“Cashmoneyramen, that’s my hashtag!” a woman exclaimed the other night in Long Island City. Half an hour had passed since she and her companion had high-fived upon sitting down at Mu Ramen, the brick-and-mortar incarnation of Josh and Heidy Smookler’s lauded pop-up, and now they were scraping their bowls. If Mu exemplifies the argument, put forth by David Chang on the Web site of his food quarterly, Lucky Peach, that innovation in American ramen-making has plateaued (“Ramen is dead”), none of the people at the restaurant’s Tetris-shaped communal table seemed to care. Nor did those waiting for their seats, who were perched like the audience at a runway show along the perimeter of the mood-lit room, and staring as intently. Everyone had heard the buzz that this ramen might be the city’s best.