Abstract
This paper presents the inaugural investigation of beyond the Standard Model (BSM) radiation processes, framed as a generalized, process- and model-independent parton shower algorithm within Herwig 7, based on direct translations of Universal FeynRules Output (UFO) constructed via Herwig’s ufo2herwig module. Leveraging the fact that shower kinematics are dictated by the spins of involved particles, we calculate comprehensive helicity-dependent branching kernels for all feasible splittings of scalars, fermions, and vector bosons, tailored to Herwig 7’s angular-ordering (AO) parton shower algorithm. Utilizing these kernels, we derive BSM splitting functions in the quasi-collinear limit, ensuring compatibility with the Standard Model (SM) and supersymmetry (SUSY) splitting functions when analogous parameter conditions are applied. These newly derived functions have been integrated into the Herwig 7 event generator framework. Comparative analyses with fixed-order matrix element calculations show good agreement for single radiation events. Moreover, the results showcase the influence of BSM radiation at the Large Hadron Collider (LHC) and envisage its implications for future collider endeavours. This research augments our comprehension of BSM radiation effects, with significant bearings on present and prospective collider-based inquiries.
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References
B. Pontecorvo, Neutrino Experiments and the Problem of Conservation of Leptonic Charge, Zh. Eksp. Teor. Fiz. 53 (1967) 1717 [INSPIRE].
Super-Kamiokande collaboration, Evidence for oscillation of atmospheric neutrinos, Phys. Rev. Lett. 81 (1998) 1562 [hep-ex/9807003] [INSPIRE].
SNO collaboration, Measurement of the rate of νe + d → p + p + e− interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory, Phys. Rev. Lett. 87 (2001) 071301 [nucl-ex/0106015] [INSPIRE].
CDF collaboration, High-precision measurement of the W boson mass with the CDF II detector, Science 376 (2022) 170 [INSPIRE].
S. Bifani, S. Descotes-Genon, A. Romero Vidal and M.-H. Schune, Review of Lepton Universality tests in B decays, J. Phys. G 46 (2019) 023001 [arXiv:1809.06229] [INSPIRE].
Muon g-2 collaboration, Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm, Phys. Rev. Lett. 126 (2021) 141801 [arXiv:2104.03281] [INSPIRE].
M. Bähr et al., Herwig++ Physics and Manual, Eur. Phys. J. C 58 (2008) 639 [arXiv:0803.0883] [INSPIRE].
J. Bellm et al., Herwig 7.0/Herwig++ 3.0 release note, Eur. Phys. J. C 76 (2016) 196 [arXiv:1512.01178] [INSPIRE].
J. Bellm et al., Herwig 7.2 release note, Eur. Phys. J. C 80 (2020) 452 [arXiv:1912.06509] [INSPIRE].
G. Bewick et al., Herwig 7.3 Release Note, arXiv:2312.05175 [INSPIRE].
M.R. Masouminia and P. Richardson, Hadronization and Decay of Excited Heavy Hadrons in Herwig 7, arXiv:2312.02757 [INSPIRE].
C. Bierlich et al., A comprehensive guide to the physics and usage of PYTHIA 8.3, SciPost Phys. Codeb. 2022 (2022) 8 [arXiv:2203.11601] [INSPIRE].
T. Gleisberg et al., Event generation with SHERPA 1.1, JHEP 02 (2009) 007 [arXiv:0811.4622] [INSPIRE].
Sherpa collaboration, Event Generation with Sherpa 2.2, SciPost Phys. 7 (2019) 034 [arXiv:1905.09127] [INSPIRE].
S. Höche, S. Kuttimalai, S. Schumann and F. Siegert, Beyond Standard Model calculations with Sherpa, Eur. Phys. J. C 75 (2015) 135 [arXiv:1412.6478] [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].
S. Frixione et al., Automated simulations beyond the Standard Model: supersymmetry, JHEP 12 (2019) 008 [arXiv:1907.04898] [INSPIRE].
W. Beenakker and A. Werthenbach, New insights into the perturbative structure of electroweak Sudakov logarithms, Phys. Lett. B 489 (2000) 148 [hep-ph/0005316] [INSPIRE].
N. Darvishi and M.R. Masouminia, Signature of the Maximally Symmetric 2HDM via W±/Z-Quadruplet Productions at the LHC, Phys. Rev. D 103 (2021) 095031 [arXiv:2012.14746] [INSPIRE].
J.R. Christiansen and T. Sjöstrand, Weak Gauge Boson Radiation in Parton Showers, JHEP 04 (2014) 115 [arXiv:1401.5238] [INSPIRE].
M.R. Masouminia and P. Richardson, Implementation of angularly ordered electroweak parton shower in Herwig 7, JHEP 04 (2022) 112 [arXiv:2108.10817] [INSPIRE].
