出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present a new study of SU(3).breaking corrections in hyperon vector form factors relevant
for the extraction of Vus. A lattice quenched simulation has been performed, showing that it
is possible to reach the required precision to extract SU(3).breaking corrections in the regime of
simulated masses. In order to perform the chiral extrapolation we calculated the chiral corrections
to the vector form factor in HBChPT. Besides the one-loop O(p2) contribution, we included also
the subleading O(p3) and O(1=MB) corrections that, due to the Ademollo-Gatto theorem, are
free from the contamination of unknown low energy constants. The results complete and correct
previous calculations, and show that subleading corrections cannot be neglected. We also studied
decuplet contributions within HBChPT and show that, in this case, the chiral expansion breaks
down, rising doubts on the consistency of the theory.
