Do you want to publish a course? Click here

Measurements of the CKM angle $phi_3/gamma$

94   0   0.0 ( 0 )
 Added by Tagir Aushev
 Publication date 2009
  fields
and research's language is English
 Authors T. Aushev




Ask ChatGPT about the research

In this report we summarize the most recent results of measurements of the angle $gamma/phi_3$ of the Unitarity Triangle.



rate research

Read More

A combination of measurements sensitive to the CKM angle $gamma$ from LHCb is performed. The inputs are from analyses of time-integrated $B^{+}rightarrow DK^+$, $B^{0} rightarrow D K^{*0}$, $B^{0} rightarrow D K^+ pi^-$ and $B^{+} rightarrow D K^+pi^+pi^-$ tree-level decays. In addition, results from a time-dependent analysis of $B_{s}^{0} rightarrow D_{s}^{mp}K^{pm}$ decays are included. The combination yields $gamma = (72.2^{+6.8}_{-7.3})^circ$, where the uncertainty includes systematic effects. The 95.5% confidence level interval is determined to be $gamma in [55.9,85.2]^circ$. A second combination is investigated, also including measurements from $B^{+} rightarrow D pi^+$ and $B^{+} rightarrow D pi^+pi^-pi^+$ decays, which yields compatible results.
A combination of three LHCb measurements of the CKM angle gamma is presented. The decays B->DK and B->Dpi are used, where D denotes an admixture of D0 and D0-bar mesons, decaying into K+K-, pi+pi-, K+-pi-+, K+-pi-+pi+-pi-+, KSpi+pi-, or KSK+K- final states. All measurements use a dataset corresponding to 1.0 fb-1 of integrated luminosity. Combining results from B->DK decays alone a best-fit value of gamma = 72.0 deg is found, and confidence intervals are set gamma in [56.4,86.7] deg at 68% CL, gamma in [42.6,99.6] deg at 95% CL. The best-fit value of gamma found from a combination of results from B->Dpi decays alone, is gamma = 18.9 deg, and the confidence intervals gamma in [7.4,99.2] deg or [167.9,176.4] deg at 68% CL, are set, without constraint at 95% CL. The combination of results from B->DK and B->Dpi decays gives a best-fit value of gamma = 72.6 deg and the confidence intervals gamma in [55.4,82.3] deg at 68% CL, gamma in [40.2,92.7] deg at 95% CL are set. All values are expressed modulo 180 deg, and are obtained taking into account the effect of D0-D0bar mixing.
We present the first model-independent measurement of the CKM unitarity triangle angle $phi_3$ using $B^{pm}to D(K_{rm S}^0pi^+pi^-pi^0)K^{pm}$ decays, where $D$ indicates either a $D^{0}$ or $overline{D}^{0}$ meson. Measurements of the strong-phase difference of the $D to K_{rm S}^0pi^+pi^-pi^0$ amplitude obtained from CLEO-c data are used as input. This analysis is based on the full Belle data set of $772times 10^{6}$ $Boverline{B}$ events collected at the $Upsilon(4S)$ resonance. We obtain $phi_3 = (5.7~^{+10.2}_{-8.8} pm 3.5 pm 5.7)^{circ}$ and the suppressed amplitude ratio $r_{B} = 0.323 pm 0.147 pm 0.023 pm 0.051$. Here the first uncertainty is statistical, the second is the experimental systematic, and the third is due to the precision of the strong-phase parameters measured from CLEO-c data. The 95% confidence interval on $phi_3$ is $(-29.7,~109.5)^{circ}$, which is consistent with the current world average.
Crucial inputs for a variety of $CP$-violation studies can be determined through the analysis of pairs of quantum-entangled neutral $D$ mesons, which are produced in the decay of the $psi(3770)$ resonance. The relative strong-phase parameters between $D^0$ and $bar{D}^0$ in the decays $D^0rightarrow K^0_{S,L}pi^+pi^-$ are studied using 2.93~${rm fb}^{-1}$ of $e^+e^-$ annihilation data delivered by the BEPCII collider and collected by the BESIII detector at a center-of-mass energy of 3.773 GeV. Results are presented in regions of the phase space of the decay. These are the most precise measurements to date of the strong-phase parameters in $D to K_{S,L}^0pi^+pi^-$ decays. Using these parameters, the associated uncertainty on the Cabibbo-Kobayashi-Maskawa angle $gamma/phi_3$ is expected to be between $0.7^circ$ and $1.2^circ$, for an analysis using the decay $B^{pm}rightarrow DK^{pm}$, $Drightarrow K^0_Spi^+pi^-$, where $D$ represents a superposition of $D^0$ and $bar{D^0}$ states. This is a factor of three smaller than that achievable with previous measurements. Furthermore, these results provide valuable input for charm-mixing studies, other measurements of $CP$ violation, and the measurement of strong-phase parameters for other $D$-decay modes.
We report the first determination of the relative strong-phase difference between D^0 -> K^0_S,L K^+ K^- and D^0-bar -> K^0_S,L K^+ K^-. In addition, we present updated measurements of the relative strong-phase difference between D^0 -> K^0_S,L pi^+ pi^- and D^0-bar -> K^0_S,L pi^+ pi^-. Both measurements exploit the quantum coherence between a pair of D^0 and D^0-bar mesons produced from psi(3770) decays. The strong-phase differences measured are important for determining the Cabibbo-Kobayashi-Maskawa angle gamma/phi_3 in B^- -> K^- D^0-tilde decays, where D^0-tilde is a D^0 or D^0-bar meson decaying to K^0_S h^+ h^- (h=pi,K), in a manner independent of the model assumed to describe the D^0 -> K^0_S h^+ h^- decay. Using our results, the uncertainty in gamma/phi_3 due to the error on the strong-phase difference is expected to be between 1.7 and 3.9 degrees for an analysis using B^- K^- D^0-tilde D^0-tilde -> K^0_S pi^+ pi^- decays, and between 3.2 and 3.9 degrees for an analysis based on B^- -> K^- D^0-tilde, D^0-tilde -> K^0_S K^+ K^- decays. A measurement is also presented of the CP-odd fraction, F_-, of the decay D^0 -> K^0_S K^+ K^- in the region of the phi -> K^+ K^- resonance. We find that in a region within 0.01 GeV^2/c^4 of the nominal phi mass squared F_- > 0.91 at the 90% confidence level.
comments
Fetching comments Fetching comments
Sign in to be able to follow your search criteria
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا