[Paper Review] Tevatron-for-LHC Report: Preparations for Discoveries

V Buescher, Marcela Carena+60 more|ArXiv.org|Aug 30, 2006

Particle physics theoretical and experimental studies4 citations

TL;DR

This TeV4LHC report synthesizes Tevatron experimental and theoretical insights to prepare for new physics discoveries at the LHC, emphasizing complementary search strategies for BSM particles like $Z^\prime$, $W^\prime$, vectorlike quarks, and SUSY. It demonstrates that high-precision top quark mass measurements at the Tevatron significantly improve the determination of key SUSY parameters such as $\tan\beta$, enhancing LHC sensitivity even before discovery.

ABSTRACT

This is the "TeV4LHC" report of the "Physics Landscapes" Working Group, focused on facilitating the start-up of physics explorations at the LHC by using the experience gained at the Tevatron. We present experimental and theoretical results that can be employed to probe various scenarios for physics beyond the Standard Model.

Motivation & Objective

• To leverage Tevatron experience in experimental techniques and theoretical modeling to accelerate LHC physics exploration.
• To identify complementary discovery channels between the Tevatron and LHC for new physics beyond the Standard Model.
• To improve precision in key SUSY parameters—especially $\tan\beta$—through high-accuracy top quark mass measurements at the Tevatron.
• To develop and validate tools like SFitter and Fittino for interpreting future LHC signals in terms of underlying BSM models.
• To guide LHC search strategies by identifying scenarios where the Tevatron has superior sensitivity, such as light resonances decaying to $b$ jets or long-lived charged particles.

Proposed method

• Adapting Tevatron reconstruction and identification algorithms for electrons, photons, muons, taus, jets, and missing $E_T$ to LHC conditions.
• Using Tevatron data to model and predict Standard Model backgrounds for LHC SUSY searches, particularly in $\tau$-tagged and missing energy channels.
• Applying model-independent and model-based phenomenology to predict LHC signatures for $Z^\prime$, $W^\prime$, vectorlike quarks, triplet Higgs, and $s$-channel resonances.
• Performing global fits of SUSY parameters using combined Tevatron top quark mass measurements and LHC Higgs mass constraints to assess sensitivity improvements.
• Employing SFitter and Fittino tools to simulate and interpret potential LHC signals, enabling parameter extraction from early data.
• Analyzing the complementarity of $p\bar{p}$ (Tevatron) and $pp$ (LHC) collisions in probing quark-flavor-dependent couplings of new gauge bosons like $Z^\prime$.

Experimental results

Research questions

• RQ1 How can Tevatron experimental techniques for object reconstruction and background estimation be transferred to enhance LHC analysis capabilities?
• RQ2 In what scenarios does the Tevatron offer superior sensitivity compared to the LHC for discovering new physics, particularly for light resonances or specific SUSY states?
• RQ3 To what extent does improving the precision of the top quark mass measurement at the Tevatron enhance the determination of $\tan\beta$ and other SUSY parameters in the MSSM?
• RQ4 How can the combination of Tevatron and LHC data improve the measurement of $Z^\prime$ couplings to up and down quarks through complementary flavor sensitivity?
• RQ5 What role do tools like SFitter and Fittino play in interpreting early LHC signals and extracting fundamental BSM parameters from combined data sets?

Key findings

• Improving the Tevatron top quark mass measurement from 2 GeV to 1 GeV uncertainty enhances the precision of $\tan\beta$ determination by approximately 20%.
• With 10 fb$^{-1}$ of integrated luminosity, the improvement in $\tan\beta$ precision due to better top mass measurement is limited to about 5%, indicating diminishing returns at high luminosity.
• The top quark mass precision at the Tevatron reduces uncertainties in $m_0$ and $m_{1/2}$ parameters in the mSUGRA model, even in the absence of direct Higgs boson mass measurements.
• Tevatron data can significantly constrain the $Z^\prime$ couplings to quarks, especially when combined with LHC measurements, enabling separate determination of couplings to up and down quarks.
• For certain BSM scenarios—such as weakly coupled $s$-channel resonances decaying to $b$ jets—the Tevatron offers a cleaner environment than the LHC, potentially enabling earlier discovery.
• The synergy between Tevatron and LHC is most powerful when both machines probe the same resonance: Tevatron data can constrain couplings to specific quark flavors, while LHC data can access complementary combinations, leading to full coupling determination.