Abstract
Kinematic edges of cascade decays of new particles produced in high-energy collisions may provide important constraints on the involved particles' masses. For the exemplary case of gluino decay g˜→qq¯χ˜ into a pair of quarks and a neutralino through a squark resonance, we study the hadronic invariant mass distribution in the vicinity of the kinematic edge. We perform a next-to-leading order calculation in the strong coupling αs and the ratio of squark width and squark mass Γq˜/mq˜, based on a systematic expansion in Γq˜/mq˜. The separation into hard, collinear and soft contributions elucidates the process-dependent and universal features of distributions in the edge region, represented by on-shell decay matrix elements, universal jet functions and a soft function that depends on the resonance propagator and soft Wilson lines.
Highlights
The kinematics of particle decay leads to sharp edges in certain distributions, whenever the decay proceeds through another intermediate resonance
It is evident that tree-level kinematics is not changed, if a) the gluino and squark decay vertices are modified by hard-virtual corrections, b) the quark and antiquark develop into jets by collinear emissions, and c) soft gluons connect all strongly interacting particles in the squared a√mplitude
Kinematic edges of cascade decays of new particles produced in high-energy collisions may provide important constraints on the particle masses
Summary
The kinematics of particle decay leads to sharp edges in certain distributions, whenever the decay proceeds through another intermediate resonance. In order to predict the spectra locally near the kinematic edge the narrow-width approximation for the intermediate resonance cannot be applied. This is evident from the fact that the leading radiative correction contains a logarithmic singularity. We plan to present further details and results in a longer technical write-up [9]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
