using cyrillic in php regexp

regexp.php

<?php
/*
 * about task
 * strings like "Artist1 & Artist2" or "Artist1 feat. Artist2" or "Исполнитель1 и Исполнитель2"
 * are splited into ["Artist1", "Artist2"]
 */

/*
 * using modifier u (PCRE_UTF8) to include cyrillic in regexp
 * @see http://php.net/manual/en/reference.pcre.pattern.modifiers.php
 * not working coz preg_split works only with single byte symbols
 * NOTICE: `/` around regexp
 */
$artists = preg_split("/\s*(&|vs|((F|f)(ea)?t\.?)|и)\s*/u", $trimedArtist);

/*
 * using mb_* functions for multi byte symbols
 * NOTICE: no `/` around regexp
 * so, there is no place for modifiers like after `/`
 * thereby, we'll encode cyrillic symbols escape sequence \xhh
 * @see http://php.net/manual/en/regexp.reference.escape.php
 * 'd0b8' == 'и'
 */
$artists = mb_split("\s*(&|vs|((F|f)(ea)?t\.?)|\x{d0b8})\s*", $trimedArtist);