Abstract
We present a phenomenological analysis of asymmetric bottom- and charm-quark production within the LHCb acceptance relevant for pp collisions at \( \sqrt{s}=13 \) TeV. Predictions are provided for both anti-kt bottom- and charm-jet pairs, which are kept differentially with respect to the invariant mass of the jet pair. It is quantified how data in this region can provide sensitivity to the couplings of the Z boson to heavy quarks, and we investigate what precision is needed to compete with LEP. We also discuss how asymmetry and rate measurements can provide constraints on a particular class of new-physics models, which contains gauge bosons with small/moderate couplings to light/heavy quarks and masses of the order of 100GeV. Predictions are obtained including all relevant QCD and QED/weak contributions up to next-to-leading order, which have been implemented in a Fortran code which allows to directly compute the asymmetric cross sections. We provide all relevant analytic formulas for our computations.
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References
ALEPH, DELPHI, L3, OPAL, SLD, LEP Electroweak Working Group, SLD Electroweak Group and SLD Heavy Flavour Group collaborations, Precision electroweak measurements on the Z resonance, Phys. Rept. 427 (2006) 257 [hep-ex/0509008] [INSPIRE].
D0 collaboration, Measurement of the forward-backward asymmetry in the production of B ± mesons in \( p\overline{p} \) collisions at \( \sqrt{s}=1.96 \) TeV, Phys. Rev. Lett. 114 (2015) 051803 [arXiv:1411.3021] [INSPIRE].
CDF collaboration, Measurement of the forward-backward asymmetry in low-mass bottom-quark pairs produced in proton-antiproton collisions, Phys. Rev. D 93 (2016) 112003 [arXiv:1601.06526] [INSPIRE].
LHCb collaboration, First measurement of the charge asymmetry in beauty-quark pair production, Phys. Rev. Lett. 113 (2014) 082003 [arXiv:1406.4789] [INSPIRE].
Y. Bai, J.L. Hewett, J. Kaplan and T.G. Rizzo, LHC predictions from a Tevatron anomaly in the top quark forward-backward asymmetry, JHEP 03 (2011) 003 [arXiv:1101.5203] [INSPIRE].
D. Kahawala, D. Krohn and M.J. Strassler, Measuring the bottom-quark forward-central asymmetry at the LHC, JHEP 01 (2012) 069 [arXiv:1108.3301] [INSPIRE].
P. Saha, Bottom pair production and search for heavy resonances, Phys. Lett. B 700 (2011) 221 [arXiv:1101.5797] [INSPIRE].
A.V. Manohar and M. Trott, Electroweak Sudakov corrections and the top quark forward-backward asymmetry, Phys. Lett. B 711 (2012) 313 [arXiv:1201.3926] [INSPIRE].
J. Drobnak, J.F. Kamenik and J. Zupan, Flipping \( t\overline{t} \) asymmetries at the Tevatron and the LHC, Phys. Rev. D 86 (2012) 054022 [arXiv:1205.4721] [INSPIRE].
C. Delaunay, O. Gedalia, Y. Hochberg and Y. Soreq, Predictions from heavy new physics interpretation of the top forward-backward asymmetry, JHEP 12 (2012) 053 [arXiv:1207.0740] [INSPIRE].
S. Ipek, Light axigluon contributions to \( b\overline{b} \) and \( c\overline{c} \) asymmetry and constraints on flavor changing axigluon currents, Phys. Rev. D 87 (2013) 116010 [arXiv:1301.3990] [INSPIRE].
B. Grinstein and C.W. Murphy, Bottom-quark forward-backward asymmetry in the Standard Model and beyond, Phys. Rev. Lett. 111 (2013) 062003 [Erratum ibid. 112 (2014) 239901] [arXiv:1302.6995] [INSPIRE].
C.W. Murphy, Bottom-quark forward-backward and charge asymmetries at hadron colliders, Phys. Rev. D 92 (2015) 054003 [arXiv:1504.02493] [INSPIRE].
R. Gauld, U. Haisch, B.D. Pecjak and E. Re, Beauty-quark and charm-quark pair production asymmetries at LHCb, Phys. Rev. D 92 (2015) 034007 [arXiv:1505.02429] [INSPIRE].
LHCb collaboration, collaboration, The LHCb detector at the LHC, 2008 JINST 3 S08005 [INSPIRE].
LHCb collaboration, Identification of beauty and charm quark jets at LHCb, 2015 JINST 10 P06013 [arXiv:1504.07670] [INSPIRE].
LHCb collaboration, First observation of forward \( Z\to b\overline{b} \) production in pp collisions at \( \sqrt{s}=8 \) TeV, Phys. Lett. B 776 (2018) 430 [arXiv:1709.03458] [INSPIRE].
