Dr Michael Schmidt
Senior Lecturer

Dr Michael Schmidt

2005-2008 PhD in Theoretical Particle Physics (TU Munich and Max Planck Institut for Nuclear Physics), summa cum laude
Running Neutrino Masses and Flavor Symmetries, Supervisor: Prof. Dr Manfred Lindner

1999-2004 Physik Diplom (TU Munich, Germany), Supervisor: Prof. Dr. Manfred Lindner

Science
School of Physics

Dr. Michael Schmidt obtained his Physik Diplom and PhD at the Technische Universität München in Germany. His PhD was on theoretical neutrino physics. After two postdoctoral research positions at the Institute for Particle Physics Phenomenology at the University of Durham (2008-2011) and the University of Melbourne (2011-2014), he worked for four years as a Lecturer at the University of Sydney (2014-2018), before starting at the University of New South Wales as Senior Lecturer in 2018. His current research is focused on neutrino and flavour physics, but he is generally interested in new physics beyond the Standard Model and astroparticle physics.

Phone
+61-2-9065 3045
Location
Old Main Building Level 1, room 121
  • Journal articles | 2022
    Coy R; Schmidt MA, 2022, 'Freeze-in and freeze-out of sterile neutrino dark matter', Journal of Cosmology and Astroparticle Physics, vol. 2022, pp. 070 - 070, http://dx.doi.org/10.1088/1475-7516/2022/08/070
    Journal articles | 2022
    Felkl T; Herrero-García J; Schmidt MA, 2022, 'Erratum to: The singly-charged scalar singlet as the origin of neutrino masses (Journal of High Energy Physics, (2021), 2021, 5, (122), 10.1007/JHEP05(2021)122)', Journal of High Energy Physics, vol. 2022, http://dx.doi.org/10.1007/JHEP05(2022)073
    Journal articles | 2022
    Herrero-García J; Molinaro E; Schmidt MA, 2022, 'Erratum to: Dark matter direct detection of a fermionic singlet at one loop (The European Physical Journal C, (2018), 78, 6, (471), 10.1140/epjc/s10052-018-5935-5)', European Physical Journal C, vol. 82, http://dx.doi.org/10.1140/epjc/s10052-022-10009-5
    Journal articles | 2021
    Felkl T; Herrero-García J; Schmidt MA, 2021, 'The singly-charged scalar singlet as the origin of neutrino masses', Journal of High Energy Physics, vol. 2021, http://dx.doi.org/10.1007/JHEP05(2021)122
    Journal articles | 2021
    Felkl T; Li SL; Schmidt MA, 2021, 'A tale of invisibility: constraints on new physics in b → sνν', Journal of High Energy Physics, vol. 2021, http://dx.doi.org/10.1007/JHEP12(2021)118
    Journal articles | 2021
    Li T; Ma XD; Schmidt MA; Zhang RJ, 2021, 'Implication of J /ψ → (γ+)invisible for the effective field theories of neutrino and dark matter', Physical Review D, vol. 104, http://dx.doi.org/10.1103/PhysRevD.104.035024
    Journal articles | 2021
    Li T; Schmidt MA; Yao CY; Yuan M, 2021, 'Charged lepton flavor violation in light of the muon magnetic moment anomaly and colliders', European Physical Journal C, vol. 81, http://dx.doi.org/10.1140/epjc/s10052-021-09569-9
    Journal articles | 2020
    Balaji S; Schmidt MA, 2020, 'Unified SU(4) theory for the R-D(*) and R-K(*) anomalies', PHYSICAL REVIEW D, vol. 101, http://dx.doi.org/10.1103/PhysRevD.101.015026
    Journal articles | 2020
    Kobakhidze A; Schmidt MA; Talia M, 2020, 'Thermal dark matter abundance under non-standard macroscopic conditions in the early universe', Journal of Cosmology and Astroparticle Physics, vol. 2020, http://dx.doi.org/10.1088/1475-7516/2020/03/059
    Journal articles | 2020
    Li T; Ma XD; Schmidt MA, 2020, 'Constraints on the charged currents in general neutrino interactions with sterile neutrinos', Journal of High Energy Physics, vol. 2020, http://dx.doi.org/10.1007/JHEP10(2020)115
    Journal articles | 2020
    Li T; Ma XD; Schmidt MA, 2020, 'General neutrino interactions with sterile neutrinos in light of coherent neutrino-nucleus scattering and meson invisible decays', Journal of High Energy Physics, vol. 2020, pp. 152, http://dx.doi.org/10.1007/JHEP07(2020)152
    Journal articles | 2020
