Electroweak Standard Model Physics

Abstract

In its first running period, the LHC has produced more W bosons than any accelerator before. This makes the LHC experiments hotbeds of electroweak physics. Although the ultimate precision in the measurement of electroweak parameters in many cases is still held by LEP, SLC or the Tevatron, the LHC has opened new views on measurements at high scales, especially in the field of multi-boson couplings. Furthermore, at the LHC the electroweak gauge bosons are used in a wide range of measurements that constrain the parton densities of the proton in ways that are complementary to previous results. The future promises further exciting results, among them W -boson mass measurements with unprecedented precision and the detailed study of vector-boson scattering. IntroductionPrecision measurements of electroweak (EW) parameters at the LHC are commonly limited in precision by the high pile-up and by the more complicated initial state compared to lepton colliders. Nevertheless, measurements of EW parameters are still of interest, especially for parameters that have a scale dependence because the high centre-of-mass energy of the LHC allows for studying previously inaccessible values of the scale. The measurements will typically have considerable uncertainties due to the underlying proton parton distribution functions (PDFs) and to other aspects of M. Boonekamp (B) CEA, IRFU,

Exclusive LHC physics with heavy ions: SuperChic 3

“…Other available MC implementations include: FPMC [13], which generates a smaller selection of final-states and does not include a differential treatment of survival effects, although it also generates more inclusive diffractive processes, beyond pure CEP; an implementation of CEP in Pythia described in [14], which provides a full treatment of initial-state showering effects for a small selection of processes, allowing both pure CEP and semi-exclusive production to be treated on the same footing, while the survival factor is included via the standard Pythia treatment of multi-particle interactions (MPI); the Starlight MC [15] generates a range of photon-initiated and photoproduction processes in heavy ion collisions; ExHuME [16], for QCDinitiated production of a small selection of processes; CepGen [17], which considers photoninitiated production but aims to allow the user to add in arbitrary processes; for lower mass QCD-initiated production, the Dime [18], ExDiff [19] and GenEx [20] MCs.…”

“…ted to the transverse-momentum dependent (or unintegrated) gluon distribution (see nces therein). Let us try to understand the behaviour of the amplitude A salient 58 C-even, couples to gluons C-odd, couples to photons + gluons 6 ilities… chievable [3,11], [13]- [18]. In particular, due to J z = 0 selection, leadingtion is suppressed by a factor (m b /E T ) 2 , where E T is the transverse energy ore, for a low mass Higgs, M H < ∼ 150 GeV, there is a possibility to observe mechanism for the exclusive process pp → p + X + p. The system X is on of two active gluons, with a screening gluon exchanged to neutralize 2 X = H, jj...…”