# Presentation: 016094

## Neutrino Scattering Physics with

**the Fermilab Proton Driver**

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

## Outline

- What motivates further study of neutrino scattering physics?
- EPP needs
- NP needs
- 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

## 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: Conclusions- Neutrino Oscillation: Requirements D. Harris - Proton Driver Workshop

- e appearance needs:
- Coherent pion cross sections
- Robust predictions from CC process to NC process
- 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

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

- Four major topics:
- 	Nucleon Form Factors
- 	Duality
- 	Parton Distribution Functions - overlap with EPP
- 	Generalized Parton Distributions - overlap with EPP

## 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
- Associated experiments to help flux determination - HARP, BNL E910, MIPP (E907)
- Jlab High precision elastic scattering to help QE analysis
- T2K-I  (no input as to scattering physics expectations)
- FINeSSE

## MiniBooNE8 GeV Protons

**Main physics channels quasi-elastic, resonant and coherent 1-******** production**

- Review current experiments to assess scope of physics and
- potential of detector techniques at FPD

## K2K Near Detectors12 GeV Protons

- SciBar

**E******** (GeV)**

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

- T2K: 40 - 50 GeV Protons

## MINERAMI 120 GeV Protons

- Active target of scintillator bars
- 6t total, 3 - 5 t fiducial
- Surrounded by calorimeters
- upstream calorimeters are Pb, Fe targets (~1t each)
- magnetized side and downstream tracker/calorimeter

- C, Fe and Pb
- Nuclear targets

- Move target only

- Move target and
- Second horn

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

## MINERA will have the statistics to cover awide variety of important  physics topics

**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****	****	**

- Assume **9x10****20**** POT**: **MINOS chooses **7**.0x**1020** in LE ********beam, 1.2x**1020** in sME and 0.8x**1020** in sHE**

-  Event Rates per fiducial ton
- Process		CC	  NC
- Quasi-elastic	103 K	  42 K
- Resonance		196 K	  70 K
- Transition		210 K         	  65 K
- DIS		420 K	125 K
- Coherent		 8.4 K	 4.2 K
**TOTAL****	****	****940 K****	****305 K**

**Typical Fiducial Volume = **
**3-5 tons CH,  0.6 ton C, ≈ 1 ton Fe **
**and ≈ 1 ton Pb**
**3 - 4.5 M events in CH**
**0.5 M events in C**
**1 M events in Fe**
**1 M events in Pb**

## Neutrino Scattering TopicsWhat will we know and not know at time snapshot? 

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

## (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

## Neutrino Scattering: 8 GeV Proton Driver - Rex Tayloe

- - 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-E e recoil energy behavior
-    - rates are low!  Require highest-intensity beam.

- FINeSSE could give us a first look at these topics

## Nucleon Form Factors - NP Interest

- JLab experiments have shown unexpected difference between Q2 dependence of electric and magnetic form factors

- The behavior of the axial form factor is almost completely unknown.  Precision measurement on hydrogen needed.

## 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._
_**We will NOT have elastic **__****__** -nucleus nor **__****__** / **__****__** - nucleon as well**_

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

## 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._
- _We will NOT have measured_
- ___ __- coherent scattering well_

## CC Resonant Single-Pion Production

- Existing data inconsistent (factor 2 variations)
- Treatment of nuclear effects unclear
- Renewed theoretical interest
- Rein - Sehgal used for decades
**Sato-**Uno-Lee model gives a better fit to (poor) data
- Very comprehensive  Paschos -Lalakulich model just released

- K2K S. Nakayama
-          M. Hasegawa

- MiniBooNE H. Tanaka:

- 0

- 0

## MINERA Resonance Production - 

- Total Cross-section and d/dQ2 for the ++ assuming 50% detection efficiency
**DO  NOT FORGET RADIATIVE DECAYS AS BACKGROUND TO************ ****--> ********e**

- T

- Errors are statistical only

-  **produced 1-******** and 2- ******** states will be well measured by time of FPD**
****** ****resonant ******** production NOT well measured**

## Resonant Multi-pion Production and transition to DIS Quark/Hadron Duality

- Recent JLAB data have revived interest in quark/hadron duality
- Bodek and Yang have shown that DIS cross-sections can be extended into the resonance regime, and match the “average” of the resonant cross-section
- We need more than just the “average” knowledge of the transition region - hills and valleys
- Beyond kinematic range of K2K and MiniBooNE.
- MINERA - 600K events

- Bodek and Yang

## Duality - NP Interest

- JLab experiments have shown strong correlation of structure functions measured in resonance region with DIS.

