ترغب بنشر مسار تعليمي؟ اضغط هنا

Measurements of time-dependent CP violation in B^0 -> psi(2S) K_S decays

229   0   0.0 ( 0 )
 نشر من قبل Himansu Sahoo
 تاريخ النشر 2008
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We report improved measurements of time-dependent CP violation parameters for B^0(bar{B}^0) -> psi(2S) K_S. This analysis is based on a data sample of 657x10^6 BBbar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. We fully reconstruct one neutral B meson in the psi(2S) K_S CP-eigenstate decay channel, and the flavor of the accompanying B meson is identified to be either B^0 or bar{B}^0 from its decay products. CP violation parameters are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays: S (psi(2S) K_S) = +0.72 +/- 0.09(stat) +/- 0.03(syst), A (psi(2S) K_S) = +0.04 +/- 0.07(stat) +/- 0.05(syst). These results are in agreement with results from measurements of B^0 -> J/psi K^0.



قيم البحث

اقرأ أيضاً

106 - Belle Collaboration 2006
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 report a measurement of time-dependent $CP$ violation parameters in ${B^0 to K_S^0 eta gamma}$ decays. The study is based on a data sample, containing ${772 times 10^6 Bbar{B}}$ pairs, that was collected at the $Upsilon(4S)$ resonance with the Bel le detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We obtain the $CP$ violation parameters of ${{cal S} = -1.32 pm 0.77 {rm (stat.)} pm 0.36{rm (syst.)}}$ and ${{cal A} = -0.48 pm 0.41 {rm (stat.)} pm 0.07{rm (syst.)}}$ for the invariant mass of the $K_S^0 eta$ system up to 2.1 GeV/$c^2$.
We present a measurement of the time-dependent $CP$ violation parameters in $B^0toetaK^0$ decays. The measurement is based on the full data sample containing $772times 10^6$ $Bbar{B}$ pairs collected at the $Upsilon(4S)$ resonance using the Belle det ector at the KEKB asymmetric-energy $e^+e^-$ collider. The measured values of the mixing-induced and direct $CP$ violation parameters are: begin{align} sin 2 phi^{rm eff}_1 &= +0.68pm 0.07 pm 0.03, onumber mathcal{A}_{etaK^0} &= +0.03pm 0.05pm 0.04, onumber end{align} where the first uncertainty is statistical and the second is systematic. The values obtained are the most accurate to date. Furthermore, these results are consistent with our previous measurements and with the world-average value of $sin 2phi_1$ measured in $B^0to J/psi K^0$ decays.}
We report a measurement of time-dependent $CP$ violation in $B^0 to K^0_S pi^0 pi^0$ decays using a data sample of $772 times 10^6$ $Bbar{B}$ pairs collected by the Belle experiment runnin g at the $Upsilon (4S)$ resonance at the KEKB $e^+ e^-$ colli der. This decay proceeds mainly via a $bto sdbar{d}$ penguin amplitude. The results are $sin 2phi^{rm eff}_1 = 0.92^{+0.27}_{-0.31}~$ (stat.) $pm 0.11$ (syst.) and $mathcal{A} = 0.28 pm 0.21$ (stat.) $pm 0.04$ (syst.), which are the most precise measurements of $CP$ violati on in this decay mode to date. The value for the $CP$-violating parameter $sin 2phi^{rm eff}_1$ is consistent with that obtained using decay modes proceeding via a $bto cbar{c}s$ tree amplitude.
Measurements are presented of the $CP$ violation observables $S$ and $C$ in the decays of $B^0$ and $overline{B}{}^0$ mesons to the $J/psi K^0_S$ final state. The data sample corresponds to an integrated luminosity of $3.0,text{fb}^{-1}$ collected wi th the LHCb experiment in proton-proton collisions at center-of-mass energies of $7$ and $8,text{TeV}$. The analysis of the time evolution of $41500$ $B^0$ and $overline{B}{}^0$ decays yields $S = 0.731 pm 0.035 , text{(stat)} pm 0.020 ,text{(syst)}$ and $C = -0.038 pm 0.032 , text{(stat)} pm 0.005,text{(syst)}$. In the Standard Model, $S$ equals $sin(2beta)$ to a good level of precision. The values are consistent with the current world averages and with the Standard Model expectations.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا