اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSearch for $CP$ violation in $D_s^+to K_S^0 pi^+$, $D^+to K_S^0 K^+$ and $D^+to phi pi^+$ decays
79
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
A search for charge-parity ($CP$) violation in Cabibbo-suppressed $D_s^+to K_S^0 pi^+$, $D^+to K_S^0 K^+$ and $D^+to phi pi^+$ decays is reported using proton-proton collision data, corresponding to an integrated luminosity of 3.8 fb$^{-1}$, collected at a center-of-mass energy of 13 TeV with the LHCb detector. High-yield samples of kinematically and topologically similar Cabibbo-favored $D_{(s)}^+$ decays are analyzed to subtract nuisance asymmetries due to production and detection effects, including those induced by $CP$ violation in the neutral kaon system. The results are begin{align*} mathcal{A}_{CP}(D_s^+to K_S^0 pi^+) &=left(phantom{-}1.3phantom{0}pm1.9phantom{0}pm0.5phantom{0}right)times10^{-3}, mathcal{A}_{CP}(D^+to K_S^0 K^+) &=left(-0.09pm0.65pm0.48right)times10^{-3}, mathcal{A}_{CP}(D^+to phi pi^+) &=left(phantom{-}0.05pm0.42pm0.29right)times10^{-3}, end{align*} where the first uncertainties are statistical and the second systematic. They are the most precise measurements of these quantities to date, and are consistent with $CP$ symmetry.
قيم البحث
اقرأ أيضاً
Based on an $e^{+}e^{-}$ collision data sample corresponding to an integrated luminosity of 2.93 $mathrm{fb}^{-1}$ collected with the BESIII detector at $sqrt{s}=3.773 mathrm{GeV}$, the first amplitude analysis of the singly Cabibbo-suppressed decay
$D^{+}to K^+ K_S^0 pi^0$ is performed. From the amplitude analysis, the $K^*(892)^+ K_S^0$ component is found to be dominant with a fraction of $(57.1pm2.6pm4.2)%$, where the first uncertainty is statistical and the second systematic. In combination with the absolute branching fraction $mathcal{B}(D^+to K^+ K_S^0 pi^0)$ measured by BESIII, we obtain $mathcal{B}(D^+to K^*(892)^+ K_S^0)=(8.69pm0.40pm0.64pm0.51)times10^{-3}$, where the third uncertainty is due to the branching fraction $mathcal{B}(D^+to K^+ K_S^0 pi^0)$. The precision of this result is significantly improved compared to the previous measurement.
A search for time-dependent violation of the charge-parity symmetry in $D^0 to K^+ K^-$ and $D^0 to pi^+ pi^-$ decays is performed at the LHCb experiment using proton-proton collision data recorded from 2015 to 2018 at a centre-of-mass energy of 13 T
eV, corresponding to an integrated luminosity of 6 fb$^{-1}$. The $D^0$ meson is required to originate from a $D^*(2010)^+ to D^0 pi^+$ decay, such that its flavour at production is identified by the charge of the accompanying pion. The slope of the time-dependent asymmetry of the decay rates of $D^0$ and $bar{D}^0$ mesons into the final states under consideration is measured to be $Delta Y_{K^+ K^-} = (-2.3 pm 1.5 pm 0.3) times 10^{-4}$, $Delta Y_{pi^+ pi^-} = (-4.0 pm 2.8 pm 0.4)times 10^{-4}$, where the first uncertainties are statistical and the second are systematic. These results are compatible with the conservation of the $CP$ symmetry at the level of 2 standard deviations and improve the precision by nearly a factor of two.
We present measurements of time-dependent CP asymmetries in $B^0 to omega K_S^0$, $f_0 (980) K_S^0$, $K_S^0 pi^0$ and $K^+ K^- K_S^0$ based on a sample of 535 $times 10^6$ $Bbar{B}$ pairs collected at the $Upsilon(4S)$ resonance with the Belle detect
or at the KEKB energy-asymmetric $e^+ e^-$ collider. One neutral $B$ meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying $B$ meson is identified from its decay products. CP-violation parameters for each of the decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays.
We study the processes $e^+ e^-to K_S^0 K_L^0 gamma$, $K_S^0 K_L^0 pi^+pi^-gamma$, $K_S^0 K_S^0 pi^+pi^-gamma$, and $K_S^0 K_S^0 K^+K^-gamma$, where the photon is radiated from the initial state, providing cross section measurements for the hadronic
states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ of data collected with the BaBar detector at SLAC. We observe the $phi(1020)$ resonance in the $K_S^0 K_L^0$ final state and measure the product of its electronic width and branching fraction with about 3% uncertainty. We present a measurement of the $e^+ e^-to K_S^0 K_L^0 $ cross section in the energy range from 1.06 to 2.2 GeV and observe the production of a resonance at 1.67 GeV. We present the first measurements of the $e^+ e^-to K_S^0 K_L^0 pi^+pi^-$, $K_S^0 K_S^0 pi^+pi^-$, and $K_S^0 K_S^0 K^+K^-$ cross sections, and study the intermediate resonance structures. We obtain the first observations of jpsi decay to the $K_S^0 K_L^0 pi^+pi^-$, $K_S^0 K_S^0 pi^+pi^-$, and $K_S^0 K_S^0 K^+K^-$ final states.
The first measurements of the coherence factor R_{K_S^0Kpi} and the average strong--phase difference delta^{K_S^0Kpi} in D^0 to K_S^0 K^mppi^pm decays are reported. These parameters can be used to improve the determination of the unitary triangle ang
le gamma in B^- rightarrow $widetilde{D}K^-$ decays, where $widetilde{D}$ is either a D^0 or a D^0-bar meson decaying to the same final state, and also in studies of charm mixing. The measurements of the coherence factor and strong-phase difference are made using quantum-correlated, fully-reconstructed D^0D^0-bar pairs produced in e^+e^- collisions at the psi(3770) resonance. The measured values are R_{K_S^0Kpi} = 0.70 pm 0.08 and delta^{K_S^0Kpi} = (0.1 pm 15.7)$^circ$ for an unrestricted kinematic region and R_{K*K} = 0.94 pm 0.12 and delta^{K*K} = (-16.6 pm 18.4)$^circ$ for a region where the combined K_S^0 pi^pm invariant mass is within 100 MeV/c^2 of the K^{*}(892)^pm mass. These results indicate a significant level of coherence in the decay. In addition, isobar models are presented for the two decays, which show the dominance of the K^*(892)^pm resonance. The branching ratio {B}(D^0 rightarrow K_S^0K^+pi^-)/{B}(D^0 rightarrow K_S^0K^-pi^+) is determined to be 0.592 pm 0.044 (stat.) pm 0.018 (syst.), which is more precise than previous measurements.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