- Origins of duality still unknown.  Flavor dependence of duality should give insight into this phenomenon.

- approx. x) dependence of F2 in DIS (black line) and resonance (colors) region

**Need precision measurements on hydrogen targets**

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

## DIS: Parton Distribution Functions Ability 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**

## Generalized Parton Distribution Functions - NP Interest

- One of the most exciting theoretical developments – gives the opportunity to determine complete 3-D picture of the nucleon.  Gives transverse distribution as function of momentum fraction of parton.

- Difficult experimentally – requires exclusive measurements (e.g. n  p )

**Best done with nucleon (hydrogen or deuterium) targets.**
**Cross section is small – need high intensity neutrino and anti-neutrino beams.**

## Nuclear Effects - modified interaction probabilities

**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 - B. Bernstein

**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.

## After initial (parasitic to MINOS) run -could add a Liquid H2/D2(/O/Ar) TargetNOT APPROVED FOR THIS

- H_2/D_2

- MINOS Near

- Fid. vol:
- r = 80 cm. l = 150 cm.
- 350 K CC events in LH2
- 800 K CC events in LD2
- per year he- running.  Few events with E ≈ 1 GeV.

- Technically **easy/inexpensive** to build and operate.
- Meeting **safety** specifications the **major **effort.

- Planes of C, Fe, Pb
- For part of run

## Measuring Six Structure Functions for Maximal Information on PDF’s

- X = 0.1 - 0.125
- Q2 = 2 - 4 GeV2
- Kinematic cuts in (1-y)
- not shown

- + y2 FL

- (1-y)2

- R = Rwhitlow
- Neutrino
- 1 year he-beam
- Anti-Neutrino
- 2 years he-beam

## Presentations and Discussions:Neutrino Scattering Physics at the Fermilab Proton Driver (FPD)

- Summary of APS Neutrino Study, Neutrino Scattering Physics  	Bonnie Fleming
- Summary of NuFact'04 Neutrino Scattering Group		Jorge G. Morfin
- Neutrino Probes of Hadronic Structure				Wally Melnitchouk
- Deeply Virtual Neutrino Scattering				Ales Psakar
- C C Neutrino Induced Nuclear Reactions at Intermediate Energies	Manuel Valverde
- Neutrino-nucleon Elastic Scattering with the Proton Driver		Chuck Horowitz
- A High Intensity Neutrino Beam Using 8 GeV Protons		Geoff Mills
- Neutrino Scattering Measurements: What do Oscillation
- 				Experiments Really Need	Debbie Harris
- Status of Neutrino Cross-Sections				Sam Zeller
- General Discussion: What experimenters need from theorists
- 				and vice versa
- Overview of Neutrino Beams					Bob Bernstein
- COUPP, Using Contemporary Techniques to Develop a
- 		WIMP-sensitive Bubble Chamber at FNAL	Juan Collar
- A LAr TPC Near Detector					Adam Para

## Nuclear Effects - Low  low Q2 shadowing

- Q2 distribution for SciBar detector

***MiniBooNE***
*From J. Raaf*
*(NOON04)*

- 	All “known” nuclear effects taken into account:
- Pauli suppression, Fermi Motion, Final State Interactions
-            They have **not included** low- shadowing that is only
-         allowed with axial-vector (Boris Kopeliovich at NuInt04)
- 	Lc = 2 / (m2 + Q2)  ≥  RA	**(not **m2**)**
-  _L__c__ __**100 times shorter with **_m_**allowing low **____**-low **__Q__2__** shadowing**_
**     **ONLY MEASURABLE VIA NEUTRINO - NUCLEUS
-     INTERACTIONS!**  MINER********A WILL **_**MEASURE**_** THIS **
**   ****ACROSS A WIDE **** AND **Q2** RANGE WITH  C : Fe : Pb**

- Problem has existed
- for over two years

- Larger than expected rollover at low Q2