اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدStudy of Electromagnetic Decays of Orbitally Excited $Xi_c$ Baryons
187
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Using 980 $fb^-1$ of data collected with the Belle detector operating at the KEKB asymmetric-energy e^+e^- collider, we report a study of the electromagnetic decays of excited {charmed baryons} $Xi_c(2790)$ and $Xi_c(2815)$. A clear signal (8.6 standard deviations) is observed for $Xi_c(2815)^0 to Xi_c^0gamma$, and we measure: $B[Xi_c(2815)^0 to Xi_c^0gamma]/B[Xi_c(2815)^0 to Xi_c(2645)^+pi^- to Xi_c^0pi^+pi^-] = 0.41 pm 0.05 pm 0.03$. We also present evidence (3.8 standard deviations) for the similar decay of the $Xi_c(2790)^0$ and measure: $B[Xi_c(2790)^{0}toXi_c^{0}gamma]/B[Xi_c(2790)^0toXi_c^{prime +}pi^{-}toXi_c^{+}gamma pi^-] = 0.13 pm 0.03 pm 0.02$. The first quoted uncertainties are statistical and the second systematic. We find no hint of the analogous decays of the $Xi_c(2815)^+$ and $Xi_c(2790)^+$ baryons and set upper limits at the 90% confidence level of: $B[Xi_c(2815)^{+}toXi_c^{+}gamma]/B[Xi_c(2815)^+toXi_c(2645)^0pi^+toXi_c^+pi^-pi^+] < 0.09,$ and $B[Xi_c(2790)^{+}toXi_c^{+}gamma]/B[Xi_c(2790)^+toXi_c^{prime 0}pi^{+}toXi_c^{0}gamma pi^+] < 0.06.$ Approximate values of the partial widths of the decays are extracted, which can be used to discriminate between models of the underlying quark structure of these excited states.
قيم البحث
اقرأ أيضاً
Using a data sample of 980 ${rm fb}^{-1}$ of $e^+e^-$ annihilation data taken with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider, we report the results of a study of excited $Xi_c$ states that decay, via the emission of
photons and/or charged pions, into $Xi_c^0$ or $Xi_c^+$ ground state charmed-strange baryons. We present new measurements of the masses of all members of the $Xi_c^{prime}$, $Xi_c(2645)$, $Xi_c(2790)$, $Xi_c(2815)$, and $Xi_c(2980)$ isodoublets, measurements of the intrinsic widths of those that decay strongly, and evidence of previously unknown transitions.
The first observation of the $Omega_b^-toXi_c^+ K^- pi^-$ decay is reported using proton-proton collision data at centre-of-mass energies of $7$, $8$ and $13,mathrm{TeV}$ collected by the LHCb experiment, corresponding to an integrated luminosity of
$9,mathrm{fb}^{-1}$. Four excited $Omega_c^0$ baryons are observed in the $Xi_c^+ K^-$ mass projection of the $Omega_b^-toXi_c^+ K^- pi^-$ decays with significance exceeding five standard deviations. Their relative production rates, masses and natural widths are measured, and a test of spin hypotheses is performed. Moreover, the branching ratio of $Omega_b^-toXi_c^+ K^- pi^-$ is measured relative to the $Omega_b^-to Omega_c^0 pi^-$ decay mode and a precise measurement of the $Omega_b^-$ mass of $6044.3 pm 1.2 pm 1.1^{,+0.19}_{,-0.22},mathrm{MeV}$ is obtained.
The BaBar Collaboration has recently reported branching fractions for semileptonic decays of the $B$ meson into final states with charged and neutral $D_{1}(2420)$ and $D_{2}^{ast}(2460)$, two narrow orbitally excited charmed mesons. We evaluate thes
e branching fractions within the framework of a constituent quark model in two steps, one which involves a semileptonic decay and the other one mediated by a strong process. Our results are in agreement with the experimental data.
We calculate the two-body strong decays of the orbitally excited scalar mesons $D_0^*(2400)$ and $D_J^*(3000)$ by using the relativistic Bethe-Salpeter (BS) method. $D_J^*(3000)$ was observed recently by the LHCb Collaboration, the quantum number of
which has not been determined yet. In this paper, we assume that it is the $0^+(2P)$ state and obtain the transition amplitude by using the PCAC relation, low-energy theorem and effective Lagrangian method. For the $1P$ state, the total widths of $D_0^*(2400)^{0}$ and $ D_0^*(2400)^+$ are 226 MeV and 246 MeV, respectively. With the assumption of $0^+(2P)$ state, the widths of $D_J^*(3000)^0$ and $D_J^*(3000)^+$ are both about 131 MeV, which is close to the present experimental data. Therefore, $D_J^*(3000)$ is a strong candidate for the $2^3P_0$ state.
Using the full CDF Run II data sample, we report evidence for a new resonance, which we refer to as $B(5970)$, found simultaneously in the $B^0pi^+$ and $B^+pi^-$ mass distributions with a significance of 4.4 standard deviations. We further report th
e first study of resonances consistent with orbitally excited $B^{+}$ mesons and an updated measurement of the properties of orbitally excited $B^0$ and $B_s^0$ mesons. We measure the masses and widths of all states, as well as the relative production rates of $B_1$, $B_2^*$, and $B(5970)$ states and the branching fraction of the $B_{s2}^{*0}$ state to either $B^{*+} K^-$ and $B^{+} K^-$. Furthermore, we measure the production rates of the orbitally excited $B^{0,+}$ states relative to the $B^{0,+}$ ground state. The masses of the new $B(5970)$ resonances are $5978pm5(textrm{stat})pm12(textrm{syst}) textrm{ MeV/c}^{2}$ for the neutral state and $5961pm5(textrm{stat})pm12(textrm{syst}) textrm{ MeV/c}^{2}$ for the charged state, assuming that the resonance decays into $Bpi$ final states. The properties of the orbitally excited and the new $B(5970)^{0,+}$ states are compatible with isospin symmetry.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
