ترغب بنشر مسار تعليمي؟ اضغط هنا

Direct CP violation in beauty and charm hadron decays

155   0   0.0 ( 0 )
 نشر من قبل Carla Gobel
 تاريخ النشر 2020
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

Since the discovery of CP violation more than 5 decades ago, this phenomenon is still attracting a lot of interest. Among the many fascinating aspects of this subject, this review is dedicated to direct CP violation in non-leptonic decays. The advances within the last decade have been enormous, driven by the increasingly large samples of b- and c-hadron decays, and have led to very interesting results such as large CP asymmetries in charmless B decays and the observation of direct CP violation in the charm sector. We address the quest for understanding the origin of strong phases, the importance of final state interactions and the relation with CPT symmetry, and different approaches to measure direct CP violation in these decays. The main experimental results and their implications are then discussed.



قيم البحث

اقرأ أيضاً

315 - Michael Gronau 2007
Precision tests of the Kobayashi-Maskawa model of CP violation are discussed, pointing out possible signatures for other sources of CP violation and for new flavor-changing operators. The current status of the most accurate tests is summarized.
102 - Gauthier Durieux 2016
Beauty baryons are being observed in large numbers in the LHCb detector. The rich kinematic distributions of their multibody decays are therefore becoming accessible and provide us with new opportunities to search for CP violation. We analyse the ang ular distributions of some three- and four-body decays of spin-$1/2$ baryons using the Jacob-Wick helicity formalism. The asymmetries that provide access to small differences of CP-odd phases between decay amplitudes of identical CP-even phases are notably discussed. The understanding gained on processes featuring specific resonant intermediate states allows us to establish which asymmetries are relevant for what purpose. It is for instance shown that some CP-odd angular asymmetries measured by the LHCb collaboration in the $Lambda_b to Lambda,varphi to p,pi, K^+ K^-$ decay are expected to vanish identically.
164 - Brian Meadows 2008
The phenomenon of mixing in neutral meson systems has now been observed in all flavours, but only in the past year in the D0 system. The standard model anticipated that, for the charm sector, the mixing rate would be small, and also that CP violation , either in mixing or in direct decay, would be below the present levels of observability. It is hoped that further study of these phenomena might reveal signs of new physics. A review of recently available, experimental results is given.
78 - S. Sandilya 2021
We present the measurements, performed by the Belle II experiment, related to the B and D meson decays. These results are based on 63 fb$^{-1}$ and 9 fb$^{-1}$ of $e^+e^-$ collision data recorded by the Belle II detector at a center-of-mass energy co rresponding to the mass of the Y(4S) resonance and 60 MeV below the Y(4S) resonance. The results reassure that Belle II is in the right direction in pursuit of measuring the Standard Model predictions with improved precision.
First observations of the decays $Lambda_b^0 to Lambda_c^+ D_{(s)}^-$ are reported using data corresponding to an integrated luminosity of $3,{rm fb}^{-1}$ collected at 7 and 8 TeV center-of-mass energy in proton-proton collisions with the LHCb detec tor. In addition, the most precise measurement of the branching fraction ${mathcal{B}(B_s^0 to D^+D_s^-)}$ is made and a search is performed for the decays $B^0_{(s)} to Lambda_c^+ Lambda_c^-$. The results obtained are begin{eqnarray*} mathcal{B}(Lambda_b^0 to Lambda_c^+ D^-)/mathcal{B}(Lambda_b^0 to Lambda_c^+ D_{s}^-) &=& 0.042 pm 0.003({rm stat}) pm 0.003({rm syst}), left[frac{mathcal{B}(Lambda_b^0 to Lambda_c^+ D_{s}^-)}{mathcal{B}({kern 0.2em}overline{kern -0.2em B}_d^0 to D^+D_s^-)}right]big/left[frac{mathcal{B}(Lambda_b^0 to Lambda_c^+pi^-)}{mathcal{B}({kern 0.2em}overline{kern -0.2em B}_d^0 to D^+pi^-)}right] &=& 0.96 pm 0.02({rm stat}) pm 0.06({rm syst}), mathcal{B}(B_s^0 to D^+D_s^-)/mathcal{B}({kern 0.2em}overline{kern -0.2em B}_d^0 to D^+D_s^-) &=& 0.038pm0.004({rm stat})pm0.003({rm syst}), mathcal{B}({kern 0.2em}overline{kern -0.2em B}^0 to Lambda_c^+ Lambda_c^-)/mathcal{B}({kern 0.2em}overline{kern -0.2em B}_d^0 to D^+D_s^-) & < & 0.0022; [95% ; {rm C.L.}], mathcal{B}(B^0_{s} to Lambda_c^+ Lambda_c^-)/mathcal{B}(B_s^0 to D^+D_s^-) & < & 0.30; [95% ; {rm C.L.}]. end{eqnarray*} Measurement of the mass of the $Lambda_b^0$ baryon relative to the $B^0$ meson gives ${M(Lambda_b^0) -M(B^0) = 339.72pm 0.24({rm stat}) pm 0.18({rm syst})}$ MeV$/c^2$. This result provides the most precise measurement of the mass of the $Lambda_b^0$ baryon to date.
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