Lepton asymmetry and neutrino hierarchy after Planck

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:


110 Mpc s km 2.25 74.08H

Riess et al (2011) Friedmann et al. (2012)

110 Mpcs km 1.2 67.3H Planck+WP+highL :


0.030.89/0.27)(Ωσ 0.46m8

04.0744.0/0.27)(Ωσ 0.020.46m8

Planck+WP+highL :

CFHTLenS:

Heymans et al. (2013)

(68% errors)


Planck+WP+highL+BAO


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:

eV 0.15mυ Verde et al. (2013)

8.36.3 Neff

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)

101.5Ω 107 2K

3

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



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


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


Neutrino freeze out earlier with direct effect on n-p interactions:

Aver et al. (2012)

BBN

n/p goes down goes down

sensitive to expansion ratePY epnυe eυ~pne

PY sensitive to

eξ

eee~ than more 0ξ

PY


Degenerate massive neutrinos

Planck + WP + highL +BAO

0.19 3.33N ; eV 0.25m effυ

0.22 3.40N ; eV 0.35m effυ

(68% CL)


0.13 3.22N ; eV 0.21m eV; 0.23m effeffs

0.22 3.40N ; eV 0.43m eV; 0.28m effeffs


(Vikhlinin et al. 2009)


Non-degenerate massive neutrinos


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


(68% error)


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.

Lepton asymmetry and neutrino hierarchy after Planck

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