4,785 research outputs found
Transitions in the Standard Model Effective Field Theory
The anomalies observed in decays
have attracted much attention in recent years. In this paper, we study the
, , , , and decays, all
being mediated by the same quark-level transition, in the
Standard Model Effective Field Theory. The most relevant dimension-six
operators for these processes are , , ,
and in the Warsaw basis. Evolution of the corresponding Wilson
coefficients from the new physics scale ~TeV down to the
characteristic scale is performed at three-loop in QCD and
one-loop in EW/QED. It is found that, after taking into account the constraint
, a single
or
can still be used to resolve the
anomalies at , while a single
is already ruled out by the
measured at more than . By minimizing the
function constructed based on the current data on ,
, , , and , we obtain eleven most
trustworthy scenarios, each of which can provide a good explanation of the
anomalies at . To further discriminate these different
scenarios, we predict thirty-one observables associated with the processes
considered under each NP scenario. It is found that most of the scenarios can
be differentiated from each other by using these observables and their
correlations.Comment: 43 pages, 3 figures and 5 tables; references updated and more
discussions added, final version to be published in the journa
Research on forming quality of poly-wedge pulley spinning
As an important power transmission part, pulleys are widely used in automobile industry, agricultural machinery, pumps and machines. A near-net forming process for six-wedge belt pulleys manufacturing was put forward. For this purpose, the required tooth shape and size can be formed directly by spinning without machining. The whole manufacturing procedures include blanking, drawing and spinning. The spinning procedure includes five processes, performing, drumming, thickening, toothing and finishing. The forming defects occurred during each forming processes of poly-wedge pulley spinning, such as the drumming failure, flanged opening-end, folded side-wall, insufficient bottom size, flashed opening-end, cutting-off bottom, are introduced, and the factors influencing the defects are analyzed. The corresponding preventive measures are put forward
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