Abstract
At the proposed electron-proton collider LHeC electroweak interactions can be uniquely studied in a largely unexplored kinematic region of spacelike momentum transfer. We simulate inclusive neutral- and charged-current deep-inelastic lepton proton scattering cross section data at center-of-mass energies of 1.2 and 1.3 TeV, and estimate the uncertainties of Standard Model parameters as well as of parameters describing physics beyond the Standard Model. A precision at sub-percent level is expected for the measurement of the weak neutral-current couplings of the light-quarks to the Z boson, g_{A/V}^{u/d}, improving their present precision by more than an order of magnitude. The weak mixing angle can be determined with a precision of about Delta sin ^2theta _text {W}=pm ,0.00015, and its scale dependence can be studied in the range between about 25 and 700 GeV. An indirect determination of the W-boson mass in the on-shell scheme is possible with an experimental uncertainty down to Delta m_{W}=pm ,6,text {MeV}. We discuss how measurements in deep-inelastic scattering compare with those in the timelike domain, and which aspects are unique, for instance electroweak parameters in charged-current interactions. We conclude that the LHeC will determine electroweak physics parameters, in the spacelike region, with unprecedented precision leading to thorough tests of the Standard Model and possibly beyond.
Highlights
Precision electroweak measurements have to be performed
We conclude that the Large Hadron-electron Collider (LHeC) will determine electroweak physics parameters, in the spacelike region, with unprecedented precision leading to thorough tests of the Standard Model and possibly beyond
The values of T and U can be disentangled only if their contributions to NC and CC deep inelastic scattering (DIS) are combined, but not from NC DIS alone. These linear combinations can be determined with very high precision – a fact which makes the DIS measurement useful since it is complementary to determinations of S, T and U from Z -pole data
Summary
Precision electroweak measurements have to be performed. Such high-precision measurements can be considered as a portal to new physics, since non-SM contributions may lead to significant deviations for some precisely measurable and calculable observables. Its electron beam energy may be chosen to be 60 or 50 GeV Considerations in this choice, as for example cost reasons, are discussed in the forthcoming thorough update of the physics and conceptual accelerator and detector design report [3]. In both cases its kinematic reach extends to much higher scales in comparison to HERA, which together with the huge increase of the expected integrated luminosity will allow to perform highprecision electroweak measurements at high scales in DIS for the first time. The potential of experiments at the LHeC with exclusive final states, for example W - or Z -boson production, or production of the Higgs boson, has been studied elsewhere [27,28,29,30]; the possible improvement in our knowledge of parton distribution functions due to LHeC experiments was described in Refs. [31,32] (see Refs. [1,3,19] and references therein)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
