Researcher

Dr Michael Andreas Schmidt

My Expertise

particle physics, theoretical particle physics, beyond the Standard Model physics, neutrino physics, neutrino masses, flavour physics, B physics, dark matter, supersymmetry

Keywords

Fields of Research (FoR)

Particle and high energy physics, Astroparticle physics and particle cosmology, Particle physics, Theoretical Physics, Particle Physics

SEO tags

Biography

Dr. Michael Schmidt is a theoretical particle physicists working on physics beyond the Standard Model and astroparticle physics.


My Grants

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


My Qualifications

1999-2004 Physik Diplom (TU Munich, Germany)

2005-2008 PhD in Theoretical Particle Physics (TU Munich and Max Planck Institut for Nuclear Physics), summa cum laude
Running...view more

Dr. Michael Schmidt is a theoretical particle physicists working on physics beyond the Standard Model and astroparticle physics.


My Grants

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


My Qualifications

1999-2004 Physik Diplom (TU Munich, Germany)

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

 


My Awards

2009 Otto-Hahn medal


My Research Activities

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 mea-
surements 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 h̄ 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:
i) 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. 
ii) I showed how to consistently define a CP symmetry in the presence of a discrete flavour symmetry. This is a neces-
sary 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 semileptonic 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. 

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. 

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.


My Research Supervision


Areas of supervision

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.

 

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 am offering projects on building models of neutrino mass, phenomenological studies to find new ways to distinguish between different mechanisms of neutrino mass generation, and more generally on other physics related to neutrino masses, e.g. dark matter and explanations of the matter-antimatter asymmetry in the Universe.

 

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. I am offering projects on building models of flavour, develop explanation of anomalous measurements, and phenomenological studies in flavour physics.

 

Dark Matter

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. I am offering projects on dark matter model building, studies of (direct/indirect) detection and its cosmological implications.

 

Phase Transitions in the Early Universe

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 offering projects on different aspects of phase transitions in the early Universe.

 

Collider Physics

Currently, the highest energy collisions are achieved at the Large Hadron Collider (LHC), which ultimately will collide protons at a centre of mass energy of 14 TeV. It provides the testing ground for particle physics at the highest energies in a lab. I am offering projects in collider physics which use the LHC or future colliders as a probe for a variety of new physics scenarios including the origin of neutrino masses, flavour physics and dark matter.

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Location

Old Main Building Level 1, room 121

Contact

+61-2-9065 3045

Publications

by Dr Michael Andreas Schmidt