There isn't a distinction in Japanese. For example, restaurant can be said using the gairaigo レストラン　and live (as in a live concert) is written ライブ. As you can see, there isn't a special katakana used for the l sound of live. In fact, ラリルレロare pronounced neither with a complete r sound nor a complete l sound. Rather, there is the "Japanese r sound" which sounds like a mix between an r and an l. This Japanese r sound, however, is commonly represented in romaji as just a plain "r", though it is not pronounced like the English "r" sound. See https://www.youtube.com/watch?v=V2wzUuGm7yw and http://en.wikipedia.org/wiki/Perception_of_/r/_and_/l/_by_Japanese_speakers for more info on the sound.

Hi, Yes, When we pronounce "らりるれろ" is "Ra Ri Ru Re Ro". We don't use "L" like English. That's why a lot of Japanese people struggle with pronouncing " L" in English. Yes, we pronounce "R" instead of " L". For instance, When we say "Love" in Katakana, we pronounce "Rabu". I hope it helps you:)