Review and outlook of accelerator-related codes and their interplay with the experiments software

Powerful flexible computer codes are essential for the design and optimisation of accelerator and experiments. We briefly review what already exists and what is needed in terms of accelerator codes. For the FCC-ee, it will be important to include the effects of beamstrahlung and beam–beam interaction as well as machine imperfections and sources of beam-induced backgrounds relevant for the experiments and consider the possibility of beam polarisation. The experiment software Key4hep, which aims to provide a common software stack for future experiments, is described, and the possibility of extending this concept to machine codes is discussed. We analyse how to interface and connect the accelerator and experiment codes in an efficient and flexible way for optimisation of the FCC-ee interaction region design and discuss the possibility of using shared data formats as an interface.

Prospects of measuring the branching fraction of the Higgs boson decaying into muon pairs at the International Linear Collider

The prospects for measuring the branching fraction of $$H \rightarrow \mu ^{+} \mu ^{-}$$ H → μ + μ - at the International Linear Collider (ILC) have been evaluated based on a full detector simulation of the International Large Detector (ILD) concept, considering centre-of-mass energies ($$\sqrt{s}$$ s ) of 250 GeV and 500 GeV with two different beam polarisation configurations of $${\mathcal {P}} (e^{-}, e^{+}) = (-\,80{\%}, +\,30{\%})$$ P ( e - , e + ) = ( - 80 % , + 30 % ) and $$(+\,80{\%}, -\,30{\%})$$ ( + 80 % , - 30 % ) . For both $$\sqrt{s}$$ s cases, the two final states $$e^{+} e^{-} \rightarrow q\overline{q}H$$ e + e - → q q ¯ H and $$e^{+} e^{-} \rightarrow \nu \overline{\nu }H$$ e + e - → ν ν ¯ H have been analyzed. For integrated luminosities of 2 $$\hbox {ab}^{-1}$$ ab - 1 at $$\sqrt{s} =250$$ s = 250 GeV and 4 $$\hbox {ab}^{-1}$$ ab - 1 at $$\sqrt{s} =500$$ s = 500 GeV, the combined precision on the branching fraction of $$H \rightarrow \mu ^{+} \mu ^{-}$$ H → μ + μ - is estimated to be 17%. The impact of the transverse momentum resolution for this analysis is also studied.

RECENT RESULTS FROM GRAAL

A polarised and tagged [Formula: see text] ray beam is produced at GRAAL by the Compton scattering of laser light on the high energy electron of the ESRF storage ring. We present results on the beam polarisation asymmetries and cross sections in the photoproduction of mesons on hydrogen and deuterium target in the energy region 500-1500 MeV. These very precise results cover the angular range 30°-150°, providing stringent constraints to theoretical models.

Single Reflection Method for Pole-Density Measurements Accounting for Secondary Extinction in Textured Films

A method of pole density measurements is described, which uses the differences in X-ray beam polarisation of two monochromators. The method requires a single reflection at an intermediate diffraction angle. Experimental verification is provided by pole density measurements of Ag films and comparison the results obtained with the proposed method with results from the reflection-pair method [8-10].