Abstract
We discuss the implications of the significant excesses in the diphoton final state observed by the LHC experiments ATLAS and CMS around a diphoton invariant mass of 750 GeV. The interpretation of the excess as a spin-zero s-channel resonance implies model-independent lower bounds on both its branching ratio and its coupling to photons, which stringently constrain dynamical models. We consider both the case where the excess is described by a narrow and a broad resonance. We also obtain model-independent constraints on the allowed couplings and branching fractions to final states other than diphotons, by including the interplay with 8 TeV searches. These results can guide attempts to construct viable dynamical models of the resonance. Turning to specific models, our findings suggest that the anomaly cannot be accounted for by the presence of only an additional singlet or doublet spin-zero field and the Standard Model degrees of freedom; this includes all two-Higgs-doublet models. Likewise, heavy scalars in the MSSM cannot explain the excess if stability of the electroweak vacuum is required, at least in a leading-order analysis. If we assume that the resonance is broad we find that it is challenging to find a weakly coupled explanation. However, we provide an existence proof in the form of a model with vectorlike quarks with large electric charge that is perturbative up to the 100 TeV scale. For the narrow-resonance case a similar model can be perturbative up to high scales also with smaller charges. We also find that, in their simplest form, dilaton models cannot explain the size of the excess. Some implications for flavor physics are briefly discussed.
Article PDF
Similar content being viewed by others
Explore related subjects
Find the latest articles, discoveries, and news in related topics.Avoid common mistakes on your manuscript.
References
ATLAS collaboration, Search for resonances decaying to photon pairs in 3.2 fb−1 of pp collisions at \( \sqrt{s}=13 \) TeV with the ATLAS detector, ATLAS-CONF-2015-081, CERN, Geneva Switzerland (2015).
CMS collaboration, Search for new physics in high mass diphoton events in proton-proton collisions at \( \sqrt{s}=13 \) TeV, CMS-PAS-EXO-15-004, CERN, Geneva Switzerland (2015).
L.D. Landau, On the angular momentum of a system of two photons, Dokl. Akad. Nauk Ser. Fiz. 60 (1948) 207 [INSPIRE].
C.-N. Yang, Selection rules for the dematerialization of a particle into two photons, Phys. Rev. 77 (1950) 242 [INSPIRE].
J. Alwall et al., The automated computation of tree-level and next-to-leading order differential cross sections and their matching to parton shower simulations, JHEP 07 (2014) 079 [arXiv:1405.0301] [INSPIRE].
A. Alloul, N.D. Christensen, C. Degrande, C. Duhr and B. Fuks, FeynRules 2.0 — a complete toolbox for tree-level phenomenology, Comput. Phys. Commun. 185 (2014) 2250 [arXiv:1310.1921] [INSPIRE].
S. Dawson, The effective W approximation, Nucl. Phys. B 249 (1985) 42 [INSPIRE].
G.L. Kane, W.W. Repko and W.B. Rolnick, The effective W ± , Z 0 approximation for high-energy collisions, Phys. Lett. B 148 (1984) 367 [INSPIRE].
R.D. Ball et al., Parton distributions with LHC data, Nucl. Phys. B 867 (2013) 244 [arXiv:1207.1303] [INSPIRE].
C. Schmidt, J. Pumplin, D. Stump and C.P. Yuan, CT14QED parton distribution functions from isolated photon production in deep inelastic scattering, Phys. Rev. D 93 (2016) 114015 [arXiv:1509.02905] [INSPIRE].
L.A. Harland-Lang, V.A. Khoze and M.G. Ryskin, The production of a diphoton resonance via photon-photon fusion, JHEP 03 (2016) 182 [arXiv:1601.07187] [INSPIRE].
W. Altmannshofer, J. Galloway, S. Gori, A.L. Kagan, A. Martin and J. Zupan, 750 GeV diphoton excess, Phys. Rev. D 93 (2016) 095015 [arXiv:1512.07616] [INSPIRE].
S. Fichet, G. von Gersdorff and C. Royon, Scattering light by light at 750 GeV at the LHC, Phys. Rev. D 93 (2016) 075031 [arXiv:1512.05751] [INSPIRE].
CMS collaboration, Search for resonances decaying to dijet final states at \( \sqrt{s}=8 \) TeV with scouting data, CMS-PAS-EXO-14-005, CERN, Geneva Switzerland (2014).
