We report a measurement of the CP-odd fraction and the time-dependent CP violation in B0 to D*+D*- decays, using 657.10^6 BBbar events collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We measure a CP-odd fraction of Rperp=0.125+/-0.043(stat)+/-0.023(syst). From the distributions of the proper-time intervals between a B0to D*+D*- decay and the other B meson in the event, we obtain evidence of CP violation with measured parameters AD*+D*-=0.15+/-0.13(stat)+/-0.04(syst) and SD*+D*-=-0.96+/-0.25(stat)-0.16+0.13(syst).
I present here the most recent experimental results in the search for Lepton Flavor and Lepton Number Violating decays of charged leptons, and the perspectives in this field for the next future.
Multibody charm decays have a rich phenomenology and potentially unique sensitivity to CP violation. In these proceedings we discuss recent results, challenges and prospects in searches for CP violation in three and four body charm decays.
The latest experimental results in charmless B decays are presented with a focus on CP violation measurements. These include the first observation of CP violation in B_s decays, evidence for CP violation in charmless three-body B+ decays, branching fraction measurements of B+ --> ppK+ decays and the first observation of the decay B_s --> phi K*0 from LHCb, a comparison of B+ --> K+K-K+ CP violation measurements between LHCb and BaBar, and the first evidence for the decay B0 --> K+K-pi0 obtained by Belle.
Recent measurements of mixing and $CP$ violation in charm decays at LHCb are presented. These include searches for direct $CP$ violation in $D^{0}\rightarrow K_{S}^{0}K_{S}^{0}$, $D_{(s)}^{+}\rightarrow h^{+} π^{0} $ and $D_{(s)}^{+}\rightarrow h^{+}η$ decays, and a search for time-dependent $CP$ violation in $D^{0}\rightarrow h^{+}h^{-}$ decays, where $h^{+}$ is either a $π^{+}$ or $K^{+}$ meson.
It is well known that observing CP violation in many-body decays could provide strong evidence for physics beyond the Standard Model. Many searches have been carried out; however, no 5sigma evidence for CP violation has yet been found in these types of decays. A novel model-independent method for observing CP violation in many-body decays is presented in this paper. It is shown that the sensitivity of this method is significantly larger than those used to-date.
Model-independent techniques for CP violation searches in multi-body charm decays are discussed. Examples of recent analyses from BaBar and LHCb are used to illustrate the experimental challenges involved.
$CP$ violation and branching fraction measurements in $D$ decays are interesting topics as any difference with respect to the Standard Model prediction would be an indication of new physics. With the large data sample collected by the Belle detector, which sits at the interaction point of KEKB asymmetric $e^{+} e^{-}$ collider in Japan, we present the results of searches for $CP$ violation in $D^{0}\rightarrow Vγ~(V = ϕ, \overline{K}^{*0}, ρ^{0})$ decay and the rare $D$ decay $D^{0}\rightarrow γγ$.
Charmless B hadrons decays offer rich opportunities to test the Standard Model. CP violation in charmless charged two-body and three-body B decays provides ways to measure the CKM angle $γ$ and to search for New Physics. Also, vector-vector final states provide additional interesting observables. Hereby, we present the latest LHCb results on hadronic charmless B decays putting emphasis on the direct CP violation measurements.
The SuperB experiment at the Cabibbo Laboratory will provide new possibilities to study the physics of charm. The potential physics reach of the experiment when performing studies of rare decays, mixing and CP violation in charm decays is presented here and the implications of such measurements for new physics scenarios is discussed.
Searches for lepton flavour and lepton number violation in kaon decays by the NA48/2 and NA62 experiments at CERN are presented. A new measurement of the helicity suppressed ratio of charged kaon leptonic decay rates $RK=BR(Ke2)/BR(Kmu2) to sub-percent relative precision is discussed. An improved upper limit on the lepton number violating K+- --> pi-+mu+-mu+- decay rate is also presented.
We report a measurement of the CP violation in B^0 -> J/ψK^0_S decays. We perform a time-dependent analysis of the decays reconstructed in 35/pb of LHCb data that was taken in 2010. We measure the CP asymmetry parameter
Studies of charm physics with the 2010 LHCb data sample are presented. Time-integrated searches for CP violation in D+ -> K- K+ pi+ and D0 -> K- K+, pi- pi+ are discussed.
