With an eye toward the precision physics of the LHC, FCC-ee and possible high energy muon colliders, we present the extension of the CEEX (coherent exclusive exponentiation) realization of the YFS approach to resummation in our KK MC to include the p
rocesses fbar{f}rightarrow fbar{f}, f=mu,tau, q, u_ell, f=e, mu,tau, q, u_ell, q=u,d,s,c,b,t, ell =e,mu,tau with f e f. After giving a brief summary of the CEEX theory with reference to the older EEX (exclusive exponentiation) theory, we illustrate theoretical results relevant to the LHC, FCC-ee, and possible muon collider physics programs.
We present the Monte Carlo event generator WINHAC for Drell-Yan processes in proton-proton, proton-antiproton, proton-ion and ion-ion collisions. It features multiphoton radiation within the Yennie-Frautschi-Suura exclusive exponentiation scheme with
O(alpha) electroweak corrections for the charged-current (W+/W-) processes and multiphoton radiation generated by PHOTOS for neutral-current (Z+gamma) ones. For the initial-state QCD/QED parton shower and hadronisation it is interfaced with PYTHIA. It includes several options, e.g. for the polarized W-boson production, generation of weighted/unweighted events, etc. WINHAC was cross-checked numerically at the per-mille level with independent Monte Carlo programs, such as HORACE and SANC. It has been used as a basic tool for developing and testing some new methods of precise measurements of the Standard Model parameters at the LHC, in particular the W-boson mass. Recently, it has been applied to simulations of double Drell-Yan processes resulting from double-parton scattering, in order to assess their influence on the Higgs-boson detection at the LHC in its ZZ and W+W- decay channels.
We present the upgrade of the coherent exclusive (CEEX) exponentiation realization of the Yennie-Frautschi-Suura (YFS) theory used in our Monte Carlo ({cal KK} MC) to the processes fbar{f}rightarrow fbar{f}, f=mu,tau,q, u_ell, f=e,mu,tau,q, u_ell, q=
u,d,s,c,b,t, ell=e,mu,tau with f e f, with an eye toward the precision physics of the LHC and possible high energy muon colliders. We give a brief summary of the CEEX theory in comparison to the older (EEX) exclusive exponentiation theory and illustrate theoretical results relevant to the LHC and possible muon collider physics programs.
This work covers methodology of solving QCD evolution equation of the parton distribution using Markovian Monte Carlo (MMC) algorithms in a class of models ranging from DGLAP to CCFM. One of the purposes of the above MMCs is to test the other more so
phisticated Monte Carlo programs, the so-called Constrained Monte Carlo (CMC) programs, which will be used as a building block in the parton shower MC. This is why the mapping of the evolution variables (eikonal variable and evolution time) into four-momenta is also defined and tested. The evolution time is identified with the rapidity variable of the emitted parton. The presented MMCs are tested independently, with ~0.1% precision, against the non-MC program APCheb especially devised for this purpose.
