We present an analysis of both the Neutral Current (NC) and Charged Current
(CC) Drell-Yan processes at the LHC within a 4 Dimensional realization of a
Composite Higgs model studying the cross sections and taking into account the
possible impact of the extra fermions present in the spectrum.Comment: Conference proceeding, XII IFAE Edition, 3-5 April 2013, Cagliari. 2
  pages, 2 figures; v2 typo correcte

Barducci, D.

Belyaev, A.

De Curtis, S.

Moretti, S.

Pruna, G. M.

English

arXiv

We present an analysis of both the Neutral Current (NC) and Charged Current (CC) Drell-Yan processes at the LHC within a 4 Dimensional realization of a Composite Higgs Model studying the cross sections and taking into account the possible impact of the extra fermions present in the spectrum. © Società Italiana di Fisica

Barducci D.

Belyaev A.

De Curtis S.

Moretti S.

Pruna G. M.

Archivio della ricerca- Università di Roma La Sapienza

Production of Z′ and W′ via Drell-Yan processes in the 4D Composite Higgs Model at the LHC

We present an analysis of both the Neutral Current (NC) and

Charged Current (CC) Drell-Yan processes at the LHC within a 4 Dimensional realization of a Composite Higgs Model studying the cross sections and taking into account the possible impact of the extra fermions present in the spectrum

Scientific Open-access Literature Archive and Repository

DOI 10.1393/ncc/i2014-11702-xColloquia: IFAE 2013IL NUOVO CIMENTO Vol. 37 C, N. 1 Gennaio-Febbraio 2014Production of Z ′ and W ′ via Drell-Yan processesin the 4D Composite Higgs Model at the LHCD. Barducci(1)(∗), A. Belyaev(1), S. De Curtis(2), S. Moretti(1)and G. M. Pruna(3)(1) School of Physics and Astronomy, University of Southampton - Highfield, SO17 1BJ, UK(2) INFN, Sezione di Firenze - Via G. Sansone 1 - 50019 Sesto Fiorentino (FI), Italy(3) Paul Scherrer Institute - CH-5232 Villigen PSI, Switzerlandricevuto l’1 Ottobre 2013Summary. — We present an analysis of both the Neutral Current (NC) andCharged Current (CC) Drell-Yan processes at the LHC within a 4 Dimensionalrealization of a Composite Higgs Model studying the cross sections and taking intoaccount the possible impact of the extra fermions present in the spectrum.PACS 13.85.Qk – Inclusive production with identified leptons, photons, or othernonhadronic particles.PACS 12.60.Rc – Composite models.PACS 12.60.Cn – Extensions of electroweak gauge sector.PACS 14.80.Va – Axions and other Nambu-Goldstone bosons (Majorons, familons,etc.).1. – Introduction and model descriptionComposite Higgs models with the Higgs boson arising as a pseudo-Goldstone stateprovide an elegant solution to the hierarchy problem present in the Standard Model (SM)suggesting an alternative pattern leading to the mechanism of spontaneous electroweaksymmetry breaking. The general idea proposed in [1] and based on the minimal cosetSO(5)/SO(4) in [2] has been specialized into a 4 Dimensional (4D) description called the4D Composite Higgs Model (4DCHM) in [3].Besides the SM content the 4DCHM spectrum consists of 5 Z ′ and 3 W ′ with massesand couplings described by two parameters, the compositeness scale f  v  246GeVand the coupling constant gρ of the extra gauge fields, 4π  gρ  g, where g is the SMgauge coupling. Heavy fermions with both SM, herein collectively called t′, b′, and exoticelectric charges are also present and the value of their mass strongly modify the widthsof extra gauge bosons as shown in fig. 1.