R. Kleiss and R. Verheyen, Collinear electroweak radiation in antenna parton showers, Eur. Phys. J. C 80 (2020) 980 [arXiv:2002.09248] [INSPIRE].
J. Chen, On the Feynman Rules of Massive Gauge Theory in Physical Gauges, arXiv:1902.06738 [INSPIRE].
CMS collaboration, Search for a Narrow Resonance Lighter than 200 GeV Decaying to a Pair of Muons in Proton-Proton Collisions at \( \sqrt{s} \) = 13 TeV, Phys. Rev. Lett. 124 (2020) 131802 [arXiv:1912.04776] [INSPIRE].
CMS collaboration, Search for long-lived particles decaying into muon pairs in proton-proton collisions at \( \sqrt{s} \) = 13 TeV collected with a dedicated high-rate data stream, JHEP 04 (2022) 062 [arXiv:2112.13769] [INSPIRE].
CMS collaboration, Search for long-lived particles decaying to a pair of muons in proton-proton collisions at \( \sqrt{s} \) = 13 TeV, JHEP 05 (2023) 228 [arXiv:2205.08582] [INSPIRE].
LHCb collaboration, Searches for low-mass dimuon resonances, JHEP 10 (2020) 156 [arXiv:2007.03923] [INSPIRE].
G. Marchesini and B.R. Webber, Simulation of QCD Jets Including Soft Gluon Interference, Nucl. Phys. B 238 (1984) 1 [INSPIRE].
A. Alloul et al., FeynRules 2.0 — A complete toolbox for tree-level phenomenology, Comput. Phys. Commun. 185 (2014) 2250 [arXiv:1310.1921] [INSPIRE].
C. Degrande et al., UFO — The Universal FeynRules Output, Comput. Phys. Commun. 183 (2012) 1201 [arXiv:1108.2040] [INSPIRE].
G. Bewick, S. Ferrario Ravasio, P. Richardson and M.H. Seymour, Logarithmic accuracy of angular-ordered parton showers, JHEP 04 (2020) 019 [arXiv:1904.11866] [INSPIRE].
G. Bewick, S. Ferrario Ravasio, P. Richardson and M.H. Seymour, Initial state radiation in the Herwig 7 angular-ordered parton shower, JHEP 01 (2022) 026 [arXiv:2107.04051] [INSPIRE].
S. Höche and S. Prestel, The midpoint between dipole and parton showers, Eur. Phys. J. C 75 (2015) 461 [arXiv:1506.05057] [INSPIRE].
M. Dasgupta et al., Parton showers beyond leading logarithmic accuracy, Phys. Rev. Lett. 125 (2020) 052002 [arXiv:2002.11114] [INSPIRE].
Z. Nagy and D.E. Soper, Summations of large logarithms by parton showers, Phys. Rev. D 104 (2021) 054049 [arXiv:2011.04773] [INSPIRE].
S. Dawson, The Effective W Approximation, Nucl. Phys. B 249 (1985) 42 [INSPIRE].
S. Catani, S. Dittmaier and Z. Trócsányi, One loop singular behavior of QCD and SUSY QCD amplitudes with massive partons, Phys. Lett. B 500 (2001) 149 [hep-ph/0011222] [INSPIRE].
G. Altarelli and G. Parisi, Asymptotic Freedom in Parton Language, Nucl. Phys. B 126 (1977) 298 [INSPIRE].
S.D. Badger and E.W.N. Glover, Two loop splitting functions in QCD, JHEP 07 (2004) 040 [hep-ph/0405236] [INSPIRE].
T.G. Birthwright, E.W.N. Glover, V.V. Khoze and P. Marquard, Collinear limits in QCD from MHV rules, JHEP 07 (2005) 068 [hep-ph/0505219] [INSPIRE].
C. Degrande, Automatic evaluation of UV and R2 terms for beyond the Standard Model Lagrangians: a proof-of-principle, Comput. Phys. Commun. 197 (2015) 239 [arXiv:1406.3030] [INSPIRE].
N. Darvishi and A. Pilaftsis, Quartic Coupling Unification in the Maximally Symmetric 2HDM, Phys. Rev. D 99 (2019) 115014 [arXiv:1904.06723] [INSPIRE].
N. Darvishi, A. Pilaftsis and J.-H. Yu, Maximising CP Violation in naturally aligned Two-Higgs Doublet Models, JHEP 05 (2024) 233 [arXiv:2312.00882] [INSPIRE].
S. Amrith et al., LHC Constraints on a B − L Gauge Model using Contur, JHEP 05 (2019) 154 [arXiv:1811.11452] [INSPIRE].
F.F. Deppisch, W. Liu and M. Mitra, Long-lived Heavy Neutrinos from Higgs Decays, JHEP 08 (2018) 181 [arXiv:1804.04075] [INSPIRE].
