Pr Probing new physics via via extr trem emely ely rar are e - PowerPoint PPT Presentation

Pr Probing new physics via via extr trem emely ely rar are e dec decay sear earch h wi with h GER ERDA A and nd LEGEN END Yoann KERMAÏDIC LPSC seminar Grenoble 23 January 2020

Cru Crucial open issu ssues s in part rticle physi sics Number of baryons / antibaryons (matter) / (antimatter) Baryonic asymmetry ! = # $ − # $ = (. *++ ± -. -(. ×*- 0*- [Planck, 2018] & of the Universe (. **? ± -. *-- ×*- 0*- [Cooke, 2018] # ' Among many theoretical BSM Number of photons models: the leptogenesis!? (light) Element abundance of the Universe Cosmic Microwave Background [Planck, 2018] [Cooke, 2014] 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 2

Crucial open issu Cru ssues s in part rticle physi sics Number of baryons / antibaryons (matter) / (antimatter) Baryonic asymmetry ! = # $ − # $ = (. *++ ± -. -(. ×*- 0*- [Planck, 2018] & of the Universe (. **? ± -. *-- ×*- 0*- [Cooke, 2018] # ' Among many theoretical BSM Number of photons models: the leptogenesis!? (light) Is the neutrino its own antiparticle? Only neutral elementary fermion 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 3

Cru Crucial open issu ssues s in part rticle physi sics Number of baryons / antibaryons (matter) / (antimatter) Baryonic asymmetry ! = # $ − # $ = (. *++ ± -. -(. ×*- 0*- [Planck, 2018] & of the Universe (. **? ± -. *-- ×*- 0*- [Cooke, 2018] # ' Among many theoretical BSM Number of photons models: the leptogenesis!? (light) Is the neutrino its own antiparticle? Only neutral elementary fermion Non-zero but tiny neutrino masses See-saw mechanism? requires neutrinos to be Majorana - Lepton Number is violated in general • new mass term in the Lagrangian explaining the smallness of masses • provides a mechanism for effective leptogenesis • 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 4

Cru Crucial open issu ssues s in part rticle physi sics Number of baryons / antibaryons (matter) / (antimatter) Baryonic asymmetry ! = # $ − # $ = (. *++ ± -. -(. ×*- 0*- [Planck, 2018] & of the Universe (. **? ± -. *-- ×*- 0*- [Cooke, 2018] # ' Among many theoretical BSM Number of photons models: the leptogenesis!? (light) Is the neutrino its own antiparticle? Only neutral elementary fermion Non-zero but tiny neutrino masses See-saw mechanism? requires neutrinos to be Majorana - Lepton Number is violated in general • new mass term in the Lagrangian explaining the smallness of masses • provides a mechanism for effective leptogenesis • HOW TO RELATE THIS TO 76 Ge? 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 5

Tw Two neut neutrino nos do doubl uble e be beta dec decay - 2CDD b (def) SM particles A = i( n 26.3 h p n T U FG As 0 +×*- +* a Q 0 R S OO ] 0 2 FG Ge OJ ]] 0 0 R S FG Q 0 Se O\ n p T U h ( V , W +2) + 2 Y 0 + 2T ( V , W ) → & Such process: FG IJ LMM LOM LOG , , , , ü energetically favored in some isotopes ( Ge Se Mo Te Xe , …) ü is predicted by the SM [Goppert-Mayer – 1935] ü is measured experimentally 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 6

Neutrinoless d Ne double b beta dec decay - 0CDD Light neutrino exchange Heavy neutrino exchange SM particles BSM particles p p n n 0 0 Q 0 0 R S R S Q n T o 0 0 R S R S 0 Q n Q 0 n p n p ( V , W +2) + 2 Y 0 ( V , W +2) + 2 Y 0 ( V , W ) → ( V , W ) → Such process: ü violates the Lepton Number by 2 units = New Physics! ü determines the nature of neutrinos: Majorana particle T = T & [Valle – 1982] ü gives information on the C mass via j kk (light neutrino exchange scenario) ♾ has never been observed so far Ø High sensitivity due to the Avogadro number: ~10 Jm Ge nuclei / kg 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 7

« Li Light neutri rino exchange » + 1 (eV) v ]] -T 0* = r V s t -T u -T + p */+ + b v Y b m -T p */+ experimentally probed half-life - 1 10 r V axial vector coupling cnst = 1.25(?) u -T nuclear matrix element (NME) w Mx phase space factor - 2 10 n 3 paradigm: j y electron mass NO IO Mass hierarchy not yet probed conclusively by - 3 10 - - - - 4 3 2 1 10 10 10 10 1 m (eV) lightest • Attractive: Minimal model without requiring new particles (mediator = active C ) U = PMNS matrix [NuFit 19’] • Direct relationship with the cosmological neutrino mass sum and direct mass measurement • Rich complementarity in case of non-zero measurement in one of the channels • 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 8

