!
Where no neutrino has gone before
Back-up slides…
More about “oblique corrections”
Assumptions…• The new physics is appearing in loops,
vertex and box corrections are small• There are no additional EW guage bosons (just ,Z,W)• The new physics is large w/r/t the EW scale
This is different from the NSI scenario,where you are can be effectively introducing new gauge bosons