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arXiv · 1610.03795

Anticipating Non-Resonant New Physics in Dilepton Angular Spectra at the LHC

Nirmal Raj
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Abstract

At the LHC, dileptonic events may turn up new physics interacting with quarks and leptons. The poster child for this scenario is a resonant $Z'$, much anticipated in $\ell^+ \ell^-$ invariant mass spectra. However, angular spectra of dileptons may play an equal or stronger role in discovering a non-resonant species. This paper avails of their LHC measurements to corner the couplings and masses of leptoquarks (LQs), that can mediate $q \bar{q} \rightarrow \ell^+ \ell^-$ in the $t$-channel and dramatically alter Standard Model angular spectra. Also derived are constraints from alterations to $m_{\ell \ell}$ distributions. These dilepton probes, exploiting the high rates and small uncertainties of the Drell-Yan process, rival or outdo dedicated LHC searches for LQs in single and pair production modes. The couplings of LQs with electronic interactions are best bound today by low-energy measurements of atomic parity violation, but can be probed better by $\ell^+ \ell^-$ measurements in the high luminosity runs of the LHC, with the angular spectra leading the way. This work also advocates the experimental presentation of boost-invariant angular asymmetries that vanish in the SM.

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Nirmal Raj. 2016-10-12. Anticipating Non-Resonant New Physics in Dilepton Angular Spectra at the LHC. https://doi.org/10.1103/physrevd.95.015011

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