arXiv subjects

Masashi Hazumi

Publications and source records attributed to Masashi Hazumi.

57 records · Page 4Linked to original sources

arXiv2004

Time-Dependent CP Violation in $B^0 \to P^0P^0X^0$ Decays

We note that in decays of the type $B^0 \to P^0P^0X^0$, where $P^0$ and $X^0$ represent any CP eigenstate spin-0 neutral particles, the final state is a CP eigenstate. We consider the possibilities for studying time-dependent CP violation in decays of this type at $B$ factories with high luminosity, with particular attention to $B^0 \to \ks \ks \ks$. We also comment on some cases where $X^0$ has non-zero spin, and decays of the type $B^0 \to P^0 Q^0 X^0$, where the three final state particles are different spin-0 CP eigenstates.

hep-ph↗

arXiv2003

Large Direct CP Violation in B -> phi phi Xs Decays

We present a novel method to search for a new CP-violating phase in b -> ss~ss~s transition using B -> phi phi Xs decays, where Xs represents a final state with a specific strange flavor such as K+/-, K*+/-, or K+/-pi-/+. Direct CP violation can be enhanced due to an interference between an amplitude beyond the standard model (SM) and the SM decay amplitude through the eta_c resonance. We find that the CP asymmetry can be as large as 0.4 within the present experimental bounds on the b -> ss~s transition. These decays provide a very clean experimental signature and the background is expected to be small in particular at e+e- B factories. A simulation study for the B+/- -> phi phi K+/- decay shows that the statistical significance of CP violation can exceed 5 standard deviations with 10^9 B mesons.

hep-ph↗

arXiv2002

sin2phi1 with 45 Million BBbar Pairs at Belle

We present an improved measurement of the standard model CP violation parameter sin2phi1 (also known as sin2beta) based on a sample of 45 x 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEK asymmetric-energy e^+e^- collider. One neutral B meson is reconstructed in a J/psi Ks, psi(2s) Ks, chi_c1 Ks, eta_c Ks, J/psi K*, or J/psi KL CP-eigenstate decay channel and the flavor of accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain sin2phi1 = 0.82 +/- 0.12(stat) +/- 0.05(syst).

hep-ex↗