Abstract
Heavy scalar and pseudoscalar resonance searches through the \( gg\to S\to t\overline{t} \) process are challenging due to the peculiar behavior of the large interference effects with the standard model \( t\overline{t} \) background. Such effects generate non-trivial lineshapes from additional relative phases between the signal and background amplitudes. We provide the analytic expressions for the differential cross sections to understand the interference effects in the heavy scalar signal lineshapes. We extend our study to the case of CP-violation and further consider the effect of bottom quarks in the production and decay processes. We also evaluate the contributions from additional particles to the gluon fusion production process, such as stops and vector-like quarks, that could lead to significant changes in the behavior of the signal lineshapes. Taking into account the large interference effects, we perform lineshape searches at the LHC and discuss the importance of the systematic uncertainties and smearing effects. We present projected sensitivities for two LHC performance scenarios to probe the \( gg\to S\to t\overline{t} \) channel in various models.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
R.A. Flores and M. Sher, Higgs Masses in the Standard, Multi-Higgs and Supersymmetric Models, Annals Phys. 148 (1983) 95 [INSPIRE].
J.F. Gunion and H.E. Haber, Higgs Bosons in Supersymmetric Models. 1, Nucl. Phys. B 272 (1986) 1 [Erratum ibid. B 402 (1993) 567] [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].
B. Gripaios, A. Pomarol, F. Riva and J. Serra, Beyond the Minimal Composite Higgs Model, JHEP 04 (2009) 070 [arXiv:0902.1483] [INSPIRE].
N. Arkani-Hamed, S. Dimopoulos and G.R. Dvali, Phenomenology, astrophysics and cosmology of theories with submillimeter dimensions and TeV scale quantum gravity, Phys. Rev. D 59 (1999) 086004 [hep-ph/9807344] [INSPIRE].
L. Randall and R. Sundrum, A large mass hierarchy from a small extra dimension, Phys. Rev. Lett. 83 (1999) 3370 [hep-ph/9905221] [INSPIRE].
L. Randall and R. Sundrum, An alternative to compactification, Phys. Rev. Lett. 83 (1999) 4690 [hep-th/9906064] [INSPIRE].
H. Georgi and S.L. Glashow, Unity of All Elementary Particle Forces, Phys. Rev. Lett. 32 (1974)438 [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. Dicus, A. Stange and S. Willenbrock, Higgs decay to top quarks at hadron colliders, Phys. Lett. B 333 (1994) 126 [hep-ph/9404359] [INSPIRE].
R. Barcelo and M. Masip, Extra Higgs bosons in tt production at the LHC, Phys. Rev. D 81 (2010) 075019 [arXiv:1001.5456] [INSPIRE].
V. Barger, W.-Y. Keung and B. Yencho, Azimuthal Correlations in Top Pair Decays and The Effects of New Heavy Scalars, Phys. Rev. D 85 (2012) 034016 [arXiv:1112.5173] [INSPIRE].
Y. Bai and W.-Y. Keung, Can vanishing mass-on-shell interactions generate a dip at colliders?, Int. J. Mod. Phys. A 30 (2015) 1550120 [arXiv:1407.6355] [INSPIRE].
S. Jung, J. Song and Y.W. Yoon, Dip or nothingness of a Higgs resonance from the interference with a complex phase, Phys. Rev. D 92 (2015) 055009 [arXiv:1505.00291] [INSPIRE].
N. Craig, F. D’Eramo, P. Draper, S. Thomas and H. Zhang, The Hunt for the Rest of the Higgs Bosons, JHEP 06 (2015) 137 [arXiv:1504.04630] [INSPIRE].
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.
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.
J. Pumplin, Diffraction dissociation and the reaction γp → π+π− p, Phys. Rev. D 2 (1970) 1859 [INSPIRE].
T. Bauer, Anomalous real part in the t matrices of unstable particles, Phys. Rev. Lett. 25 (1970) 485 [INSPIRE].
J.L. Basdevant and E.L. Berger, Unitary Coupled-Channel Analysis of Diffractive Production of the a1 Resonance, Phys. Rev. D 16 (1977) 657 [INSPIRE].
J.L. Basdevant and E.L. Berger, Unstable Particle Scattering and an Analytic Quasiunitary Isobar Model, Phys. Rev. D 19 (1979) 239 [INSPIRE].
M. Carena, J.R. Ellis, A. Pilaftsis and C.E.M. Wagner, Renormalization group improved effective potential for the MSSM Higgs sector with explicit CP-violation, Nucl. Phys. B 586 (2000) 92 [hep-ph/0003180] [INSPIRE].
M. Carena, J. Ellis, J.S. Lee, A. Pilaftsis and C.E.M. Wagner, CP Violation in Heavy MSSM Higgs Scenarios, JHEP 02 (2016) 123 [arXiv:1512.00437] [INSPIRE].
NNPDF collaboration, R.D. Ball et al., Parton distributions for the LHC Run II, JHEP 04 (2015) 040 [arXiv:1410.8849] [INSPIRE].
M. Carena, I. Low, N.R. Shah and C.E.M. Wagner, Impersonating the Standard Model Higgs Boson: Alignment without Decoupling, JHEP 04 (2014) 015 [arXiv:1310.2248] [INSPIRE].