(∗) E-mail: d.barducci@soton.ac.ukc© Societa` Italiana di Fisica 265266 D. BARDUCCI, A. BELYAEV, S. DE CURTIS, ETC.Fig. 1. – Width of the Z′ (left) and W ′ (right) in function of the mass of the lightest t′. Inpurple points where the decay in a pair of heavy fermions FF¯ is kinematically not allowed, incyan the points where this processes is allowed.2. – Drell-Yan analysisThe Drell-Yan processes p p→ l+ l− (NC) and p p→ lνl + c.c. (CC) for the 14 TeVstage of the Large Hadron Collider (LHC) run for the 4DCHM [4, 5] have been studiedvia the implementation of the model in automatic tools (LanHEP [6] and CalcHEP [7])to perform a fast phenomenological analysis. Constraints on the parameter space due toelectroweak precision tests have been taken into account by requiring mρ  mZ′,W ′ 2TeV. Results for both the NC and CC channels in a regime where the widths of theZ ′s and W ′s are small are shown in fig. 2.We have shown that the 14TeV stage of the LHC places us in the position of studyingthe rich phenomenology of the gauge sector for the 4DCHM that is so testable at theLHC for 2-3TeV Z ′ and W ′, allowing, in certain regions of the parameter space, todistinguish the two lighter neutral resonances. The results are obtained for the 14TeVLHC but remain essentially valid for the next LHC run at 13TeV.Conversely the possible presence of extra fermions with a mass lower than the TeVscale represents the first possibility to test the 4DCHM already with the 7 and 8TeVLHC data.Fig. 2. – Differential cross section of the NC in invariant mass (left) and of the CC in transversemass (center) channels for f = 1.2TeV and gρ = 1.8. Integrated cross sections for the 4DCHM[SM], given as solid/black[dashed/red] lines, are 0.78 [0.21] fb (NC) and 1.11 [0.23] fb (CC).Line shape for the NC process in invariant mass (right) for the same combination of f and gρfor different values of the masses of the lightest t′. (See ref. [4] for the meaning of colors in thelast plot.) Results are for the 14TeV LHC setup.PRODUCTION OF Z′ AND W ′ VIA DRELL-YAN PROCESSES ETC. 267∗ ∗ ∗Some of us thank the NExT Institute for partial support.REFERENCES[1] Kaplan D. B. and Georgi H., Phys. Lett. B, 136 (1984) 183.[2] Agashe K., Contino R. and Pomarol A., Nucl. Phys. B, 719 (2005) 165 and arXiv:hep-ph/0412089.[3] De Curtis S., Redi M. and Tesi A., JHEP, 04 (2012) 042.[4] Barducci D., Belyaev A., De Curtis S., Moretti S. and Pruna G. M., JHEP, 04(2013) 152 and arXiv:1210.2927 [hep-ph].[5] Barducci D., Fedeli L., De Curtis S., Moretti S. and Pruna G. M., JHEP, 04 (2013)038 and arXiv:1212.4875 [hep-ph].[6] Semenov A., arXiv:1005.1909 [hep-ph].[7] Belyaev A., Christensen N. D. and Pukhov A., Comput. Phys. Commun., 184 (2013)1729 and arXiv:1207.6082 [hep-ph].

