ترغب بنشر مسار تعليمي؟ اضغط هنا

Branching fraction measurements of chi_{c0} and chi_{c2} to pi^0pi^0 and etaeta

84   0   0.0 ( 0 )
 نشر من قبل Beijiang Liu
 تاريخ النشر 2010
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

Using a sample of 1.06 times 10^8 psi^{prime} decays collected by the BESIII detector, chi_{c0} and chi_{c2} decays into pi^0pi^0 and etaeta are studied. The branching fraction results are Br(chi_{c0}topi^0pi^0)=(3.23pm 0.03pm0.23 pm 0.14)times 10^{-3}, Br(chi_{c2}topi^0pi^0)=(8.8pm 0.2pm 0.6pm0.4)times 10^{-4}, Br(chi_{c0}toetaeta)=(3.44pm 0.10pm0.24 pm0.2)times 10^{-3}, and Br(chi_{c2}toetaeta)=(6.5pm 0.4pm 0.5pm 0.3)times 10^{-4}, where the uncertainties are statistical, systematic due to this measurement, and systematic due to the branching fractions of psi^{prime}togammachi_{cJ}, respectively. The results provide information on the decay mechanism of chi_c states into pseudoscalars.



قيم البحث

اقرأ أيضاً

Using a sample of 106 million $psi(3686)$ decays, the branching fractions of $psi(3686) to gamma chi_{c0}, psi(3686) to gamma chi_{c1}$, and $psi(3686) to gamma chi_{c2}$ are measured with improved precision to be $(9.389 pm 0.014 pm 0.332),%$, $(9.9 05 pm 0.011 pm 0.353),% $, and $(9.621 pm 0.013 pm 0.272),% $, respectively, where the first uncertainties are statistical and the second ones are systematic. The product branching fractions of $psi(3686) to gamma chi_{c1}, chi_{c1} to gamma J/psi$ and $psi(3686) to gamma chi_{c2}, chi_{c2} to gamma J/psi$ and the branching fractions of $chi_{c1} to gamma J/psi$ and $chi_{c2} to gamma J/psi$ are also presented.
Prompt production of charmonium $chi_{c0}$, $chi_{c1}$ and $chi_{c2}$ mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of $sqrt{s}=7$TeV. The $chi_{c}$ mesons are identified through their decay to $J/psigamma$, w ith $J/psitomu^+mu^-$ using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of $1.0mathrm{fb}^{-1}$ collected by the LHCb detector, is used to measure the relative prompt production rate of $chi_{c1}$ and $chi_{c2}$ in the rapidity range $2.0<y<4.5$ as a function of the $J/psi$ transverse momentum from 3 to 20 GeV$/c$. First evidence for $chi_{c0}$ meson production at a high-energy hadron collider is also presented.
Based on a data sample of 106 M $psi^{prime}$ events collected with the BESIII detector, the decays $psi^{prime}argammachi_{c0, 2}$,$chi_{c0, 2}argammagamma$ are studied to determine the two-photon widths of the $chi_{c0, 2}$ states. The two-photon d ecay branching fractions are determined to be ${cal B}(chi_{c0}argammagamma) = (2.24pm 0.19pm 0.12pm 0.08)times 10^{-4}$ and ${cal B}(chi_{c2}argammagamma) = (3.21pm 0.18pm 0.17pm 0.13)times 10^{-4}$. From these, the two-photon widths are determined to be $Gamma_{gamma gamma}(chi_{c0}) = (2.33pm0.20pm0.13pm0.17)$ keV, $Gamma_{gamma gamma}(chi_{c2}) = (0.63pm0.04pm0.04pm0.04)$ keV, and $cal R$ $=Gamma_{gamma gamma}(chi_{c2})/Gamma_{gamma gamma}(chi_{c0})=0.271pm 0.029pm 0.013pm 0.027$, where the uncertainties are statistical, systematic, and those from the PDG ${cal B}(psi^{prime}argammachi_{c0,2})$ and $Gamma(chi_{c0,2})$ errors, respectively. The ratio of the two-photon widths for helicity $lambda=0$ and helicity $lambda=2$ components in the decay $chi_{c2}argammagamma$ is measured for the first time to be $f_{0/2} =Gamma^{lambda=0}_{gammagamma}(chi_{c2})/Gamma^{lambda=2}_{gammagamma}(chi_{c2}) = 0.00pm0.02pm0.02$.
We report inclusive and exclusive measurements for $chi_{c1}$ and $chi_{c2}$ production in $B$ decays. We measure $mathcal{B}(B to chi_{c1} X)$= $(3.03 pm 0.05(mbox{stat}) pm 0.24(mbox{syst})) times 10^{-3}$ and $mathcal{B}(B to chi_{c2} X)$= $(0.70 pm 0.06(mbox{stat}) pm 0.10(mbox{syst})) times 10^{-3}$. For the first time, $chi_{c2}$ production in exclusive $B$ decays in the modes $B^0 to chi_{c2}pi^- K^+$ and $B^+ to chi_{c2} pi^+ pi^- K^+$ has been observed, along with first evidence for the $B^+ to chi_{c2} pi^+ K_S^0$ decay mode. For $chi_{c1}$ production, we report the first observation in the $B^+ to chi_{c1} pi^+ pi^- K^+$, $B^0 to chi_{c1} pi^+ pi^- K_S^0$ and $B^0 to chi_{c1} pi^0 pi^- K^+$ decay modes. Using these decay modes, we observe a difference in the production mechanism of $chi_{c2}$ in comparison to $chi_{c1}$ in $B$ decays. In addition, we report searches for $X(3872)$ and $chi_{c1}(2P)$ in the $B^+ to (chi_{c1} pi^+ pi^-) K^+$ decay mode. The reported results use $772 times 10^{6}$ $Boverline{B}$ events collected at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.
The decays $chi_{c1} rightarrow J/psi mu^+ mu^-$ and $chi_{c2} rightarrow J/psi mu^+ mu^-$ are observed and used to study the resonance parameters of the $chi_{c1}$ and $chi_{c2}$ mesons. The masses of these states are measured to be m(chi_{c1}) = 35 10.71 pm 0.04(stat) pm 0.09(syst)MeV,, m(chi_{c2}) = 3556.10 pm 0.06(stat) pm 0.11(syst)MeV,, where the knowledge of the momentum scale for charged particles dominates the systematic uncertainty. The momentum-scale uncertainties largely cancel in the mass difference m(chi_{c2}) - m(chi_{c1}) = 45.39 pm 0.07(stat) pm 0.03(syst)MeV,. The natural width of the $chi_{c2}$ meson is measured to be $$Gamma(chi_{c2}) = 2.10 pm 0.20(stat) pm 0.02(syst)MeV,.$$ These results are in good agreement with and have comparable precision to the current world averages.
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