Roblox Script Generated by ScripterAI

"Create an immersive camera system that simulates realistic human head tracking based on where the mouse icon is with a limited angle of degrees and is also physics based."

Creating a realistic head tracking camera system is quite complex, but here's a simple version using the Camera Manipulation API in Roblox. This script should be placed in a LocalScript under StarterPlayerScripts.

```lua
local UserInputService = game:GetService("UserInputService")
local RunService = game:GetService("RunService")
local Players = game:GetService("Players")
local player = Players.LocalPlayer
local character
local head
local camera = workspace.CurrentCamera
local maxAngle = 45 -- Maximum angle the head can turn

local function updateHeadTrack()
    if character and head then
        local mousePosition = UserInputService:GetMouseLocation()
        local viewportSize = camera.ViewportSize
        local screenCenter = Vector2.new(viewportSize.X / 2, viewportSize.Y / 2)
        local mouseOffset = (mousePosition - screenCenter) / screenCenter

local xAngle = math.clamp(mouseOffset.Y * maxAngle, -maxAngle, maxAngle)
        local yAngle = math.clamp(mouseOffset.X * maxAngle, -maxAngle, maxAngle)

local headCFrame = CFrame.Angles(math.rad(xAngle), math.rad(yAngle), 0)
        head.CFrame = character.HumanoidRootPart.CFrame * headCFrame
    end
end

local function onCharacterAdded(newCharacter)
    character = newCharacter
    head = character:WaitForChild("Head")
end

player.CharacterAdded:Connect(onCharacterAdded)
if player.Character then
    onCharacterAdded(player.Character)
end

RunService.RenderStepped:Connect(updateHeadTrack)
```

This script will rotate the character's head based on the mouse position on the screen, within a limited angle. Note that this is not a physics-based solution, but it provides a simple head tracking effect. You can adjust the `maxAngle` variable to change the maximum angle the head can turn.