Question: Real trouble integrating this expression? Do you know how to do it ? Help needed urgently.

I really need a result to the integration below but Maple 13 just won't return one. Could you please help me or advise me as to what might be wrong or what I might try ? I'm integrating on the real line in x but even when I alter the limits of integration maple just returns the integrand.

s1:= int((1/8)*sqrt(2)*exp((1/2)*k^2*cos(x)^2/sigma^2)*exp(-(1/2)*k^2/sigma^2)*exp(-(1/2)*x^2/sigma^2)/(exp(x*k*sin(x)/sigma^2)*Pi^(5/2)*sigma)+(1/8)*sqrt(2)*exp((1/2)*k^2*cos(x)^2/sigma^2)*exp(-(1/2)*k^2/sigma^2)*exp(-(1/2)*x^2/sigma^2)*Q*exp(I*k*x)*exp(I*k*theta)/(exp(x*k*sin(x)/sigma^2)*Pi^(3/2)*sigma)+(1/8)*sqrt(2)*exp((1/2)*k^2*cos(x)^2/sigma^2)*exp(-(1/2)*k^2/sigma^2)*exp(-(1/2)*x^2/sigma^2)*Q/(exp(x*k*sin(x)/sigma^2)*Pi^(3/2)*sigma*exp(I*k*x)*exp(I*k*theta)), x = -infinity .. infinity) assuming sigma >0;