« Li Light neutri rino exchange » 1 1 1 (eV) (eV) (eV) b b b b b b m m m - - - 1 1 1 10 10 10 - - - 2 2 2 10 10 10 n Cosmo - direct: 3 paradigm: Planck min NO Planck ext IO KATRIN 5 yr - - - 3 3 3 10 10 10 - - - - - - - 4 3 2 1 1 2 1 10 10 10 10 1 10 1 10 10 1 S m (eV) m (eV) (eV) b lightest • Attractive: Minimal model without requiring new particles (mediator = active C ) U = PMNS matrix [NuFit 19’] • Direct relationship with the cosmological neutrino mass sum and direct mass measurement • Rich complementarity in case of non-zero measurement in one of the channels NB: Hubble constant “problem” shows some limitations • 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 9

Co Cosmo smological de detour ur : : H0 0 « pr probl blem em » H0 = Hubble constant in [km/s/Mpc], measuring how fast the Universe is expanding • Special workshop organized in July 2019 to review all the H0 measurements: • “ Tensions between the Early and the Late Universe” all the slides at http://online.kitp.ucsb.edu/online/enervac-c19/ [Planck, 1807.06209] [1907.04869] z. .{ ! • directly connected to the previous plots • phenomenology not 100% under control • models dependence 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 10

« Li Light neutri rino exchange » 1 1 1 (eV) (eV) (eV) b b b b b b m m m ongoing [Science 19’] - - - 1 1 1 10 10 10 - - - 2 2 2 10 10 10 n Cosmo - direct: 3 paradigm: Ge sensitivity: Planck min NO Planck ext Gerda IO KATRIN 5 yr - - - 3 3 3 10 10 10 - - - - - - - 4 3 2 1 1 2 1 10 10 10 10 1 10 1 10 10 1 S m (eV) m (eV) (eV) b lightest • Attractive: Minimal model without requiring new particles (mediator = active C ) U = PMNS matrix [NuFit 19’] • Direct relationship with the cosmological neutrino mass sum and direct mass measurement • Rich complementarity in case of non-zero measurement in one of the channels • 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 11

« Li Light neutri rino exchange » ongoing [Science 19’] • Attractive: Minimal model without requiring new particles (mediator = active C ) U = PMNS matrix [NuFit 19’] • Direct relationship with the cosmological neutrino mass sum and direct mass measurement • Rich complementarity in case of non-zero measurement in one of the channels • 23/01/2020 Yoann Kermaïdic - LPSC seminar - Grenoble 12

0CDD dec decay exper xperimen ental signa gnatur ure 2.5 Counts [/keV.kg.yr] • 2CDD c ontinuum + peak at | kk example : 76 Ge Mx = 10 J\ yr 2 } L/J ℇ = 30 kg. yr n b b 2 1.5 Mx = ln 2 . ~  Ä  . Å . ℇ . L • } 1 L/J ~ É 0.5 n b b 0 0 • Key points: 0 500 1000 1500 2000 2500 3000 high - energy resolution - low Energy [keV] o Avogadro number: Ñ 2.5 Counts [/keV.kg.yr] Ö 2 o Efficiency [%] x exposure [kg.yr]: Å . ℇ n b b 2 1.5 1 o Energy resolution [keV] 0.5 n b b 0 o BI = ~ à 0 0 500 1000 1500 2000 2500 3000 ℇ . âä [cts/(keV.kg.yr)] Energy [keV] 2.5 Counts [/keV.kg.yr] 2 • Topology : n b b 2 1.5 o Signal = Single-Site Event (SSE) 1 o Background ã = Multi-Site Event (MSE) 0.5 å/D = Surface Event n b b 0 0 0 500 1000 1500 2000 2500 3000 23/01/2020 Energy [keV] Yoann Kermaïdic - LPSC seminar - Grenoble 13

0CDD dec decay expe xperimental si sign gnature 2.5 10 Counts [/keV.kg.yr] Counts (/keV.kg.yr) example : 76 Ge Entries: 93 Bkg index : 6.0e-04 cts/(keV.kg.yr) Mx = 10 J\ yr n 2 1 0 } T : 1.0e+24 yr 1/2 L/J FWHM : 100.0 keV ℇ = 30 kg. yr n b b 2 - 1.5 1 10 - 2 1 10 - 3 0.5 10 n b b 0 n b b 2 - 4 0 10 0 500 1000 1500 2000 2500 3000 1950 2000 2050 2100 2150 high - energy resolution - low Energy [keV] Energy [keV] 10 2.5 Counts [/keV.kg.yr] Counts (/keV.kg.yr) Entries: 95 Bkg index : 6.0e-04 cts/(keV.kg.yr) n 2 1 0 T : 1.0e+24 yr 1/2 FWHM : 30.0 keV n b b 2 - 1 1.5 10 - 2 10 1 - 3 10 0.5 n b b 0 n b b 2 - 4 10 0 1950 2000 2050 2100 2150 0 500 1000 1500 2000 2500 3000 Energy [keV] Energy [keV] 2.5 10 Counts [/keV.kg.yr] Counts (/keV.kg.yr) Entries: 119 Bkg index : 6.0e-04 cts/(keV.kg.yr) 0 n 2 1 T : 1.0e+24 yr 1/2 FWHM : 3.0 keV n b b 2 - 1 1.5 10 - 1 2 10 - 3 0.5 10 n b b 0 n b b 2 - 4 0 10 0 500 1000 1500 2000 2500 3000 1950 2000 2050 2100 2150 23/01/2020 Energy [keV] Yoann Kermaïdic - LPSC seminar - Grenoble Energy [keV] 14