In the Standard Model \CP violation in charm decays is expected to be very small, at the level of 0.1% or less. A significant excess of \CP violation with respect to the Standard Model predictions would be a signature of new physics. We report on recent searches for \CP violation in charm meson decays at \babar, using a data sample corresponding to an integrated luminosity of about 470 \invfb. In particular, we report on searches for \CPV in the 3-body $\Dp\to\Kp\Km\pip$ decay and for decay modes with a \KS in the final state, such as $\Dp\to\KS\Kp$, $\Ds\to\KS\Kp$, $\Ds\to\KS\pip$. A lifetime…
We search for CP violation in a sample of 4.7x10^4 Cabibbo suppressed D0 -> K+K-pi+pi- decays. We use 470 fb-1 of data recorded by the BaBar detector at the PeP2 asymmetric-energy e+e- storage rings running at center-of-mass energies near 10.6 GeV. CP violation is searched for in the difference between the T-odd asymmetries, obtained using triple product correlations, measured for D0 and D0b decays. The measured At violation parameter is At = (1.0 +- 5.1_sta +- 4.4_sys) x 10^-3.
B mesons provide an ideal laboratory for measurements of CP violation and searches for CP violation beyond the Standard Model. Recent measurements of the mixing phases of the $B_s^0$ and $B^0$ mesons, $ϕ_s$ and $\sin2β$, using decays to $J/ψX$ final states are presented. In view of future improved measurements, a good understanding of pollution from sub-leading penguin topologies in these decays is needed. Those can be probed using suppressed decays like $B_s^0 \to J/ψK_S^0$ and $B_s^0 \to J/ψ\overline{K}^{*0}$. Recent results using these decay modes are presented.
In the Standard Model of particle physics, lepton flavour and lepton number are conserved quantities although no fundamental symmetry demands their conservation. I present recent results of searches for lepton flavour and lepton number violating hadron decays measured at the B factories and LHCb. In addition, the LHCb collaboration has recently performed a search for the lepton flavour violating decay τ^- \to μ^-μ^-μ^+. The obtained upper exclusion limit, that has been presented in this talk for the first time, is of the same order of magnitude as those observed at the B factories. This is the…
Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter alpha(Lambdac) in Lambdac --> Lambda pi decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter : A = [alpha(Lambdac)+alpha(antiLambda_c)]/[alpha(Lambdac)-alpha(antiLambda_c)]. We obtain alpha(Lambdac)=-0.78+-0.16+-0.13 and A = -0.07+-0.19+-0.12 where errors are statistical and systematic.
The recent experimental results of CP violation in Bs decays other than in the J/psi phi final state are discussed. Included are the resonant components and $ϕ_s$ determination in Bs -> J/psi pi+ pi-, CP asymmetries in Bs -> h+ h'- decays, and the Bs effective lifetimes in the CP-even state K+ K- and the CP-odd state J/psi f0(980).
We present a brief review of CPV and mixing measurements in the charm sector, with emphasys in results published or presented since the previous edition of the Physics in Collision Symposia.
We present direct CP violation measurements using the full BaBar dataset of 471 million BBbar pairs for the following charmless B decays: B0-->rho0Kstar0, B0-->f0Kstar0, B0-->rho-Kstar+ and for the Dalitz plots of B+-->K+K-K+, B+-->KsKsK+ and B0-->KsK+K-.
I report the recent searches for CP violation in tau and D decays including a K0S in the final state. The analyses herein shown are based on data samples recorded by BaBar and Belle experiments. A brief introduction on CP violation is followed by the summary of the experimental techniques and the results obtained for tau and D decays, respectively. Finally, an outlook on future development is provided.
In this proceeding, we report the recent measurements of time-dependent CP violation in B meson decays from the Belle Collaboration. The Belle experiment stopped operation in June 2010 and collected nearly 772 x 10^6 B B-bar pairs at the Υ(4S) resonance at the KEKB asymmetric-energy e^+e^- collider. We used this full data sample to measure the CP violation parameters in b->c c-bar s and b->c c-bar d decays. We also report new measurements of CPT violation parameters in B decays. Furthermore, we report the first observation of a new b->s radiative penguin decay B^0->ϕK^0 γ, as well as measureme…
The LHCb experiment has recorded the world's largest sample of charmed meson decays. This paper presents a study of a $D^0$ meson decaying into a final state containing a neutral pion in LHCb. The search for $CP$ violation exploits a novel model-independent unbinned technique to assign a $p$-value for the no $CP$ violation hypothesis. With a data sample size exceeding that of previous measurements by almost an order of magnitude the world's best sensitivity is obtained. The $p$-value of no CP violation hypothesis given data of $D^0\rightarrow π^-π^+π^0$ decay analysed is found to be $(2.6 \pm …
The $B_s^0-\bar{B}_s^0$ system can be used to look for new sources of CP violation. Time-dependent CP violation measurements of beauty mesons allow the determination of the mixing induced CP-violating phase, $ϕ_s$. The angular analysis of the $B_s^0\rightarrow ϕϕ$ decay is presented, along with two $B_s^0\rightarrow J/ψh^+h^-$ decays, where the two hadrons are either a pair of kaons or a pair of pions. The analyses are based on data collected with the LHCb detector between $2011$ and $2016$.