    Li T; Ma XD; Schmidt MA, 2020, 'Implication of K →πν ν for generic neutrino interactions in effective field theories IMPLICATION of K →πν ν ... Li Tong, Ma Xiao-Dong, and Schmidt Michael A.', Physical Review D, vol. 101, http://dx.doi.org/10.1103/PhysRevD.101.055019
    Journal articles | 2019
    Balaji S; Foot R; Schmidt MA, 2019, 'Chiral SU(4) explanation of the b →s anomalies', Physical Review D, vol. 99, http://dx.doi.org/10.1103/PhysRevD.99.015029
    Journal articles | 2019
    Herrero-García J; Schmidt MA, 2019, 'Neutrino mass models: new classification and model-independent upper limits on their scale', European Physical Journal C, vol. 79, http://dx.doi.org/10.1140/epjc/s10052-019-7465-1
    Journal articles | 2019
    Li T; Schmidt MA, 2019, 'Sensitivity of future lepton colliders and low-energy experiments to charged lepton flavor violation from bileptons', Physical Review D, vol. 100, http://dx.doi.org/10.1103/PhysRevD.100.115007
    Journal articles | 2019
    Li T; Schmidt MA, 2019, 'Sensitivity of future lepton colliders to the search for charged lepton flavor violation', Physical Review D, vol. 99, http://dx.doi.org/10.1103/PhysRevD.99.055038
    Journal articles | 2019
    Popov O; Schmidt MA; White G, 2019, 'R2 as a single leptoquark solution to RD (∗) and RK (∗)', Physical Review D, vol. 100, http://dx.doi.org/10.1103/PhysRevD.100.035028
    Journal articles | 2018
    Cai Y; Schmidt MA; Valencia G, 2018, 'Lepton-flavour-violating gluonic operators: constraints from the LHC and low energy experiments', Journal of High Energy Physics, vol. 2018, http://dx.doi.org/10.1007/JHEP05(2018)143
    Journal articles | 2018
    Hagedorn C; Herrero-García J; Molinaro E; Schmidt MA, 2018, 'Phenomenology of the generalised scotogenic model with fermionic dark matter', Journal of High Energy Physics, vol. 2018, http://dx.doi.org/10.1007/JHEP11(2018)103
    Journal articles | 2018
    Herrero-García J; Molinaro E; Schmidt MA, 2018, 'Dark matter direct detection of a fermionic singlet at one loop', European Physical Journal C, vol. 78, http://dx.doi.org/10.1140/epjc/s10052-018-5935-5
    Journal articles | 2018
    Kobakhidze A; Schmidt MA; Talia M, 2018, 'Mechanism for dark matter depopulation', Physical Review D, vol. 98, pp. 095026, http://dx.doi.org/10.1103/PhysRevD.98.095026
    Journal articles | 2017
    Cai Y; García JH; Schmidt MA; Vicente A; Volkas RR, 2017, 'From the trees to the forest: A review of radiative neutrino mass models', Frontiers in Physics, vol. 5, http://dx.doi.org/10.3389/fphy.2017.00063
    Journal articles | 2017
    Cai Y; Gargalionis J; Schmidt MA; Volkas RR, 2017, 'Reconsidering the one leptoquark solution: flavor anomalies and neutrino mass', Journal of High Energy Physics, vol. 2017, http://dx.doi.org/10.1007/JHEP10(2017)047
    Journal articles | 2017
    Medina AD; Schmidt MA, 2017, 'Enlarging regions of the MSSM parameter space for large tan β via SUSY decays of the heavy Higgs bosons', Journal of High Energy Physics, vol. 2017, http://dx.doi.org/10.1007/JHEP08(2017)095
    Journal articles | 2016
    Bell NF; Busoni G; Kobakhidze A; Long DM; Schmidt MA, 2016, 'Unitarisation of EFT amplitudes for dark matter searches at the LHC', Journal of High Energy Physics, vol. 2016, http://dx.doi.org/10.1007/JHEP08(2016)125
    Journal articles | 2016
    Cai Y; Schmidt MA, 2016, 'A case study of the sensitivity to LFV operators with precision measurements and the LHC', Journal of High Energy Physics, vol. 2016, pp. 1 - 25, http://dx.doi.org/10.1007/JHEP02(2016)176
    Journal articles | 2016
    Cai Y; Schmidt MA, 2016, 'Revisiting the RνMDM models', Journal of High Energy Physics, vol. 2016, pp. 1 - 25, http://dx.doi.org/10.1007/JHEP05(2016)028
    Journal articles | 2016
    Hagedorn C; Ohlsson T; Riad S; Schmidt MA, 2016, 'Unification of gauge couplings in radiative neutrino mass models', Journal of High Energy Physics, vol. 2016, http://dx.doi.org/10.1007/JHEP09(2016)111
    Journal articles | 2015
