The phenomenon of mixing in neutral meson systems has now been observed in all flavours, but only in the past year in the D0 system. The standard model anticipated that, for the charm sector, the mixing rate would be small, and also that CP violation, either in mixing or in direct decay, would be below the present levels of observability. It is hoped that further study of these phenomena might reveal signs of new physics. A review of recently available, experimental results is given.
The charm fragmentation function has been measured in photoproduction of jets containing D^*+- mesons. The measured function has been used to extract free parameters of different fragmentation models. Measurements of excited charm, D_1(2420)^0 and D_2^*(2460)^0, and charm-strange, D_{s1}(2536)^+-, mesons and a search for the radially excited charm meson, D^{*'}(2640)^+-, were also performed. The results are compared with those measured previously and with theoretical expectation.
LHCb has collected the world's largest sample of charmed hadrons. This sample is used to search for direct and indirect CP Violation in charm. Recent and updated measurements from several decay modes are presented.
We review recent experimental results on D0 -D0bar mixing and CP violation charm decays. These studies provide complementary constraints on many different extensions of the Standard Model. Observation of CP violation in charm decays at the current level of experimental sensitivity would be clear signals of New Physics.
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.
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.
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.
Two measurements of mixing and $CP$ violation in charm decays performed at the LHCb experiment are presented. The former is a measurement of the mixing observable $y_{CP}-y_{CP}^{Kπ}$ in two-body $D^0$ decays, while the latter is a search for direct $CP$ violation in $D^+_{(s)}\rightarrowη^{(')}π^+$ 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.
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^-…
The LHCb experiment has been able to collect the largest sample ever produced of charm-hadron decays, performing a number of measurements of observables related to $C\!P$ violation in the charm sector. In this document, the most recent results from LHCb on the search of direct $C\!P$ violation in $D^0 \to K_s^0 K_s^0$, $D_{(s)}^+ \to h^+ π^0$ and $D_{(s)}^+ \to h^+ η$ decays are summarised, in addition to the most precise measurement of time-dependent $C\!P$ asymmetry in $D^0 \to h^+ h^-$ decays and the first observation of mass difference between neutral charm-meson eigenstates.
Measurements of the CKM angle beta in charmless loop-dominated B meson decays at BaBar
本文报道了无粲中性B介子衰变到K+ K-K 0（包括共振衰变phiK 0和f0 K 0），eta'K 0，pi 0 K 0 s，K 0 sK 0 sK 0 s，K 0 sK 0 s，rho 0 K 0 s，omegaK 0 s的含时CP破坏不对称性的初步测量结果。这些结果是从SLAC PEP-2非对称能量B介子工厂的BaBar探测器收集的Y（4S）共振下e+e湮灭产生的高达3.47亿个BBbar对的数据样本中获得的。
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-.
We summarize recent results for charm physics. These results span several categories: charm mixing, indirect (time-dependent) CP violation, direct (time-integrated) CP violation, T violation, semileptonic and leptonic decays, and decays of charm baryons.
The LHCb experiment has opened the possibility to test mixing and $C\!P$ violation in the charm sector with unprecedented precision thanks to the huge number of charm hadron decays collected, $\mathcal{O}(10^8)$. The first observation of $C\!P$ violation in the decay of charm quarks in March 2019 has been a fundamental achievement. The latest LHCb measurements in the complementary sectors of mixing and time-dependent $C\!P$ violation are illustrated in these proceedings. In particular, a new measurement of the $C\!P$ violation parameter $A_Γ$ with 2015--2016 data that was presented for the fir…
Theoretical predictions of cross sections and properties of the $J/ψ$-meson production in association with an open charm hadron and formation of two open charm hadrons from two $c\bar{c}$ pairs in the LHC conditions are presented. Processes in both single and in double parton scattering mechanisms are included into consideration. Special attention is paid to the kinematic limits of the LHCb detector for which comparison with the newest experimental data is carried out.
I review recent results in theoretical and experimental analyses of CP-violation in charmed transitions, paying particular attention to constraints on parameters of beyond the Standard Model interactions.
