Abstract
Soft drop has been shown to reduce hadronisation effects at e+e− colliders for the thrust event shape. In this context, we perform fits of the strong coupling constant for the soft-drop thrust distribution at NLO+NLL accuracy to pseudo data generated by the Sherpa event generator. In particular, we focus on the impact of hadronisation corrections, which we estimate both with an analytical model and a Monte-Carlo based one, on the fitted value of αs(mZ). We find that grooming can reduce the size of the shift in the fitted value of αs due to hadronisation. In addition, we also explore the possibility of extending the fitting range down to significantly lower values of (one minus) thrust. Here, soft drop is shown to play a crucial role, allowing us to maintain good fit qualities and stable values of the fitted strong coupling. The results of these studies show that soft-drop thrust is a promising candidate for fitting αs at e+e− colliders with reduced impact of hadronisation effects.
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References
Particle Data Group collaboration, Review of particle physics, Phys. Rev. D 98 (2018) 030001 [INSPIRE].
K. Maltman and T. Yavin, αs(MZ2) from hadronic τ decays, Phys. Rev. D 78 (2008) 094020 [arXiv:0807.0650] [INSPIRE].
PACS-CS collaboration, Precise determination of the strong coupling constant in Nf = 2 + 1 lattice QCD with the Schrödinger functional scheme, JHEP 10 (2009) 053 [arXiv:0906.3906] [INSPIRE].
C. McNeile et al., High-precision c and b masses and QCD coupling from current-current correlators in lattice and continuum QCD, Phys. Rev. D 82 (2010) 034512 [arXiv:1004.4285] [INSPIRE].
B. Blossier et al., The strong running coupling at τ and Z0 mass scales from lattice QCD, Phys. Rev. Lett. 108 (2012) 262002 [arXiv:1201.5770] [INSPIRE].
B. Chakraborty et al., High-precision quark masses and QCD coupling from nf = 4 lattice QCD, Phys. Rev. D 91 (2015) 054508 [arXiv:1408.4169] [INSPIRE].
Fermilab Lattice, MILC collaboration, Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks, Phys. Rev. D 90 (2014) 074509 [arXiv:1407.3772] [INSPIRE].
JADE collaboration, Determination of the strong coupling αs from hadronic event shapes with \( O\left({\alpha}_s^3\right) \) and resummed QCD predictions using JADE data, Eur. Phys. J. C 64 (2009) 351 [arXiv:0810.1389] [INSPIRE].
G. Dissertori et al., Determination of the strong coupling constant using matched NNLO+NLLA predictions for hadronic event shapes in e+ e− annihilations, JHEP 08 (2009) 036 [arXiv:0906.3436] [INSPIRE].
G. Dissertori et al., Precise determination of the strong coupling constant at NNLO in QCD from the three-jet rate in electron-positron annihilation at LEP, Phys. Rev. Lett. 104 (2010) 072002 [arXiv:0910.4283] [INSPIRE].
OPAL collaboration, Determination of αs using OPAL hadronic event shapes at \( \sqrt{s} \) = 91–209 GeV and resummed NNLO calculations, Eur. Phys. J. C 71 (2011) 1733 [arXiv:1101.1470] [INSPIRE].
JADE collaboration, Measurement of the strong coupling αs from the three-jet rate in e+ e− -annihilation using JADE data, Eur. Phys. J. C 73 (2013) 2332 [arXiv:1205.3714] [INSPIRE].
R.A. Davison and B.R. Webber, Non-perturbative contribution to the thrust distribution in e+e− annihilation, Eur. Phys. J. C 59 (2009) 13 [arXiv:0809.3326] [INSPIRE].
R. Abbate et al., Thrust at N3 LL with power corrections and a precision global fit for αs(mZ), Phys. Rev. D 83 (2011) 074021 [arXiv:1006.3080] [INSPIRE].
T. Gehrmann, G. Luisoni and P.F. Monni, Power corrections in the dispersive model for a determination of the strong coupling constant from the thrust distribution, Eur. Phys. J. C 73 (2013) 2265 [arXiv:1210.6945] [INSPIRE].
A.H. Hoang, D.W. Kolodrubetz, V. Mateu and I.W. Stewart, C-parameter distribution at N3LL’ including power corrections, Phys. Rev. D 91 (2015) 094017 [arXiv:1411.6633] [INSPIRE].
E. Farhi, A QCD test for jets, Phys. Rev. Lett. 39 (1977) 1587 [INSPIRE].
R. Abbate et al., Precision thrust cumulant moments at N3LL, Phys. Rev. D 86 (2012) 094002 [arXiv:1204.5746] [INSPIRE].
J. Baron, S. Marzani and V. Theeuwes, Soft-drop thrust, JHEP 08 (2018) 105 [arXiv:1803.04719] [INSPIRE].
J.R. Andersen et al., Les Houches 2017: physics at TeV colliders standard model working group report, arXiv:1803.07977.
