Improved description Improved description of Charged Current of Charged Current ++

production in the production in the MiniBooNE detectorMiniBooNE detector

Jaroslaw NowakJaroslaw NowakLouisiana State UniversityLouisiana State University

on behalf of MiniBooNE collaborationon behalf of MiniBooNE collaboration

2008 Annual Fall Meeting of the APS Division of 2008 Annual Fall Meeting of the APS Division of Nuclear PhysicsNuclear Physics

Oakland, CaliforniaOakland, California

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CC CC ++ sample sample

Major background to the CCQE Major background to the CCQE for the MiniBooNE experimentfor the MiniBooNE experiment

Resonant and coherent Resonant and coherent ++ productionproduction

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Rein-Sehgal model of resonance excitations with MA=1.1GeV [Annals of Physics, 133, 79 (1981)]

Rein-Sehgal model for coherent +

production with MA=1.03 GeV [Nucl. Phys. B223, 29, (1983)] Rescale to reproduce MiniBooNE NC0

results (PLB 664, 1, 2008)

MiniBooNE Results for CCMiniBooNE Results for CC++

In the CCIn the CC++ sample we sample we see a discrepancy see a discrepancy between data and between data and predictions (presented predictions (presented at NuInt07 by at NuInt07 by B.Fleming) B.Fleming)

The same phenomenon The same phenomenon has been previously has been previously seen by the K2Kseen by the K2K

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5.68E20 proton-on-target about 46k CC+ events

K2K, PRL 95, 252301 (2005)

I will present our attempts to understand and fix the problem

Muon mass in resonace excitation modelMuon mass in resonace excitation model

Muon mass included only in the leptonic current –KLN modelMuon mass included only in the leptonic current –KLN model

[Kuzmin, Lyubushkin and Naumov, Phys. Part. Nucl. 35, S133 [Kuzmin, Lyubushkin and Naumov, Phys. Part. Nucl. 35, S133 (2004)](2004)]

Improving the KLN model by adding the pion-pole terms – BRS Improving the KLN model by adding the pion-pole terms – BRS model model [Berger and Sehgal, Phys. Rev. D 76, 113004 (2007)][Berger and Sehgal, Phys. Rev. D 76, 113004 (2007)]

Muon mass in coherent Muon mass in coherent ++ production is introduced by applying the production is introduced by applying the Adler’s screening factor Adler’s screening factor [D. Rein and L. M. Sehgal, Phys. Lett. B 657, [D. Rein and L. M. Sehgal, Phys. Lett. B 657, 207 (2007) ]207 (2007) ]

New vector form factor New vector form factor [O. Lalakulich and E. A. Paschos, Phys. Rev. D [O. Lalakulich and E. A. Paschos, Phys. Rev. D 71, 074003 (2005)] 71, 074003 (2005)]

List of necessary List of necessary improvementsimprovements

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New axial vector form factor New axial vector form factor

Hernandez et al. Hernandez et al. [Phys. Rev. D 76, 033005 (2007)][Phys. Rev. D 76, 033005 (2007)]

Lalakulich et alLalakulich et al. [Phys. Rev. D 74, 014009 (2006)]. [Phys. Rev. D 74, 014009 (2006)]

Graczyk and Sobczyk Graczyk and Sobczyk [Phys.Rev.D77:053001,2008][Phys.Rev.D77:053001,2008]

Need to be determined Form neutrino interaction

List of possible List of possible improvementsimprovements

J. NowakJ. Nowak

Muon mass effect in Rein-Sehgal Muon mass effect in Rein-Sehgal Model Model

With muon mass partial cross sections depend onThe helicity

Dynamical form factors in the RS model

Three partial cross section corresponding to left-handed, right-handed and scalar polarization of intermediate boson

Expressedby

Only threeFunctions Modified

Coherent Coherent productionproduction

The muon mass effect in The muon mass effect in coherent production is taken into coherent production is taken into account applying the Adler’s account applying the Adler’s screening factorscreening factor