CMS collaboration, Search for diphoton resonances in the mass range from 150 to 850 GeV in pp collisions at \( \sqrt{s}=8 \) TeV, Phys. Lett. B 750 (2015) 494 [arXiv:1506.02301] [INSPIRE].
ATLAS collaboration, Search for high-mass diphoton resonances in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Phys. Rev. D 92 (2015) 032004 [arXiv:1504.05511] [INSPIRE].
CMS collaboration, Search for high-mass diphoton resonances in pp collisions at \( \sqrt{s}=8 \) TeV with the CMS detector, CMS-PAS-EXO-12-045, CERN, Geneva Switzerland (2012).
CMS collaboration, Search for resonant \( t\overline{t} \) production in proton-proton collisions at \( \sqrt{s}=8 \) TeV, Phys. Rev. D 93 (2016) 012001 [arXiv:1506.03062] [INSPIRE].
ATLAS collaboration, Search for a high-mass Higgs boson decaying to a W boson pair in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, JHEP 01 (2016) 032 [arXiv:1509.00389] [INSPIRE].
CMS collaboration, Search for a Standard Model like Higgs boson in the \( H\to ZZ\to {\ell}^{+}{\ell}^{-}q\overline{q} \) decay channel at \( \sqrt{s}=8 \) TeV, CMS-PAS-HIG-14-007, CERN, Geneva Switzerland (2014).
CMS collaboration, Search for di-Higgs resonances decaying to 4 bottom quarks, CMS-PAS-HIG-14-013, CERN, Geneva Switzerland (2014).
ATLAS collaboration, Search for a new resonance decaying to a W or Z boson and a Higgs boson in the \( \ell \ell /\ell \nu /\nu \nu +b\overline{b} \) final states with the ATLAS detector, Eur. Phys. J. C 75 (2015) 263 [arXiv:1503.08089] [INSPIRE].
[23]ATLAS collaboration, Search for neutral Higgs bosons of the minimal supersymmetric Standard Model in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, JHEP 11 (2014) 056 [arXiv:1409.6064] [INSPIRE].
ATLAS collaboration, Search for new resonances in W γ and Zγ final states in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Phys. Lett. B 738 (2014) 428 [arXiv:1407.8150] [INSPIRE].
ATLAS collaboration, Search for high-mass dilepton resonances in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Phys. Rev. D 90 (2014) 052005 [arXiv:1405.4123] [INSPIRE].
CMS collaboration, Search for narrow resonances and quantum black holes in inclusive and b-tagged dijet mass spectra from pp collisions at \( \sqrt{s}=7 \) TeV, JHEP 01 (2013) 013 [arXiv:1210.2387] [INSPIRE].
CMS collaboration, Search for heavy resonances decaying into bb and bg final states in pp collisions at \( \sqrt{s}=8 \) TeV, CMS-PAS-EXO-12-023, CERN, Geneva Switzerland (2012).
ATLAS collaboration, Search for new phenomena in dijet mass and angular distributions from pp collisions at \( \sqrt{s}=13 \) TeV with the ATLAS detector, Phys. Lett. B 754 (2016) 302 [arXiv:1512.01530] [INSPIRE].
CMS collaboration, Search for narrow resonances decaying to dijets in proton-proton collisions at \( \sqrt{s}=13 \) TeV, Phys. Rev. Lett. 116 (2016) 071801 [arXiv:1512.01224] [INSPIRE].
W.D. Goldberger, B. Grinstein and W. Skiba, Distinguishing the Higgs boson from the dilaton at the Large Hadron Collider, Phys. Rev. Lett. 100 (2008) 111802 [arXiv:0708.1463] [INSPIRE].
T. Robens and T. Stefaniak, Status of the Higgs singlet extension of the Standard Model after LHC run 1, Eur. Phys. J. C 75 (2015) 104 [arXiv:1501.02234] [INSPIRE].
M. Spira, A. Djouadi, D. Graudenz and P.M. Zerwas, Higgs boson production at the LHC, Nucl. Phys. B 453 (1995) 17 [hep-ph/9504378] [INSPIRE].
M. Son and A. Urbano, A new scalar resonance at 750 GeV: towards a proof of concept in favor of strongly interacting theories, JHEP 05 (2016) 181 [arXiv:1512.08307] [INSPIRE].
[34]M.-L. Xiao and J.-H. Yu, Stabilizing electroweak vacuum in a vectorlike fermion model, Phys. Rev. D 90 (2014) 014007 [Addendum ibid. D 90 (2014) 019901] [arXiv:1404.0681] [INSPIRE].
