Evidence For CP Violation Research Articles

Study of η′ → π+π−l+l− decays at BESIII

With a sample of (10087 ± 44) × 106J/ψ events accumulated with the BESIII detector, we analyze the decays η′ → π+π−l+l−(l = e, μ) via the process J/ψ → γη′. The branching fractions are measured to be B\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{B} $$\\end{document}(η′ → π+π−e+e−) = (2.45 ± 0.02(stat.) ± 0.08(syst.)) × 10−3 and B\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{B} $$\\end{document}(η′ → π+π−μ+μ−) = (2.16 ± 0.12(stat.) ± 0.06(syst.)) × 10−5, and the ratio is Bη′→π+π−e+e−Bη′→π+π−μ+μ−=113.4±0.9stat.±3.7syst.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\frac{\\mathcal{B}\\left({\\eta}^{\\prime}\ o {\\pi}^{+}{\\pi}^{-}{e}^{+}{e}^{-}\\right)}{\\mathcal{B}\\left({\\eta}^{\\prime}\ o {\\pi}^{+}{\\pi}^{-}{\\mu}^{+}{\\mu}^{-}\\right)}=113.4\\pm 0.9\\left(\ extrm{stat}.\\right)\\pm 3.7\\left(\ extrm{syst}.\\right) $$\\end{document}. In addition, by combining the η′ → π+π−e+e− and η′ → π+π−μ+μ− decays, the slope parameter of the electromagnetic transition form factor is measured to be bη′ = 1.30 ± 0.19 (GeV/c2)−2, which is consistent with previous measurements from BESIII and theoretical predictions from the VMD model. The asymmetry in the angle between the π+π− and l+l− decay planes, which has the potential to reveal the CP-violation originating from an unconventional electric dipole transition, is also investigated. The asymmetry parameters are determined to be ACPη′→π+π−e+e−=−0.21±0.73stat.±0.01syst.%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {\\mathcal{A}}_{CP}\\left({\\eta}^{\\prime}\ o {\\pi}^{+}{\\pi}^{-}{e}^{+}{e}^{-}\\right)=\\left(-0.21\\pm 0.73\\left(\ extrm{stat}.\\right)\\pm 0.01\\left(\ extrm{syst}.\\right)\\right)\\% $$\\end{document} and ACPη′→π+π−μ+μ−=0.62±4.71stat.±0.08syst.%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {\\mathcal{A}}_{CP}\\left({\\eta}^{\\prime}\ o {\\pi}^{+}{\\pi}^{-}{\\mu}^{+}{\\mu}^{-}\\right)=\\left(0.62\\pm 4.71\\left(\ extrm{stat}.\\right)\\pm 0.08\\left(\ extrm{syst}.\\right)\\right)\\% $$\\end{document}, implying that no evidence of CP-violation is observed at the present statistics. Finally, an axion-like particle is searched for via the decay η′ → π+π−a, a → e+e−, and upper limits of the branching fractions are presented for the mass assumptions of the axion-like particle in the range of 0 − 500 MeV/c2.

Observation of J/ψ decays to e+e−e+e− and e+e−μ+μ−

Using a data sample of 4.481×108 ψ(3686) events collected with the BESIII detector, we report the first observation of the four-lepton-decays J/ψ→e+e−e+e− and J/ψ→e+e−μ+μ− utilizing the process ψ(3686)→π+π−J/ψ. The branching fractions are determined to be [5.48±0.31(stat)±0.45(syst)]×10−5 and [3.53±0.22(stat)±0.13(syst)]×10−5, respectively. The results are consistent with theoretical predictions. No significant signal is observed for J/ψ→μ+μ−μ+μ−, and an upper limit on the branching fraction is set at 1.6×10−6 at the 90% confidence level. A CP asymmetry observable is constructed for the first two channels, which is measured to be (−0.012±0.054±0.010) and (0.062±0.059±0.006), respectively. No evidence for CP violation is observed in this process. Published by the American Physical Society 2024

Measurement of CP asymmetries and branching fraction ratios of B− decays to two charm mesons

The CP asymmetries of seven B− decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb−1 of proton-proton collisions collected by the LHCb experiment. Decays involving a D*0 or Ds∗−\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {D}_s^{\\ast -} $$\\end{document} meson are analysed by reconstructing only the D0 or Ds−\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {D}_s^{-} $$\\end{document} decay products. This paper presents the first measurement of A\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{A} $$\\end{document}CP(B−→Ds∗−\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {D}_s^{\\ast -} $$\\end{document}D0) and A\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{A} $$\\end{document}CP(B−→Ds−\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {D}_s^{-} $$\\end{document}D∗0), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.

