اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدعمر الباريون المضحكين مرتين
Lifetime of doubly charmed baryons
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في هذا العمل، نقوم بتقييم عمر الباريون المضاعف الشحن $Xi_{cc}^{+}$، $Xi_{cc}^{++}$ و $Omega_{cc}^{+}$. نحسب المساهمات غير المتابعة بدقة في مستوى الذرة حيث يتم تضمين الرسومات المخفضة بواسطة كابيبو. يتم تقييم العناصر الحادية الهادونية في نموذج الذبذب الغير الانتقالي البسيط. نتائجنا الرقمية تتناسب عموما مع النتائج التي حصل عليها المؤلفون الآخرون الذين استخدموا نموذج الديكوارك. ومع ذلك، يكون جميع التنبؤات النظرية على عمر الباريون أكبر من الحد الأقصى المحدد من قبل القياس الحديث من SELEX. هذا الخلاف سيتم توضيحه بواسطة التجربة المستقبلية، إذا كان التجربة الأكثر دقة لا تؤكد قيمة مشاركة SELEX، فلا بد أن يكون هناك آلية غير معروفة للاستكشاف.
In this work, we evaluate the lifetimes of the doubly charmed baryons $Xi_{cc}^{+}$, $Xi_{cc}^{++}$ and $Omega_{cc}^{+}$. We carefully calculate the non-spectator contributions at the quark level where the Cabibbo-suppressed diagrams are also included. The hadronic matrix elements are evaluated in the simple non-relativistic harmonic oscillator model. Our numerical results are generally consistent with that obtained by other authors who used the diquark model. However, all the theoretical predictions on the lifetimes are one order larger than the upper limit set by the recent SELEX measurement. This discrepancy would be clarified by the future experiment, if more accurate experiment still confirms the value of the SELEX collaboration, there must be some unknown mechanism to be explored.
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The hadronic two-body weak decays of the doubly charmed baryons $Xi_{cc}^{++}, Xi_{cc}^+$ and $Omega_{cc}^+$ are studied in this work. To estimate the nonfactorizable contributions, we work in the pole model for the $P$-wave amplitudes and current al
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We present the ground and excited state spectra of doubly charmed baryons from lattice QCD with dynamical quark fields. Calculations are performed on anisotropic lattices of size 16^3 X 128, with inverse spacing in temporal direction 1/a_t = 5.67(4)
GeV and with a pion mass of about 390 MeV. A large set of baryonic operators that respect the symmetries of the lattice yet which retain a memory of their continuum analogues are used. These operators transform as irreducible representations of SU(3) symmetry for flavor, SU(4) symmetry for Dirac spins of quarks and O(3) for spatial symmetry. The distillation method is utilized to generate baryon correlation functions which are analysed using the variational fitting method to extract excited states. The lattice spectra obtained have baryonic states with well-defined total spins up to 7/2 and the pattern of low lying states does not support the diquark picture for doubly charmed baryons. On the contrary the calculated spectra are remarkably similar to the expectations from models with an SU(6)X O(3) symmetry. Various spin dependent energy splittings between the extracted states are also evaluated.
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