B. Gripaios, A. Pomarol, F. Riva and J. Serra, Beyond the minimal composite Higgs model, JHEP 04 (2009) 070 [arXiv:0902.1483] [INSPIRE].
A. Efrati, E. Kuflik, S. Nussinov, Y. Soreq and T. Volansky, Constraining the Higgs-dilaton with LHC and dark matter searches, Phys. Rev. D 91 (2015) 055034 [arXiv:1410.2225] [INSPIRE].
J.D. Wells, Lectures on Higgs boson physics in the Standard Model and beyond, in 39th British Universities Summer School in Theoretical Elementary Particle Physics (BUSSTEPP 2009), Liverpool U.K. August 24-September 4 2009 [arXiv:0909.4541] [INSPIRE].
B. Bellazzini, C. Csáki, J. Hubisz, J. Serra and J. Terning, A Higgslike dilaton, Eur. Phys. J. C 73 (2013) 2333 [arXiv:1209.3299] [INSPIRE].
R.S. Gupta and J.D. Wells, Next generation Higgs bosons: theory, constraints and discovery prospects at the Large Hadron Collider, Phys. Rev. D 81 (2010) 055012 [arXiv:0912.0267] [INSPIRE].
J.F. Gunion and H.E. Haber, The CP conserving two Higgs doublet model: the approach to the decoupling limit, Phys. Rev. D 67 (2003) 075019 [hep-ph/0207010] [INSPIRE].
R.S. Gupta, M. Montull and F. Riva, SUSY faces its Higgs couplings, JHEP 04 (2013) 132 [arXiv:1212.5240] [INSPIRE].
G.C. Branco, P.M. Ferreira, L. Lavoura, M.N. Rebelo, M. Sher and J.P. Silva, Theory and phenomenology of two-Higgs-doublet models, Phys. Rept. 516 (2012) 1 [arXiv:1106.0034] [INSPIRE].
D. Ghosh, R.S. Gupta and G. Perez, Is the Higgs mechanism of fermion mass generation a fact? A Yukawa-less first-two-generation model, Phys. Lett. B 755 (2016) 504 [arXiv:1508.01501] [INSPIRE].
M. Drees and M.M. Nojiri, A new signal for scalar top bound state production, Phys. Rev. Lett. 72 (1994) 2324 [hep-ph/9310209] [INSPIRE].
D. Kahawala and Y. Kats, Distinguishing spins at the LHC using bound state signals, JHEP 09 (2011) 099 [arXiv:1103.3503] [INSPIRE].
M.R. Kauth, J.H. Kuhn, P. Marquard and M. Steinhauser, Gluinonia: energy levels, production and decay, Nucl. Phys. B 831 (2010) 285 [arXiv:0910.2612] [INSPIRE].
J.M. Frere, D.R.T. Jones and S. Raby, Fermion masses and induction of the weak scale by supergravity, Nucl. Phys. B 222 (1983) 11 [INSPIRE].
J.P. Derendinger and C.A. Savoy, Quantum effects and SU(2) × U(1) breaking in supergravity gauge theories, Nucl. Phys. B 237 (1984) 307 [INSPIRE].
J.A. Casas and S. Dimopoulos, Stability bounds on flavor violating trilinear soft terms in the MSSM, Phys. Lett. B 387 (1996) 107 [hep-ph/9606237] [INSPIRE].
R. Rattazzi and U. Sarid, The unified minimal supersymmetric model with large Yukawa couplings, Phys. Rev. D 53 (1996) 1553 [hep-ph/9505428] [INSPIRE].
J. Hisano and S. Sugiyama, Charge-breaking constraints on left-right mixing of stau’s, Phys. Lett. B 696 (2011) 92 [Erratum ibid. B 719 (2013) 472] [arXiv:1011.0260] [INSPIRE].
W. Altmannshofer, M. Carena, N.R. Shah and F. Yu, Indirect probes of the MSSM after the Higgs discovery, JHEP 01 (2013) 160 [arXiv:1211.1976] [INSPIRE].
M. Carena, S. Gori, I. Low, N.R. Shah and C.E.M. Wagner, Vacuum stability and Higgs diphoton decays in the MSSM, JHEP 02 (2013) 114 [arXiv:1211.6136] [INSPIRE].
W. Altmannshofer, C. Frugiuele and R. Harnik, Fermion hierarchy from sfermion anarchy, JHEP 12 (2014) 180 [arXiv:1409.2522] [INSPIRE].
