Is it possible to leave the Beijing Capital Airport and visit Beijing without a visa?

Hello,

I will be flying into the Beijing Airport from LAX and stays there for about 13 hrs before connecting a flight to Ho Chi Minh City. I was wondering if it is possible to leave the airport and check out the city during my 13 hrs waiting.

-Will I need a visa for that?

-I will be flying through Air China straight through so will I need to pick up my luggage before leaving the airport or will my luggages be transfer straight through the next flight?