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Prospects for CP in B meson
261c
Nuclear Physics A478 (1988) 261c North-Holland, Amsterdam
PROSPECTS FOR CP IN B MESONS N.G. URALTSEV
Leningrad Nuclear Physics Institute, Gatchina, USSR
Neutral B mesons R° - hd, B° -Gs become a new laboratory for CP studies like K° mesons . the ARGUS result AmapdIT®=v".7 conc,raints Iargcly thestandard model (SIM), e.g. top quark mass -100 GeV. This results in more definite predictions for all parameters . e'Je in K,°, decay is expected (2-4) x 10' in agreement with recent CERN and FNAL results. In contrast to K°, in B° the "superweak" manifestations of CP violation (i .e. due to the CP odd mixing of "B," and "B2", say, charge asymmetry A of leptons in their decays) is inevitably small. In the SM ABd :z 5 x 10 -°, AB, !z 5 x :10-5. In Bâ and B°, however, certain processes should exhibit large CP asymmetries of "milliweak" nature even in the SM . These are the partial widths, differerces for come decays of B° and B° to the same final states with the definite CP parity, e.g . Bâ, Bâ->J/ty+Ks or B;, i3 ;-sp(w,-,rr)+Ks. For these decays S=(I'(B°-~f)-l''~°~f))J (l'(B°-* f)+r(B°-1- f)) is expected to be about 8% for Bâ and -30% for B,. The relevant branchings are to be, however, near 10-' for Bâ and .10'' for B;. Hence, more than 106 B mesons are needed to measure CP here . Another problem is that tagged B° are needed. The realistic way to do it was found by I. Bigi and A. Sanda for e+ annihilation, and forhadronic collisions by Ya. Azimov, V. Khoze and N. Uraltsev. In the latter case the realization of explicit Pais-Piccioni type experiments is possible. The observation of such CP asymmetries would lead to direct measurement of the CP odd phase in the quark mixing matrix in the SM . Beyond SM, larger CP asymmetries are generally expected . Their detaileû study will enable us not only to check the SM, but also distinguish between the main classes of possible modifications of the SM . If new generations of quarks do exist then CP violation could drastically change. For the supersymmetric generalization of the SM, we expect that the pattern of the CP Violation in B mesons should be as in the SM.
e
Nuclear Physics A478 (1988) 261c North-Holland, Amsterdam
PROSPECTS FOR CP IN B MESONS N.G. URALTSEV
Leningrad Nuclear Physics Institute, Gatchina, USSR
Neutral B mesons R° - hd, B° -Gs become a new laboratory for CP studies like K° mesons . the ARGUS result AmapdIT®=v".7 conc,raints Iargcly thestandard model (SIM), e.g. top quark mass -100 GeV. This results in more definite predictions for all parameters . e'Je in K,°, decay is expected (2-4) x 10' in agreement with recent CERN and FNAL results. In contrast to K°, in B° the "superweak" manifestations of CP violation (i .e. due to the CP odd mixing of "B," and "B2", say, charge asymmetry A of leptons in their decays) is inevitably small. In the SM ABd :z 5 x 10 -°, AB, !z 5 x :10-5. In Bâ and B°, however, certain processes should exhibit large CP asymmetries of "milliweak" nature even in the SM . These are the partial widths, differerces for come decays of B° and B° to the same final states with the definite CP parity, e.g . Bâ, Bâ->J/ty+Ks or B;, i3 ;-sp(w,-,rr)+Ks. For these decays S=(I'(B°-~f)-l''~°~f))J (l'(B°-* f)+r(B°-1- f)) is expected to be about 8% for Bâ and -30% for B,. The relevant branchings are to be, however, near 10-' for Bâ and .10'' for B;. Hence, more than 106 B mesons are needed to measure CP here . Another problem is that tagged B° are needed. The realistic way to do it was found by I. Bigi and A. Sanda for e+ annihilation, and forhadronic collisions by Ya. Azimov, V. Khoze and N. Uraltsev. In the latter case the realization of explicit Pais-Piccioni type experiments is possible. The observation of such CP asymmetries would lead to direct measurement of the CP odd phase in the quark mixing matrix in the SM . Beyond SM, larger CP asymmetries are generally expected . Their detaileû study will enable us not only to check the SM, but also distinguish between the main classes of possible modifications of the SM . If new generations of quarks do exist then CP violation could drastically change. For the supersymmetric generalization of the SM, we expect that the pattern of the CP Violation in B mesons should be as in the SM.
e