A. Djouadi, The anatomy of electro-weak symmetry breaking. II. The Higgs bosons in the minimal supersymmetric model, Phys. Rept. 459 (2008) 1 [hep-ph/0503173] [INSPIRE].
F. Borzumati, G.R. Farrar, N. Polonsky and S.D. Thomas, Soft Yukawa couplings in supersymmetric theories, Nucl. Phys. B 555 (1999) 53 [hep-ph/9902443] [INSPIRE].
K. Harigaya and Y. Nomura, Composite models for the 750 GeV diphoton excess, Phys. Lett. B 754 (2016) 151 [arXiv:1512.04850] [INSPIRE].
Y. Mambrini, G. Arcadi and A. Djouadi, The LHC diphoton resonance and dark matter, Phys. Lett. B 755 (2016) 426 [arXiv:1512.04913] [INSPIRE].
M. Backovic, A. Mariotti and D. Redigolo, Di-photon excess illuminates dark matter, JHEP 03 (2016) 157 [arXiv:1512.04917] [INSPIRE].
A. Angelescu, A. Djouadi and G. Moreau, Scenarii for interpretations of the LHC diphoton excess: two Higgs doublets and vector-like quarks and leptons, Phys. Lett. B 756 (2016) 126 [arXiv:1512.04921] [INSPIRE].
Y. Nakai, R. Sato and K. Tobioka, Footprints of new strong dynamics via anomaly and the 750 GeV diphoton, Phys. Rev. Lett. 116 (2016) 151802 [arXiv:1512.04924] [INSPIRE].
S. Knapen, T. Melia, M. Papucci and K. Zurek, Rays of light from the LHC, Phys. Rev. D 93 (2016) 075020 [arXiv:1512.04928] [INSPIRE].
D. Buttazzo, A. Greljo and D. Marzocca, Knocking on new physics’ door with a scalar resonance, Eur. Phys. J. C 76 (2016) 116 [arXiv:1512.04929] [INSPIRE].
A. Pilaftsis, Diphoton signatures from heavy axion decays at the CERN Large Hadron Collider, Phys. Rev. D 93 (2016) 015017 [arXiv:1512.04931] [INSPIRE].
R. Franceschini et al., What is the γγ resonance at 750 GeV?, JHEP 03 (2016) 144 [arXiv:1512.04933] [INSPIRE].
S. Di Chiara, L. Marzola and M. Raidal, First interpretation of the 750 GeV diphoton resonance at the LHC, Phys. Rev. D 93 (2016) 095018 [arXiv:1512.04939] [INSPIRE].
T. Higaki, K.S. Jeong, N. Kitajima and F. Takahashi, The QCD axion from aligned axions and diphoton excess, Phys. Lett. B 755 (2016) 13 [arXiv:1512.05295] [INSPIRE].
S.D. McDermott, P. Meade and H. Ramani, Singlet scalar resonances and the diphoton excess, Phys. Lett. B 755 (2016) 353 [arXiv:1512.05326] [INSPIRE].
J. Ellis, S.A.R. Ellis, J. Quevillon, V. Sanz and T. You, On the interpretation of a possible ∼750 GeV particle decaying into γγ, JHEP 03 (2016) 176 [arXiv:1512.05327] [INSPIRE].
M. Low, A. Tesi and L.-T. Wang, A pseudoscalar decaying to photon pairs in the early LHC run 2 data, JHEP 03 (2016) 108 [arXiv:1512.05328] [INSPIRE].
B. Bellazzini, R. Franceschini, F. Sala and J. Serra, Goldstones in diphotons, JHEP 04 (2016) 072 [arXiv:1512.05330] [INSPIRE].
C. Petersson and R. Torre, 750 GeV diphoton excess from the Goldstino superpartner, Phys. Rev. Lett. 116 (2016) 151804 [arXiv:1512.05333] [INSPIRE].
E. Molinaro, F. Sannino and N. Vignaroli, Minimal composite dynamics versus axion origin of the diphoton excess, arXiv:1512.05334 [INSPIRE].
J. Jaeckel, M. Jankowiak and M. Spannowsky, LHC probes the hidden sector, Phys. Dark Univ. 2 (2013) 111 [arXiv:1212.3620] [INSPIRE].
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1512.05332
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Gupta, R.S., Jäger, S., Kats, Y. et al. Interpreting a 750 GeV diphoton resonance. J. High Energ. Phys. 2016, 145 (2016). https://doi.org/10.1007/JHEP07(2016)145
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP07(2016)145