A slice object gets created as a result of an extended indexing syntax of lists e.g. a[1: 4]. Those slice objects are shallow copies of the original list.

>>> a = [1, 2, 3, 4]
>>> b = a[1:3]
>>> b
[2, 3]
>>> a[1] = 'x'
>>> a
[1, 'x', 3, 4]
>>> b
[2, 3] # This is the proof of that b is not referencing the same data as a
>>> a = None
>>> b
[2, 3] # Additional proof.

>>> a = [1, {"a": "alpha", "b": "beta"}, 3, 4]
>>> b = a[1:3]
>>> a[1]["g"] = "gamma"
>>> a
[1, {'a': 'alpha', 'b': 'beta', 'g': 'gamma'}, 3, 4]
>>> b
[{'a': 'alpha', 'b': 'beta', 'g': 'gamma'}, 3]

So, here is the conclusion.

Appendix

If you copy the list, b is referencing the same data as a. This is, by the way, not called a shallow copy.

>>> a = [1, 2, 3, 4]
>>> b = a
>>> a[1] = 'x'
>>> a
[1, 'x', 3, 4]
>>> b
[1, 'x', 3, 4] # This is the proof that b is referencing a

Reference

Built-in Functions — Python 3.9.4 documentation