# Presentation: 481132

## Neutrino Scattering Physics with

**the Fermilab Proton Driver**
**Introductory Overview**

- Conveners:
- Jorge G. Morfín (Fermilab)
- Ron Ransome (Rutgers)
- Rex Tayloe (Indiana)

## A bit of history... 1930-Wolfgang Pauli Dear Radioactive Ladies and Gentlemen....

## Milestones in the History of Neutrino Physics

- 1934 - Enrico Fermi develops a comprehensive theory of radioactive decays, including Pauli's 		hypothetical particle, which Fermi coins the neutrino (Italian: "little neutral one").
- 1959 - Discovery of a particle fitting the expected characteristics of the neutrino is announced by 	Clyde Cowan and Fred Reines.
- 1962 - Experiment at Brookhaven National Laboratory discovered a second type of neutrino ()
- 1968 - The first experiment to detect e produced by the Sun's burning (using a liquid Chlorine target 	deep underground) reports that less than half the expected neutrinos are observed.
- 1985 - The IMB experiment observes fewer atmospheric interactions than expected.
- 1989 - Kamiokande becomes the second experiment to detect  e from the Sun finding only about 1/3 	the expected rate.
- 1994 - Kamiokande finds that  travelling the greatest distances from the point of production to the 	detector exhibit the greatest depletion.
- 1997 - Super-Kamiokande reports a deficit of cosmic-ray and solar e, at rates agreeing with earlier experiments.
- 1998 - The Super-Kamiokande collaboration announces evidence of non-zero neutrino mass at the Neutrino '98 conference.
- 2000 - First direct evidence for the  announced at Fermilab by DONUT collaboration.
- 2004 - APS Multi-divisional Neutrino Study.
- 2005 - MiniBooNe announces result - yes/no/maybe LSND correct, MINOS starts data-taking.

## What are the Open Questions in Neutrino PhysicsFrom the APS Multi-Divisional Study on the Physics of Neutrinos

- What are the masses of the neutrinos?
- What is the pattern of mixing among the different types of neutrinos?
- Are neutrinos their own antiparticles?
- Do neutrinos violate the symmetry CP?
- Are there “sterile” neutrinos?
- Do neutrinos have unexpected or exotic properties?
- What can neutrinos tell us about the models of  new physics beyond the Standard Model?
**The answer to almost every one of these questions involves understanding how neutrinos interact with matter!**
- Among the APS study assumptions about the current and future program:
- “determination of the neutrino reaction and production cross sections required for a precise understanding of neutrino-oscillation physics and the neutrino astronomy of astrophysical and cosmological sources. **Our broad and exacting program of neutrino physics is built upon precise knowledge of how neutrinos interact with matter.”**

## Outline of the Study of Neutrino Scattering Physics

- What motivates further study of neutrino scattering physics?
- EPP needs	 - future Wednesday talk
- NP needs	 - future Wednesday talk
- What will we know by the start of a Fermilab Proton Driver (FPD)?
- Snapshot of expected experimental results at FPD start-up
- What can best/only be done with the FPD?
- Is there anything left to do and reason to do it?
- What tools do we need to do it?
- “Designer” beams
- Specialized detectors

## What’s actually happening in Neutrino-Nucleus Scattering

- N / qH
- Nucleus/nucleon/quark                   NC / CC

- We don’t know incoming neutrino energy.
- We don’t know, a priori, if it interacts with nucleus, nucleon or quark.
- For CC event, we infer incoming neutrino energy from measured final-state energy.
- Since T is small (order 10-(38-40) cm2) need intense neutrino beams and/or massive target/detectors.
- Using a massive target/detectors masks details of the final state including the energy.
- We need an intense neutrino beam so we can gather significant statistics with a fine-grained, low-A target/detector to see details.

## In spite of (because of) the experimental challenges, Neutrino Scattering Physics at FPD brings together several communities

- EPP - motivated by increased understanding of physics relevant  		to neutrino oscillation experiments, properties of the 		neutrino and structure of nucleon
- NP - motivated by understanding of physics complementary to 			the Jlab program (form factors, structure of nucleon)

**Neutrinos from 8 GeV Protons**
- Limited scope of physics topics
- Minimize backgrounds from
- higher energies
- Specialized study of very
- low-energy phenomena

**Neutrinos from 120 GeV Protons**
- Extended scope of physics topics
- to cover quasi-elastic to DIS
- Must understand/study “backgrounds”
- Neutrino energies similar to JLab

