اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدBottom Baryon Decays in Non-relativistic Quark Model
128
0
0.0
(
0
)
تأليف
A. Limphirat
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The reactions $Sigma_b^* to Lambda_b pi$, $Sigma_b to Lambda_b pi$, and $Xi_b^* to Xi_b pi$ are studied in the $^3P_0$ non-relativistic quark model with all the model parameters fixed in the sector of light quarks. The theoretical predictions for the decay widths $Gamma_{Sigma_b^* to Lambda_b pi}$ and $Gamma_{Sigma_b to Lambda_b pi}$ are consistent with the experimental data of the CDF Collaboration. Using as an input the recent mass of $Xi_b$ and the theoretical predictions mass of $Xi_b^{*}$, a narrow decay width about 1 MeV is predicted for the bottom baryon $Xi_b^*$. The work suggests that the $^3P_0$ quark dynamics is of independence of environments where heavy quarks may or may not be a component of baryons.
قيم البحث
اقرأ أيضاً
In the framework chiral SU(3) quark model, the baryon spectra within the band of $Nleq 2$ are studied, and the effect of the confining potential in different configurations, namely the $Delta$-mode and Y-mode are compared. In the same way, the baryon
spectra in the extended chiral SU(3) quark model, in which additional vector meson exchanges are introduced, are also calculated. It is shown that a reasonable baryon spectrum in the chiral SU(3) quark model can be achieved no matter whether the $Delta$-mode or the Y-mode confining potential is employed. In the extended chiral SU(3) quark model, several energy levels are further improved. The resultant binding energies of excited baryon states in different confining modes deviate just by a few to several tens MeV, and it is hard to justify which confining mode is the dominant one. The non-strange baryon strong decay widths are further discussed in the point-like meson emission model by using the wave-function obtained in the spectrum calculation. The resultant widths can generally explain the experimental data but still cannot distinguish which confining mode is more important in this simple decay mode.
Exclusive semileptonic decays of bottom and charm baryons are considered within a relativistic three-quark model with a Gaussian shape for the baryon-three-quark vertex and standard quark propagators. We calculate the baryonic Isgur-Wise functions, decay rates and asymmetry parameters.
We propose CP asymmetries based on triple product correlations in the decays sbottom_m -> top chargino_j with subsequent decays of top and chargino_j. For the subsequent chargino_j decay into a leptonic final state l^- u neutralino_1 we consider the
three possible decay chains chargino_j -> l^- sneutrino -> l^- u neutralino_1, chargino_j -> slepton_n u -> l^- u neutralino_1 and chargino_j -> W^- neutralino_1 -> l^- u neutralino_1. We consider two classes of CP asymmetries. In the first class it must be possible to distinguish between different leptonic chargino_j decay chains, whereas in the second class this is not necessary. We consider also the 2-body decay chargino_j -> W^- neutralino_1, and we assume that the momentum of the W boson can be measured. Our framework is the minimal supersymmetric standard model with complex parameters. The proposed CP asymmetries are non-vanishing due to non-zero phases for the parameters mu and/or A_b. We present numerical results and estimate the observability of these CP asymmetries.
The strong decays of charm-strange baryons up to N=2 shell are studied in a chiral quark model. The theoretical predictions for the well determined charm-strange baryons, $Xi_c^*(2645)$, $Xi_c(2790)$ and $Xi_c(2815)$, are in good agreement with the e
xperimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons $Xi_c(2930)$, $Xi_c(2980)$, $Xi_c(3055)$, $Xi_c(3080)$ and $Xi_c(3123)$. Our predictions are given as follows. (i) $Xi_c(2930)$ might be the first $P$-wave excitation of $Xi_c$ with $J^P=1/2^-$, favors the $|Xi_c ^2P_lambda 1/2^->$ or $|Xi_c ^4P_lambda 1/2^->$ state. (ii) $Xi_c(2980)$ might correspond to two overlapping $P$-wave states $|Xi_c ^2P_rho 1/2^->$ and $|Xi_c ^2P_rho 3/2^->$, respectively. The $Xi_c(2980)$ observed in the $Lambda_c^+bar{K}pi$ final state is most likely to be the $|Xi_c ^2P_rho 1/2^->$ state, while the narrower resonance with a mass $msimeq 2.97$ GeV observed in the $Xi_c^*(2645)pi$ channel favors to be assigned to the $|Xi_c ^2P_rho 3/2^->$ state. (iii) $Xi_c(3080)$ favors to be classified as the $|Xi_c S_{rhorho} 1/2^+>$ state, i.e., the first radial excitation (2S) of $Xi_c$. (iv) $Xi_c(3055)$ is most likely to be the first $D$-wave excitation of $Xi_c$ with $J^P=3/2^+$, favors the $|Xi_c ^2D_{lambdalambda} 3/2^+>$ state. (v) $Xi_c(3123)$ might be assigned to the $|Xi_c ^4D_{lambdalambda} 3/2^+>$, $|Xi_c ^4D_{lambdalambda} 5/2^+>$, or $|Xi_c ^2D_{rhorho} 5/2^+>$ state. As a by-product, we calculate the strong decays of the bottom baryons $Sigma_b^{pm}$, $Sigma_b^{*pm}$ and $Xi_b^*$, which are in good agreement with the recent observations as well.
Combining the recent developments of the observations of $Omega$ sates we calculate the $Omega$ spectrum up to the $N=2$ shell within a nonrelativistic constituent quark potential model. Furthermore, the strong and radiative decay properties for the
$Omega$ resonances within the $N=2$ shell are evaluated by using the masses and wave functions obtained from the potential model. It is found that the newly observed $Omega(2012)$ resonance is most likely to be the spin-parity $J^P=3/2^-$ $1P$-wave state $Omega(1^{2}P_{3/2^{-}})$, it also has a large potential to be observed in the $Omega(1672)gamma$ channel. Our calculation shows that the 1$P$-, 1$D$-, and 2$S$-wave $Omega$ baryons have a relatively narrow decay width of less than 50 MeV. Based on the obtained decay properties and mass spectrum, we further suggest optimum channels and mass regions to find the missing $Omega$ resonances via the strong and/or radiative decay processes.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
