## 8D likelihood effective Higgs couplings extraction framework in h → 4ℓ

## Abstract

We present an overview of a comprehensive analysis framework aimed at performing direct extraction of all possible effective Higgs couplings to neutral electroweak gauge bosons in the decay to electrons and muons, the so called ‘golden channel’. Our framework is based primarily on a maximum likelihood method constructed from analytic expressions of the fully differential cross sections for h → 4l and for the dominant irreducible $$ q\overline{q} $$ → 4l background, where 4l = 2e2μ, 4e, 4μ. Detector effects are included by an explicit convolution of these analytic expressions with the appropriate transfer function over all center of mass variables. Utilizing the full set of observables, we construct an unbinned detector-level likelihood which is continuous in the effective couplings. We consider possible ZZ, Zγ, and γγ couplings simultaneously, allowing for general CP odd/even admixtures. A broad overview is given of how the convolution is performed and we discuss the principles and theoretical basis of the framework. This framework can be used in a variety of ways to study Higgs couplings in the golden channel using data obtained at the LHC and other future colliders.

- Authors:

- California Institute of Technology, Pasadena, CA (United States)
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. Paris-Sud, Orsay Cedex (France); Northwestern Univ., Evanston, IL (United States)

- Publication Date:

- Research Org.:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)

- OSTI Identifier:
- 1155855

- Report Number(s):
- CALT-68-2874; FERMILAB-PUB-13-555-T; NUHEP-TH-13-06; LPT-Orsay-13-100

Journal ID: ISSN 1029-8479; PII: 9643; TRN: US1500456

- Grant/Contract Number:
- AC02-07CH11359

- Resource Type:
- Accepted Manuscript

- Journal Name:
- Journal of High Energy Physics (Online)

- Additional Journal Information:
- Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2015; Journal Issue: 1; Journal ID: ISSN 1029-8479

- Publisher:
- Springer Berlin

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Hadron-Hadron Scattering; Higgs physics

### Citation Formats

```
Chen, Yi, Di Marco, Emanuele, Lykken, Joe, Spiropulu, Maria, Vega-Morales, Roberto, and Xie, Si. 8D likelihood effective Higgs couplings extraction framework in h → 4ℓ. United States: N. p., 2015.
Web. doi:10.1007/JHEP01(2015)125.
```

```
Chen, Yi, Di Marco, Emanuele, Lykken, Joe, Spiropulu, Maria, Vega-Morales, Roberto, & Xie, Si. 8D likelihood effective Higgs couplings extraction framework in h → 4ℓ. United States. doi:10.1007/JHEP01(2015)125.
```

```
Chen, Yi, Di Marco, Emanuele, Lykken, Joe, Spiropulu, Maria, Vega-Morales, Roberto, and Xie, Si. Fri .
"8D likelihood effective Higgs couplings extraction framework in h → 4ℓ". United States. doi:10.1007/JHEP01(2015)125. https://www.osti.gov/servlets/purl/1155855.
```

```
@article{osti_1155855,
```

title = {8D likelihood effective Higgs couplings extraction framework in h → 4ℓ},

author = {Chen, Yi and Di Marco, Emanuele and Lykken, Joe and Spiropulu, Maria and Vega-Morales, Roberto and Xie, Si},

abstractNote = {We present an overview of a comprehensive analysis framework aimed at performing direct extraction of all possible effective Higgs couplings to neutral electroweak gauge bosons in the decay to electrons and muons, the so called ‘golden channel’. Our framework is based primarily on a maximum likelihood method constructed from analytic expressions of the fully differential cross sections for h → 4l and for the dominant irreducible $ q\overline{q} $ → 4l background, where 4l = 2e2μ, 4e, 4μ. Detector effects are included by an explicit convolution of these analytic expressions with the appropriate transfer function over all center of mass variables. Utilizing the full set of observables, we construct an unbinned detector-level likelihood which is continuous in the effective couplings. We consider possible ZZ, Zγ, and γγ couplings simultaneously, allowing for general CP odd/even admixtures. A broad overview is given of how the convolution is performed and we discuss the principles and theoretical basis of the framework. This framework can be used in a variety of ways to study Higgs couplings in the golden channel using data obtained at the LHC and other future colliders.},

doi = {10.1007/JHEP01(2015)125},

journal = {Journal of High Energy Physics (Online)},

number = 1,

volume = 2015,

place = {United States},

year = {2015},

month = {1}

}