S. Marzani, G. Soyez and M. Spannowsky, Looking inside jets: an introduction to jet substructure and boosted-object phenomenology, arXiv:1901.10342 [INSPIRE].
A.J. Larkoski, I. Moult and B. Nachman, Jet substructure at the Large Hadron Collider: a review of recent advances in theory and machine learning, arXiv:1709.04464 [INSPIRE].
R. Kogler et al., Jet substructure at the Large Hadron Collider: experimental review, arXiv:1803.06991 [INSPIRE].
A.J. Larkoski, S. Marzani, G. Soyez and J. Thaler, Soft drop, JHEP 05 (2014) 146 [arXiv:1402.2657] [INSPIRE].
E. Bothmann et al., Event generation with Sherpa 2.2, SciPost Phys. 7 (2019) 034 [arXiv:1905.09127] [INSPIRE].
T. Gleisberg et al., Event generation with SHERPA 1.1, JHEP 02 (2009) 007 [arXiv:0811.4622] [INSPIRE].
Y.L. Dokshitzer, G.D. Leder, S. Moretti and B.R. Webber, Better jet clustering algorithms, JHEP 08 (1997) 001 [hep-ph/9707323] [INSPIRE].
M. Wobisch and T. Wengler, Hadronization corrections to jet cross-sections in deep inelastic scattering, hep-ph/9907280 [INSPIRE].
J.M. Butterworth, A.R. Davison, M. Rubin and G.P. Salam, Jet substructure as a new Higgs search channel at the LHC, Phys. Rev. Lett. 100 (2008) 242001 [arXiv:0802.2470] [INSPIRE].
M. Dasgupta, A. Fregoso, S. Marzani and G.P. Salam, Towards an understanding of jet substructure, JHEP 09 (2013) 029 [arXiv:1307.0007] [INSPIRE].
M. Cacciari, G.P. Salam and G. Soyez, FastJet user manual, Eur. Phys. J. C 72 (2012) 1896 [arXiv:1111.6097] [INSPIRE].
C. Frye, A.J. Larkoski, M.D. Schwartz and K. Yan, Factorization for groomed jet substructure beyond the next-to-leading logarithm, JHEP 07 (2016) 064 [arXiv:1603.09338] [INSPIRE].
A. Kardos, G. Somogyi and Z. Trócsányi, Soft-drop event shapes in electron–positron annihilation at next-to-next-to-leading order accuracy, Phys. Lett. B 786 (2018) 313 [arXiv:1807.11472] [INSPIRE].
S. Marzani, L. Schunk and G. Soyez, A study of jet mass distributions with grooming, JHEP 07 (2017) 132 [arXiv:1704.02210] [INSPIRE].
S. Catani and M.H. Seymour, The dipole formalism for the calculation of QCD jet cross-sections at next-to-leading order, Phys. Lett. B 378 (1996) 287 [hep-ph/9602277] [INSPIRE].
S. Catani and M.H. Seymour, A general algorithm for calculating jet cross-sections in NLO QCD, Nucl. Phys. B 485 (1997) 291 [Erratum ibid. B 510 (1998) 503] [hep-ph/9605323] [INSPIRE].
A. Banfi, G.P. Salam and G. Zanderighi, Principles of general final-state resummation and automated implementation, JHEP 03 (2005) 073 [hep-ph/0407286] [INSPIRE].
E. Gerwick, S. Hoeche, S. Marzani and S. Schumann, Soft evolution of multi-jet final states, JHEP 02 (2015) 106 [arXiv:1411.7325] [INSPIRE].
A. Banfi, G.P. Salam and G. Zanderighi, Phenomenology of event shapes at hadron colliders, JHEP 06 (2010) 038 [arXiv:1001.4082] [INSPIRE].
S. Catani, L. Trentadue, G. Turnock and B.R. Webber, Resummation of large logarithms in e+e− event shape distributions, Nucl. Phys. B 407 (1993) 3 [INSPIRE].
R.W.L. Jones et al., Theoretical uncertainties on αs from event shape variables in e+e− annihilations, JHEP 12 (2003) 007 [hep-ph/0312016] [INSPIRE].
S. Schumann and F. Krauss, A parton shower algorithm based on Catani-Seymour dipole factorisation, JHEP 03 (2008) 038 [arXiv:0709.1027] [INSPIRE].
S. Frixione and B.R. Webber, Matching NLO QCD computations and parton shower simulations, JHEP 06 (2002) 029 [hep-ph/0204244] [INSPIRE].
