Which scrum meeting is suitable to perform technical analysis/architecture design on a story?
There are no special events for that kind of activities.
Technical analysis or architecture design may be a part of backlog refinement or story implementation itself (or both).
However, despite the fact that the Scrum Guide does not describe any special events, there are no obstacles to hold a special meeting for these purposes. Scrum is a framework and it can be configured flexibly. Everything which is not forbidden is allowed ;-)
Scrum promotes self-organization and the team implementing processes within the framework to support the contextual needs of those performing the effort. Therefore there is no specific event designated for such needs. All aspects of the work should be discussed as necessary throughout the effort. Often these topics are discussed during Product Backlog refinement, Sprint Planning, and while creating the Increment within the Sprint.
Product Backlog refinement usually includes adding estimates to high priority items which may be implemented in the very near future. In order to estimate the effort, the Development Team might need to perform initial or additional analysis and discuss how such a feature might affect the architecture.
During the Sprint Planning event, the first few days of work is decomposed which almost always includes design and may require additional analysis or architectural discussions. This is often the most explicit opportunity for these discussions to occur.
As the work is underway during the Sprint, new information could be uncovered that requires the current plan to be revisited. If the emerging work affects the Development Team's forecast for the Sprint then a discussion with the Product Owner should occur.