Multiply by Adler’sscreening factor

Nuance

The change in overall CC+

Production is small, but it is Included in all following results 10/25/0810/25/08J. NowakJ. Nowak

[D. Rein and L. M. Sehgal, Phys. Lett. B 657, 207 (2007) ]

Improvements – vector Improvements – vector form factorform factorThe relationship between vector form factor in The relationship between vector form factor in

the Rein-Sehgal model and the Rarita-the Rein-Sehgal model and the Rarita-Schwinger form factors from Graczyk and Schwinger form factors from Graczyk and Sobczyk, Phys.Rev.D77:053001,2008Sobczyk, Phys.Rev.D77:053001,2008

Form factor from O. Lalakulich et al., Phys. Rev. Form factor from O. Lalakulich et al., Phys. Rev. D 74, 014009 (2006)D 74, 014009 (2006)

10/25/0810/25/08J. NowakJ. Nowak

Muon mass and new vector Muon mass and new vector form factorform factor

2/ndf(Q2) = 58.2(RS) ->33.3(BRS) -> 20.4(new GV)

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New models with Adler’s screening factor for the coherent production

The best we can do using extension of RS models and data from electron scattering

•Dipole form of axial Dipole form of axial form factor in RS form factor in RS modelmodel

•The Adler model The Adler model assumedassumed

From Graczyk and From Graczyk and Sobczyk the for of the Sobczyk the for of the axial form factor axial form factor

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ANL

BNL

Two parameters: CA5(0) and axial mass MA

New axial vector form New axial vector form factorfactor

2/ndf(Q2) = 19.5(Hernandez) , 14.9(Lalakulich), 55.1(G&S 1), 28.05(G&S 2)

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All with BRS and new GV

ConclusionsConclusionsCharged current Charged current ++ production models were production models were extended to include the mass of charged lepton in extended to include the mass of charged lepton in final state. final state.

Vector form factor was updated using fit from Vector form factor was updated using fit from electron scattering.electron scattering.

All above changes improved our agreement with All above changes improved our agreement with data.data.

A number of the existing parameterizations of A number of the existing parameterizations of axial vector form factor were investigated but axial vector form factor were investigated but none of them is significantly better then our none of them is significantly better then our model with modifications.model with modifications.

We will fit a general form of the the axial vector We will fit a general form of the the axial vector form factor to our high statistic data.form factor to our high statistic data.

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BACKUP SLIDESBACKUP SLIDES

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MiniBooNE MiniBooNE experimentexperiment

Main goal: check LSND results for Main goal: check LSND results for different systematic.different systematic.

The same L/E. The same L/E. LSND: 30m/50MeV,LSND: 30m/50MeV,MB: about 540m / 800MeV.MB: about 540m / 800MeV.

Detector: 12m diameter sphere Detector: 12m diameter sphere filled with ~800 t of mineral oil. filled with ~800 t of mineral oil. 1280 inner phototubes and 240 1280 inner phototubes and 240 veto phototubes.veto phototubes.

MiniBooNE detector gives a MiniBooNE detector gives a opportunity of studying neutrino opportunity of studying neutrino cross section with high statisticscross section with high statistics

~80 Scientists in 16 institutions

Booster

K+

target and horn detector

dirt decay region absorber

primary beam tertiary beamsecondary beam

e

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450m

Be

Event Event selectionselection87% purity and 12% 87% purity and 12%

efficiency efficiency

Veto hits < 6 (cosmic Veto hits < 6 (cosmic muons)muons)

Tank hits for 1Tank hits for 1stst subevent> subevent> 200 – removes Michel 200 – removes Michel electronselectrons

Three subevents cut, muon Three subevents cut, muon and 2 Michel electrons, and 2 Michel electrons, reduces the background.reduces the background.

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Else | 6.56Else | 6.56

Muon mass effectMuon mass effectCross sectionCross section

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Coherent Coherent productionproduction

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Graczyk and Sobczyk, Phys.Rev.D77:053001,2008