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