Atmospheric neutrino selection
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Atmospheric neutrino selection. goal: improve efficiencies for both E -2 and atmospheric neutrinos strategy improved hitcleaning track resolution (paraboloid fit) zenith restricted fit Phit/Pnohit fit no neural networks (or similar). Efficiency of New Analysis.

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Atmospheric neutrino selection

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Atmospheric neutrino selection

Atmospheric neutrino selection

  • goal: improve efficiencies for both E-2 and atmospheric neutrinos

  • strategy

    • improved hitcleaning

    • track resolution (paraboloid fit)

    • zenith restricted fit

    • Phit/Pnohit fit

    • no neural networks (or similar)

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Efficiency of new analysis

Efficiency of New Analysis

atmo. neutrinos45 % E-2 neutrinos40 %

  • efficiency > 60% above 120°

relative to L2

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Neutrino candidates

Neutrino Candidates

NatmoMC: ± 25%

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Effective area

Effective Area

  • zenith angle dependence

new

std.

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Atmospheric neutrinos

Atmospheric Neutrinos

  • neutrino-effective area for energies above 50 GeV

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Corrected zenith angle spectrum

Corrected Zenith Angle Spectrum

  • account for acceptance and oscillations

SuperKamiokande:

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Restrictions on m 2

systematic error

Restrictions on Δm2?

  • neutrino flux relative to flux with

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


What do we expect from 6 years

What do we expect from 6 years?

  • 10000 atmospheric neutrinos

  • study high energy

  • restrictions on alternative oscillation modells

90% with energies from 0.1 – 10 TeV

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Medianres zenith hard cuts q z 110

MedianRes, Zenith (hard cuts Qz> 110°)

data 00-03

data 2000

data 2001

data 2002

data 2003

... years behave differently number of dead OM‘s is important!

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Lorentz invariance test

Lorentz invariance test

Glashow - hep-ph/0407087

  • neutrino species can have different maximal velocities v1, v2, v3 < c

  • velocity eigenstates rotated w.r.t. flavor eigenstates by v(and phase )

  • define Ecritical = Ec=sqrt(m²c / 2v)

E < Ec mass oscillation dominant

Ec < E Lorentz violation dominant

examine 2 extreme cases:

case 1:velocity eigenstates = flavor eigenstates

case 2:velocity eigenstates = mass eigenstates

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Amanda s range

AMANDA‘s range

survival probability for a  for case 2 with Ec = 100 GeV

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Case 1 q v 0

Case 1: Qv = 0

Ec = 1 GeV

Ec = 10 GeV

Ec = 100 GeV

Ec = 1 TeV

Ec = 10 TeV

Ec = 100 TeV

Ec = 1 PeV

Ec = 10 PeV

Ec = 100 PeV

hardly accessible for AMANDA

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Case 2 q v p 4

Case 2: Qv = p/4

Ec = 1 GeV

Ec = 10 GeV

Ec = 100 GeV

Ec = 100 TeV

Ec = 1 TeV

Ec = 10 TeV

Ec = 1 PeV

Ec = 10 PeV

Ec = 100 PeV

well accessible for AMANDA for Ec< 1TeV

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


E c cos h plane

Ec - cos(h) - plane

exclusion regions

case 2:

(only 2002 data,

preliminary)

90 % C.L.

Ec ~ 102.5 = 316 GeV

v/c ~ 1.2*10-26

log ( Ec / GeV )

99 % C.L.

Ec ~ 102.2 = 158 GeV

v/c ~ 4.6*10-26

cos(h)

Depends on assumed systematic errors (needs to be studied in detail)

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Other studies

Other studies

There are many (exotic) models around that can be tested:

Quantum decoherence

 extra dimensions

... and lots of other ideas

extensive ANTARES Monte Carlo study

... see Francis talk

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Additional plots not shown

Additional plots (not shown)

Note: analysis 2000-2003 is very preliminary!

