Searching for Axionlike Particles in Flavor-Changing Neutral Current Processes.

Area of Science:

• High Energy Physics
• Particle Physics
• Beyond Standard Model Physics

Background:

• Axionlike particles (ALPs) are hypothetical particles beyond the Standard Model.
• Flavor-changing neutral current (FCNC) processes offer unique avenues for discovering new physics.
• The coupling of ALPs to W bosons is often overlooked but crucial for FCNC production.

Purpose of the Study:

• To propose novel search strategies for axionlike particles (ALPs) produced in FCNC processes.
• To exploit the W boson coupling of ALPs for enhanced FCNC production.
• To improve sensitivity to ALP couplings to Standard Model particles and explore discovery prospects for invisibly decaying ALPs.

Main Methods:

• Investigating resonant ALP production in decays like B→K^{(*)}a and K→πa, with subsequent decay of the ALP to photon pairs (a→γγ).
• Analyzing the production of ALPs via FCNC processes, facilitated by their coupling to W^{±} bosons.
• Determining constraints and discovery potential for both visibly and invisibly decaying ALPs.

Main Results:

• Proposed searches can significantly improve upon current sensitivity to ALP couplings.
• Demonstrated that FCNC production of ALPs is possible even without direct fermion couplings.
• Established analogous constraints and discovery prospects for invisibly decaying ALPs.

Conclusions:

• The proposed FCNC-based searches offer a powerful new strategy for discovering axionlike particles.
• Exploiting the W boson coupling of ALPs is key to unlocking new discovery potential.
• These searches have the potential to significantly advance our understanding of physics beyond the Standard Model.