M. Cacciari, G.P. Salam and G. Soyez, The anti-k t jet clustering algorithm, JHEP 04 (2008) 063 [arXiv:0802.1189] [INSPIRE].
J.C. Collins, D.E. Soper and G.F. Sterman, Factorization of hard processes in QCD, Adv. Ser. Direct. High Energy Phys. 5 (1989) 1 [hep-ph/0409313] [INSPIRE].
P. Nason, S. Dawson and R.K. Ellis, The total cross-section for the production of heavy quarks in hadronic collisions, Nucl. Phys. B 303 (1988) 607 [INSPIRE].
P. Nason, S. Dawson and R.K. Ellis, The one particle inclusive differential cross-section for heavy quark production in hadronic collisions, Nucl. Phys. B 327 (1989) 49 [Erratum ibid. B 335 (1990) 260] [INSPIRE].
M.L. Mangano, P. Nason and G. Ridolfi, Heavy quark correlations in hadron collisions at next-to-leading order, Nucl. Phys. B 373 (1992) 295 [INSPIRE].
W. Beenakker, W.L. van Neerven, R. Meng, G.A. Schuler and J. Smith, QCD corrections to heavy quark production in hadron hadron collisions, Nucl. Phys. B 351 (1991) 507 [INSPIRE].
W. Beenakker, H. Kuijf, W.L. van Neerven and J. Smith, QCD corrections to heavy quark production in \( p\overline{p} \) collisions, Phys. Rev. D 40 (1989) 54 [INSPIRE].
J.H. Kühn, A. Scharf and P. Uwer, Electroweak corrections to top-quark pair production in quark-antiquark annihilation, Eur. Phys. J. C 45 (2006) 139 [hep-ph/0508092] [INSPIRE].
J.H. Kühn, A. Scharf and P. Uwer, Electroweak effects in top-quark pair production at hadron colliders, Eur. Phys. J. C 51 (2007) 37 [hep-ph/0610335] [INSPIRE].
W. Bernreuther, M. Fücker and Z.-G. Si, Weak interaction corrections to hadronic top quark pair production, Phys. Rev. D 74 (2006) 113005 [hep-ph/0610334] [INSPIRE].
W. Hollik and M. Kollar, NLO QED contributions to top-pair production at hadron collider, Phys. Rev. D 77 (2008) 014008 [arXiv:0708.1697] [INSPIRE].
J.H. Kühn, A. Scharf and P. Uwer, Weak effects in b-jet production at hadron colliders, Phys.Rev. D 82 (2010) 013007 [arXiv:0909.0059] [INSPIRE].
A. Buckley et al., LHAPDF6: parton density access in the LHC precision era, Eur. Phys. J. C 75 (2015) 132 [arXiv:1412.7420] [INSPIRE].
T. Hahn, CUBA: a library for multidimensional numerical integration, Comput. Phys. Commun. 168 (2005) 78 [hep-ph/0404043] [INSPIRE].
A. van Hameren, C.G. Papadopoulos and R. Pittau, Automated one-loop calculations: a proof of concept, JHEP 09 (2009) 106 [arXiv:0903.4665] [INSPIRE].
A. van Hameren, OneLOop: for the evaluation of one-loop scalar functions, Comput. Phys. Commun. 182 (2011) 2427 [arXiv:1007.4716] [INSPIRE].
S. Frixione, P. Nason and G. Ridolfi, A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction, JHEP 09 (2007) 126 [arXiv:0707.3088] [INSPIRE].
V. Hirschi, R. Frederix, S. Frixione, M.V. Garzelli, F. Maltoni and R. Pittau, Automation of one-loop QCD corrections, JHEP 05 (2011) 044 [arXiv:1103.0621] [INSPIRE].
V. Hirschi and O. Mattelaer, Automated event generation for loop-induced processes, JHEP 10 (2015) 146 [arXiv:1507.00020] [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].
Computing the interference of loop-induced diagrams with a tree-level background with MadEvent in MG5aMC webpage, https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/LoopInducedTimesTree.
T. Hahn, Generating Feynman diagrams and amplitudes with FeynArts 3, Comput. Phys. Commun. 140 (2001) 418 [hep-ph/0012260] [INSPIRE].
T. Hahn and M. Pérez-Victoria, Automatized one loop calculations in four-dimensions and D-dimensions, Comput. Phys. Commun. 118 (1999) 153 [hep-ph/9807565] [INSPIRE].
B.W. Harris and J.F. Owens, The two cutoff phase space slicing method, Phys. Rev. D 65 (2002) 094032 [hep-ph/0102128] [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].
