EPS Paper of the Month Award

Exploring the structure of the Higgs sector


The Englert-Brout-Higgs mechanism of spontaneous electroweak symmetry breaking was introduced in the 1960s to complete the formulation of the Standard Model of particle physics by explaining how the W and Z bosons obtain their mass. The Higgs boson is a massive elementary particle which appears in the most economic implementation of the mechanism. The masses of the fermions in the Standard Model are generated through Yukawa couplings to the Higgs boson.

On 4th July 2012, with strong involvement and leadership of the Birmingham group, the ATLAS and CMS Collaborations announced the observation of a particle consistent with the Standard Model Higgs boson with a mass of about 125 GeV. Further details can be found in the official CERN Press Release, University press release and also at BBC News, July 2012. Following the discovery, the experimental focus shifted to the measurement of its properties, notably its couplings to other particles, as well as searches for physics beyond the Standard Model through an extended Higgs sector:

Study of the SM-like Higgs boson (h)
The Birmingham group has leading involvement in analyses of ATLAS data, studying its mass and coupling properties using h→ZZ decays, and h→b anti-b decays produced in association with a Z or W boson. We also contribute significantly to the combination of all ATLAS Higgs boson measurements, probing the predictions of the Standard Model.
Study of the Yukawa sector
The group has pioneered searches for rare Higgs decays to the exclusive final state h→Qγ, where Q=J/ψ, Υ, and φ, as well as the previously unobserved analogous decays of the Z boson.
Search for additional Higgs bosons
We are performing a comprehensive set of searches for additional Higgs bosons, including the pseudo-scalar Higgs boson A in its decay to Zh, the heavy scalar H in its decay through ZZ and the charged Higgs bosons decaying to WZ. We are also looking for beyond the SM contributions to resonant and non-resonant di-Higgs boson production.

University of Birmingham main campus at Edgbaston

You can have a look at our talks in conferences, seminars, and our publications. We have hosted the "ATLAS UK Run 2 Physics and Performance Meeting" (October 20, 2014) and the "ATLAS UK Higgs Meeting" (September 25-26, 2014). A poster for our outreach activity, see here.

EPS Paper of the Month Award

We have been awarded University of Birmingham Engineering and Physical Sciences Paper of the Month (September 2016) for searching "for Higgs and Z Boson Decays to φγ with the ATLAS Detector" (Phys. Rev. Lett. 117 (2016) 11, 111802).
Read the full article: here.

The ERC Starting Grant "ExclusiveHiggs" (under grant agreement no 714893) has been awarded for work on the study of the Higgs interactions to the quarks of the first two generations. The project is starting March 1, 2017.

University of Birmingham main campus at Edgbaston
University of Birmingham main campus at Edgbaston

This project has received funding from the European Union’s 7th Framework Programme for research, technological development and demonstration under grant agreement no 334034 (EWSB), and from European Union's Horizon 2020 research and innovation programme under grant agreement no 660524 (hh).

Interactions with the phenomenology community have been supported in part by the IPPP Associateship programme.

University of Birmingham main campus at Edgbaston

Completed Ph.D. theses

Conference/Workshop contributions related to our Higgs sector work

Seminars/Colloquia related to our Higgs sector work

  • P. Thompson, "Latest Higgs boson results from the LHC", Seminar, University of Liverpool, July 26, 2017
  • R. Owen, "Searches at ATLAS for Rare Higgs boson Decays", Seminar, Rutherford Appleton Laboratory, May 24, 2017
  • R. Owen, "Searches at ATLAS for Rare Higgs boson Decays", Seminar, University of Birmingham, January 11, 2017
  • K. Nikolopoulos, "Searches for Higgs boson decays to
a meson and a photon", Seminar, University of Mainz, December 13, 2016
  • K. Nikolopoulos, "Probing the Higgs Yukawa couplings at the LHC", Seminar, University of Bristol, December 2, 2015
  • K. Nikolopoulos, "Probing the Higgs Yukawa couplings at the LHC", Seminar, Laboratoire de Physique Nucléaire et de Hautes énergies Paris, France, November 30, 2015
  • K. Nikolopoulos, "Probing the Higgs Yukawa couplings at the LHC", Seminar, Laboratoire de l'Accélérateur Linéaire Orsay, France, September 25, 2015.
  • A. Chisholm, "Probing Higgs Yukawa couplings with rare decays", Seminar, University of Birmingham, UK, May 13, 2015.
  • K. Nikolopoulos, "Probing the Higgs Yukawa couplings at the LHC", Seminar, University of Sussex, UK, April 23, 2015.
  • R. Mudd, "ATLAS Higgs Coupling measurements", Seminar, University of Sheffield, UK, April 16, 2015.
  • R. Mudd, "ATLAS Higgs Coupling measurements", Seminar, University of Warwick, UK, February 16, 2015.
  • K. Nikolopoulos, "Recent ATLAS results on the Higgs sector", Seminar, Imperial College London, UK, February 11, 2015.
  • R. Mudd, "Higgs Coupling Measurements at ATLAS", Seminar, University of Birmingham, UK, November 12, 2015.
  • L. Aperio Bella, "ATLAS Higgs results", Seminar, University of Edinburgh, UK, November 4, 2014.
  • P. Thompson, "The Search with ATLAS for Higgs Decays to Beauty", Seminar, University of Birmingham, UK, October 15, 2014.
  • L. Aperio Bella, "Probing the Higgs Boson Properties at ATLAS", Seminar, University of Birmingham, UK, January 15, 2014.
  • K. Nikolopoulos, "The discovery of a SM-like Higgs boson at the LHC", Colloqium, University of Birmingham, UK, May 15, 2013.
  • K. Nikolopoulos, "Higgs boson physics with ATLAS", Seminar, LIP, Portugal, November 18, 2013.
  • K. Nikolopoulos, "Higgs boson physics with ATLAS", Seminar, University of Oxford, UK, October 29, 2013.
  • K. Nikolopoulos, "Observation of an excess of events in the Search for the Higgs Boson with ATLAS at the LHC", Seminar, University of Birmingham, UK, July 26, 2012.

Publications

The following ATLAS publications related to the Higgs sector had a strong contribution from our group.

ATLAS Public Notes