S. Hoeche, F. Krauss, M. Schonherr and F. Siegert, A critical appraisal of NLO+PS matching methods, JHEP 09 (2012) 049 [arXiv:1111.1220] [INSPIRE].
S. Hoeche, F. Krauss, M. Schonherr and F. Siegert, QCD matrix elements + parton showers: the NLO case, JHEP 04 (2013) 027 [arXiv:1207.5030] [INSPIRE].
F. Cascioli, P. Maierhofer and S. Pozzorini, Scattering amplitudes with open loops, Phys. Rev. Lett. 108 (2012) 111601 [arXiv:1111.5206] [INSPIRE].
J.-C. Winter, F. Krauss and G. Soff, A modified cluster hadronization model, Eur. Phys. J. C 36 (2004) 381 [hep-ph/0311085] [INSPIRE].
T. Sjöstrand, The Lund Monte Carlo for jet fragmentation, Comput. Phys. Commun. 27 (1982) 243 [INSPIRE].
T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 physics and manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].
A. Buckley et al., Rivet user manual, Comput. Phys. Commun. 184 (2013) 2803 [arXiv:1003.0694] [INSPIRE].
T. Gehrmann et al., NLO QCD matrix elements + parton showers in e+e− → hadrons, JHEP 01 (2013) 144 [arXiv:1207.5031] [INSPIRE].
ALEPH collaboration, Studies of QCD at e+e− centre-of-mass energies between 91 GeV and 209 GeV, Eur. Phys. J. C 35 (2004) 457 [INSPIRE].
S. Höche, D. Reichelt and F. Siegert, Momentum conservation and unitarity in parton showers and NLL resummation, JHEP 01 (2018) 118 [arXiv:1711.03497] [INSPIRE].
T. Sjöstrand, S. Mrenna and P.Z. Skands, A brief introduction to PYTHIA 8.1, Comput. Phys. Commun. 178 (2008) 852 [arXiv:0710.3820] [INSPIRE].
M. Bahr et al., HERWIG++ physics and manual, Eur. Phys. J. C 58 (2008) 639 [arXiv:0803.0883] [INSPIRE].
S. Höche and S. Prestel, The midpoint between dipole and parton showers, Eur. Phys. J. C 75 (2015) 461 [arXiv:1506.05057] [INSPIRE].
A. Verbytskyi et al., High precision determination of αs from a global fit of jet rates, JHEP 08 (2019) 129 [arXiv:1902.08158] [INSPIRE].
A.H. Hoang, S. Mantry, A. Pathak and I.W. Stewart, Nonperturbative corrections to soft drop jet mass, arXiv:1906.11843 [INSPIRE].
A. Buckley et al., General-purpose event generators for LHC physics, Phys. Rept. 504 (2011) 145 [arXiv:1101.2599] [INSPIRE].
M. Dasgupta, L. Magnea and G.P. Salam, Non-perturbative QCD effects in jets at hadron colliders, JHEP 02 (2008) 055 [arXiv:0712.3014] [INSPIRE].
S. Marzani, L. Schunk and G. Soyez, The jet mass distribution after soft drop, Eur. Phys. J. C 78 (2018) 96 [arXiv:1712.05105] [INSPIRE].
A. Banfi, H. McAslan, P.F. Monni and G. Zanderighi, A general method for the resummation of event-shape distributions in e+e− annihilation, JHEP 05 (2015) 102 [arXiv:1412.2126] [INSPIRE].
S. Catani, B.R. Webber and G. Marchesini, QCD coherent branching and semiinclusive processes at large x, Nucl. Phys. B 349 (1991) 635 [INSPIRE].
J. Bellm et al., HERWIG 7.0/HERWIG++ 3.0 release note, Eur. Phys. J. C 76 (2016) 196 [arXiv:1512.01178] [INSPIRE].
B.R. Webber, A QCD model for jet fragmentation including soft gluon interference, Nucl. Phys. B 238 (1984) 492 [INSPIRE].
S. Gieseke, C. Rohr and A. Siodmok, Colour reconnections in HERWIG++, Eur. Phys. J. C 72 (2012) 2225 [arXiv:1206.0041] [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].
R. Corke and T. Sjöstrand, Interleaved parton showers and tuning prospects, JHEP 03 (2011) 032 [arXiv:1011.1759] [INSPIRE].
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ArXiv ePrint: 1906.10504
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Marzani, S., Reichelt, D., Schumann, S. et al. Fitting the strong coupling constant with soft-drop thrust. J. High Energ. Phys. 2019, 179 (2019). https://doi.org/10.1007/JHEP11(2019)179
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DOI: https://doi.org/10.1007/JHEP11(2019)179