interplay between cosmology and laboratory experiments: two

50th Rencontres de Moriond, Cosmology Session21 March 2016

Interplay between cosmology andlaboratory experiments:

two examples from neutrino physics

Martina GerbinoOKC and Nordita, Stockholm University

[email protected]

M. Gerbino 50th Rencontres de Moriond, Cosmology 1/13

● Two examples of the interplay between cosmology andlaboratory searches

● The three active massive neutrinos: how we constraintheir mass

OscillationsCosmologyKinematic measurementsNeutrinoless double beta decay

● The additional (MeV) sterile neutrino: is it a viablesolution to the Lithium problem?

Overview

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COSMOLOGY

OSCILLATIONS

DOUBLE BETA DECAY

BETA DECAY

The jigsaw pieces

50th Rencontres de Moriond, Cosmology

M. Gerbino 3/13

Lesgourgues and Pastor, 2006

Neutrino oscillations

Oscillations are only sensitiveto the squared mass difference

Open questions:● What is the hierarchy?● What is the absolute scale mass● What is the neutrino nature?

Degenerate


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Abazaijan et al, 2013

Cosmological probes

TT spectrum

Matter spectrum

BB spectrum Lensing potentialspectrum


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Tightest constraints from cosmologyBUT

model dependent

PL -> power law shape of the primordial PSPCHIP -> Polynomial interpolation, noassumption about primordial shape

Di Valentino, Gariazzo, MG, Giusarma, Mena, 2016

Limits from cosmology


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Kinematic measurements


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Neutrinoless double-beta decay


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Normal HierarchyInverted Hierarchy

PlanckTT,TE,EE+lowP+BAO+Oscillations (2014 global fit)

Currently and in thenear future, cosmology

is the most powerfulprobe for neutrino

masses

MG, Lattanzi, Melchiorri, 2016

Joint constraints from current data


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Currently and in the near future, cosmology isthe most powerful probe for neutrino massesNext Generation laboratory experiments areexpected to be as constraining as cosmology

Crucial role of NME uncertainties

MG, Lattanzi, Melchiorri, 2016

Normal Hierarchy Inverted Hierarchy

Current dataForthcomingNext Generation INext Generation II

Dashed -> FiducialNMESolid -> Marginalized

Joint constraints from current and future data


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MeV-sterile neutrino decay as a viable cosmological solution to the ''Lithium problem'' (Poulin and Serpico, 2015)

Photodisintegration of 7Beafter thermal BBNprevent 7Li production(non-thermal BBN)

Pagano, Salvati, Lattanzi, MG, Melchiorri, in prep.

MeV sterile neutrino decay and 7Li


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Mixing angles withactive neutrinos

Sterile neutrino mass

● Additional non-thermal relativistic degrees of freedomconstraints from CMB anisotropies

● Energy injection from electromagnetic decay channelsconstraints from CMB spectral distorsionsconstraints from baryon-to-photon ratio and baryon abundance from BBN andCMB anisotropies

● Constraints on the mixing angles from laboratory (distinguish between Dirac andMajorana)

● Constraints on element abundances (Li and D) from astrophysics measurements

Responsible for Bephotodisintegration

Decay channels and observable effects


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DIRAC

MAJORANA

Pagano, Salvati, Lattanzi, MG, Melchiorri, in prep.

Limits on the sterile-active mixing angles


Preliminary

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● Neutrino physics is a preferred scenario for the interplay betweencosmology and laboratory measurements

● Cosmological probes are currently the most powerful in constrainingneutrino masses

● The possibility to discard inverted hierarchy and to measure theneutrino mass from cosmology only seems around the corner

● Next generation laboratory avenues are expected to be as sensitive ascosmological probes

● Perfect agreement between cosmological and laboratory bounds onMeV-sterile neutrino as a solution to the Lithium problem

● Slight improvement of the constraints on the sterile-active mixingangles (though highly model dependent)

Conclusions


interplay between cosmology and laboratory experiments: two

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