Status of CC Analysis

J.Thomas for

CC working group

NUMI performance

Everything looks reasonable as function of pot and time

Data Preselection

Set of standard cuts agreed upon to select runs with ‘good’ beam

Set of loose cuts to get into MC/Data ball park

Data PreselectionEfficiency about 90%

Purity about 80%

LE-10(170,185,200) pME pHE

5 special runs were taken to check out beam modelling

MC/Data disagreement changes with beam energy

Points to beam modelling, not detector modelling

PTxF

Different beams map out different areas of pT and xF.

Attempt to learn about secondary hadron production as well as beam settings from this informationBased on BMPT parametrization, try to fit it

SKZP Parametrization

SKZP Parametrization

First done for simple additional cuts on top of preselection

The results depend on the event selection.

The results shown are for the CC event selection described later

MC/Data Comparisons

Investigate the low level quantities: problem is always to make sure MC and Data are both apples before you compare themMake assumption that CC events better modelled/understood than NCEvent selection relies more heavily on muon modelling than shower modelling

SR fitter is used to track muons

SR Fitter Efficiency

Muon Tracking

Variables for CC selection

Variables for CC Selection

Agreement between MC and Data is not perfect at this stage

These variables are put into a PDF to select a high purity sample of CC events

PDF MC

Cut is imposed at –0.2 for ND and –0.1 for FD

MC/Data comparisons

Now that data and MC resemble each other, it is possible to compare low level quantities

Shower Ph/plane is NOT well modelled.

We have not seen this level of ‘dirty laundry’ from Super-K or K2K

EM modelling, reconstruction effects…..

Muon and Shower Energy

y and Total E Distribution

Intensity Studies

Special runs were carried out to study the effect of intensity on event selection

No non-linearities were observed

Very low intensity data proved this

Summary of data checks

The main worry is that the modelling agreement between Data and MC differs between ND and FD

There is no evidence that this is the case, even when MC and Data do not agree

Since Oxford, agreement between Data and MC has been significantly improved at low y by a reconstruction fixAn important cross check for all parameter measurement methods is to assume all ND data/MC difference is due to such problems

Oscillation Parameter MeasurementsThere are 4 methods currently being used to study our sensitivity

Fixing MC Generator parameters and systematics in the ND (DP)

F/N MC ratio to extrapolate ND data to FD predicted spectrum (TV)

GNUMI flux matrix to relate neutrinos of energy Ef in FD to neutrinos of energy En in near detector multiplies ND data to give predicted FD spectrum (NS)

Fitting of systematics, generator parameters in grid of E and y in ND (MI)

DP Fit

F/N extrapolation (TV)

This approach uses reconstructed energy dependent F/N to multiply contents of ND data energy bin to produce FD predicted spectrum

Oscillations are applied to Etrue in each bin of Ereco

MINUIT fitting allows exhaustive systematic studies to be carried out by means of 100s of ‘pseudo runs’ to estimate the combination of systematics at 1e20 statistics

F/N Pseudo Run : vanilla

F/N systematic checks

F/N Systematic Error

Matrix Method (NS)

This method uses the GNUMI flux files to generate a matrix which relates a neutrino of energy Ef in FD to one of energy En in ND

Ereco to Etrue in ND, cross section matrices cancel, efficiency of ND selection, matrix,FD efficiency,Etrue to Ereco via oscillations

Matrix Method Extrapolation

Matrix Method (NS)Systematic studies have been carried out on the sensitivity of this methodParticular systematics are applied to the FD or ND and FD spectra and then the fits carried out

Matrix Method (NS)

Data has 9% more events than MC in ND

m2 (eV2) sin2(2)

TRUE 0.002200 0.90

BEST FIT 0.002225 0.96

2006 MDC

A new MDC was carried out last week.

100 sub-runs of 1e20 were generated

100e20 data set was used to measure possible statistical biases in fit methods

All four methods were in agreement within errors

Second batch of MDC has been generated with combinations of systematics.

Some analysis have analised this too, but not all, not enough time

Systematics have been studied exhaustively in any case

F/N 2006 MDC

F/N 2006 MDC

Difference between pseudo runs and 100e20 is negligible in m2

Difference of 0.04 in sin22

Matrix 2006 MDCRight plots indicate the statistical fluctuations one might expect with 1e20 p.o.t

Left plot for 200e20

2006 MDC resultsDP method

m2 = 0.00225

sin22= 0.940

2=33.1/18

F/N

m2 = 0.0023+/-0.00006

sin22= 0.950 +/-0.027

2=64/57

Matrix

m2 = 0.00220+0.00005-0.00002

sin22= 0.96-0.025

2=43/12

Masaki

m2 = 0.00236

sin22= 0.933

2=33.1/18

Status of Cross Checks

F/N has been checked out by Niki

Matrix is being studied by Chris

David has been cross checked by Brian and Alycia

Masaki has not been cross checked

We will hear from Brian and Chris at this meeting

These cross checks will be completed before we go public

What now?

Exhaustive checks on data have been carried out10% statistical error suggests we are in a region of diminishing gainsSystematics are understood to be well below the statistical error

cc group proposal is to open the box tonightResults will be available tomorrow morningProgramme of cross-checks has to be put in place for the run up to the W&CProposal is for W&C to be on Thursday of Collaboration meeting

But first……

I’ve given a brief overview of where we are to put it all in context

Now we will listen in detail to the analyses

Questions should be addressed to the speaker as we go along

And finally, the FD spectrum

From ND data, predict the FD spectrum for no oscillation case

4 different methods give 4 different answers

ND selection the obvious culprit…