## Motivation: EPP - Neutrino Oscillation requirements Future Wednesday talk for details

- e appearance needs:
- Coherent pion cross sections
- Robust predictions from CC and NC processes
- High y  cross sections
- If signal is seen, we really need QE and
-     resonance cross sections much better than we have now
- Control neutrino/anti-neutrino systematics at 1 percent level for mass hierarchy and CP studies.
- High Statistics  disappearance needs:
- Measurements of Nuclear effects in neutrinos
- “neutrino energy calibration”
- Ratio of Quasi-elastic to non-Quasi-elastic cross sections

## Motivation: Nuclear Physics Interest - Ron Ransome Future Wednesday talk for details

- Significant overlap with JLab physics for 1-10 GeV neutrinos

- Four major topics:
- 	Nucleon Form Factors - particularly the axial vector FF
- 	Duality - transition from resonance to DIS (non-perturbative  			to perturbative QCD)
- 	Parton Distribution Functions - particularly high-xBJ
- 	Generalized Parton Distributions - multi-dimensional 			description of partons within the nucleon

## Neutrino Scattering Topics

**	****	****	****	****	**
**Quasi-elastic ****	****	****	****	****	**
- Resonance Production - 1pi
- Resonance Production - npi, transition region - resonance to DIS
- Deep-Inelastic Scattering**	****	****	**
**Coherent Pion Production****	**
- Strange and Charm Particle Production******	**
******T**** , Structure Functions and PDFs **
**s(x) and c(x)**
**High-x parton distribution functions**
**Nuclear Effects**** ****	****	****	**
- Spin-dependent parton distribution functions
- Generalized Parton Distributions** ****	**

## State of our Knowledge at start of FPD - Time SnapshotAssume following experiments complete...

- K2K - 12 GeV protons
- MiniBooNE  - 8 GeV protons
- MINERA (Running parasitically to MINOS) - 120 GeV protons
- HARP, BNL E910, MIPP (E907) - Associated experiments to help flux determination
- Jlab - High precision elastic scattering to help QE analysis
- T2K-I  (no input as to scattering physics expectations)
- FINeSSE

## Completed experiments by FPD-time

**Main physics channels: **
**quasi-elastic, **
**resonant and **
**coherent 1-******** production**
**May also have a reasonable**
****** ****sample of the above **
**channels **

**Main physics channels:**
**quasi-elastic, **
**Resonant and coherent 1-********, **
**and low-W, multi- ******** channels**

**E******** (GeV)**

## MINERAMI -120 GeV Protons

- C, Fe and Pb
- Nuclear targets

- Move target only

**Main Physics Topics with Expected Produced Statistics**
**Quasi-elastic**** ****	****	****	****	****300 K events off 3 tons CH**
**Resonance Production**** ****	****	****	****600 K total, 450 K 1******
**Coherent Pion Production****	********25 K CC / 12.5 K NC**
**Nuclear Effects**** ****	****	****	****	****C:0.6M, Fe: 1M and Pb: 1 M**
**DIS and Structure Functions**** ****	****	****2.8 M total /1.2 M DIS event**
**Strange and Charm Particle Production**** ****	****> 60 K fully reconstructed events**
**Generalized Parton Distributions**** ****	****	****few K events****	****	**

**Notes:**
here’s what results from that exercise.  surrounding active; calorimeters, OD and MR magnetized

## (Quasi)-elastic Scattering

- Dominant reaction up to ~1 GeV energy
- Essential for E measurement in K2K/T2K
- The “well-measured” reaction
- Uncertain to “only” 20% or so for neutrinos
- Worse in important threshold region and for anti-neutrinos
- Axial form-factor not accessible to electron scattering
- Essential to modeling q2 distribution
- Recoil proton reconstruction requires fine-grained design - impractical for oscillation detectors
- Recent work focuses on non-dipole form-factors, non-zero GnE measurements

- Current status

## Neutrino Scattering: 8 GeV Proton Driver - Rex Tayloe Future Wednesday talk for details

- - NC elastic scattering
-   - A measurement of NC elastic scattering is sensitive to axial, isoscalar  	             component of proton (strange quark contribution to proton spin, s)
-    - Ratio of NC/CC reduces systematics
-    - proton driver would enable this measurement  with 
-    - and perhaps (with high intensity) measurement on nucleon  targets (H/D) allowing elimination of nuclear structure errors.

