We propose the B c → B * u γ decay as the most suitable probe for the flavour changing neutral transition c → uγ. We estimate the short and long distance contributions to this decay within the standard model and we find them to be comparable; this is in contrast to radia-tive decays of D mesons, that are completely dominated by the long distance contributions. Since the c → uγ transition is ver...

This study presents a novel category of Transformer architectures known as comb transformers, which effectively reduce the space complexity self-attention layer from quadratic to sub-quadratic level. is achieved by processing sequence segments independently and incorporating X -word embeddings ...