Selena Gomez Name in Chinese: 赛琳娜·戈梅茲 or 戈麦斯?
On her weibo site, her name in Chinese is 赛琳娜·戈麦斯. Though, according to Wikipedia ( 賽琳娜·戈梅茲 ), it's 戈梅茲 used in China, Taiwan, and Disney Channel too.
It appears, there's not really a systematic way of transcription of English names to Chinese. There's only a amassed, ad-hoc, reference. See: Transcription into Chinese characters. Quote:
In People's Republic of China, the official guide for the transcription of people's names is the Names of the World's Peoples: a Comprehensive Dictionary of Names in Roman-Chinese (世界人名翻译大辞典), compiled by the Proper Names and Translation Service of the Xinhua News Agency. See the English transcription table further below in this article or those for a number of other languages that are provided by the work.
Different regions (e.g. Hong Kong, Taiwan), sometimes uses different Chinese characters for foreign person or place names. e.g. New Zealand is 纽西兰/紐西蘭 Niǔxīlán in Taiwan, and 新西兰/新西蘭 in China.
For one of her song, see: Selena Gomez - Love You Like a Love Song.