Template argument deduction failure while passing address of const type

template <typename T>
T go(T a, T *b){ T *t; return *t;}

int main() {
    const int x = 10;
    go(x, &x);
    return 0;
}

Gives compiler error:

error: no matching function for call to ‘go(const int&, const int*)’

Why is the first argument a reference type const int& instead of just const int?

To fix this compilation error, I overrode the compiler deduction process by specifying the type of arguments go<const int>(x, &x);, but again why do I need to do that?