Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMeasurement of the Dynamics of the Decays ${ D_s^+ rightarrow eta^{(prime)} e^{+} u_e}$
68
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Using $e^+e^-$ annihilation data corresponding to an integrated luminosity of 3.19,fb$^{-1}$ collected at a center-of-mass energy of 4.178~GeV with the BESIII detector, we measure the absolute branching fractions $mathcal{B}_{D_s^+ rightarrow eta e^{+} u_e }$ = $(2.323pm0.063_{rm stat}pm0.063_{rm syst})%$ and $mathcal{B}_{D_s^+ rightarrow eta^{prime} e^{+} u_e}$ = $(0.824pm0.073_{rm stat}pm0.027_{rm syst})%$ via a tagged analysis technique, where one $D_s$ is fully reconstructed in a hadronic mode. Combining these measurements with previous BESIII measurements of $mathcal{B}_{D^+toeta^{(prime)} e^{+} u_e}$, the $eta-eta^prime$ mixing angle in the quark flavour basis is determined to be $phi_{rm P} = (40.1pm2.1_{rm stat}pm0.7_{rm syst})^circ$. From the first measurements of the dynamics of $D^+_sto eta^{(prime)}e^+ u_e$ decays, the products of the hadronic form factors $f_+^{eta^{(prime)}}(0)$ and the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cs}|$ are determined with different form factor parameterizations. For the two-parameter series expansion, the results are $f^{eta}_+(0)|V_{cs}| = 0.4455pm0.0053_{rm stat}pm0.0044_{rm syst}$ and $f^{eta^{prime}}_+(0)|V_{cs}| = 0.477pm0.049_{rm stat}pm0.011_{rm syst}$.
rate research
Read More
A search for $CP$ violation in $D^{pm}rightarrow eta^{prime} pi^{pm}$ and $D^{pm}_{s}rightarrow eta^{prime} pi^{pm}$ decays is performed using proton-proton collision data, corresponding to an integrated luminosity of $3$ fb$^{-1}$, recorded by the LHCb experiment at centre-of-mass energies of $7$ and $8$ TeV. The measured $CP$-violating charge asymmetries are $A_{CP}(D^{pm} rightarrow eta^{prime} pi^{pm})=(-0.61pm 0.72 pm 0.53 pm 0.12)%$ and $A_{CP}(D^{pm}_{s}rightarrow eta^{prime} pi^{pm})=(-0.82pm 0.36 pm 0.22 pm 0.27)%$, where the first uncertainties are statistical, the second systematic, and the third are the uncertainties on the $A_{CP}(D^{pm} rightarrow K^0_S pi^{pm})$ and $A_{CP}(D^{pm}_{s}rightarrow phi pi^{pm})$ measurements used for calibration. The results represent the most precise measurements of these asymmetries to date.
A search for the rare radiative leptonic decay $D_s^+togamma e^+ u_e$ is performed for the first time using electron-positron collision data corresponding to an integrated luminosity of 3.19 fb$^{-1}$, collected with the BESIII detector at a center-of-mass energy of 4.178 GeV. No evidence for the $D_s^+togamma e^+ u_e$ decay is seen and an upper limit of $mathcal B(D_s^+togamma e^+ u_e)<1.3times 10^{-4}$ is set on the partial branching fraction at a 90% confidence level for radiative photon energies $E_{gamma}^*>0.01$~GeV.
We report on new measurements of Cabibbo-suppressed semileptonic $D_s^+$ decays using $3.19~mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data sample collected at a center-of-mass energy of 4.178~GeV with the BESIII detector at the BEPCII collider. Our results include branching fractions $mathcal B({D^+_srightarrow K^0 e^+ u_{e}})=(3.25pm0.38({rm stat.})pm0.16({rm syst.}))times10^{-3}$ and $mathcal B({D^+_srightarrow K^{*0} e^+ u_{e}})=(2.37pm0.26({rm stat.})pm0.20({rm syst.}))times10^{-3}$ which are much improved relative to previous measurements, and the first measurements of the hadronic form-factor parameters for these decays. For $D^+_srightarrow K^0 e^+ u_{e}$, we obtain $f_+(0)=0.720pm0.084({rm stat.})pm0.013({rm syst.})$, and for $D^+_srightarrow K^{*0} e^+ u_{e}$, we find form-factor ratios $r_V=V(0)/A_1(0)=1.67pm0.34({rm stat.})pm0.16({rm syst.})$ and $r_2=A_2(0)/A_1(0)=0.77pm0.28({rm stat.})pm0.07({rm syst.})$.
We report measurements of the branching fractions and $CP$ asymmetries for $D_s^{+} rightarrow K^{+} eta $, $D_s^{+} rightarrow K^{+} pi^0 $, and $D_s^{+} rightarrow pi^{+} eta $ decays, and the branching fraction for $D_s^{+} rightarrow pi^{+} pi^0$. Our results are based on a data sample corresponding to an integrated luminosity of 921 fb$^{-1}$ collected by the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider. Our measurements of $CP$ asymmetries in these decays are the most precise to-date; no evidence for $CP$ violation is found.
Based on a sample of $1.31 times 10^9$ $J/psi$ events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays $eta^prime rightarrow pi^+pi^-pi^0$ and $eta^prime rightarrow pi^0pi^0pi^0$ is performed. A significant $P$-wave contribution from $eta^prime rightarrow rho^{pm} pi^{mp}$ is observed for the first time in $eta^prime rightarrow pi^+pi^-pi^0$. The branching fraction is determined to be ${mathcal B}(eta^prime rightarrow rho^{pm}pi^{mp})=(7.44pm0.60pm1.26pm1.84)times 10^{-4}$, where the first uncertainty is statistical, the second systematic, and the third model dependent. In addition to the nonresonant $S$-wave component, there is a significant $sigma$ meson component. The branching fractions of the combined $S$-wave components are determined to be ${mathcal B}(eta^prime rightarrow pi^+pi^-pi^0)_S=(37.63pm0.77pm2.22pm4.48)times 10^{-4}$ and ${mathcal B}(eta^prime rightarrow pi^0pi^0pi^0)=(35.22pm0.82pm2.54)times 10^{-4}$, respectively. The latter one is consistent with previous BESIII measurements.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
