TRISTAN measurements at Troitsk nu-mass experiment Tim Brunst - - PowerPoint PPT Presentation

TRISTAN measurements at Troitsk nu-mass experiment Tim Brunst - September 12 th 2019 - Toyama (Japan) Topics in Astroparticle and Underground Physics Conference 2019 Max Planck Institute for Physics Technical University of Munich www.mpp.mpg.de www.tum.de

Sterile neutrinos n- Minimal Standard Model Quarks Particle Physics The existence of right-handed partners for neutrinos introduces neutrino mass Leptons Sterile neutrinos are a natural and minimal extension of the SM Cosmology 4%: Atoms In agreement with cosmological observations 96%: A sterile neutrino in the keV mass range is a prime Dark Matter, Dark Energy candidate for Dark Matter 12-Sep-19 KATRIN Collaboration 2 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Sterile neutrinos in tritium decay d𝛥 d𝐹 = cos 2 (𝜄) dΓ d𝐹 (𝑛 β ) + sin 2 𝜄 d𝛥 d𝐹 (𝑛 s ) Characteristic spectral distortion and kink-like signature Active-to-sterile Mass of sterile mixing amplitude neutrino 12-Sep-19 KATRIN Collaboration 3 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Troitsk nu-mass experiment V. N. Aseev, A. I. Belesev, A. I. Berlev, et al., Upper limit on the electron antineutrino mass from the Troitsk experiment , Phys. Rev. D 84 (Dec, 2011) 112003. magnet spectrometer tritium pumps 12-Sep-19 KATRIN Collaboration 4 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Troitsk nu-mass experiment V. N. Aseev, A. I. Belesev, A. I. Berlev, et al., Upper limit on the electron antineutrino mass from the Troitsk experiment , Phys. Rev. D 84 (Dec, 2011) 112003. magnet spectrometer tritium pumps TRISTAN detector 12-Sep-19 KATRIN Collaboration 5 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

TRISTAN prototype 7-pixel SDD prototype by 7 CUBE ASICs by XGLab HLL MPG • CMOS technology in • 2 mm pixel diameter pulsed-reset mode • • Intrinsic ENC 3.4 e - 450 µm thickness 8 mm •  125 eV (fwhm) at 6 keV 12 drift rings • • Dead layer < 100 nm Intrinsic rise time < 10 ns • • Monolithic design DAQ time synchronized  no dead area • Anode capacitance 110 fF  low noise 12-Sep-19 KATRIN Collaboration 6 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Measurement modes integral mode change retarding energy in steps to cut lower part of the spectrum use detector to count electrons Energy resolution determined by spectrometer 12-Sep-19 KATRIN Collaboration 7 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Measurement modes integral mode differential mode set main spectrometer to 0 kV or change retarding energy in steps to small non-zero potential cut lower part of the spectrum use detector to use detector to measure energy count electrons Energy resolution determined Energy resolution determined by spectrometer by detector 12-Sep-19 KATRIN Collaboration 8 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Probability for electrons to change energy, direction of motion, and/or position Model Measurement Retarding energy Tritium Backscattering background 12-Sep-19 KATRIN Collaboration 9 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Probability for electrons to change energy, direction of motion, and/or position Expressed as response matrices Response Model Measurement Retarding energy Tritium Backscattering background 12-Sep-19 KATRIN Collaboration 10 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Probability for electrons to change energy, direction of motion, and/or position Expressed as response matrices Response of Troitsk nu-mass setup separated into three parts Trapping Transport Detector 12-Sep-19 KATRIN Collaboration 11 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Probability for electrons to change energy, direction of motion, and/or position Expressed as response matrices Response of Troitsk nu-mass setup separated into three parts Trapping Transport Detector 12-Sep-19 KATRIN Collaboration 12 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Probability for electrons to change energy, direction of motion, and/or position Expressed as response matrices Response of Troitsk nu-mass setup separated into three parts Trapping Transport Detector 12-Sep-19 KATRIN Collaboration 13 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Probability for electrons to change energy, direction of motion, and/or position Expressed as response matrices Response of Troitsk nu-mass setup separated into three parts Trapping Transport Detector 12-Sep-19 KATRIN Collaboration 14 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Probability for electrons to change energy, direction of motion, and/or position Expressed as response matrices Response of Troitsk nu-mass setup separated into three parts Trapping Transport Detector Determined via simulations and calibration data 12-Sep-19 KATRIN Collaboration 15 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Detector response 12-Sep-19 KATRIN Collaboration 16 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Detector response 12-Sep-19 KATRIN Collaboration 17 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Experimental response Detector response Include as nuisance parameters in the differential fit 12-Sep-19 KATRIN Collaboration 18 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Integral mode integral mode differential mode set main spectrometer to 0 kV or change retarding energy in steps to small non-zero potential cut lower part of the spectrum use detector to use detector to measure energy count electrons 12-Sep-19 KATRIN Collaboration 19 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Integral mode Amount of data Total of 5.8 million electrons Lowest retarding energy 12-Sep-19 KATRIN Collaboration 20 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Integral mode Amount of data Total of 5.8 million electrons Fit χ 2 / dof = 134 / 129 = 1.042 p-value = 35.5 % 12-Sep-19 KATRIN Collaboration 21 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Integral mode Amount of data Total of 5.8 million electrons Fit χ 2 / dof = 134 / 129 = 1.042 p-value = 35.5 % Systematics treatment Covariance matrix method 12-Sep-19 KATRIN Collaboration 22 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Integral mode Covariance matrix method Vary parameters of systematic correction within (correlated) uncertainties O (10 4 ) times Generate MC model spectrum for each variation Calculate covariance matrix from MC spectra Account for systematic uncertainties in χ 2 -fit χ 2 = 𝑧 𝑈 𝑁 −1 Ԧ 𝑦 − Ԧ Ԧ 𝑦 − Ԧ 𝑧 12-Sep-19 KATRIN Collaboration 23 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Integral mode Covariance matrix method Vary parameters of systematic correction within (correlated) uncertainties O (10 4 ) times Generate MC model spectrum for each variation Calculate covariance matrix from MC spectra Account for systematic uncertainties in χ 2 -fit χ 2 = 𝑧 𝑈 𝑁 −1 Ԧ 𝑦 − Ԧ Ԧ 𝑦 − Ԧ 𝑧 Systematics dominant below 15 keV 12-Sep-19 KATRIN Collaboration 24 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Differential mode integral mode differential mode set main spectrometer to 0 kV or change retarding energy in steps to small non-zero potential cut lower part of the spectrum use detector to use detector to measure energy count electrons 12-Sep-19 KATRIN Collaboration 25 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019

Differential mode Amount of data Retarding energy Total of 1.7 million electrons Tritium Backscattering background 12-Sep-19 KATRIN Collaboration 26 TRISTAN measurements at Troitsk nu-mass experiment TRISTAN Group Tim Brunst - TAUP 2019