اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSpectroscopy and lifetime of bottom and charm hadrons
210
0
0.0
(
0
)
تأليف
Fumihiko Ukegawa
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We review recent experimental results on spectroscopy and lifetime of bottom and charm hadrons.
قيم البحث
اقرأ أيضاً
We report on recent results in spectroscopy from BaBar. This includes the discovery of a new $Lambda_c$ baryon, detailed studies of the $D^*_{sJ}(2317)^+$, $D_{sJ}(2460)^+$, X(3872) and Y(4260) particles and the first measurement of hadronic non-$Bbar{B}$ decays of the $Upsilon(4S)$ meson.
We report on mass and lifetime measurements of several ground state charmed and bottom baryons, using a data sample corresponding to 9.6 $textrm{fb}^{-1}$ from $pbar p$ collisions at $sqrt{s}=1.96$ TeV, and recorded with the Collider Detector at Ferm
ilab. Baryon candidates are reconstructed from data collected with an online event selection designed for the collection of long-lifetime heavy-flavor decay products and a second event selection designed to collect $J/psi rightarrow mu^+ , mu^-$ candidates. First evidence for the process $Omega_b^- rightarrow Omega_c^0 , pi^-$ is presented with a significance of $3.3sigma$. We measure the following baryon masses: begin{eqnarray} M(Xi_c^{0}) = 2470.85pm0.24(stat)pm0.55(syst) , MeV/c^2, onumber M(Xi_c^{+}) = 2468.00pm0.18(stat)pm0.51(syst) , MeV/c^2, onumber M(Lambda_b) = 5620.15pm0.31(stat)pm0.47(syst) , MeV/c^2, onumber M(Xi_b^-) = 5793.4pm1.8(stat)pm0.7(syst) , MeV/c^2, onumber M(Xi_b^0) = 5788.7pm4.3(stat)pm1.4(syst) , MeV/c^2, , and onumber M(Omega_b^-) = 6047.5pm3.8(stat)pm0.6(syst) , MeV/c^2. onumber end{eqnarray} The isospin splitting of the $Xi_b^{-,0}$ states is found to be $M(Xi_b^-)-M(Xi_b^0)=4.7pm4.7(stat)pm0.7(syst)$ MeV/$c^2$. The isospin splitting of the $Xi_c^{0,+}$ states is found to be $M(Xi_c^0)-M(Xi_c^+)$ = $2.85pm0.30(stat)pm0.04(syst)$ MeV/$c^2$. The following lifetime measurements are made: begin{eqnarray} tau(Lambda_b) = 1.565pm0.035(stat)pm0.020(syst) , ps, onumber tau(Xi_b^-) = 1.32pm0.14(stat)pm0.02(syst) , ps, onumber tau(Omega_b^-) = 1.66^{+0.53}_{-0.40}(stat)pm0.02(syst) , ps. onumber end{eqnarray}
LHCb continues to expand its world-leading sample of charmed hadrons collected during LHCs Run 1 (2010-2012) and Run 2 (2015-present). This sample is yielding some of the most stringent tests of the Standard Model understanding of charm physics. This
includes precise measurements of the neutral D-meson mixing parameters and some of the most sensitive searches for direct and indirect CP violation in charm interactions.
We search for new charmless decays of neutral $b$--hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb$^{-1}$ of integrated luminosity, we report the first observ
ation of the BsKpi decay, with a significance of $8.2sigma$, and measure $BR(BsKpi) = (5.0 pm 0.7stat pm 0.8syst)times 10^{-6}$. We also report the first observation of charmless $b$--baryon decays in the channels Lbppi and LbpK with significances of $6.0sigma$ and $11.5sigma$ respectively, and we measure $BR(Lbppi) = (3.5 pm 0.6stat pm 0.9syst)times 10^{-6}$ and $BR(LbpK) = (5.6 pm 0.8stat pm 1.5syst)times 10^{-6}$. No evidence is found for the decays BdKK and Bspipi, and we set an improved upper limit $BR(Bspipi) < 1.2times 10^{-6}$ at the 90% confidence level. All quoted branching fractions are measured using $BR(BdKpi)$ as a reference.
We investigate heavy quark symmetries for heavy light meson-antimeson systems in a contact-range effective field theory. In the SU(3) light flavor limit, the leading order Lagrangian respecting heavy quark spin symmetry contains four independent coun
ter-terms. Neglecting $1/m_Q$ corrections, three of these low energy constants can be determ1ined by theorizing a molecular description of the $X(3872)$ and $Z_b(10610)$ states. Thus, we can predict new hadronic molecules, in particular the isovector charmonium partners of the $Z_b(10610)$ and the $Z_b(10650)$ states. We also discuss hadron molecules composed of a heavy meson and a doubly-heavy baryon, which would be related to the heavy meson-antimeson molecules thanks to the heavy antiquark-diquark symmetry. Finally, we also study the $X(3872) to D^0bar D^0pi^0$ decay, which is not only sensitive to the short distance part of the $X(3872)$ molecular wave function, as the $J/psipipi$ and $J/psi3pi$ $X(3872)$ decay modes are, but it is also affected by the long-distance structure of the resonance. Furthermore, this decay might provide some information on the interaction between the $Dbar D$ charm mesons.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