Search for CP violation in {D}_{(s)}^{+} → K−K+K+ decays

A search for direct CP violation in the Cabibbo-suppressed decay {D}_s^{+} → K−K+K+ and in the doubly Cabibbo-suppressed decay D+ → K−K+K+ is reported. The analysis is performed with data collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 5.6 fb−1. The search is conducted by comparing the {D}_{(s)}^{+} and {D}_{(s)}^{-} Dalitz-plot distributions through a model-independent binned technique, based on fits to the K−K+K+ invariant-mass distributions, with a total of 0.97 (1.27) million {D}_s^{+} (D+) signal candidates. The results are given as p-values for the hypothesis of CP conservation and are found to be 13.3% for the {D}_s^{+} → K−K+K+ decay and 31.6% for the D+→ K−K+K+ decay. No evidence for CP violation is observed in these decays.

Doubly cabibbo-suppressed D decays at BESIII

BESIII reports the first observation of the doubly Cabibbo-Suppressed decay D + → K+π +π −π 0 and the first evidence for D + → K+ω using an e +e − collision data sample corresponding to an integrated luminosity of 2.93 fb−1 taken at a center-of-mass energy of 3.773 GeV. The ratio of the branching fractions of D + → K+π +π −π 0 over D + → K−π +π +π 0 is significantly larger than other doubly CabibboSuppressed decays in the charm sector. The CP asymmetry in the separated charge-conjugate branching fractions for D + → K+π +π −π 0 is determined and no evidence of CP violation is found. An independent measurement of D + → K+π +π −π 0 with semileptonic tags is also reported.

Measurement of branching fractions and search for CP violation in D0 \u2192 \u03c0+\u03c0\u2212\u03b7, D0 \u2192 K+K\u2212\u03b7, and D0 \u2192 \u03d5\u03b7 at Belle