M. Czakon, P. Fiedler and A. Mitov, Resolving the Tevatron top quark forward-backward asymmetry puzzle: fully differential next-to-next-to-leading-order calculation, Phys. Rev. Lett. 115 (2015) 052001 [arXiv:1411.3007] [INSPIRE].
J. Currie, E.W.N. Glover and J. Pires, Next-to-next-to leading order QCD predictions for single jet inclusive production at the LHC, Phys. Rev. Lett. 118 (2017) 072002 [arXiv:1611.01460] [INSPIRE].
LHC Higgs Cross Section Working Group collaboration, Handbook of LHC Higgs cross sections: 4. Deciphering the nature of the Higgs sector, arXiv:1610.07922 [INSPIRE].
A. Manohar, P. Nason, G.P. Salam and G. Zanderighi, How bright is the proton? A precise determination of the photon parton distribution function, Phys. Rev. Lett. 117 (2016) 242002 [arXiv:1607.04266] [INSPIRE].
A. Banfi, G.P. Salam and G. Zanderighi, Infrared safe definition of jet flavor, Eur. Phys. J. C 47 (2006) 113 [hep-ph/0601139] [INSPIRE].
M. Czakon, P. Fiedler and A. Mitov, Total top-quark pair-production cross section at hadron colliders through O(α 4 S ), Phys. Rev. Lett. 110 (2013) 252004 [arXiv:1303.6254] [INSPIRE].
NNPDF collaboration, Parton distributions from high-precision collider data, Eur. Phys. J. C 77 (2017) 663 [arXiv:1706.00428] [INSPIRE].
M. Cacciari, M. Greco and P. Nason, The p T spectrum in heavy flavor hadroproduction, JHEP 05 (1998) 007 [hep-ph/9803400] [INSPIRE].
D. de Florian, G.F.R. Sborlini and G. Rodrigo, QED corrections to the Altarelli-Parisi splitting functions, Eur. Phys. J. C 76 (2016) 282 [arXiv:1512.00612] [INSPIRE].
L.A. Harland-Lang, V.A. Khoze and M.G. Ryskin, The photon PDF in events with rapidity gaps, Eur. Phys. J. C 76 (2016) 255 [arXiv:1601.03772] [INSPIRE].
L.A. Harland-Lang, V.A. Khoze and M.G. Ryskin, Photon-initiated processes at high mass, Phys. Rev. D 94 (2016) 074008 [arXiv:1607.04635] [INSPIRE].
A.V. Manohar, P. Nason, G.P. Salam and G. Zanderighi, The photon content of the proton, JHEP 12 (2017) 046 [arXiv:1708.01256] [INSPIRE].
NNPDF collaboration, Illuminating the photon content of the proton within a global PDF analysis, SciPost Phys. 5 (2018) 008 [arXiv:1712.07053] [INSPIRE].
D. Pagani, I. Tsinikos and M. Zaro, The impact of the photon PDF and electroweak corrections on \( t\overline{t} \) distributions, Eur. Phys. J. C 76 (2016) 479 [arXiv:1606.01915] [INSPIRE].
M. Czakon, D. Heymes, A. Mitov, D. Pagani, I. Tsinikos and M. Zaro, Top-pair production at the LHC through NNLO QCD and NLO EW, JHEP 10 (2017) 186 [arXiv:1705.04105] [INSPIRE].
M. Czakon, D. Heymes, A. Mitov, D. Pagani, I. Tsinikos and M. Zaro, Top-quark charge asymmetry at the LHC and Tevatron through NNLO QCD and NLO EW, Phys. Rev. D 98 (2018) 014003 [arXiv:1711.03945] [INSPIRE].
J. Fleischer, O.V. Tarasov and F. Jegerlehner, Two loop heavy top corrections to the ρ parameter: a simple formula valid for arbitrary Higgs mass, Phys. Lett. B 319 (1993) 249 [INSPIRE].
A. Denner, S. Dittmaier, M. Roth and L.H. Wieders, Electroweak corrections to charged-current e + e − → 4 fermion processes: technical details and further results, Nucl. Phys. B 724 (2005) 247 [Erratum ibid. B 854 (2012) 504] [hep-ph/0505042] [INSPIRE].
A.L. Kagan, J.F. Kamenik, G. Perez and S. Stone, Top LHCb physics, Phys. Rev. Lett. 107 (2011) 082003 [arXiv:1103.3747] [INSPIRE].
R. Gauld, Feasibility of top quark measurements at LHCb and constraints on the large-x gluon PDF, JHEP 02 (2014) 126 [arXiv:1311.1810] [INSPIRE].
