ترغب بنشر مسار تعليمي؟ اضغط هنا

Measurement of the Decays $B^0_sto J/psi,phi(1020)$, $B^0_{s}to J/psi,f_2(1525)$ and $B^0_sto J/psi,K^+K^-$ at Belle

127   0   0.0 ( 0 )
 نشر من قبل Felicitas Thorne
 تاريخ النشر 2013
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We report a measurement of the branching fraction of the decay $B^0_sto J/psi,phi(1020)$, evidence and a branching fraction measurement for $B^0_sto J/psi,f_2(1525)$, and the determination of the total $B^0_sto J/psi,K^+K^-$ branching fraction, including the resonant and non-resonant contributions to the $K^+K^-$ channel. We also determine the $S$-wave contribution within the $phi(1020)$ mass region. The absolute branching fractions are $mathcal{B}[B^0_sto J/psi,phi(1020)]=(1.25 pm 0.07left(mathrm{stat}right)pm 0.08left(mathrm{syst}right)pm 0.22left(f_sright))times 10^{-3}$, $mathcal{B}[B^0_sto J/psi,f_2(1525)]=(0.26pm 0.06left(mathrm{stat}right)pm 0.02left(mathrm{syst}right) pm 0.05left(f_sright))times 10^{-3}$ and $mathcal{B}[B^0_sto J/psi,K^+K^-] = (1.01pm 0.09left(mathrm{stat}right) pm 0.10left(mathrm{syst}right)pm 0.18left(f_sright))times 10^{-3}$, where the last systematic error is due to the branching fraction of $bbar{b}to B^{(*)}_s B^{(*)}_s$. The branching fraction ratio is found to be $mathcal{B}[B^0_sto J/psi,f_2(1525)]/mathcal{B}[B^0_sto J/psi,phi(1020)]=(21.5pm 4.9left(mathrm{stat}right) pm2.6left(mathrm{syst}right))%$. All results are based on a 121.4 fb$^{-1}$ data sample collected at the $Upsilon(5S)$ resonance by the Belle experiment at the KEKB asymmetric-energy $e^+e^-$ collider.



قيم البحث

اقرأ أيضاً

The first full amplitude analysis of $B^+to J/psi phi K^+$ with $J/psitomu^+mu^-$, $phito K^+K^-$ decays is performed with a data sample of 3 fb$^{-1}$ of $pp$ collision data collected at $sqrt{s}=7$ and $8$ TeV with the LHCb detector. The data canno t be described by a model that contains only excited kaon states decaying into $phi K^+$, and four $J/psiphi$ structures are observed, each with significance over $5$ standard deviations. The quantum numbers of these structures are determined with significance of at least $4$ standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed $X(4140)$ state. The model includes significant contributions from a number of expected kaon excitations, including the first observation of the $K^{*}(1680)^+tophi K^+$ transition.
A flavour-tagged time-dependent angular analysis of $B^0_sto J/psiphi$ decays is presented where the $J/psi$ meson is reconstructed through its decay to an $e^+e^-$ pair. The analysis uses a sample of $pp$ collision data recorded with the LHCb experi ment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb$^{-1}$. The $CP$-violating phase and lifetime parameters of the $B^0_s$ system are measured to be $phi_s=0.00pm0.28pm0.07$ rad, $DeltaGamma_s=0.115pm0.045pm0.011$ ps$^{-1}$ and $Gamma_s=0.608pm0.018pm0.012$ ps$^{-1}$ where the first uncertainty is statistical and the second systematic. This is the first time that $CP$-violating parameters are measured in the $B^0_sto J/psiphi$ decay with an $e^+e^-$ pair in the final state. The results are consistent with previous measurements in other channels and with the Standard Model predictions.
A search for the rare decay of a $B^{0}$ or $B^{0}_{s}$ meson into the final state $J/psigamma$ is performed, using data collected by the LHCb experiment in $pp$ collisions at $sqrt{s}=7$ and $8$ TeV, corresponding to an integrated luminosity of 3 fb $^{-1}$. The observed number of signal candidates is consistent with a background-only hypothesis. Branching fraction values larger than $1.7times 10^{-6}$ for the $B^{0}to J/psigamma$ decay mode are excluded at 90% confidence level. For the $B^{0}_{s}to J/psigamma$ decay mode, branching fraction values larger than $7.4times 10^{-6}$ are excluded at 90% confidence level, this is the first branching fraction limit for this decay.
The decay Bs -> J/psi K+ K- is investigated using 0.16/fb of data collected with the LHCb detector using 7 TeV pp collisions. Although the J/psi phi channel is well known, final states at higher K+K- masses have not previously been studied. In the K+ K- mass spectrum we observe a significant signal in the f2(1525) region as well as a non-resonant component. After subtracting the non-resonant component, we find B(Bs->J/psi f_2(1525))/B(Bs->J/psi phi)=(26.4 +/- 2.7 +/- 2.4)%.
A measurement is presented of decay-time-dependent $CP$ violation in the decays $B^0rightarrow J/psi K^0_mathrm{S}$ and $B^0rightarrowpsi(2S) K^0_mathrm{S}$, where the $J/psi$ is reconstructed from two electrons and the $psi(2S)$ from two muons. The analysis uses a sample of $pp$ collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 $mathrm{fb}^{-1}$. The $CP$-violation observables are measured to be begin{equation*} begin{aligned} Cleft(B^0rightarrow J/psi K^0_mathrm{S}right)&=phantom{+},0.12,pm,0.07pm,0.02,, Sleft(B^0rightarrow J/psi K^0_mathrm{S}right)&=phantom{+},0.83,pm,0.08pm,0.01,, Cleft(B^0rightarrowpsi(2S) K^0_mathrm{S}right)&=-,0.05,pm,0.10pm,0.01,, Sleft(B^0rightarrowpsi(2S) K^0_mathrm{S}right)&=phantom{+},0.84,pm,0.10pm,0.01,, end{aligned} end{equation*} where $C$ describes $CP$ violation in the direct decay, and $S$ describes $CP$ violation in the interference between the amplitudes for the direct decay and for the decay after $B^0$-$overline{B}^0$ oscillation. The first uncertainties are statistical and the second are systematic. The two sets of results are compatible with the previous LHCb measurement using $B^0rightarrow J/psi K^0_mathrm{S}$ decays, where the $J/psi$ meson was reconstructed from two muons. The averages of all three sets of LHCb results are begin{equation*} begin{aligned} Cleft(B^0rightarrow[cbar{c}]K^0_mathrm{S}right)&=-0.017 pm 0.029,, Sleft(B^0rightarrow[cbar{c}]K^0_mathrm{S}right)&=phantom{+}0.760 pm 0.034,, end{aligned} end{equation*} under the assumption that higher-order contributions to the decay amplitudes are negligible. The uncertainties include statistical and systematic contributions.
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