We measure the branching fractions and CP asymmetries for the singly Cabibbo-suppressed decays D0 → π+π−η, D0 → K+K−η, and D0 → ϕη, using 980 fb−1 of data from the Belle experiment at the KEKB e+e− collider. We obtainBD0→π+π−η=1.22±0.02stat±0.02syst±0.03Bref×10−3,BD0→K+K−η=1.80−0.06+0.07stat±0.04syst±0.05Bref×10−4,BD0→ϕη=1.84±0.09stat±0.06syst±0.05Bref×10−4,\\documentclass[12pt]{minimal}\t\t\t\t\\usepackage{amsmath}\t\t\t\t\\usepackage{wasysym}\t\t\t\t\\usepackage{amsfonts}\t\t\t\t\\usepackage{amssymb}\t\t\t\t\\usepackage{amsbsy}\t\t\t\t\\usepackage{mathrsfs}\t\t\t\t\\usepackage{upgreek}\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\t\t\t\t\\begin{document}$$ {\\displaystyle \\begin{array}{c}\\mathcal{B}\\left({D}^0\\to {\\pi}^{+}{\\pi}^{-}\\eta \\right)=\\left[1.22\\pm 0.02\\left(\\mathrm{stat}\\right)\\pm 0.02\\left(\\mathrm{syst}\\right)\\pm 0.03\\left({\\mathcal{B}}_{\\mathrm{ref}}\\right)\\right]\\times {10}^{-3},\\\\ {}\\mathcal{B}\\left({D}^0\\to {K}^{+}{K}^{-}\\eta \\right)=\\left[{1.80}_{-0.06}^{+0.07}\\left(\\mathrm{stat}\\right)\\pm 0.04\\left(\\mathrm{syst}\\right)\\pm 0.05\\left({\\mathcal{B}}_{\\mathrm{ref}}\\right)\\right]\\times {10}^{-4},\\\\ {}\\mathcal{B}\\left({D}^0\\to \\phi \\eta \\right)=\\left[1.84\\pm 0.09\\left(\\mathrm{stat}\\right)\\pm 0.06\\left(\\mathrm{syst}\\right)\\pm 0.05\\left({\\mathcal{B}}_{\\mathrm{ref}}\\right)\\right]\\times {10}^{-4},\\end{array}} $$\\end{document}where the third uncertainty ( mathcal{B} ref) is from the uncertainty in the branching fraction of the reference mode D0 → K−π+η. The color-suppressed decay D0 → ϕη is observed for the first time, with very high significance. The results for the CP asymmetries areACPD0π+π−η=0.9±1.2stat±0.5syst%,ACPD0→K+K−η=−1.4±3.3stat±1.1syst%,ACPD0→ϕη=−1.9±4.4stat±0.6syst%.\\documentclass[12pt]{minimal}\t\t\t\t\\usepackage{amsmath}\t\t\t\t\\usepackage{wasysym}\t\t\t\t\\usepackage{amsfonts}\t\t\t\t\\usepackage{amssymb}\t\t\t\t\\usepackage{amsbsy}\t\t\t\t\\usepackage{mathrsfs}\t\t\t\t\\usepackage{upgreek}\t\t\t\t\\setlength{\\oddsidemargin}{-69pt}\t\t\t\t\\begin{document}$$ {\\displaystyle \\begin{array}{c}{A}_{CP}\\left({D}^0\\ {\\pi}^{+}{\\pi}^{-}\\eta \\right)=\\left[0.9\\pm 1.2\\left(\\mathrm{stat}\\right)\\pm 0.5\\left(\\mathrm{syst}\\right)\\right]\\%,\\\\ {}{A}_{CP}\\left({D}^0\\to {K}^{+}{K}^{-}\\eta \\right)=\\left[-1.4\\pm 3.3\\left(\\mathrm{stat}\\right)\\pm 1.1\\left(\\mathrm{syst}\\right)\\right]\\%,\\\\ {} ACP\\ \\left({D}^0\\to \\phi \\eta \\right)=\\left[-1.9\\pm 4.4\\left(\\mathrm{stat}\\right)\\pm 0.6\\left(\\mathrm{syst}\\right)\\right]\\%.\\end{array}} $$\\end{document}The results for D0 → π+π−η are a significant improvement over previous results. The branching fraction and ACP results for D0 → K+K−η, and the ACP result for D0 → ϕη, are the first such measurements. No evidence for CP violation is found in any of these decays.

CPT and CP, an entangled couple

Even though it is undoubtedly very appealing to interpret the latest T2K results as evidence of CP violation, this claim assumes CPT conservation in the neutrino sector to an extent that has not been tested yet. As we will show, T2K results are not robust against a CPT-violating explanation. On the contrary, a CPT-violating CP-conserving scenario is in perfect agreement with current neutrino oscillation data. Therefore, to elucidate whether T2K results imply CP or CPT violation is of utter importance. We show that, even after combining with data from NOνA and from reactor experiments, no claims about CP violation can be made. Finally, we update the bounds on CPT violation in the neutrino sector.

Measurement of the CP violation parameter $A_{\Gamma}$ A Γ in $D^{0} \rightarrow K^{+}K^{-}$ D 0 → K + K - and $D^{0} \rightarrow \pi^{+} \pi^{-}$ D 0 → π + π - decays

Asymmetries in the time-dependent rates of singly Cabibbo-suppressed $D^{0}\rightarrow K^{+}K^{-}$ and $D^{0}\rightarrow \pi^{+}\pi^{-}$ decays are measured in pp collision data sample collected with the LHCb detector during LHC Run 1, corresponding to an integrated luminosity of 3 fb-1. The asymmetries in effective decay widths between D0 and $\overline{D}^{0}$ decays, sensitive to indirect CP violation, are measured. These measurements show no evidence for CP violation and improve on the precision of the previous best measurements by nearly a factor of two.

