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Lepton asymmetry and neutrino hierarchy after Planck

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Lepton asymmetry and neutrino

hierarchy after Planck

Lucia A. Popa

Institute of Space Sciences, Bucharest

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Tension between Planck constraints and local Universe measurements?

- Planck found quite large changes in some parameters of the base ΛCDM model when compared with those from other astrophysical measurements:

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Riess et al (2011)

Friedmann et al. (2012)

Planck+WP+highL :

Heymans et al. (2013)

Planck+WP+highL :

(68% errors)

CFHTLenS:

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Planck+WP+highL+BAO

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

- Possible interpretation of the existing tension
- Some sources of systematic error in cosmological measurements are not completely understood – Planck Collaboration (2013), Spergel et al. (2013)
- Existing tension between different data-sets -Hou et al. (2013)
- Extrapolation of CMB measurements (z~1000) to z=0 within the base ΛCMB model that can be inadequate or incomplete.
- Extensions of the based ΛCMB model
- massive neutrinos with
- extra radiation energy density:

Verde et al. (2013)

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

- sterile neutrino with eV-mass scale required by the SBL data Gariazzo et al. (2013); Wyman et al. (2013)

- phantom values of dark energy equation of state (w ∼ −1.2) or small positive curvature
- Verde,Protopapas,Jimenez (2013)

No single parameter extension to the baseline ΛCDM model helps to alleviate the tension

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Lepton Asymmetric Universe ?

- Affleck-Dine mechanism during or after reheating
- Active-sterile neutrino oscillations after the electroweak phase transition
- Large lepton asymmetry can postpone symmetry restoration in non- supersymmetric or supersymmetric models.

chemical potential

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

LSS - delay of matter-radiation equality shifts the power spectrum turnover position toward larger scales, suppressing the power at small scales.

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Neutrino freeze out earlier with direct effect

on n-p interactions:

sensitive to expansion rate

BBN

Aver et al. (2012)

sensitive to

n/p goes down

goes down

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Degenerate massive neutrinos

Planck + WP + highL +BAO

(68% CL)

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

(Vikhlinin et al. 2009)

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Non-degenerate massive neutrinos

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Global fit of neutrino mixing parameters (Maltoni et al. 2013):

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

(68% error)

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014

Conclusions:

- For all cosmological asymmetric models we find a preference of cosmological data for smaller values of active and sterile neutrino masses when compared with base ΛCDM case.
- An increased tension between cosmological asymmetric models and short baseline neutrino oscillation data that favors a sterile neutrino with the mass of ∼ 1 eV.
- For the case of degenerate massive neutrinos , tensions between direct determination of Hubble constant and cluster abundance are alleviated (at about 1.3 σ level)
- Preference of cosmological data (at ~2 σ statistical significance) for normal neutrino hierarchy.

Cosmological data favor the leptonic asymmetric extension of the base ΛCDM model and normal neutrino mass hierarchy over the models with additional sterile neutrino species and/or inverted neutrino mass hierarchy.

49th Rencontres de Moriond Lucia A. Popa March 22-29, 2014