P.S. Bhupal Dev and A. Pilaftsis, Maximally Symmetric Two Higgs Doublet Model with Natural Standard Model Alignment, JHEP 12 (2014) 024 [Erratum ibid. 11 (2015) 147] [arXiv:1408.3405] [INSPIRE].
J. Hajer, Y.-Y. Li, T. Liu and J.F.H. Shiu, Heavy Higgs Bosons at 14 TeV and 100 TeV, JHEP 11 (2015) 124 [arXiv:1504.07617] [INSPIRE].
N. Chen, J. Li and Y. Liu, LHC searches for heavy neutral Higgs bosons with a top jet substructure analysis, Phys. Rev. D 93 (2016) 095013 [arXiv:1509.03848] [INSPIRE].
S. Gori, I.-W. Kim, N.R. Shah and K.M. Zurek, Closing the Wedge: Search Strategies for Extended Higgs Sectors with Heavy Flavor Final States, Phys. Rev. D 93 (2016) 075038 [arXiv:1602.02782] [INSPIRE].
N. Craig, J. Hajer, Y.-Y. Li, T. Liu and H. Zhang, Heavy Higgs Bosons at Low tan β: from the LHC to 100 TeV, arXiv:1605.08744 [INSPIRE].
D. Goncalves and D. Lopez-Val, Boosting to identify: pseudoscalar searches with di-leptonic tops, Phys. Rev. D 94 (2016) 095005 [arXiv:1607.08614] [INSPIRE].
B.A. Dobrescu and A.D. Peterson, W ′ signatures with odd Higgs particles, JHEP 08 (2014) 078 [arXiv:1312.1999] [INSPIRE].
B.A. Dobrescu and Z. Liu, Heavy Higgs bosons and the 2 TeV W ′ boson, JHEP 10 (2015) 118 [arXiv:1507.01923] [INSPIRE].
M.J. Ramsey-Musolf and S. Su, Low Energy Precision Test of Supersymmetry, Phys. Rept. 456 (2008) 1 [hep-ph/0612057] [INSPIRE].
G. von Gersdorff, E. Pontón and R. Rosenfeld, The Dynamical Composite Higgs, JHEP 06 (2015) 119 [arXiv:1502.07340] [INSPIRE].
S. Fichet, G. von Gersdorff, E. Pontón and R. Rosenfeld, The Excitation of the Global Symmetry-Breaking Vacuum in Composite Higgs Models, JHEP 09 (2016) 158 [arXiv:1607.03125] [INSPIRE].
S. Fichet, G. von Gersdorff, E. Pontón and R. Rosenfeld, The Global Higgs as a Signal for Compositeness at the LHC, arXiv:1608.01995 [INSPIRE].
M. Carena, I. Low and C.E.M. Wagner, Implications of a Modified Higgs to Diphoton Decay Width, JHEP 08 (2012) 060 [arXiv:1206.1082] [INSPIRE].
M. Carena, S. Heinemeyer, C.E.M. Wagner and G. Weiglein, Suggestions for benchmark scenarios for MSSM Higgs boson searches at hadron colliders, Eur. Phys. J. C 26 (2003) 601 [hep-ph/0202167] [INSPIRE].
M. Carena, S. Heinemeyer, C.E.M. Wagner and G. Weiglein, MSSM Higgs boson searches at the Tevatron and the LHC: Impact of different benchmark scenarios, Eur. Phys. J. C 45 (2006)797 [hep-ph/0511023] [INSPIRE].
M. Carena, S. Heinemeyer, O. Stal, C.E.M. Wagner and G. Weiglein, MSSM Higgs Boson Searches at the LHC: Benchmark Scenarios after the Discovery of a Higgs-like Particle, Eur. Phys. J. C 73 (2013) 2552 [arXiv:1302.7033] [INSPIRE].
R. Franceschini et al., What is the γγ resonance at 750 GeV?, JHEP 03 (2016) 144 [arXiv:1512.04933] [INSPIRE].
R. Franceschini et al., Digamma, what next?, JHEP 07 (2016) 150 [arXiv:1604.06446] [INSPIRE].
A. Strumia, Interpreting the 750 GeV digamma excess: a review, arXiv:1605.09401 [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].
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].
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].
B. Bellazzini, R. Franceschini, F. Sala and J. Serra, Goldstones in Diphotons, JHEP 04 (2016) 072 [arXiv:1512.05330] [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].
R.S. Gupta, S. Jäger, Y. Kats, G. Perez and E. Stamou, Interpreting a 750 GeV Diphoton Resonance, JHEP 07 (2016) 145 [arXiv:1512.05332] [INSPIRE].
A. Kobakhidze, F. Wang, L. Wu, J.M. Yang and M. Zhang, 750 GeV diphoton resonance in a top and bottom seesaw model, Phys. Lett. B 757 (2016) 92 [arXiv:1512.05585] [INSPIRE].
L. Bian, N. Chen, D. Liu and J. Shu, Hidden confining world on the 750 GeV diphoton excess, Phys. Rev. D 93 (2016) 095011 [arXiv:1512.05759] [INSPIRE].