Measurement of CP asymmetries in two-body B(s)0 -meson decays to charged pions and kaons

The time-dependent $C\!P$ asymmetries in $B^0\to\pi^+\pi^-$ and $B_s^0\to K^+\!K^-$ decays are measured using a data sample of $pp$ collisions corresponding to an integrated luminosity of 3.0 fb$^{-1}$, collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. The same data sample is used to measure the time-integrated $C\!P$ asymmetries in $B^0\to K^+\pi^-$ and $B_s^0\to\pi^+ K^-$ decays. The results are $C_{\pi^+\pi^-} = -0.34 \pm 0.06 \pm 0.01$, $S_{\pi^+\pi^-} = -0.63 \pm 0.05 \pm 0.01$, $C_{K^+\!K^-} = 0.20 \pm 0.06 \pm 0.02$, $S_{K^+\!K^-} = 0.18 \pm 0.06 \pm 0.02$, $C_{K^+\!K^-}^{\Delta\Gamma} = -0.79 \pm 0.07 \pm 0.10$, $A_{C\!P}^{B^0} = -0.084 \pm 0.004 \pm 0.003$, and $A_{C\!P}^{B_s^0} = 0.213 \pm 0.015 \pm 0.007$, where the first uncertainties are statistical and the second systematic. Evidence for $C\!P$ violation is found in the $B_s^0\to K^+\!K^-$ decay for the first time.

Measurement of the CP asymmetry in B\u2212\u2009\u2192\u2009Ds\u2212D0 and B\u2212 \u2192 D\u2212D0 decays

The CP asymmetry in B− → Ds−D0 and B− → D−D0 decays is measured using LHCb data corresponding to an integrated luminosity of 3.0 fb−1, collected in pp collisions at centre-of-mass energies of 7 and 8 TeV. The results are {mathcal{A}}^{CP}left({B}^{-}to {D}_s^{-}{D}^0right)=left(-0.4pm 0.5pm 0.5right)%kern0.5em mathrm{and}kern0.5em {mathcal{A}}^{CP}left({B}^{-}to {D}^{-}{D}^0right)=left(2.3pm 2.7pm 0.4right)% , where the first uncertainties are statistical and the second systematic. This is the first measurement of {mathcal{A}}^{CP}left({B}^{-}to {D}_s^{-}{D}^0right) and the most precise determination of {mathcal{A}}^{CP}left({B}^{-}to {D}^{-}{D}^0right) . Neither result shows evidence of CP violation.

Measurement of CP asymmetry in Bs0\u2009\u2192\u2009Ds\u2213K\xb1 decays

We report the measurements of the CP -violating parameters in Bs0 → Ds∓K± decays observed in pp collisions, using a data set corresponding to an integrated luminosity of 3.0 fb−1 recorded with the LHCb detector. We measure Cf = 0.73 ± 0.14 ± 0.05, AfΔΓ = 0.39 ± 0.28 ± 0.15, {A}_{overline{f}}^{varDelta varGamma }=0.31pm 0.28pm 0.15 , Sf = −0.52 ± 0.20 ± 0.07, {S}_{overline{f}}=-0.49pm 0.20pm 0.07 , where the uncertainties are statistical and systematic, respectively. These parameters are used together with the world-average value of the Bs0 mixing phase, −2βs, to obtain a measurement of the CKM angle γ from Bs0 → Ds∓K± decays, yielding γ = (128− 22+ 17)° modulo 180°, where the uncertainty contains both statistical and systematic contributions. This corresponds to 3.8 σ evidence for CP violation in the interference between decay and decay after mixing.

