We show that most spectra in the semileptonic decay B -> X-u + l + nu(l), such as for example the distribution in the light-cone momentum p(+) E-X - vertical bar(p) over barx vertical bar recently considered, do not have the same long-distance structure of the photon spectrum in the radiative decay B -> X-s + gamma. On the contrary, the semileptonic distribution in the final hadron energy E-X is connected to the radiative spectrum via short-distance factors only. The E-X distribution also has a specific infrared structure known as the "Sudakov shoulder". We also discuss an explicit check of the resummation formula for the semileptonic decays, based on a recent second-order computation.
Non-universal effects in semi-inclusive B decays / Aglietti, Ugo Giuseppe. - In: NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS. - ISSN 0920-5632. - STAMPA. - 157:1(2006), pp. 141-146. (Intervento presentato al convegno 7th International Symposium on Radiative Corrections (RADCOR 2005) tenutosi a Shonan Village, JAPAN nel OCT 02-07, 2005) [10.1016/j.nuclphysbps.2006.03.019].
Non-universal effects in semi-inclusive B decays
AGLIETTI, Ugo Giuseppe
2006
Abstract
We show that most spectra in the semileptonic decay B -> X-u + l + nu(l), such as for example the distribution in the light-cone momentum p(+) E-X - vertical bar(p) over barx vertical bar recently considered, do not have the same long-distance structure of the photon spectrum in the radiative decay B -> X-s + gamma. On the contrary, the semileptonic distribution in the final hadron energy E-X is connected to the radiative spectrum via short-distance factors only. The E-X distribution also has a specific infrared structure known as the "Sudakov shoulder". We also discuss an explicit check of the resummation formula for the semileptonic decays, based on a recent second-order computation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
