In your opinion what is the best way to improve the relationship between sales and marketing teams and is there a possibility to formalize their responsibilities?

Nothing to add since both Mr.Sayed Fathy and Prabath Mishra submittted wonderul answers herein. 

There is a long history of pain and misalignment between sales and marketing teams – but they are not doomed to that fate.

Define mutual goals and responsibilities for marketing-sales alignment.

Develop a productive relationship between your marketing and salesteams by establishing concrete metrics and mutual responsibilities for both groups.To work in a real-world business setting, this relationship needs to be both concrete andimmediate, and it must hold both marketing and sales accountable for results. It can’t just be an abstract 30-day plan that neither team truly gets around to following. For example,create a service-level agreement (SLA). An SLA gives both teams a measure for success by defining expectations. It gives marketing hard numbers on how many quality leads to generate each month and sales a plan for how to follow up with those leads. 

In other words you have to aproach inbound marketing in your facility by emphasising each job role and a strong monitor on reults.

"Communication GAP" is the bone of contension.  Try to organize Corporate Quiz/Game/Seminar etc. in your Organization where the importance of each other's(Sales & Marketing) must be realize by both the team, because in many cases both the teams always try to prove themselves superior and other inferior which directly impacts an Organization growth.  Both the depatement should understand that they are helping each other to get benifit if one loosess other will definatly get effected financially and mentally.