Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userObservation of $D^+toetaetapi^+$ and improved measurement of $D^{0(+)}toetapi^+pi^{-(0)}$
65
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Using an $e^+e^-$ annihilation data sample corresponding to an integrated luminosity of $2.93,rm fb^{-1}$ collected at the center-of-mass energy of 3.773,GeV with the BESIII detector, we measure the absolute branching fractions of $D^+toetaetapi^+$, $D^+toetapi^+pi^0$, and $D^0toetapi^+pi^-$ to be $(2.96 pm 0.24 pm 0.13)times 10^{-3}$, $(2.23 pm 0.15 pm 0.11)times 10^{-3}$, and $(1.20 pm 0.07 pm 0.04)times 10^{-3}$, respectively, where the first uncertainties are statistical and the second ones systematic. The $D^+toetaetapi^+$ decay is observed for the first time and the branching fractions of $D^{+(0)}toetapi^+pi^{0(-)}$ are measured with much improved precision. In addition we test for $CP$ asymmetries in the separated charge-conjugate branching fractions; no evidence of $CP$ violation is found.
rate research
Read More
We present an observation and rate measurement of the decay D0 -> K+pi-pi0 produced in 9/fb of e+e- collisions near the Upsilon(4S) resonance. The signal is inconsistent with an upward fluctuation of the background by 4.9 standard deviations. We measured the rate of D0 -> K+pi-pi0 normalized to the rate of D0bar -> K+pi-pi0 to be 0.0043 +0.0011 -0.0010 (stat) +/- 0.0007 (syst). This decay can be produced by doubly-Cabibbo-suppressed decays or by the D0 evolving into a D0bar through mixing, followed by a Cabibbo-favored decay to K+pi-pi0. We also found the CP asymmetry A=(8 +25 -22)% to be consistent with zero.
By analyzing $2.93 rm fb^{-1}$ of data taken at a center-of-mass energy of 3.773~GeV with the BESIII detector, we measure the branching fractions of the Cabibbo-favored hadronic decays $D^0to K^-pi^+eta^prime$, $D^0to K^0_Spi^0eta^prime$ and $D^+to K^0_Spi^+eta^prime$, which are determined to be $(6.43 pm 0.15_{rm stat.} pm 0.31_{rm syst.})times 10^{-3}$, $(2.52 pm 0.22_{rm stat.} pm 0.15_{rm syst.})times 10^{-3}$ and $(1.90 pm 0.17_{rm stat.} pm 0.13_{rm syst.})times 10^{-3}$, respectively. The precision of the branching fraction of $D^0to K^-pi^+eta^prime$ is significantly improved, and the processes $D^0to K^0_Spi^0eta^prime$ and $D^+to K^0_Spi^+eta^prime$ are observed for the first time.
Charm meson oscillations are observed in a time-dependent analysis of the ratio of $D^0to K^+pi^-pi^+pi^-$ to $D^0to K^-pi^+pi^-pi^+$ decay rates, using data corresponding to an integrated luminosity of $3.0,{rm fb}^{-1}$ recorded by the LHCb experiment. The measurements presented are sensitive to the phase-space averaged ratio of doubly Cabibbo-suppressed to Cabibbo-favoured amplitudes $r_{D}^{K3pi}$ and the product of the coherence factor $R_{D}^{K3pi}$ and a charm mixing parameter $y^{}_{K3pi}$. The constraints measured are $r_{D}^{K3pi}=(5.67 pm 0.12)times10^{-2}$, which is the most precise determination to date, and $R_{D}^{K3pi} cdot y^{}_{K3pi} = (0.3 pm 1.8)times 10^{-3}$, which provides useful input for determinations of the CP-violating phase $gamma$ in $B^pm to D K^pm, D to K^mppi^pmpi^mppi^pm$ decays. The analysis also gives the most precise measurement of the $D^0to K^+pi^-pi^+pi^-$ branching fraction, and the first observation of $D^0-bar D^0$ oscillations in this decay mode, with a significance of 8.2 standard deviations.
Using $2.92$ fb$^{-1}$ of electron-positron annihilation data collected at $sqrt{s} = 3.773$~GeV with the BESIII detector, we report the results of a search for the flavor-changing neutral current process $D^0togammagamma$ using a double-tag technique. We find no signal and set an upper limit at $90%$ confidence level for the branching fraction of $B(D^0togammagamma) < 3.8times10^{-6}$. We also investigate $D^0$-meson decay into two neutral pions, obtaining a branching fraction of $B(D^0topi^0pi^0) = (8.24pm0.21(text{stat.})pm0.30(text{syst.}))times10^{-4}$, the most precise measurement to date and consistent with the current world average
The first observation of the decay $B^0 rightarrow D^0 overline{D}{}^0 K^+ pi^-$ is reported using proton-proton collision data corresponding to an integrated luminosity of 4.7 $mathrm{fb}^{-1}$ collected by the LHCb experiment in 2011, 2012 and 2016. The measurement is performed in the full kinematically allowed range of the decay outside of the $D^{*-}$ region. The ratio of the branching fraction relative to that of the control channel $B^0 rightarrow D^{*-} D^0 K^+$ is measured to be $mathcal{R} = (14.2 pm 1.1 pm 1.0)%$, where the first uncertainty is statistical and the second is systematic. The absolute branching fraction of $B^0 rightarrow D^0 overline{D}{}^0 K^+ pi^-$ decays is thus determined to be $mathcal{B}(B^0 rightarrow D^0 overline{D}{}^0 K^+ pi^-) = (3.50 pm 0.27 pm 0.26 pm 0.30) times 10^{-4}$, where the third uncertainty is due to the branching fraction of the control channel. This decay mode is expected to provide insights to spectroscopy and the charm-loop contributions in rare semileptonic decays.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