Production of Z and W via Drell-Yan processes

in the 4D Composite Higgs Model at the LHC

We present an analysis of both the Neutral Current (NC) and Charged Current (CC) Drell-Yan processes at the LHC within a 4 Dimensional realization of a Composite Higgs Model studying the cross sections and taking into account the possible impact of the extra fermions present in the spectrum. © Società Italiana di Fisica

Archivio della Ricerca - Università di Pisa

XII IFAE Edition 3-5 April 2013, Cagliari 1SHEP-13-11PSI-PR-13-08Production of Z ′ and W ′ via Drell-Yan processes in the4D Composite Higgs Model at the LHCD. Barducci, A. Belyaev, S. MorettiSchool of Physics and Astronomy, University of Southampton, Highfield, SO17 1BJ, UK.∗S. De CurtisINFN, Sezione di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Italy.†G.M. PrunaPaul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.‡We present an analysis of both the Neutral Current (NC) and Charged Current (CC) Drell-Yanprocesses at the LHC within a 4 Dimensional realization of a Composite Higgs model studyingthe cross sections and taking into account the possible impact of the extra fermions present in thespectrum.I. INTRODUCTION AND MODEL DESCRIPTIONComposite Higgs models with the Higgs boson arising as a pseudo-Goldstone state provide an elegant solutionto the hierarchy problem present in the Standard Model (SM) suggesting an alternative pattern leading to themechanism of spontaneous electroweak symmetry breaking. The general idea proposed in [1] and based on theminimal coset SO(5)/SO(4) in [2] has been specialized into a 4 Dimensional (4D) description called the 4DComposite Higgs Model (4DCHM) in [3].Besides the SM content the 4DCHM spectrum consists of 5 Z ′ and 3 W ′ with masses and couplings describedby two parameters, the compositeness scale f  v ' 246 GeV and the coupling constant gρ of the extra gaugefields, 4π  gρ  g, where g is the SM gauge coupling. Heavy fermions with both SM, herein collectively calledt′, b′, and exotic electric charges are also present and the value of their mass strongly modify the widths of extragauge bosons as shown in Fig. 1.ææææææææææææææææææææææææ ææææææææ ææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææ æææææææææææææææææææææææææææææææææææææææææàà à àààààààà ààà ààààà àààààààà àààà à ààààààààààà ààà àà ààààààààààààà ààààà ààààà ààààààààààà ààà à àààààààààà ààà0.5 1.0 1.5 2.0020040060080010001200mt 'HTeV LGZ'HGeVL à F F Closeæ F F Openææææææææææææææææææææææææææææææææææææææææææææææææææææææææ ææææææææææææææææææææææææææææææææææææææææææææææææææææææææææææ æææææææææ ææææææææææææææææææææææææææææææææææ æææææææææææææææææàààààààààààààààààààà àààààààààààà ààààààààààààààà àààààààààààààà ààààààààààààààààààààà àààààààààààààààààààààààààààààààààà àààààààààà0.5 1.0 1.5 2.002004006008001000mt 'HTeV LGW'HGeVLà F F Closeæ F F OpenFIG. 1: Width of the Z′ and W ′ in function of the mass of the lightest t′. In purple points where the decay in a pair ofheavy fermions FF̄ is kinematically not allowed, in cyan the points where this processes is allowed.∗Electronic address: d.barducci,a.belyaev,s.moretti@soton.ac.uk†Electronic address: decurtis@fi.infn.it‡Electronic address: giovanni-marco.pruna@psi.charXiv:1306.5652v2  [hep-ph]  25 Jun 2013XII IFAE Edition 3-5 April 2013, Cagliari 2II. DRELL-YAN ANALYSISThe Drell-Yan processes p p → l+ l− (NC) and p p → lνl + c.c. (CC) for the 14 TeV stage of theLarge Hadron Collider (LHC) run for the 4DCHM [4, 5] have been studied via the implementation of themodel in automatic tools (LanHEP [6] and CalcHEP [7]) to perform a fast phenomenological analysis. Con-straints on the parameter space due to electroweak precision tests have been taken into account by requiringmρ ' mZ′,W ′ >∼ 2 TeV. Results for both the NC and CC channels in a regime where the widths of the Z ′s andW ′s are small are shown in Fig. 2.We have shown that the 14 TeV stage of the LHC places us in the position of studying the rich phenomenologyof the gauge sector for the 4DCHM that is so testable at the LHC for 2-3 TeV Z ′ and W ′, allowing, in certainregions of the parameter space, to distinguish the two lighter neutral resonances. The results are obtained forthe 14 TeV LHC but remain essentially valid for the next LHC run at 13 TeV.Conversely the possible presence of extra fermions with a mass lower than the TeV scale represents the firstpossibility to test the 4DCHM already with the 7 and 8 TeV LHC data.FIG. 2: Differential cross section of the NC (left) and CC (center) channels for f = 1.2 TeV and gρ = 1.8. Integratedcross sections for the 4DCHM[SM], given as solid/black[dashed/red] lines, are 1.37[0.21] fb (NC) and 1.33[0.23] fb (CC).Line shape for the NC process (right) for the same combination of f and gρ for different values of the masses of thelightest t′ (See Ref. [4] for the meaning of colors in the last plot). Results are for the 14 TeV LHC setup.AcknowledgmentsSome of us thank the NExT Institute for partial support.[1] H. Georgi, L. Kaplan, D. Morin, and A. Schenk, Phys.Rev. D51, 3888 (1995), hep-ph/9410307.[2] K. Agashe, R. Contino, and A. Pomarol, Nucl.Phys. B719, 165 (2005), hep-ph/0412089.[3] S. De Curtis, M. Redi, and A. Tesi, JHEP 1204, 042 (2012), 1110.1613.[4] D. Barducci, A. Belyaev, S. De Curtis, S. Moretti, and G. M. Pruna, JHEP04, 152 (2013), 1210.2927.[5] D. Barducci, L. Fedeli, S. Moretti, S. Curtis, and G. Pruna, JHEP 1304, 038 (2013), 1212.4875.[6] A. Semenov (2010), 1005.1909.[7] A. Belyaev, N. D. Christensen, and A. Pukhov, Comput.Phys.Commun. 184, 1729 (2013), 1207.6082.

Production of Z' and W' via Drell-Yan processes in the 4D Composite Higgs Model at the LHC

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