Database Does Not Appear In Management Studio

i use VSC 2013 (C#, .net4.5, ADO) and i installed SQL Express 2014 on a PC Under W8.1pro. I succeeded to create and access a database with my application. My database is created with a code like:

using ( var connection = new System.Data.SqlClient.SqlConnection(
"Data Source=(local); Integrated Security=true;User Instance=True;" ) )
{
connection.Open();
using ( var command = connection.CreateCommand() )
{
command.CommandText =
String.Format( "CREATE DATABASE {0} ON PRIMARY (NAME={0}, FILENAME='{1}')", dataBaseName, dbFileName );
command.ExecuteNonQuery();
command.CommandText =
String.Format( "EXEC sp_detach_db '{0}', 'true'", dataBaseName );
command.ExecuteNonQuery();
}
}

My problem is to manage this database with "Microsoft SQL Server Management Studio"; i fact, i never succeeded to see my database in this tool. The .mdf file of my databae is located in a directory "C:UsersmyuseraccountDocumentsSQLServerExpDBs".

I tried to join my mdf file, but MSqlSMS refuse to display the content of all my user account directories.how to manage such DB in MSqlSMS?