In the Standard Model of particle physics, the strength of the couplings of the b quark to the u and c quarks, /Vub/ and /Vcb/, are governed by the coupling of the quarks to the Higgs boson. Using data from the LHCb experiment at the Large Hadron Collider, the probability for the Λb0 baryon to decay into the pμ-vμ final state relative to the Λc+μ-vμ final state is measured. Combined with theoretical calculations of the strong interaction and a previously measured value of /Vcb/, the first /Vub/ measurement to use a baryonic decay is performed. This measurement is consistent with previous determinations of /Vub/ using B meson decays to specific final states and confirms the existing incompatibility with those using an inclusive sample of final states.
Determination of the quark coupling strength vertical bar V-ub vertical bar using baryonic decays
COGONI, VIOLETTA;Dettori, F.;Lai, A.;MANCA, GIULIA;OLDEMAN, RUDOLF GERHARD CHRISTIAAN;SAITTA, BIAGIO;VACCA, CLAUDIA;
2015-01-01
Abstract
In the Standard Model of particle physics, the strength of the couplings of the b quark to the u and c quarks, /Vub/ and /Vcb/, are governed by the coupling of the quarks to the Higgs boson. Using data from the LHCb experiment at the Large Hadron Collider, the probability for the Λb0 baryon to decay into the pμ-vμ final state relative to the Λc+μ-vμ final state is measured. Combined with theoretical calculations of the strong interaction and a previously measured value of /Vcb/, the first /Vub/ measurement to use a baryonic decay is performed. This measurement is consistent with previous determinations of /Vub/ using B meson decays to specific final states and confirms the existing incompatibility with those using an inclusive sample of final states.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.