Mixing and CP violation in charm meson decays provide a unique probe of possible physics beyond the standard model. In this paper, we give a brief review of the current measurements from the BABAR experiment.
We review measurements of semileptonic and leptonic charm meson decays performed by the Belle experiment, and we use these results to estimate the sensitivity of the follow-on Belle II experiment to these decays.
In this paper, we perform a combined study of $2S$ and $1D$ open-charm mesons with natural spin-parity. Our results indicate that $D^*_1(2600)/D^*_{s1}(2700)$ and $D^*_1(2760)/D^*_{s1}(2860)$ are predominantly the $2^3S_1$ and $1^3D_1$ charmed/charmed-strange mesons, respectively, while $D_3^*(2760)/D_{s3}^*(2860)$ can be regarded as the $1^3D_3$ charmed/charmed-strange mesons. In addition, some typical ratios of partial widths of the discussed natural states are predicted, by which future experiments can test these assignments, especially for the $2S$-$1D$ mixing scheme existing in $D^*_1(260…
Inspired by the present experimental status of charmed-strange mesons, we perform a systematic study of the charmed-strange meson family, in which we calculate the mass spectra of the charmed-strange meson family by taking a screening effect into account in the Godfrey-Isgur model and investigate the corresponding strong decays via the quark pair creation model. These phenomenological analyses of charmed-strange mesons not only shed light on the features of the observed charmed-strange states, but also provide important information on future experimental search for the missing higher radial an…
In this article, we tentatively identify the charmed mesons $D_J(2580)$, $D_J^*(2650)$, $D_J(2740)$, $D^*_J(2760)$, $D_J(3000)$, $D_J^*(3000)$ observed by the LHCb collaboration according to their spin, parity and masses, then study their strong decays to the ground state charmed mesons plus light pseudoscalar mesons with the heavy meson effective theory in the leading order approximation, and obtain explicit expressions of the decay widths. The ratios among the decay widths can be used to confirm or reject the assignments of the newly observed charmed mesons. The strong coupling constants in …
We discuss how to classify the $c{\bar s}$ meson $D_{sJ}(3040)$ recently discovered by the BaBar Collaboration. We consider four possible assignments, together with signatures useful to distinguish among them.
Charm mixing and CP violation observables are examined in the light of the recently reported evidence from LHCb for CP violation in the charm sector. If the result is confirmed as being due to direct CP violation at the 1% level, its effect will need to be taken into account in the interpretation of CP violation observables. The contributions of direct and indirect CP violation to the decay rate asymmetry difference DeltaACP and the ratios of effective lifetimes AGamma and yCP are considered here. Terms relevant to the interpretation of future high precision measurements which have been neglec…
With the one-boson-exchange model we have studied the possible existence of the very loosely bound hidden-charm molecular baryons composed of anti-charmed meson and charmed baryon. Our numerical results indicate that there exist $Σ_c\bar{D}^*$ states with $I(J^P)=1/2(1/2^-), 1/2(3/2^-), 3/2(1/2^-), 3/2(3/2^-)$ and $Σ_c\bar{D}$ state with $3/2(1/2^-)$. But the $Λ_c \bar{D}$ and $Λ_c \bar{D}^*$ molecular states do not exist.
We present ground state spectra of mesons containing a charm and a bottom quark. For the charm quark we use overlap valence quarks while a non-relativistic formulation is utilized for the bottom quark on a background of 2+1+1 flavors HISQ gauge configurations generated by the MILC collaboration. The hyperfine splitting between $1S$ states of $B_c$ mesons is found to be $56^{+4}_{-3}$ MeV. We also study the baryons containing only charm and bottom quarks and predict their ground state masses. Results are obtained at three lattice spacings.
We propose that the charged-particle multiplicity dependence of the charm-baryon-to-meson ratio observed in high-energy $pp$ collisions can be explained by canonical treatment of quantum charges in the statistical hadronization model (SHM). Taking the full particle listings of PDG complemented by additional charm-baryon states from relativistic quark model predictions, we evaluate the canonical partition function and the charm-hadron chemical factors that measure the canonical suppression arising from the requirement of strict conservation of quantum charges. We demonstrate that, while charm n…