D. Aloni, K. Blum, A. Dery, A. Efrati and Y. Nir, On a possible large width 750 GeV diphoton resonance at ATLAS and CMS, JHEP 08 (2016) 017 [arXiv:1512.05778] [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].
N. Craig, P. Draper, C. Kilic and S. Thomas, Shedding Light on Diphoton Resonances, Phys. Rev. D 93 (2016) 115023 [arXiv:1512.07733] [INSPIRE].
P.S.B. Dev, R.N. Mohapatra and Y. Zhang, Quark Seesaw, Vectorlike Fermions and Diphoton Excess, JHEP 02 (2016) 186 [arXiv:1512.08507] [INSPIRE].
LHC Higgs Cross section Working Group collaboration, S. Dittmaier et al., Handbook of LHC Higgs Cross sections: 1. Inclusive Observables, arXiv:1101.0593 [INSPIRE].
S. Jung, J. Song and Y.W. Yoon, How Resonance-Continuum Interference Changes 750 GeV Diphoton Excess: Signal Enhancement and Peak Shift, JHEP 05 (2016) 009 [arXiv:1601.00006] [INSPIRE].
N. Craig, S. Renner and D. Sutherland, Exploring Peaks and Valleys in the Diphoton Spectrum, Phys. Rev. D 94 (2016) 075011 [arXiv:1607.06074] [INSPIRE].
S.P. Martin, Signal-background interference for a singlet spin-0 digluon resonance at the LHC, Phys. Rev. D 94 (2016) 035003 [arXiv:1606.03026] [INSPIRE].
ATLAS collaboration, A search for \( t\overline{t} \) resonances using lepton-plus-jets events in proton-proton collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, JHEP 08 (2015) 148 [arXiv:1505.07018] [INSPIRE].
CMS collaboration, Measurement of the differential cross section for top quark pair production in pp collisions at \( \sqrt{s}=8 \) TeV, Eur. Phys. J. C 75 (2015) 542 [arXiv:1505.04480] [INSPIRE].
ATLAS collaboration, Search for heavy particles decaying to pairs of highly-boosted top quarks using lepton-plus-jets events in proton-proton collisions at \( \sqrt{s}=13 \) TeV with the ATLAS detector, ATLAS-CONF-2016-014.
D.E. Kaplan, K. Rehermann, M.D. Schwartz and B. Tweedie, Top Tagging: A Method for Identifying Boosted Hadronically Decaying Top Quarks, Phys. Rev. Lett. 101 (2008) 142001 [arXiv:0806.0848] [INSPIRE].
K. Rehermann and B. Tweedie, Efficient Identification of Boosted Semileptonic Top Quarks at the LHC, JHEP 03 (2011) 059 [arXiv:1007.2221] [INSPIRE].
T. Plehn, M. Spannowsky, M. Takeuchi and D. Zerwas, Stop Reconstruction with Tagged Tops, JHEP 10 (2010) 078 [arXiv:1006.2833] [INSPIRE].
G. Cowan, K. Cranmer, E. Gross and O. Vitells, Asymptotic formulae for likelihood-based tests of new physics, Eur. Phys. J. C 71 (2011) 1554 [Erratum ibid. C 73 (2013) 2501] [arXiv:1007.1727] [INSPIRE].
G. Cowan, Discovery sensitivity for a counting experiment with background uncertainty, (2012), http://www.pp.rhul.ac.uk/~cowan/stat/medsig/medsigNote.pdf and also talk slides http://www-conf.slac.stanford.edu/statisticalissues2012/talks/glen_cowan_slac_4jun12.pdf.
W. Bernreuther, P. Galler, C. Mellein, Z.G. Si and P. Uwer, Production of heavy Higgs bosons and decay into top quarks at the LHC, Phys. Rev. D 93 (2016) 034032 [arXiv:1511.05584] [INSPIRE].
B. Tweedie, Better Hadronic Top Quark Polarimetry, Phys. Rev. D 90 (2014) 094010 [arXiv:1401.3021] [INSPIRE].
A. Djouadi, J. Ellis and J. Quevillon, Interference effects in the decays of spin-zero resonances into γγ and \( t\overline{t} \), JHEP 07 (2016) 105 [arXiv:1605.00542] [INSPIRE].
B. Hespel, F. Maltoni and E. Vryonidou, Signal background interference effects in heavy scalar production and decay to a top-anti-top pair, JHEP 10 (2016) 016 [arXiv:1606.04149] [INSPIRE].
ATLAS collaboration, Search for heavy Higgs bosons A/H decaying to a top-quark pair in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, ATLAS-CONF-2016-073.
H.H. Patel, Package-X: A Mathematica package for the analytic calculation of one-loop integrals, Comput. Phys. Commun. 197 (2015) 276 [arXiv:1503.01469] [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: 1608.07282
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
Carena, M., Liu, Z. Challenges and opportunities for heavy scalar searches in the \( t\overline{t} \) channel at the LHC. J. High Energ. Phys. 2016, 159 (2016). https://doi.org/10.1007/JHEP11(2016)159
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP11(2016)159