Cook pasta in a large pot of boiling salted water until tender to the bite, 9 to 12 minutes or according to package directions. Drain and rinse thoroughly under cold water until completely cool (see Notes).
In a medium bowl, whisk together ricotta, sour cream, lemon zest and juice, 1 tsp. salt, and 1/2 tsp. pepper.
In a large bowl, toss together pasta, corn, red onion, chicken, tomatoes, and basil. Add ricotta-lemon dressing to pasta mixture and stir to evenly coat pasta. Season with salt and pepper to taste.
Note: Nutritional analysis is per 1 1/2-cup serving.