    Adulpravitchai A; Schmidt MA, 2015, 'A fresh look at keV sterile neutrino dark matter from frozen-in scalars', Journal of High Energy Physics, vol. 2015, pp. 1 - 22, http://dx.doi.org/10.1007/JHEP01(2015)006
    Journal articles | 2015
    Adulpravitchai A; Schmidt MA, 2015, 'Sterile neutrino dark matter production in the neutrino-phillic two Higgs doublet model', Journal of High Energy Physics, vol. 2015, pp. 1 - 21, http://dx.doi.org/10.1007/JHEP12(2015)023
    Journal articles | 2015
    Ballett P; King SF; Luhn C; Pascoli S; Schmidt MA, 2015, 'Precision measurements of θ12 for testing models of discrete leptonic flavour symmetries', Journal of Physics: Conference Series, vol. 598, http://dx.doi.org/10.1088/1742-6596/598/1/012014
    Journal articles | 2015
    Cai Y; Clarke JD; Schmidt MA; Volkas RR, 2015, 'Testing radiative neutrino mass models at the LHC', Journal of High Energy Physics, vol. 2015, http://dx.doi.org/10.1007/JHEP02(2015)161
    Journal articles | 2015
    Gherghetta T; Von Harling B; Medina AD; Schmidt MA; Trott T, 2015, 'SUSY implications from WIMP annihilation into scalars at the Galactic Center', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 91, http://dx.doi.org/10.1103/PhysRevD.91.105004
    Journal articles | 2015
    Samanta A; Latimer D; Schmidt MA, 2015, 'Editorial: Through neutrino eyes: The search for new physics', Advances in High Energy Physics, vol. 2015, http://dx.doi.org/10.1155/2015/875185
    Journal articles | 2014
    Angel PW; Cai Y; Rodd NL; Schmidt MA; Volkas RR, 2014, 'Erratum to Testable two-loop radiative neutrino mass model based on an LLQdcQdc effective operator (JHEP, 10, 2013 (118))', Journal of High Energy Physics, vol. 2014, http://dx.doi.org/10.1007/JHEP11(2014)092
    Journal articles | 2014
    Ballett P; King SF; Luhn C; Pascoli S; Schmidt MA, 2014, 'Testing atmospheric mixing sum rules at precision neutrino facilities', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 89, http://dx.doi.org/10.1103/PhysRevD.89.016016
    Journal articles | 2014
    Ballett P; King SF; Luhn C; Pascoli S; Schmidt MA, 2014, 'Testing solar lepton mixing sum rules in neutrino oscillation experiments', Journal of High Energy Physics, vol. 2014, http://dx.doi.org/10.1007/JHEP12(2014)122
    Journal articles | 2014
    Gherghetta T; Von Harling B; Medina AD; Schmidt MA, 2014, 'The price of being SM-like in SUSY', Journal of High Energy Physics, vol. 2014, http://dx.doi.org/10.1007/JHEP04(2014)180
    Journal articles | 2013
    Angel PW; Cai Y; Rodd NL; Schmidt MA; Volkas RR, 2013, 'Testable two-loop radiative neutrino mass model based on an LLQd cQdc effective operator', Journal of High Energy Physics, vol. 2013, http://dx.doi.org/10.1007/JHEP10(2013)118
    Journal articles | 2013
    Antusch S; Holthausen M; Schmidt MA; Spinrath M, 2013, 'Solving the strong CP problem with discrete symmetries and the right unitarity triangle', Nuclear Physics B, vol. 877, pp. 752 - 771, http://dx.doi.org/10.1016/j.nuclphysb.2013.10.028
    Journal articles | 2013
    Farzan Y; Pascoli S; Schmidt MA, 2013, 'Recipes and ingredients for neutrino mass at loop level', Journal of High Energy Physics, vol. 2013, http://dx.doi.org/10.1007/JHEP03(2013)107
    Journal articles | 2013
    Gherghetta T; Von Harling B; Medina AD; Schmidt MA, 2013, 'The scale-invariant NMSSM and the 126 GeV Higgs boson', Journal of High Energy Physics, vol. 2013, http://dx.doi.org/10.1007/JHEP02(2013)032
    Journal articles | 2013
    Holthausen M; Lindner M; Schmidt MA, 2013, 'CP and discrete flavour symmetries', Journal of High Energy Physics, vol. 2013, pp. 1 - 31, http://dx.doi.org/10.1007/JHEP04(2013)122
    Journal articles | 2013
    Holthausen M; Lindner M; Schmidt MA, 2013, 'Lepton flavor at the electroweak scale: A complete A4 model', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 87, http://dx.doi.org/10.1103/PhysRevD.87.033006
    Journal articles | 2012
    Holthausen M; Schmidt MA, 2012, 'Natural vacuum alignment from group theory: The minimal case', Journal of High Energy Physics, vol. 2012, http://dx.doi.org/10.1007/JHEP01(2012)126
