Probing axionlike particles with γγ final states from vector boson fusion processes at the LHC

Andrés Flórez,Paul Sheldon,Elijah Sheridan,Alfredo Gurrola,Will Johns,Brandon Soubasis,Kuver Sinha

doi:10.1103/physrevd.103.095001

Andrés Flórez, Paul Sheldon + Show 5 more

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https://doi.org/10.1103/physrevd.103.095001

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Abstract

We perform a feasibility study to search for axionlike particles (ALPs) using vector boson fusion (VBF) processes at the LHC. We work in an effective field theory framework with a cutoff scale $\mathrm{\ensuremath{\Lambda}}$ and ALP mass ${m}_{a}$, and assume that ALPs couple to photons with strength $\ensuremath{\propto}1/\mathrm{\ensuremath{\Lambda}}$. Assuming proton-proton collisions at $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$, we present the total VBF ALP production cross sections, ALP decay widths and lifetimes, and relevant kinematic distributions as a function of ${m}_{a}$ and $\mathrm{\ensuremath{\Lambda}}$. We consider the $a\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$ decay mode to show that the requirement of an energetic diphoton pair combined with two forward jets with large dijet mass and pseudorapidity separation can significantly reduce the Standard Model backgrounds, leading to a $5\ensuremath{\sigma}$ discovery reach for $10\text{ }\text{ }\mathrm{MeV}\ensuremath{\lesssim}{m}_{a}\ensuremath{\lesssim}1\text{ }\text{ }\mathrm{TeV}$ with $\mathrm{\ensuremath{\Lambda}}\ensuremath{\lesssim}2\text{ }\text{ }\mathrm{TeV}$, assuming an integrated luminosity of $3000\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. In particular, this extends the LHC sensitivity to a previously unstudied region of the ALP parameter space.

Highlights

A major current focus of searches beyond the Standard Model (SM) is the QCD axion [1,2,3] and more general pseudoscalar axionlike particles (ALPs) a, which are ubiquitous in string theory [4,5]
The sensitivity was calculated considering the integrated luminosity already collected by ATLAS and CMS experiments during the so called run-II phase, 150 fb−1, and for the 3000 fb−1 expected by the end of the LHC era
The expected experimental sensitivity of the search was presented for two different luminosity scenarios, 150 fb−1, the current integrated luminosity collected by ATLAS and CMS experiments, and the 3000 fb−1 expected by the end of the LHC era

Summary

Introduction

A major current focus of searches beyond the Standard Model (SM) is the QCD axion [1,2,3] and more general pseudoscalar axionlike particles (ALPs) a, which are ubiquitous in string theory [4,5] These hypothetical particles are being probed by a wide array of methods that exploit the ALP-photon coupling [6,7,8,9,10]. While astrophysical searches (for example, using neutron stars [12,13,14,15,16,17]) provide a potentially rich avenue for constraining ALPs, lab-based searches are important given the control over both production and detection. Light-shiningthrough-wall experiments [10], which rely on ALP-photon conversions, probe smaller ALP masses ma ≲ 10−3 eV; beam dumps that rely on ALP decay typically probe larger

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Results

Conclusion