# Presentation: 883556

**NO********A Beam Requirements**
**SNuMI Meeting**
**Fermilab**
**16 October 2006**
**Gary Feldman**

## NOA:NuMI Off-Axis e Appearance Experiment

**NO********A is a proposed 2nd generation experiment on the NuMI beamline.**
**Its main physics goal will be the study of ************ ******** ********e**** oscillations at the atmospheric oscillation length.  It will improve MINOS’s capability for this study by approximately an order of magnitude.**
**The Far Detector will be located near Ash River, MN, 810 km from Fermilab and 12 km off the center of the NuMI beamline.**
**The unique characteristic of NO********A is its long baseline, which allows access to matter effects, which can be used to determine the ordering of the neutrino mass states.  The Ash River site provides the longest baseline that is still in the U.S.**
**The off-axis location provides a narrow-band beam about the oscillation maximum.  This maximizes the relevant flux and decreases the background.**

- DoE Review June 26, 2000

## NOA:NuMI Off-Axis e Appearance Experiment

**We will baseline the Far Detector at 20 kT, ****although we hope to expand it to 25 kT ****through earned contingency and foreign ****contributions.**
**The Far Detector will be a totally active, ****tracking liquid scintillator calorimeter.  **
**The basic detector element is liquid****scintillator contained in a 4 cm wide, ****6 cm deep, 15.7 m long, highly reflective**** PVC cell.  The cell is readout through****a wavelength-shifting fiber into an APD.  **
**This gives a longitudinal sampling of 0.15 ****radiation lengths compared to 1.5 radiation****lengths for MINOS.**

- DoE Review June 26, 2000

## The Far Detector

**                                              ****The cells are made from**
**                                           ****32-cell extrusions.  **
**                                       ****12 extrusion modules make**
**                                   ****up a plane.  The planes****                                   alternate horizontal and vertical.**
**                                    **
**                          ****For structural reasons, the planes are****                       arranged in 31-plane blocks, beginning****                       and ending in a vertical plane.  **
**               ****There are 54 blocks = 1654 planes (for****            25 kT).  The detector can start taking data as****            soon as blocks are filled and the electronics****            connected.**

- DoE Review June 26, 2000

## The Near Detector

**4.1 m**

**2.9 m**

**14.4 m**

**Veto region**

**Target region**

**Shower containment region**

**Muon catcher**
**1 m iron**

**209 T**
**126 T totally active**
**23 T fiducial**

**   ****The Near Detector will be****placed off-axis in the MINOS****access tunnel.**** **

- DoE Review June 26, 2000

## Event Quality

**Event Quality**

**Longitudinal sampling is 0.15 X0, which gives excellent ********-*****e***** separation.**

**A 2-GeV muon is 60 planes long.**

- DoE Review June 26, 2000

## Neutrino Oscillations

**Neutrino oscillations occur because the weak eigenstates and not identical to the mass eigenstates.**
**The relationship between the weak eigenstates and the mass eigenstates is given by a unitary rotation matrix:**

- DoE Review June 26, 2000

## Mixing Matrix

**The mixing matrix can be specified by 3 angles and one complex phase:**
**	**

**Atmospheric****    ************ ******** **********

**Solar**

**Atmospheric ****   *********e***** ******** ******************

- DoE Review June 26, 2000

## What We Know and What We Don’t Know

**What We Know and ****What We Don’t Know**

- O. Mena and S. Parke, hep-ph/0312131

- DoE Review June 26, 2000

## How Do We MeasureThese Parameters?

**sin****2****(2********13****) is measured by the rate of the sum of ****                                                         (Slight oversimplification)**
**Both the CP-violating phase ******** and the mass ordering are both measured by the difference between****oscillations. **
**The mass ordering is ****only**** sensitive to a coherent interaction between *********e*****’s and electrons in the earth.   It is significant only for long-baseline experiments, such as NO********A.  (It is a false CP-violating effect due to the presence of electrons and not positrons in the earth.)**
**   **** **
** **

- DoE Review June 26, 2000

## Parameters Consistent witha 2%   e Oscillation

- DoE Review June 26, 2000

## Parameters Consistent witha 2%   e Oscillation

**NO********A**

**T2K**

- DoE Review June 26, 2000

## 3  Sensitivity to 13 ≠ 0

- DoE Review June 26, 2000

## Importance of the Mass Ordering

**Window on very high energy scales: grand unified theories favor the normal mass ordering, but other approaches favor the inverted ordering.**
**If we establish the inverted ordering, then the next generation of neutrinoless double beta decay experiment can decide whether the neutrino is its own antiparticle.  However, if the normal ordering is established, a negative result from these experiments will be inconclusive.**
**To measure CP violation, we need to resolve the mass ordering, since it contributes an apparent CP violation that we must correct  for.**

- DoE Review June 26, 2000

## 95% CL Resolution of the Mass Ordering

- DoE Review June 26, 2000

##  vs. sin2(213) Contours

- DoE Review June 26, 2000

## Measurement of sin2(223)

**Whether the atmospheric mixing is maximal is an important question both practically (comparison of reactor and accelerator measurements) and theoretically (Is there a symmetry that induces maximal mixing?).**
**The combination of the narrow-band beam and NO********A’s excellent energy resolution allows it to do a high-precision measurement of sin****2****(2********23****) by measuring quasielastic ************ CC events.  (Again, about an order of magnitude more precisely than MINOS.)**

- DoE Review June 26, 2000

## Measurement of sin2(223)

**If sin****2****(2********23****) = 1, ****then it can be ****measured to 0.004.**
**Otherwise, it can ****be measured to**
**~0.01.**

- DoE Review June 26, 2000

## Horn Alignment Requirements 

**Wes Smart and Zarko Pavlovic calculated ************ fluxes for various shifts in positions of beam components.  These can be used to estimate our sensitivity to misalignments for the *********e***** appearance measurements.**
**Tingjun Yang used these calculations to study the effect of misalignments on the ************ disappearance measurements.**
**NO********A is most sensitive to horn 1 shifts along the horizontal direction, since these effectively change the off-axis angle.**

- DoE Review June 26, 2000

## Changes in Near/Far Ratioby ± 2 mm Horn 1 Shift

**Integral changes by 0.2% for +2 mm and by 0.8% for -2 mm.**

- DoE Review June 26, 2000

## Changes in  Disappearance by ± 2 mm Horn 1 Shift

**Maximum bias ~1%**

- DoE Review June 26, 2000

## Conclusions

**NO********A is statistics limited.**
**The most cost-effective way of providing higher statistics is through beam intensity improvements.**
**The proposed 1.5 mm beam alignment tolerance appears adequate for NO********A’s needs.**

- DoE Review June 26, 2000