CP Violation in b- and c-hadron decays at LHCb

Testing the Standard Model of particle physics by precision measurements of CP violating observables in the decays of b and c hadrons has been one of the design goals of the LHCb experiment. World-leading measurements have been performed of the semileptonic asymmetry, , and of the mixing-induced CP-violating phase ϕs in the system. The CKM angle γ is still the least known angle of the Unitarity Triangle, and the only one easily accessible using tree-level decays. A recent combination of LHCb measurements in various B → DK decay modes has yielded the most precise determination of γ from a single experiment to date. The LHCb experiment is collecting unprecedented samples of beauty baryons, allowing for the first time to study CP violating observables in their decays. A recent analysis provided the first evidence for CP violation in the beauty baryon sector. Finally, LHCb has the largest samples of charmed hadron decays collected by any experiment to date. These samples yield some of the world’s most sensitive searches for direct and indirect CP violation in the charm sector.

On the difference of time-integrated CP asymmetries in D0 → K+K− and D0 → π+π− decays: Unparticle physics contribution

The LHCb Collaboration has recently measured the difference of time-integrated CP asymmetry in D0→K+K− and D0→π+π− decays, more precisely. The reported value is ΔACP=−0.10±0.08(stat)±0.03(syst)% which indicates no evidence for CP violation. We consider the possible unparticle physics contribution in this quantity and by using the LCHb data try to constrain the parameter space of unparticle stuff.

Amplitude analyses of D0 \u2192 \u03c0+\u03c0\u2212\u03c0+\u03c0\u2212 and D0 \u2192 K+K\u2212\u03c0+\u03c0\u2212 decays

The resonant substructure of D0 → π+π−π+π− decays is studied using data collected by the CLEO-c detector. An amplitude analysis is performed in order to disentangle the various intermediate state contributions. To limit the model complexity a data driven regularization procedure is applied. The prominent contributions are the decay modes D0 → a1(1260)+ π−, D0 → σ f0(1370) and D0 → ρ(770)0ρ(770)0. The broad resonances a1(1260)+, π(1300)+ and a1(1640)+ are studied in detail, including quasi-modelindependent parametrizations of their lineshapes. The mass and width of the a1(1260)+ meson are determined to be ma1(1260)+ = [1225 ± 9 (stat) ± 17 (syst) ± 10 (model)] MeV/c2 and Γa1(1260)+ = [430 ± 24 (stat) ± 25 (syst) ± 18 (model)] MeV. The amplitude model of D0 → K+K−π+π− decays obtained from CLEO II.V, CLEO III, and CLEO-c data is revisited with improved lineshape parametrizations. The largest components are the decay modes D0 → ϕ(1020)ρ(770)0, D0 → K1(1270)+K− and D0 → K(1400)+K−.The fractional CP -even content of the decay D0 → π+π−π+π− is calculated from the amplitude model to be F+4π = [72.9 ± 0.9(stat) ± 1.5(syst) ± 1.0(model)] %, consistent with that obtained from a previous model-independent measurement. For D0 → K+K−π+π− decays, the CP -even fraction is measured for the first time and found to be F+KKππ = [75.3 ± 1.8 (stat) ± 3.3 (syst) ± 3.5 (model)] %.The global decay rate asymmetries between D0 and {overline{D}}^0 decays are measured to be {mathcal{A}}_{CP}^{4uppi}=left[+0.54pm 1.04 left(mathrm{stat}right)pm 0.51 left(mathrm{syst}right)right]% and {mathcal{A}}_{CP}^{KKpi pi}=left[+1.84pm 1.74 left(mathrm{stat}right)pm 0.30 left(mathrm{syst}right)right]% . A search for CP asymmetries in the amplitude components yields no evidence for CP violation in either decay mode.

ϕ1 Measurements at Belle

We present the recent measurements of the B0→η′K0 and the B→ωK decay modes based on the full data set of 772×106BB‾ pairs collected by the Belle detector at the KEKB e+e− collider. In the B0→η′K0 mode, we obtain the CP-violating parametersAη′K0=+0.03±0.05 (stat)±0.04 (syst),Sη′K0=+0.68±0.07 (stat)±0.03 (syst).This is the world's most precise result on the η′K0CP parameters. In B→ωK decays, we measure the branching fractionsBB0→ωK0=(4.5±0.4 (stat)±0.3 (syst))×10−6,BB−→ωK−=(6.8±0.4 (stat)±0.4 (syst))×10−6,which are their current most precise results. We measure the first evidence of CP violation in the B0→ωKS0 decay mode, obtaining the CP-violating parametersAωKS0=−0.36±0.19 (stat)±0.05(syst),SωKS0=+0.91±0.32 (stat)±0.05 (syst).In the B−→ωK− mode, we measure the direct CP-violation parameterAωK−=−0.03±0.04 (stat)±0.01 (syst),which is its most precise measurement to date.