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Standard analysis

Standard Analysis

  • optimized for best sensitivity (E-2 – spectrum)

  • selected neutrinos 2002

  • efficiencies

Ndata = 470 NatmoMC= 402 ± 100

(for θ>90°)

atmo. neutrinos11 % E-2 neutrinos28 %

relative to L2

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Efficiency of new analysis1

Efficiency of New Analysis

atmo. neutrinos45 % E-2 neutrinos40 %

  • efficiency > 60% above 120°

relative to L2

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Neutrino candidates1

Ndata

Ndata

NatmoMC

NatmoMC

θ>90°

2021

1793

θ>90°

459

437

θ>110°

1194

1238

θ>110°

283

312

Neutrino Candidates

Standard analysis

New analysis

NatmoMC: ± 25%

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Effective area1

Effective Area

  • zenith angle dependence

  • energy dependence

new

std.

new (for different spectra)

new

std.

E-2

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Atmospheric neutrinos1

Atmospheric Neutrinos

  • neutrino-effective area

  • remaining background

contribution to systematic error ~10%

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Data 2000 2003

Data 2000-2003

Level 5 data from Zeuthen 00-03 analysis

Level 6a fits with

T.Becka‘s hit cleaning

pandel (seeded 32-Pandel)

bayes (seeded 64-Bayes)

PhPnh (seeded 10-PhPnh)

ParabolaFit on PhPnh

Softer cuts:

Ldiff>25

spaceangle(JAMS,phpnh)<30

spaceangle(pandel,phpnh)<10

Smoothness > -0.4

MedianRes<5

„Soccer cut“

Hard cuts:

Ldiff>30

spaceangle(JAMS,phpnh)<10

spaceangle(pandel,phpnh)<10

0.4 > Smoothness > -0.4

MedianRes<5

„Soccer cut“

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Data 2000 20031

year

2000

2001

2002

2003

lifetime

197

193

204

213

events L6a

149,404

200,159

238,475

257,874

Qz>90°, flare<10, Irun

30,955

35,468

41,370

44,985

softer cuts

Qz>90°

2309

2918

3195

3543

softer cuts Qz>110°

1075

1364

1574

1679

hard cuts Qz>90°

1075

1424

1690

1819

hard cuts Qz>110°

746

955

1138

1176

Data 2000-2003

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Gps day vs zenith no cuts

GPS day vs. Zenith (no cuts)

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Zenith vs cogz no cuts

Zenith vs. Cogz (no cuts)

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Zenith vs cogz hard cuts q z 90

Zenith vs. Cogz (hard cuts Qz> 90°)

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Medianres vs cogz no cuts

MedianRes vs. Cogz (no cuts)

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Medianres vs cogz hard cuts q z 90

MedianRes vs. Cogz (hard cuts Qz> 90°)

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Spaceangle jams phpnh spaceangle pandel phpnh ldiff smoothness no cuts

spaceangle(JAMS,phpnh), spaceangle(pandel,phpnh),Ldiff, Smoothness -- (no cuts)

data 00-03

data 2000

data 2001

data 2002

data 2003

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Spaceangle jams phpnh spaceangle pandel phpnh ldiff smoothness softer cuts q z 90

spaceangle(JAMS,phpnh), spaceangle(pandel,phpnh),Ldiff, Smoothness -- (softer cuts Qz> 90°)

data 00-03

data 2000

data 2001

data 2002

data 2003

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Spaceangle jams phpnh spaceangle pandel phpnh ldiff smoothness hard cuts q z 90

spaceangle(JAMS,phpnh), spaceangle(pandel,phpnh),Ldiff, Smoothness -- (hard cuts Qz> 90°)

data 00-03

data 2000

data 2001

data 2002

data 2003

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Spaceangle jams phpnh spaceangle pandel phpnh ldiff smoothness hard cuts q z 110

spaceangle(JAMS,phpnh), spaceangle(pandel,phpnh),Ldiff, Smoothness -- (hard cuts Qz> 110°)

data 00-03

data 2000

data 2001

data 2002

data 2003

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


Medianres zenith hard cuts q z 90

MedianRes, Zenith (hard cuts Qz> 90°)

data 00-03

data 2000

data 2001

data 2002

data 2003

Jens Ahrens and Thomas Becka, Atmospheric Neutrinos, Berkeley, March 2005


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