Override derived template class method in C++11/14

I need to override the method createT() of a Base template class with the one in a Derived template class with a different number of input parameters. I've developed this very simple example:

#include <iostream>

class Helper
{
public:
  Helper(std::string s): _s(s)
  {}

  void display()
  {
     std::cout << _s << std::endl;
  }

private:
  std::string _s;
};

class Helper2
{
public:
  Helper2(std::string s, int i):
    _s(s), _i(i)
  {}

  void display()
  {
    std::cout << _s << " + " << std::to_string(_i) << std::endl;
  }

private:
  std::string _s;
  int _i;
};

template<class T> class Base
{
public:
  Base()
  {
    _pTBase = createT();
  }

  void test()
  {
    _pTBase->display();
  }

protected:
  /// Subclasses can override this method.
  virtual T* createT()
  {
    return new T("### BASE ###");
  }

private:
 T* _pTBase;

}; //template<class T> class Base


template<class T> class Derived : public Base<T>
{
public:
  Derived() : Base<T>()
  {
    _pTDerived = createT();
  }

  void test()
  {
    _pTDerived->display();
  }

protected:
  virtual T* createT()
  {
    return new T("### DERIVED ###", 5);
  }

private:

 T* _pTDerived;

}; //template<class T> class Derived : public Base<T>


int main()
{
  Derived<Helper2> a;

  a.test();

  return 0;
}

When I try to compile i receive this message:

error: no matching function for call to ‘Helper2::Helper2(const char [13])’
     return new T("### BASE ###");
                                ^

It seems that the compiler cannot use the createT() method in the derived class Of course everything works correctly if I use the Base class with the Helper (not the Helper2) class. What's the right way to solve this situation?

Best regards