ترغب بنشر مسار تعليمي؟ اضغط هنا

Residues of $Lambda_Q$-type and $Sigma_Q$-type Baryons in the Bethe-Salpeter Equation Approach

116   0   0.0 ( 0 )
 نشر من قبل Qixin Yu
 تاريخ النشر 2018
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We study the residues of $Lambda_Q$-type baryons ($Lambda_Q$ and $Xi_Q^A$) $(Q=b,c)$ and $Sigma_Q$-type baryons ($Sigma_Q^{(ast)}$, $Xi_Q^{S(ast)}$ and $Omega_Q^{(ast)}$) in the quark-diquark model within the Bethe-Salpeter (BS) formalism. These residues can be used, for example, in the calculations of the amplitudes in the scattering processes. After constructing the baryonic currents in the BS formalism, we derive the relations between the BS wave functions and the residues for these baryons. The BS equations are solved numerically with the kernel including the scalar confinement and the one gluon exchange terms and with the covariant instantaneous approximation being employed in the calculations. Finally, we obtain the numerical values of the residues $0.103,rm GeVsim0.224,rm GeV$ for $Lambda_Q$, $0.143,rm GeVsim0.215,rm GeV$ for $Xi_Q^A$, $0.262,rm GeVsim0.361,rm GeV$ for $Sigma_Q^{(ast)}$, $0.313,rm GeVsim0.460,rm GeV$ for $Xi_Q^{S(ast)}$ and $0.473,rm GeVsim0.571,rm GeV$ for $Omega_Q^{(ast)}$ in the ranges of the parameters in our model.



قيم البحث

اقرأ أيضاً

We study the possible bound states of the $D_1D$ system in the Bethe-Salpeter (BS) formalism in the ladder and instantaneous approximations. By solving the BS equation numerically with the kernel containing one-particle exchange diagrams and introduc ing three different form factors (monopole, dipole, and exponential form factors) at the vertices, we investigate whether the isoscalar and isovector $D_1D$ bound states may exist, respectively. We find that $Y(4260)$ could be accommodated as a $D_1D$ molecule, whereas the interpretation of $Z_2^+(4250)$ as a $D_1D$ molecule is disfavored. The bottom analog of $Y(4260)$ may exist but that of $Z_2^+(4250)$ does not.
The off-mass shell scattering amplitude, satisfying the Bethe-Salpeter equation for spinless particles in Minkowski space with the ladder kernel, is computed for the first time.
In this paper we study the properties of diquarks (composed of $u$ and/or $d$ quarks) in the Bethe-Salpeter formalism under the covariant instantaneous approximation. We calculate their BS wave functions and study their effective interaction with the pion. Using the effective coupling constant among the diquarks and the pion, in the heavy quark limit $m_Qtoinfty$, we calculate the decay widths of $Sigma_Q^{(*)}$ ($Q=c,b$) in the BS formalism under the covariant instantaneous approximation and then give predictions of the decay widths $Gamma(Sigma_b^{(*)}toLambda_b+pi)$.
We interpret the $X_1(2900)$ as an $S$-wave $bar{D}_1K$ molecular state in the Bethe-Salpeter equation approach with the ladder and instantaneous approximations for the kernel. By solving the Bethe-Salpeter equation numerically with the kernel contai ning one-particle-exchange diagrams and introducing three different form factors (monopole, dipole, and exponential form factors) in the verties, we find the bound state exists. We also study the decay width of the decay $X_1(2900)$ to $D^-K^+$.
In this work, we assume that the observed state $Xi(1620)$ is a $s$-wave $Lambdabar{K}$ or $Sigmabar{K}$ bound state. Based on this molecule picture, we establish the Bethe-Salpeter equations for $Xi(1620)$ in the ladder and instantaneous approximati ons. We solve the Bethe-Salpeter equations for the $Lambdabar{K}$ and $Sigmabar{K}$ systems numerically and find that the $Xi(1620)$ can be explained as $Lambdabar{K}$ and $Sigmabar{K}$ bound states with $J^P=1/2^-$, respectively. Then we calculate the decay widths of $Xi(1620)rightarrowXipi$ in these two different molecule pictures systems, respectively.
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