Project Title
Copilot said: Dynamic Vacuum Selection in Extensions of the Standard Model: Cosmological Consequences in the Context of Experimental Research
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Type
Project
Principal investigator
Type of achievement
Basic research
Keywords
Description
A major triumph of particle physics and the study of fundamental interactions is the development of the Standard Model (SM), which successfully describes the results of experiments conducted at energies above the Fermi scale, that is, the energy at which electroweak symmetry is restored and electromagnetic and weak interactions behave, to a good approximation, as a single unified interaction. However, despite its remarkable experimental success, the Standard Model contains many free parameters and suffers from several important theoretical shortcomings. We still do not understand the relationships between its parameters, nor do we understand why their values differ so dramatically from one another. Moreover, the Standard Model is unable to provide a satisfactory explanation for several fundamental cosmological phenomena, including baryogenesis and cosmic inflation, not to mention the puzzle of selecting the correct low-energy vacuum state, which is closely related to the hierarchy problem. One of the reasons for these difficulties is that the Standard Model is expected to be embedded in a more fundamental and self-consistent theory capable of describing the Universe at extremely high energies and temperatures, possibly far above the Fermi scale.
Physicists believe that the Large Hadron Collider (LHC) will continue to improve our understanding of the mechanism responsible for electroweak symmetry breaking and will help guide the construction of a truly fundamental theory of elementary interactions. At the same time, the early Universe provides a natural laboratory for processes governed by particle physics. Recently, an important breakthrough in this area was achieved through the discovery of gravitational waves emitted by the merger of two black holes by the LIGO/Virgo collaboration. This discovery opened the way toward the development of gravitational-wave astronomy and spectroscopy. Gravitational radiation offers a powerful new method for probing the structure and history of the Universe because virtually all significant cosmological events generate gravitational waves.
In this project, we aim to combine cosmological and astrophysical observations with the results of precision measurements performed at the LHC in order to reduce the freedom and arbitrariness involved in constructing theories that extend beyond the Standard Model (BSM). In particular, we will focus on problems related to baryogenesis, the (meta)stability of the vacuum, and the possibility of realizing a mechanism of dynamic, rather than accidental, vacuum selection during the evolution of the early Universe.
Our investigations will concentrate on simple and theoretically well-motivated models featuring an extended Higgs sector, including models containing light scalar and pseudoscalar fields. The analysis of high-energy extensions of the Standard Model in the context of data from the LHC and complementary cosmological tests, as proposed in this project, will allow us to address two fundamental questions.
First, how does Nature select, from among many possible vacua, the low-energy vacuum state that corresponds to the observed hierarchy of mass scales?
Second, how is the stability of this vacuum maintained in the presence of potentially catastrophic cosmological processes, while simultaneously generating a sufficiently large baryon asymmetry of the Universe?
We also hope to expand our understanding of the history and evolution of the Universe. Ultimately, this research should provide new insights into the mathematical structure of extensions of the Standard Model and contribute to the development of a more complete theory of fundamental interactions.
Physicists believe that the Large Hadron Collider (LHC) will continue to improve our understanding of the mechanism responsible for electroweak symmetry breaking and will help guide the construction of a truly fundamental theory of elementary interactions. At the same time, the early Universe provides a natural laboratory for processes governed by particle physics. Recently, an important breakthrough in this area was achieved through the discovery of gravitational waves emitted by the merger of two black holes by the LIGO/Virgo collaboration. This discovery opened the way toward the development of gravitational-wave astronomy and spectroscopy. Gravitational radiation offers a powerful new method for probing the structure and history of the Universe because virtually all significant cosmological events generate gravitational waves.
In this project, we aim to combine cosmological and astrophysical observations with the results of precision measurements performed at the LHC in order to reduce the freedom and arbitrariness involved in constructing theories that extend beyond the Standard Model (BSM). In particular, we will focus on problems related to baryogenesis, the (meta)stability of the vacuum, and the possibility of realizing a mechanism of dynamic, rather than accidental, vacuum selection during the evolution of the early Universe.
Our investigations will concentrate on simple and theoretically well-motivated models featuring an extended Higgs sector, including models containing light scalar and pseudoscalar fields. The analysis of high-energy extensions of the Standard Model in the context of data from the LHC and complementary cosmological tests, as proposed in this project, will allow us to address two fundamental questions.
First, how does Nature select, from among many possible vacua, the low-energy vacuum state that corresponds to the observed hierarchy of mass scales?
Second, how is the stability of this vacuum maintained in the presence of potentially catastrophic cosmological processes, while simultaneously generating a sufficiently large baryon asymmetry of the Universe?
We also hope to expand our understanding of the history and evolution of the Universe. Ultimately, this research should provide new insights into the mathematical structure of extensions of the Standard Model and contribute to the development of a more complete theory of fundamental interactions.