CP violation in B decays at Belle

Using the full data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider, we present three recent measurements of time-dependent CP violation in B decays that are sensitive to potential new physics contributions and a measurement of branching fraction of the B0 → π0π0 decay. We studied B → ωK decays and measured the values of CP violation parameters in B0 → ωK0S to be AωK0S = 0.36 ± 0.19 ± 0.05 and SωK0S = +0.91 ± 0.32 ± 0.05, which gives the first evidence of CP violation in this decay. From the measurement of CP violation parameters in the B0 → η'K0 decay we obtain Sη'K0 = 0.68 ± 0.07 ± 0.03 and Aη'K0 = +0.03 ± 0.05 ± 0.04, which are the world's most precise values to date. We present the Belle first measurement of CP violation parameters in B0 → K0Sηγ decay, where we measure SK0Sηγ = -1.32 ± 0.77 ± 0.36 and AK0Sηγ = -0.48 ± 0.41 ± 0.07 (preliminary). Finally we present our preliminary measurement of the B0 → π0π0 branching fraction. We measure B(B0 → π0π0) = (0.89 ± 0.12 ± 0.10) × 10-6, with significantly improved sensitivity compared to previously available results.

Experimental evidences of CP violation in charged charmless three-body B decays

We present CP violation investigations on B±→h±h+h−(h=p,Kπ) decays in the LHCb experiment. The inclusive charge asymmetries of these modes are measured. In addition, we observe large local asymmetries in several regions of the phase space. This is the first evidence for CP violation in decays involving baryons in the channel B±→pp¯K±.

Charmless B decays at BABAR

Recent results from the BABAR experiment in charmless B decays are presented, in particular the results of a search for the decays B0 → ωω and B0 → ωϕ and preliminary results of a Dalitz-plot analysis of B+ → K0Sπ+π°. The latter includes first evidence for CP violation in the intermediate decay B+ → K*(892)+π0.

Search for CP violation in D ± → K S 0 K ± and D s ± → K S 0 π ± decays

A search for C P violation in D+ -> phi pi(+) decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb(-1) at a centre of mass energy of 7 TeV. The CP-violating asymmetry is measured to be (-0.04 +/- 0.14 +/- 0.14)% for candidates with K-K+ mass within 20 MeV/c(2) of the phi meson mass. A search for a CP-violating asymmetry that varies across the phi mass region of the D+ -> K-K+pi(+) Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D-s(+) -> K-S(0)pi(+) decay is measured to be (0.61 +/- 0.83 +/- 0.14)%.

Evidence for CP violation in B+ → ppK+ decays.

Three-body B+ → ppK+ and B(+) → ppπ(+) decays are studied using a data sample corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV. Evidence of CP violation in the B(+) → ppK(+) decay is found in regions of the phase space, representing the first measurement of this kind for a final state containing baryons. Measurements of the forward-backward asymmetry of the light meson in the pp rest frame yield A(FB)(ppK(+),m(pp)<2.85 GeV/c(2)) = 0.495 ± 0.012 (stat) ± 0.007 (syst) and A(FB)(ppπ(+),m(pp) <2.85 GeV/c(2)) = -0.409 ± 0.033 (stat) ± 0.006 (syst). In addition, the branching fraction of the decay B(+) → Λ(1520)p is measured to be B(B(+) → Λ(1520)p) = (3.15 ± 0.48 (stat) ± 0.07 (syst) ± 0.26 (BF)) × 10(-7), where BF denotes the uncertainty on secondary branching fractions.