Regex-group of words with special characters,symbols and space character

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PHP

regular-expression

Example
$s = 'This is a example string with some testing cases \cite{author1,author2,author3}.
Then {another example} \citeauthor{author3,author4} and finally
\citeP{author1} \citesome text{author5} \citesome text with[.]$"{author6}and string completes here.';

$output= preg_replace_callback('/\\\\(cite(?:\w+)?){([^}]*)}/', function($m) {
  return preg_replace('/([^,]+)(?:,|$)/' ,'<xref '. $m[1] . ' >$1</xref>', $m[2]); },
  $s);

Output:

This is a example string with some testing cases <xref cite="">author1<xref cite="">author2<xref cite="">author3.
Then {another example} <xref citeauthor="">author3<xref citeauthor="">author4 and finally
<xref citep="">author1 \citesome text{author5} \citesome text with[.]$"{author6}and string completes here.

Expected output:

This is a example string with some testing cases <xref cite >author1</xref><xref cite >author2</xref><xref cite >author3</xref>. 
Then {another example} <xref citeauthor >author3</xref><xref citeauthor >author4</xref> and finally
<xref citeP >author1</xref>  <xref citesome text>author5</xref> <xref citesome text with[.]$">author6</xref>and string completes here.

Question:

/\\\\(cite(?:\w+)?)

- only get group of words. I need to get group of words with space symbols special character everything. What would be the regex