- -  e elastic scattering
-   - sensitive to  magnetic moment => new physics
-    - measured by low-Ee recoil energy behavior
-    - rates are low!  Require highest-intensity beam.

- FINeSSE could give us a first look at these topics

## MINERA CC Quasi-Elastic MeasurementsFully simulated analysis, including realistic detector simulation and reconstruction

- _We will understand ____ - nucleus elastic scattering by the time of FPD._
_**Except for possible MiniBooNe, low E sample, we will NOT**_
_**have elastic  **__****__** -nucleus  and certainly not  **__****__** / **__****__** - nucleon as well**_

- Average: eff. = 74 % and purity = 77%

**Expected MiniBooNE **
**and K2K measurements**

## Coherent Pion Production

- Characterized by a small energy transfer to the nucleus, forward going . NC (0 production) significant background for  --> e oscillation search.
- Data has not been precise enough  to discriminate   between several very different models.
**K2K, with their SciBar detector, and MiniBooNE will attempt to explicitly measure this channel ****- important low E********measurement**
** **
- Expect 25K events and roughly (30-40)% detection efficiency with MINERA**.**
- Can also study A-dependence with MINERA

## MINERA: Coherent Pion Production 25 K CC / 12.5 K NC events off C - 8.3 K CC/ 4.2 K NC off Fe and Pb

- MINERA

**Expected MiniBooNE **
**and K2K measurements**

- Rein-Seghal

- Paschos-
- Kartavtsev

- _We will understand ____coherent_
- _scattering well by the time of FPD._
- _Except for a possible MiniBooNe_
- _low E sample__**, **__we will NOT have_
- _measured ____ - coherent scattering._

## Parton Distribution FunctionsCTEQ uncertainties in u and d quark fits

## DIS: Parton Distribution Functions Ability of  to taste different quarks allows isolation of flavors

- At high x

*F**2****p** - xF**3****p** = 4xu** *

**No messy nuclear corrections!**

*F**2****p** + xF**3****p** = 4xu** *

****** ****- Proton** **Scattering**

**EPP and NP interest in PDFs**
**Need ******** and p/n target**

## Nuclear Effects - studied only with charged leptons

**shadowing**

**original **
**EMC finding**

**Fermi motion**

*x** *

**sea quark**

**valence quark**

**EXPECTED to be different for**** ********!!**

**valence-quark**

**antiquark**

- S. Kumano

## Difference between  and  nuclear effectsSergey Kulagin

**Need significant ******** statistics to**
**fully understand nuclear effects**
**with the weak current**

## What will we need beyond MiniBooNE, K2K and MINERA for neutrino scattering at FPD?

**HIGH-STATISTICS ANTINEUTRINO EXPOSURE**
**Need to improve purity of ******** beam?**
**HYDROGEN AND DEUTERIUM TARGET FOR ******** and ******** **
**Need reasonable event rates at E ≈ 1 GEV**
**NARROW BAND BEAM FOR DETAILED LOOK AT NC**
**Is off-axis beam sufficiently narrow?**
**IMPROVED DETECTOR TECHNIQUES**
**Particularly good neutron detection for ******** **
**Need a fully-active detector for H****2**** and D****2**** exposures**

## Need a Very Efficient  Beam

**Low energy NuMI ‘****”””****’ beam yields around**
**1.1 ********  events**
**for every ******** event! **

**Resulting beam is almost pure ******** beam:**
** ****in ******** mode = 4 x 10****-3**** **
**Loose factor five in intensity compared to NuMI + factor 3.5 compared to ******

## Need a large H2/D2 target

- An efficient fully-active CCD coupled tracking detector
- Bubble Chamber
- A Chicago - Fermilab collaboration developing
- Contemporary large BC design/construction/operation
- Techniques including CCD readout

- H_2/D_2

- BC Placed in the upstream
- part of MINERA

## Summary

- At the completion of MiniBooNE, K2K and the MINERA parasitic run we will have reasonable results for neutrino-nucleus interactions including exclusive cross-sections, form factors and nuclear effects.
- We will need the FPD, with both an 8 GeV (proton) and 120 GeV (proton) neutrino program, to have similarly reasonable results for:
-  -nucleus cross-sections,
- and  - proton and neutron (D2) cross-sections,
-  - e elastic scattering
- high-statistics narrow-band studies of NC (and CC) channels.
**There is considerable work to be done in detailing the neutrino scattering program at the FPD.  Your participation is most welcome.**