New Physics at the LHC: A Les Houches Report. Physics at Tev Colliders 2007 -- New Physics Working Group

TL;DR

The paper surveys a broad array of beyond-Standard-Model signatures for the LHC, organizing signatures by final-state leptons and other observables. It delivers detailed studies across MUED (four-lepton final states), Higgsless/W' scenarios with multi-lepton channels, low-scale technicolor (including the TCSM framework), and holographic technicolor (HTC) approaches, plus generic dilepton searches. Key contributions include projected discovery potentials for MUED and W' signals, strategies to discriminate MUED from SUSY, and exploratory simulations of technicolor resonances and their angular/mass observables. Collectively, the work aims to guide early LHC data analyses and motivate comprehensive search programs across multiple beyond-SM scenarios. The practical impact lies in providing concrete benchmarks, selection strategies, and observable signatures to optimize trigger choices and analysis pipelines at ATLAS and CMS in the TeV-scale regime.

Abstract

We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. The signatures are organized according to the experimental objects that appear in the final state, and in particular the number of high pT leptons. Our report, which includes brief experimental and theoretical reviews as well as original results, summarizes the activities of the "New Physics'' working group for the "Physics at TeV Colliders" workshop (Les Houches, France, 11-29 June, 2007).

Figures (18)

• Figure 1: Cumulative efficiency and cross section after each selection cut for the MUED signal ($\mathrm{R^{-1}}\in\{300, 500, 700, 900\}$ GeV, $\rm m_{H}=120$ GeV, $\Lambda\mathrm{R}=20$) and the background for all channels. Only the upper statistical uncertainties are shown.
• Figure 1: Integrated luminosities required for $3\sigma$ and $5\sigma$ detection of $W'$ signals as a function of $M_{W'}$. The dotted and dashed-dotted curves are for the $W Z Z$ channel, while the dashed and solid curves are for the $W Z jj$ channel. From ref. He:2007ge.
• Figure 1: Signal and background distributions of a $300\,{\rm GeV}$$\rho_{T}^\pm \rightarrow W^\pm Z^0 \rightarrow \ell^\pm \nu_\ell \ell^+\ell^-$ for $10\,{\rm fb}^{-1}$ at the LHC; $p_T(W,Z) > 50\,{\rm GeV}$ and $H_{T}({\rm jets}) < 125\,{\rm GeV}$. The open black histograms are the signal contributions.
• Figure 1: Lefthand side: line of $S=0$ in the $o_A, o_V$ plane with the two sample points on the $o_A = 0$ axis. Righthand side: setting $o_A = 0$ and $M_{W_{1}}=500\ {\rm GeV}$, value of the trilinear gauge coupling $g_1^Z$ as a function of $o_V$. The two horizontal lines correspond to the 1$\sigma$ bounds Yao:2006px.
• Figure 2: The discovery potential of MUED signals ($\mathrm{R^{-1}}\in\{300, 500, 700, 900\}$ GeV, $\rm m_{H}=120$ GeV, $\Lambda\mathrm{R}=20$) in the four-lepton channels is defined as the integrated luminosity needed to measure a signal with a significance ($\rm S_{cP}$) of five standard deviations. The dashed (solid) lines show results including (not including) systematical uncertainties. The uncertainties due to the limited understanding of the detector performance and characteristic of the early phase of the LHC data taking are not considered and may limit the sensitivity below one $fb^{-1}$(horizontal 'First data uncertainty' line).