    Journal articles | 2012
    Schmidt MA, 2012, 'Erratum: Renormalization group evolution in the type i and type II seesaw model', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 85, http://dx.doi.org/10.1103/PhysRevD.85.099903
    Journal articles | 2012
    Schmidt MA; Smirnov AY, 2012, 'Neutrino masses and a fourth generation of fermions', Nuclear Physics B, vol. 857, pp. 1 - 27, http://dx.doi.org/10.1016/j.nuclphysb.2011.11.023
    Journal articles | 2011
    Adulpravitchai A; Schmidt MA, 2011, 'Flavored orbifold GUT - An SO(10) × S4 model', Journal of High Energy Physics, vol. 2011, http://dx.doi.org/10.1007/JHEP01(2011)106
    Journal articles | 2011
    Ray S; Rodejohann W; Schmidt MA, 2011, 'Lower bounds on the smallest lepton mixing angle', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 83, http://dx.doi.org/10.1103/PhysRevD.83.033002
    Journal articles | 2010
    Farzan Y; Pascoli S; Schmidt MA, 2010, 'AMEND: A model explaining neutrino masses and dark matter testable at the LHC and MEG', Journal of High Energy Physics, vol. 2010, http://dx.doi.org/10.1007/JHEP10(2010)111
    Journal articles | 2010
    Holthausen M; Lindner M; Schmidt MA, 2010, 'Radiative symmetry breaking of the minimal left-right symmetric model', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 82, http://dx.doi.org/10.1103/PhysRevD.82.055002
    Journal articles | 2009
    Hagedorn C; Schmidt MA; Smirnov AY, 2009, 'Lepton mixing and cancellation of the Dirac mass hierarchy in SO(10) GUTs with flavor symmetries T7 and Σ(81)', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 79, http://dx.doi.org/10.1103/PhysRevD.79.036002
    Journal articles | 2007
    Schmidt MA, 2007, 'Renormalization group evolution in the type I and type II seesaw model', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 76, http://dx.doi.org/10.1103/PhysRevD.76.073010
    Journal articles | 2006
    Rodejohann W; Schmidt MA, 2006, 'Flavor symmetry Lμ - Lτ and quasidegenerate neutrinos', Physics of Atomic Nuclei, vol. 69, pp. 1833 - 1841, http://dx.doi.org/10.1134/S1063778806110056
    Journal articles | 2006
    Schmidt MA, 2006, 'Running neutrino mass parameters in see-saw models', Physica Scripta T, vol. T127, pp. 67 - 69, http://dx.doi.org/10.1088/0031-8949/2006/T127/024
    Journal articles | 2006
    Schmidt MA; Smirnov AY, 2006, 'Quark lepton complementarity and renormalization group effects', Physical Review D - Particles, Fields, Gravitation and Cosmology, vol. 74, http://dx.doi.org/10.1103/PhysRevD.74.113003
    Journal articles | 2005
    Antusch S; Kersten J; Linder M; Ratz M; Schmidt MA, 2005, 'Running neutrino mass parameters in see-saw scenarios', JOURNAL OF HIGH ENERGY PHYSICS, http://dx.doi.org/10.1088/1126-6708/2005/03/024
    Journal articles | 2005
    Antusch S; Kersten J; Lindner M; Ratz M; Schmidt MA, 2005, 'Running neutrino mass parameters in see-saw scenarios', Journal of High Energy Physics, pp. 553 - 603, http://dx.doi.org/10.1088/1126-6708/2005/03/024
    Journal articles | 2005
    Lindner M; Ratz M; Schmidt MA, 2005, 'Renormalization group evolution of Dirac neutrino masses', Journal of High Energy Physics, http://dx.doi.org/10.1088/1126-6708/2005/09/081
    Journal articles | 2005
    Lindner M; Schmidt MA; Smirnov AY, 2005, 'Screening of Dirac flavor structure in the seesaw and neutrino mixing', Journal of High Energy Physics, pp. 1191 - 1220, http://dx.doi.org/10.1088/1126-6708/2005/07/048
  • Preprints | 2022
    Bigaran I; Felkl T; Hagedorn C; Schmidt MA, 2022, Flavour anomalies meet flavour symmetry, http://arxiv.org/abs/2207.06197v1
    Preprints | 2022
    Calibbi L; Li T; Marcano X; Schmidt MA, 2022, Indirect constraints on lepton-flavour-violating quarkonium decays, http://arxiv.org/abs/2207.10913v1
    Preprints | 2022
    Coy R; Schmidt MA, 2022, Freeze-in and freeze-out of sterile neutrino dark matter, http://dx.doi.org/10.1088/1475-7516/2022/08/070

