In the original batchnorm paper they mention learnable params beta and gamma:

  
      arxiv.org
  
  
    
1502.03167.pdf 46

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And in pytorch the batchnorm implementation has weights and bias in addition to running mean and running standard deviation.
http://pytorch.org/docs/master/_modules/torch/nn/modules/batchnorm.html 82
Edit: The weights and bias are used to scale and shift the output of the layer.