R. Gauld, Leptonic top-quark asymmetry predictions at LHCb, Phys. Rev. D 91 (2015) 054029 [arXiv:1409.8631] [INSPIRE].
LHCb collaboration, First observation of top quark production in the forward region, Phys. Rev. Lett. 115 (2015) 112001 [arXiv:1506.00903] [INSPIRE].
LHCb collaboration, Measurement of forward top pair production in the dilepton channel in pp collisions at \( \sqrt{s}=13 \) TeV, JHEP 08 (2018) 174 [arXiv:1803.05188] [INSPIRE].
M. Czakon et al., Resummation for (boosted) top-quark pair production at NNLO+NNLL’ in QCD, JHEP 05 (2018) 149 [arXiv:1803.07623] [INSPIRE].
LHCb collaboration, Physics case for an LHCb upgrade II — opportunities in flavour physics and beyond, in the HL-LHC era, arXiv:1808.08865 [INSPIRE].
D. Liu, J. Liu, C.E.M. Wagner and X.-P. Wang, Bottom-quark forward-backward asymmetry, dark matter and the LHC, Phys. Rev. D 97 (2018) 055021 [arXiv:1712.05802] [INSPIRE].
A.B. Arbuzov et al., ZFITTER: a semi-analytical program for fermion pair production in e + e − annihilation, from version 6.21 to version 6.42, Comput. Phys. Commun. 174 (2006) 728 [hep-ph/0507146] [INSPIRE].
Particle Data Group collaboration, Review of particle physics, Phys. Rev. D 98 (2018) 030001 [INSPIRE].
CMS collaboration, Search for low mass vector resonances decaying into quark-antiquark pairs in proton-proton collisions at \( \sqrt{s}=13 \) TeV, JHEP 01 (2018) 097 [arXiv:1710.00159] [INSPIRE].
ATLAS collaboration, Search for the neutral Higgs bosons of the minimal supersymmetric Standard Model in pp collisions at \( \sqrt{s}=7 \) TeV with the ATLAS detector, JHEP 02 (2013) 095 [arXiv:1211.6956] [INSPIRE].
ATLAS collaboration, Search for new high-mass phenomena in the dilepton final state using fb −1 of proton-proton collision data at \( \sqrt{s}=13 \) TeV with the ATLAS detector, JHEP 10 36fb (2017) 182 [arXiv:1707.02424] [INSPIRE].
P. Schwaller, D. Stolarski and A. Weiler, Emerging jets, JHEP 05 (2015) 059 [arXiv:1502.05409] [INSPIRE].
U. Haisch and J.F. Kamenik, Searching for new spin-0 resonances at LHCb, Phys. Rev. D 93 (2016) 055047 [arXiv:1601.05110] [INSPIRE].
P. Ilten, Y. Soreq, J. Thaler, M. Williams and W. Xue, Proposed inclusive dark photon search at LHCb, Phys. Rev. Lett. 116 (2016) 251803 [arXiv:1603.08926] [INSPIRE].
LHCb collaboration, Search for dark photons produced in 13TeV pp collisions, Phys. Rev. Lett. 120 (2018) 061801 [arXiv:1710.02867] [INSPIRE].
P. Ilten, Y. Soreq, M. Williams and W. Xue, Serendipity in dark photon searches, JHEP 06 (2018) 004 [arXiv:1801.04847] [INSPIRE].
U. Haisch, J.F. Kamenik, A. Malinauskas and M. Spira, Collider constraints on light pseudoscalars, JHEP 03 (2018) 178 [arXiv:1802.02156] [INSPIRE].
LHCb collaboration, Search for a dimuon resonance in the ϒ mass region, JHEP 09 (2018) 147 [arXiv:1805.09820] [INSPIRE].
J. Jersak, E. Laermann and P.M. Zerwas, Electroweak production of heavy quarks in e + e − annihilation, Phys. Rev. D 25 (1982) 1218 [Erratum ibid. D 36 (1987) 310] [INSPIRE].
W. Hollik and D. Pagani, The electroweak contribution to the top quark forward-backward asymmetry at the Tevatron, Phys. Rev. D 84 (2011) 093003 [arXiv:1107.2606] [INSPIRE].
J.H. Kühn and G. Rodrigo, Charge asymmetry of heavy quarks at hadron colliders, Phys. Rev. D 59 (1999) 054017 [hep-ph/9807420] [INSPIRE].
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Gauld, R., Haisch, U. & Pecjak, B.D. Asymmetric heavy-quark hadroproduction at LHCb: predictions and applications. J. High Energ. Phys. 2019, 166 (2019). https://doi.org/10.1007/JHEP03(2019)166
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DOI: https://doi.org/10.1007/JHEP03(2019)166