I figured it out myself.
For some reason, It is being stopped becos it thinks it requires some kind of input from the keyboard.
As:
0 : Standard Input (Generally the Keyboard)
1 : Standard Output (Generally the Monitor)
2 : Standard Error
So I added the standard input to read from /dev/null.
I modified my cmd as follows:
[root@someIp somePath]# php /path/to/myPhpScript.php arg1 arg2 arg3 0</dev/null 1 >/dev/null 2>log.txt &
OR
[root@someIp somePath]# php /path/to/myPhpScript.php arg1 arg2 arg3 </dev/null >/dev/null 2>log.txt &
Thanks!