CP ASYMMETRIES IN NONLEPTONIC DECAY OF NEUTRAL B MESONS FOR THREE AND FOUR GENERATIONS

1989 ◽  
Vol 04 (25) ◽  
pp. 2465-2471 ◽  
Author(s):  
TSUTOM HASUIKE ◽  
TOSHIHIKO HATTORI ◽  
TOSHIO HAYASHI ◽  
SEIICHI WAKAIZUMI

We investigate the effects of CP violation in nonleptonic decays of neutral B mesons (Bd, Bs) in the Kobayashi-Maskawa model through the quark exchange diagram in terms of the Wolfenstein matrix. In our calculation, we use the new data of mixing parameter xd= 0.70±0.13 which is derived from ARGUS and CLEO measurements and the new data on the branching ratio for Bd meson. We obtain the results that CP violating asymmetries for Bd→D+D−, π+π− and K+K− reach about 50% and the number of [Formula: see text] quark pairs needed to detect the asymmetry is O(106~107) at 3σ level, and the asymmetries for [Formula: see text], D−π+, D0π0 and D+π− reach the order of 20% and the number of [Formula: see text] pairs is O(108). Therefore, we may conclude that the CP violation for these decay modes is possibly observable at the present stage. The effects of fourth generation quarks on CP violation are also studied.

2002 ◽  
Vol 17 (supp01) ◽  
pp. 47-57
Author(s):  
Paul H. Frampton

We propose a model of soft CP violation that evades the strong CP problem and can describe observed CP violation in the neutral kaon sector, both direct and indirect. Our model requires two "duark" mesons carrying quark number two that have complex (CP-violating) bare masses and are coupled to quark pairs. Aside from the existence of these potentially observable new particles with masses of several hundred GeV, we predict a flat unitarily triangle (i.e., no observable direct CP violation in the B-meson sector) and a possibly anomalous branching ratio for the decay mode [Formula: see text].


1999 ◽  
Vol 14 (35) ◽  
pp. 2453-2462 ◽  
Author(s):  
CHAO-SHANG HUANG ◽  
WU-JUN HUO ◽  
YUE-LIANG WU

If the fourth generation fermions exist, the new quarks could influence the branching ratios of the decays of B→Xsγ and B→Xsl+l-. We obtain two solutions of the fourth generation CKM factor [Formula: see text] from the decay of B→ Xsγ. We use these two solutions to calculate the new contributions of the fourth generation quark to Wilson coefficients of the decay of B→ Xsl+l-. The branching ratio and the forward–backward asymmetry of the decay of B→ Xsl+l- in the two cases are calculated. Our results are quite different from that of SM in one case, almost the same in another case. If Nature chooses the former, the B meson decays could provide a possible test of the fourth generation existence.


2004 ◽  
Vol 19 (06) ◽  
pp. 794-807
Author(s):  
T. R. WYATT

The CDF and DØ detectors were fully commissioned for physics running in Run II at the Tevatron [Formula: see text] collider in early 2002. Since then both experiments have collected data samples corresponding to an integrated luminosity of around ∫L=200 pb -1 at a [Formula: see text] centre-of-mass energy of [Formula: see text]. Datasets corresponding ∫L=120 pb-1 have been analyzed for physics so far. Recent electroweak measurements from Run II are reviewed. Cross section times branching ratio measurements (σ· Br ) are presented for the intermediate vector bosons (IVB's) in their leptonic decay modes: W→ℓν and Z→ℓ+ℓ-. For the first time, a combination of the σ· Br results from the CDF and DØ experiments is made; this includes using a consistent choice of the total inelastic [Formula: see text] cross section for the luminosity determinations of the two experiments. Quantities derived from these σ· Br values are also updated. These include: R ℓ the ratio of the σ· Br values for W and Z; Br (W→ℓν), the leptonic branching ratio of the W; and Γw, the total decay width of the W. Other measurements using events containing W and Z leptonic decays are presented, including studies that probe the QCD phenomenology of W/Z production and searches for events containing two intermediate vector bosons.


2020 ◽  
Vol 35 (15) ◽  
pp. 2050122
Author(s):  
H. R. Khan ◽  
E. H. Raslan ◽  
R. A. Reem

We present an analytic calculation of Branching Ratio (BR) and Charge-Parity (CP) violating asymmetries of the [Formula: see text] meson decays to [Formula: see text] by calculating the amplitude and the decay width of the process including the chiral loop and gluon condensate to first-order. We find the BR of [Formula: see text] which is in agreement with other experimental measurements and theoretical predictions. We also calculate the direct CP violation, CP violation in mixing and CP violation due to interference which are [Formula: see text], [Formula: see text] and [Formula: see text], respectively.


2019 ◽  
Vol 34 (06) ◽  
pp. 1950043
Author(s):  
Mahboobeh Sayahi

In this paper, the non-leptonic three-body decays [Formula: see text], [Formula: see text], [Formula: see text] are studied by introducing two-meson distribution amplitude for the [Formula: see text], [Formula: see text] and [Formula: see text] pairs in naive and QCD factorization (QCDF) approaches, such that the analysis is simplified into quasi-two body decays. By considering that the vector meson is being ejected in factorization, the resonant and non-resonant contributions are analyzed by using intermediate mesons in Breit–Wigner resonance formalism and the heavy meson chiral perturbation theory (HMChPT), respectively. The calculated values of the resonant and non-resonant branching ratio of [Formula: see text], [Formula: see text] and [Formula: see text] decay modes are compared with the experimental data. For [Formula: see text] and [Formula: see text], the non-resonant contributions are about 70–80% of experimental data, for which the total results by considering resonant contributions are in good agreement with the experiment.


2014 ◽  
Vol 35 ◽  
pp. 1460413
Author(s):  
GIANLUIGI CIBINETTO ◽  

CP violation in charm decays is expected to be very small in the Standard Model, at the level of 0.1% or less. A sizable excess of CP violation with respect to the Standard Model predictions could be a signature of new physics. We report on recent searches for CP violation in charm meson decays at BABAR and Belle experiments. In particular we report a lifetime ratio analysis of D0 → K+K−, π+π− with respect to D0 → K−π+ decays, which is sensitive to [Formula: see text] mixing and CP violation. We report also on searches for CPV in the 3-body D+ → K+K−π+ decay and for decay modes with a [Formula: see text] in the final state, such as [Formula: see text].


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