Baryogenesis in a flat direction with neither baryon nor lepton charge

Area of Science:

• Cosmology and Particle Physics
• Baryon Asymmetry Generation

Background:

• Standard baryogenesis models typically require derivative coupling between scalar fields and baryon currents.
• Understanding the origin of the universe's baryon asymmetry is a fundamental challenge in physics.

Purpose of the Study:

• To propose a new mechanism for spontaneous baryogenesis.
• To explore baryogenesis via coupling to a global U(1)(Q) symmetry current.
• To demonstrate the feasibility of this mechanism in a specific model.

Main Methods:

• Introduced a scalar field derivatively coupled to a current of a global U(1)(Q) symmetry.
• Identified the necessity of simultaneous baryon and U(1)(Q) symmetry violation for baryogenesis.
• Investigated a concrete example in a flat direction lacking baryon or lepton charge.

Main Results:

• Demonstrated that baryogenesis is possible without direct scalar field-baryon current coupling.
• Showcased a viable baryogenesis scenario through interaction violating both baryon and U(1)(Q) symmetries.
• Confirmed the mechanism's applicability in a simplified theoretical setting.

Conclusions:

• The proposed mechanism offers an alternative pathway for generating the universe's baryon asymmetry.
• This model relaxes stringent coupling requirements found in conventional baryogenesis scenarios.
• Further research can explore the implications of this mechanism in more complex cosmological models.