L. Basso, A. Belyaev, S. Moretti and C.H. Shepherd-Themistocleous, Phenomenology of the minimal B-L extension of the Standard model: Z’ and neutrinos, Phys. Rev. D 80 (2009) 055030 [arXiv:0812.4313] [INSPIRE].
Z. Sullivan, Fully Differential W′ Production and Decay at Next-to-Leading Order in QCD, Phys. Rev. D 66 (2002) 075011 [hep-ph/0207290] [INSPIRE].
D. Duffty and Z. Sullivan, Model independent reach for W-prime bosons at the LHC, Phys. Rev. D 86 (2012) 075018 [arXiv:1208.4858] [INSPIRE].
G. Marchesini and B.R. Webber, Simulation of QCD Coherence in Heavy Quark Production and Decay, Nucl. Phys. B 330 (1990) 261 [INSPIRE].
S. Gieseke, P. Stephens and B. Webber, New formalism for QCD parton showers, JHEP 12 (2003) 045 [hep-ph/0310083] [INSPIRE].
S. Gieseke et al., Herwig++ 1.0: An event generator for e+e− annihilation, JHEP 02 (2004) 005 [hep-ph/0311208] [INSPIRE].
D. Reichelt, P. Richardson and A. Siodmok, Improving the Simulation of Quark and Gluon Jets with Herwig 7, Eur. Phys. J. C 77 (2017) 876 [arXiv:1708.01491] [INSPIRE].
J. Bellm et al., Herwig 7.1 Release Note, arXiv:1705.06919 [INSPIRE].
W. Beenakker, R. Höpker, M. Spira and P.M. Zerwas, Squark and gluino production at hadron colliders, Nucl. Phys. B 492 (1997) 51 [hep-ph/9610490] [INSPIRE].
F. Arco, S. Heinemeyer and M.J. Herrero, Exploring sizable triple Higgs couplings in the 2HDM, Eur. Phys. J. C 80 (2020) 884 [arXiv:2005.10576] [INSPIRE].
F. Arco, S. Heinemeyer and M.J. Herrero, Triple Higgs couplings in the 2HDM: the complete picture, Eur. Phys. J. C 82 (2022) 536 [arXiv:2203.12684] [INSPIRE].
J.F. Gunion and H.E. Haber, Higgs Bosons in Supersymmetric Models. 1, Nucl. Phys. B 272 (1986) 1 [INSPIRE].
A. Pilaftsis and C.E.M. Wagner, Higgs bosons in the minimal supersymmetric standard model with explicit CP violation, Nucl. Phys. B 553 (1999) 3 [hep-ph/9902371] [INSPIRE].
Y.L. Dokshitzer, Perturbative QCD for Beginners, in QCD Perspectives on Hot and Dense Matter, J.P. Blaizot, E. Iancu eds., Springer Netherlands (2002), p. 1–44 [https://doi.org/10.1007/978-94-010-0267-7_1].
S.D. Drell, D.J. Levy and T.-M. Yan, A Theory of Deep Inelastic Lepton-Nucleon Scattering and Lepton Pair Annihilation Processes. 1, Phys. Rev. 187 (1969) 2159 [INSPIRE].
S.D. Drell, D.J. Levy and T.-M. Yan, A Theory of Deep Inelastic Lepton-Nucleon Scattering and Lepton Pair Annihilation Processes. 3. Deep Inelastic electron-Positron Annihilation, Phys. Rev. D 1 (1970) 1617 [INSPIRE].
J. Blümlein, V. Ravindran and W.L. van Neerven, On the Drell-Levy-Yan relation to O(α2), Nucl. Phys. B 586 (2000) 349 [hep-ph/0004172] [INSPIRE].
L. Carloni and T. Sjöstrand, Visible Effects of Invisible Hidden Valley Radiation, JHEP 09 (2010) 105 [arXiv:1006.2911] [INSPIRE].
Acknowledgments
We would like to express our gratitude to our fellow Herwig authors for their invaluable contributions, with special thanks to N. Darvishi and P. Richardson for their insightful discussions and support. This work has received funding from the European Union’s Horizon 2020 research and innovation programme as part of the Marie Skłodowska-Curie Innovative Training Network MCnetITN3 (grant agreement no. 722104) and from the UK Science and Technology Facilities Council (grant numbers ST/T001011/1 and ST/T001038/1). This research was also supported in Korea by National Research Foundation grants NRF-2021R1A2C2014311, NRF-2008-00460 and the Promising-Pioneering Researcher Program through Seoul National University.
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Lee, JB., Masouminia, M.R., Seymour, M.H. et al. Generalized angular-order parton showers in Herwig 7. J. High Energ. Phys. 2024, 64 (2024). https://doi.org/10.1007/JHEP08(2024)064
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DOI: https://doi.org/10.1007/JHEP08(2024)064