ARC DP200101470 "New physics and the quark/lepton family replication puzzle"

2009 Otto-Hahn medal

I am a theoretical particle physicist working on physics beyond the Standard Model and astroparticle physics. My research focus is on neutrino physics, flavour physics, dark matter and other related new physics. I am an internationally-recognised expert on model building and phenomenology with a focus on neutrino and flavour physics.

Neutrino physics
Neutrinos are extremely light, but massive, elementary particles. However, the origin of tiny neutrino masses is unknown and an active area of research. I studied quantum corrections in the lepton sector. The work is essential to connect high-scale model predictions to measurements at precision neutrino oscillation experiments. For a large part of the parameter space, the quantum corrections are at the same level as the sensitivity of the next-generation of neutrino oscillation experiments. As part of this work I have published a widely-used code, REAP, which enables calculations for specific models.
The origin of neutrino mass is unknown. I developed systematic approaches to neutrino mass generation in contrast to the often-adopted approach to randomly study models: My main focus is on the phenomenology based on effective ∆L = 2 operators, specially I showed how to search for models based on dimension-7 ∆L = 2 operators at the LHC. Moreover, I proposed a classification based on the number of loops, i.e. an expansion in the Planck constant and most recently I proposed a new approach based on simplified models. My invited review article on neutrino mass generation from 2017 is well known in the neutrino physics community.

