The ATLAS Experiment

Higgs Boson Discovery and Measurement

This includes the original discovery of the Higgs Boson using H0 → ZZ(*) → 4 leptons, H0 → γ γ, and H0 → W+W−; we have also subsequently used these final states to understand the quantum numbers of the particle, and helped confirm its identity as a Higgs Boson. We have also searched for other Standard Model Higgs Boson decay modes, including H0 → Z0γ.

• Measurements of the Higgs boson production, fiducial and differential cross sections in the $4\ell$ decay channel at $\sqrt{s}=13~{\TeV}$ with the ATLAS detector. (June 4, 2018)

• Measurement of gluon fusion and vector boson fusion Higgs boson production cross-sections in the $H \to WW^{*} \to e\nu\mu\nu$ decay channel in pp collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector. (March 13, 2018). 

• "Study of the Higgs boson properties and search for high-mass scalar resonances in the $H \rightarrow ZZ^* \rightarrow 4\ell$ decay channel at $\sqrt{s}$ = 13 TeV with the ATLAS detector." (2016)

•  Observation and measurement of Higgs boson decays to $WW^{\ast}$ with the ATLAS detector. ATLAS Collaboration. (2014)

• Determination of spin and parity of the Higgs boson in the $WW^\ast \to e \nu \mu \nu$ decay channel with the ATLAS detector. ATLAS Collaboration. (2015)

• "Evidence for the spin-0 nature of the Higgs boson using ATLAS data." ATLAS Collaboration. Submitted for publication.

• "Search for the Standard Model Higgs boson in the H → Zγ decay mode with pp collisions at √s = 7 and 8 TeV." ATLAS Collaboration. 

• "Observation of a New Particle in the Search for the Standard Model Higgs Boson with the ATLAS Detector at the LHC.” ATLAS Collaboration. 

Higgs Decays to Fermion Final States

This category encompasses our searches for the Standard Model Higgs boson decaying to fermions in the final state. This is a flagship measurement for the ongoing LHC Run 2 and a key prediction of the Standard Model. Fermion final states also play a key role in searches for two-Higgs production, a key signature of the Higgs boson's self-interaction. In addition, searches for H0 → bb can be used for studies of physics scenarios beyond the Standard Model. Even more exotic final states (such as τν) can be used to search for new kinds of Higgs bosons.

• Evidence for the $H \rightarrow b\barb$ decay with the ATLAS detector.http://inspirehep.net/record/1609518(2017).

• Search for heavy resonances decaying to a $W$ or $Z$ boson and a Higgs boson in final states with leptons and $b$-jets in 36.1~fb$^-1$ of $pp$ collision data at $\sqrt s = 13$~\TeV with the ATLAS detector.http://cds.cern.ch/record/2273871

• Search for Higgs boson pair production in the $b\bar{b}\gamma\gamma$ final state using pp collision data at $\sqrt{s}=13$ TeV with the ATLAS detector.http://inspirehep.net/record/1427473(2016).

• Aad, others (2015). [ATLAS] Search for charged Higgs bosons decaying via $H^\pm \rightarrow \tau^\pm\nu$ in fully hadronic final states using $pp$ collision data at $\sqrts = 8$ TeV with the ATLAS detector.https://arxiv.org/ct?url=http%3A%2F%2Fdx.doi.org%2F10%252E1007%2FJHEP03%25282015%2529088&v=0e19d2c6 

Exotic Physics Scenarios

These have included searches for di-boson resonances, which would be expected if there are new particles or extra spatial dimensions beyond the three already known dimensions; searches for magnetic monopoles, which if detected would explain the quantization of electric charge in nature.

• "Search for WZ resonances in the fully leptonic channel using pp collisions at sqrt(s) = 8 TeV with the ATLAS detector". ATLAS Collaboration. Phys. Lett. B (2014) pp. 223–243.

• "Search for diphoton events with large missing transverse momentum with 1 fb-1 of 7 TeV proton-proton collision data with the ATLAS detector". ATLAS Collaboration. PLB 710 (2012) 519

• "Search for magnetic monopoles in sqrt(s) = 7 TeV pp collisions with the ATLAS detector". ATLAS Collaboration. PRL 109 (2012) 261803.

Probing the Standard Model

The Standard Model is a very battle-tested model of nature, but that doesn't mean it has yielded all of its secrets, nor that it can withstand the next test of its predictions. In these papers, our group helped to dig deep into the Standard Model to assess its reliability as a description of nature.

• "Combination of searches for WW, WZ, and ZZ resonances in pp collisions at √s=8 TeV with the ATLAS detector". ATLAS Collaboration. Phys. Lett. B 755 (2016) 285–305

• "Measurements of Zγ and Zγγ production in pp collisions at √s= 8 TeV with the ATLAS detector". ATLAS Collaboration. Phys. Rev. D 93, 112002 (2016).