Results on CP violation searches in charm decays performed by the LHCb experiment are reviewed. These include an update of the measurement of the difference in time-integrated {\em CP} asymmetry between $D^0\to K^-K^+$ and $D^0\to π^-π^+$ using $D^0$ from prompt $D^{*+}, a measurement of the same observable using an independent sample of $D^0$ from semileptonic B decays, and CP violation searches performed on charged $D$ mesons. All results have been released since FPCP 2012.
The LHCb experiment has collected the world's largest sample of charmed hadrons. This sample is used to measure observables related to $D^0 -\overline{D}^0$ mixing, direct $C\!P$ violation and $C\!P$ violation in mixing and interference in the charm sector. In this document, the most recent results from LHCb on the search of direct $C\!P$ violation in $D^0$ and $D_{(s)}^+$ decays are summarised, as well as the first observation of mass difference between neutral charm-meson eigenstates and the most precise measurement of time-dependent $C\!P$ asymmetry in $D^0 \to K^+ K^-$ and $D^0 \to π^+ π^-…
Recent results on mixing, CP violation and rare decays in charm physics from the LHCb experiment are presented. Study of ''wrong-sign'' $D^{0} \rightarrow K^+ π^-$ decays provides the highest precision measurements to date of the mixing parameters $x^{\prime 2}$ and $y^{\prime}$, and of CP violation in this decay mode. Direct and indirect CP violation in the $D^0$ system are probed to a sensitivity of around $10^{-3}$ using $D^0 \rightarrow K^+K^-$ and $D^0 \rightarrow π^+π^-$ decays and found to be consistent with zero. Searches for the rare decays $D^+_{(s)} \rightarrow π^+μ^+μ^-$, $D^+_{(s)…
We summarize recent results by the BABAR and Belle Collaborations on the search for CP violation and new physics beyond the Standard Model in several rare B meson decays. The measurements exploit the final BABAR and Belle Upsilon(4S) datasets, which consist of approximately 470 and 772 million BBbar pairs, respectively.
The ATLAS experiment at the Large Hadron Collider (LHC) has performed accurate measurements of mixing and CP violation in the neutral B mesons, and also of rare processes happening in electroweak FCNC-suppressed neutral B-mesons decays. This contribution focuses on the latest results from ATLAS, including measurements of rare processes $B^0_s \to μ^+μ^-$ and $B^0 \to μ^+μ^-$, and measurements of CP violation in $B^0_s \to J/ψϕ$.
First evidence for $C P$ violation in two-body singly Cabibbo-suppressed decays of $D^0$ mesons reported by LHCb has recently aroused great interest in charm physics. In this document the latest measurements of $C P$ violation in the charm sector are discussed. LHCb and CDF results on time-integrated $C P$ asymmetries in $D^0 \to π^-π^+$ and $D^0 \to K^-K^+$ decays are presented in some detail. A search for $C P$ violation performed by Belle in other two-body decays, namely $D^0 \to K^0_S π^0$, $D^0 \to K^0_S η^{(\prime)}$, $D^+_{(s)} \to ϕπ^+$ and $D^+ \to π^+ η^{(\prime)}$, is also presented…
During run I, the LHCb experiment at the LHC, CERN, collected 1.0 fb$^{-1}$ of pp collisions at $\sqrt{s} = 7$ TeV and 2.0 fb$^{-1}$ at $\sqrt{s} = 8$ TeV, yielding the world's largest sample of decays of charmed hadrons. This sample is used to search for direct and indirect CP violation in charm and to measure $D^{0}$ mixing parameters. Recent measurements from several complementary decay modes are presented.
We briefly discuss measurements of CP violation in Bs --> J/psi phi decay. Both the phenomenology of Bs mixing and the importance of the measurement to searches for new physics, as well as technical details and issues with the analysis are included. While current results are consistent with the standard model, even large contributions from new physics cannot be excluded.
CP-violation in the quark sector has been well established over the last decade, but has not been observed in the lepton sector. We search for CP-violating decay processes in positronium, using the angular correlation of (\vec{S}\cdot\vec{k_{1}})(\vec{S}\cdot\vec{k_{1}}\times\vec{k_{2}}), where \vec{S} is the the positronium spin and \vec{k_{1}}, \vec{k_{2}} are the directions of the positronium decay photons. To a sensitivity of 2.2\times10^{-3}, no CP-violation has been found, which is at the level of the CP-violation amplitude in the K meson. A 90% confidence interval of the CP-violation pa…
The prolific field of B meson decays and CP violation is illustrated in a few examples of recent results: The measurement of the CKM unitarity angle $β= ϕ_1$, the measurement of a significant violation of time reversal symmetry, an unexplained isospin asymmetry in penguin decays, a hint on scalar charged bosons from the semileptonic B decay to the heavy lepton $τ$, and B decays to baryons.