Flavour symmetries and CP violation in the lepton sector
The mixing angles of the lepton mixing matrix may be explained by a ”flavour symmetry”. I have extensive experiences constructing models based on these flavour symmetries. My two most significant contributions are:

  1. I proposed a new symmetry breaking mechanism to obtain the correct symmetry breaking pattern in a non-supersymmetric 4-dimensional theory without relying on extra dimensions of supersymmetry. 
  2. I showed how to consistently define a CP symmetry in the presence of a discrete flavour symmetry. This is a necessary step to build models which predict both mixing angles and (Majorana) CP phases. The CP phases have not been measured yet and are one of the main goals of the ongoing experimental program. Theoretical studies are important, because they may on the one hand guide experiments and on the other hand provide an interpretation of the experimental results. My work has been the basis for many theoretical studies of CP symmetries in the lepton sector. 

Flavour physics
One important deficiency of the Standard Model is an inadequate explanation of “flavour”, the threefold replication of the elementary particles of matter. Processes between the three different flavours provides rich information and is a sensitive probe to new physics beyond the Standard Model. At the moment, there are several anomalous measurements, which do not agree with the Standard Model prediction including the anomalous magnetic moment of the muon and the violation of lepton flavour universality in processes b to s and b to c transitions. One of the current hot topics in quark flavour physics are the anomalies in semi-leptonic B-meson decays. I suggested an explanation of the anomalies in terms of a leptoquark. For the first time we demonstrated the need for right-handed couplings to explain the anomalies.
Furthermore, I suggested a complementary way to search for charged lepton flavour violation at the Large Hadron Collider (LHC) via non-resonant production of two charged leptons of different flavour and demonstrated that high energy colliders may outperform the dedicated experiments for part of the theory space.

Early Universe cosmology
The most appealing explanation of dark matter is in terms of a new elementary particle. There are many well-motivated dark matter candidates including weakly interacting massive particles (WIMPs), sterile neutrinos, axions, and axion-like particles. However, so far we do not know the nature of dark matter. Apart from several works on weakly-interacting massive particles (WIMPs), I developed a new production mechanism for sterile neutrino dark matter in the early Universe. It allows a colder dark matter spectrum and thus opens up parameter space for light dark matter.
Phase transitions in the early Universe may have important effects on the cosmological evolution. They may be responsible for the creation of the matter-antimatter asymmetry, may substantially affect today’s dark matter abundance, or generate a large gravitational wave background. I am currently investigating phase transitions in the context of neutrino mass models.

Supersymmetry phenomenology
I pointed out that the naive fine-tuning measure used to argue for light new particles in supersymmetry has to be extended to include a tuning in the Higgs mass. In the same publication we demonstrated that the partners of the top-quark can be heavier than 1 TeV in a natural model of supersymmetry refuting the common belief that they have to be much below 1 TeV. Moreover we showed how to explain the galactic centre excess of photons within supersymmetry. 

My Research Supervision

PhD

  • Tobias Felkl
  • Adam Lackner

Honours:

  • Alix Crowe
  • Tomer Libman

My Teaching

2021

  • PHYS1221/1231 Physics 1B
  • PHYS3115 Particle Physics and the Early Universe
  • PHYS4143 Honours: Quantum Field Theory

2020

  • PHYS4143 Quantum Field Theory (4th year)
  • PHYS1221/1231 First year physics: Light/Quantum (1st year)
  • PHYS3115 Particle Physics and Cosmology (3rd year)

2019

  • PHYS4143 Quantum Field Theory (4th year)
  • PHYS3115 Particle Physics and Cosmology (3rd year)

2018

  • Quantum Field Theory (4th year)

2017

  • Particle Cosmology and Baryonic Astrophysics (4th year)
  • Senior Quantum Physics (3rd year)

2016

  • Particle Cosmology and Baryonic Astrophysics (4th year)
  • Senior Quantum Physics (3rd year)

2015

  • Particle Cosmology and Baryonic Astrophysics (4th year)
  • Senior Quantum Physics (3rd year)
  • Senior Physics Lab (3rd year)

2014

  • Quantum Field Theory (Masters)
  • Senior Physics Lab (3rd year)