DibosonResonance14TeVMC

Introduction

This page is intended to provide information about samples for diboson resonance searches at 13 and 14 TeV. The primary signal samples are sequential Standard Model (SSM) W' and Z' bosons decaying into diboson final states including the SM Higgs boson.

SSM W'/Z' Samples

The SSM W' and Z' samples are produced using PYTHIA for the following three diboson final states;

• W' -> WZ
• W' -> WH
• Z' -> ZH

The WZ samples are produced with PYTHIA8 while the WH and ZH samples are produced with PYTHIA6 (as the VH processes are not implemented yet in PYTHIA8). Foe each sample, the hadronic and leptonic decays of W/Z boson are treated separately while the Higgs boson is allowed to decay to all final states. This will allow to study different Higgs decay modes in each of the hadronic/leptonic decay channels of W and Z bosons. These samples are primarily prepared for DC14 that will start in summer 2014. The center-of-mass energy in pp collisions is set to 13 TeV for all these samples.

Common Setup

The following parameter settings are used in all the W'/Z' samples;

• Cener-of-mass energy = 13 TeV
• MSTW2008LO PDF
• AU2 tune for WZ, AUET2B tune for WH/ZH samples
• SM strength of W'/Z' coupling to fermions
• W'WZ coupling modeled by EGM : g_W'WZ = g_WWZ(SM) * (m_W/m_W')^2
• All e, mu and tau are included for leptonic W/Z decay
• Higgs mass = 125 GeV
• Higgs can decay to all SM final states

Kinematic Selection

As the mass goes higher, the off-shell production of W'/Z' becomes dominant due to a large contribution of sea-quarks in protons convoluted with the tail of a Breit-Wigner resonance shape. Since the search sensitivity comes mainly from the resonance peak region, a lower cut is applied to the mass of the (virtual) W' and Z' bosons to eliminate such off-shell contribution. The cut is chosen to be

• >1 TeV for 3 TeV nominal resonance
• >1.5 TeV for 4 TeV nominal resonance
• >2 TeV for 5 TeV nominal resonance
• >2.5 TeV for 6 TeV nominal resonance

For the WZ -> lvll channel, the cut is fixed to 1 TeV regardless of the nominal mass. The low mass tail in the lvll channel may contribute to some sensitivity gain because of a low background level compared to other channels, and therefore it would be good to use a looser requirement on that in the lvll channel.

W' -> WZ -> qqqq

ECM [TeV]	W' Mass [GeV]	xsec x BR [fb]	Width [GeV]	Validation plots
13	1000	207	35.7	W' mass, dEta(W,Z), dPhi(W,Z), W-boson mass, W-boson pT, W-boson eta, W-decay particle ID, dPhi(q,q) of W -> qq, pT of W-decay quark, Eta of W-decay quark, Z-boson mass, Z-boson pT, Z-boson eta, Z-decay particle ID, dPhi(q,q) of Z -> qq, pT of Z-decay quark, Eta of Z-decay quark
13	2000	8.87	72.3
13	3000	0.802	109
13	4000	0.0912	146
13	5000	0.0118	183
13	6000	0.00178	220

W' -> WZ -> lvqq

ECM [TeV]	W' Mass [GeV]	xsec x BR [fb]	Width [GeV]	Validation plots
13	500	1620	17.2	W' mass, dEta(W,Z), dPhi(W,Z), W-boson mass, W-boson pT, W-boson eta, W-decay particle ID, dPhi(l,v) of W -> lv, pT of W-decay lepton, Eta of W-decay lepton, Z-boson mass, Z-boson pT, Z-boson eta, Z-decay particle ID, dPhi(q,q) of Z -> qq, pT of Z-decay quark, Eta of Z-decay quark
13	1000	99.2	35.7
13	2000	4.25	72.3
13	3000	0.384	109
13	4000	0.0437	146
13	5000	0.00564	183

W' -> WZ -> qqll

ECM [TeV]	W' Mass [GeV]	xsec x BR [fb]	Width [GeV]	Validation plots
13	500	484	17.2	W' mass, dEta(W,Z), dPhi(W,Z), W-boson mass, W-boson pT, W-boson eta, W-decay particle ID, dPhi(q,q) of W -> qq, pT of W-decay quark, Eta of W-decay quark, Z-boson mass, Z-boson pT, Z-boson eta, Z-decay particle ID, dPhi(l,l) of Z -> ll, pT of Z-decay lepton, Eta of Z-decay lepton
13	1000	29.8	35.7
13	2000	1.27	72.3
13	3000	0.115	109
13	4000	0.0131	146

W' -> WZ -> lvll

ECM [TeV]	W' Mass [GeV]	xsec x BR [fb]	Width [GeV]	Validation plots
13	500	232	17.2	W' mass, dEta(W,Z), dPhi(W,Z), W-boson mass, W-boson pT, W-boson eta, W-decay particle ID, dPhi(l,v) of W -> lv, pT of W-decay lepton, Eta of W-decay lepton, Z-boson mass, Z-boson pT, Z-boson eta, Z-decay particle ID, dPhi(l,l) of Z -> ll, pT of Z-decay lepton, Eta of Z-decay lepton
13	1000	14.3	35.7
13	2000	0.610	72.3
13	3000	0.0552	109
13	4000	0.00687	146

W' -> WH -> qqX (all Higgs decays)

ECM [TeV]	W' Mass [GeV]	xsec x BR [fb]	Width [GeV]	Validation plots
13	1000	379	36.1	W' mass, dEta(W,H), dPhi(W,H), W-boson mass, W-boson pT, W-boson eta, W-decay particle ID, dPhi(q,q) of W -> qq, pT of W-decay quark, Eta of W-decay quark, H-boson mass, H-boson pT, H-boson eta, H-decay particle ID, dPhi(x,x) of H -> xx, pT of H-decay b-quark, Eta of H-decay b-quark, pT of H-decay tau-lepton, Eta of H-decay tau-lepton
13	2000	17.4	73.2
13	3000	1.59	110
13	4000	0.182	148
13	5000	0.0236	185
13	6000	0.00359	222

W' -> WH -> lvX (all Higgs decays)

ECM [TeV]	W' Mass [GeV]	xsec x BR [fb]	Width [GeV]	Validation plots
13	500	2280	17.4	W' mass, dEta(W,H), dPhi(W,H), W-boson mass, W-boson pT, W-boson eta, W-decay particle ID, dPhi(l,v) of W -> lv, pT of W-decay lepton, Eta of W-decay lepton, H-boson mass, H-boson pT, H-boson eta, H-decay particle ID, dPhi(x,x) of H -> xx, pT of H-decay b-quark, Eta of H-decay b-quark, pT of H-decay tau-lepton, Eta of H-decay tau-lepton
13	1000	165	36.1
13	2000	7.59	73.2
13	3000	0.692	110
13	4000	0.0795	148
13	5000	0.0103	185

Z' -> ZH -> llX (all Higgs decays)

ECM [TeV]	Z' Mass [GeV]	xsec x BR [fb]	Width [GeV]	Validation plots
13	500	917	15.2	Z' mass, dEta(Z,H), dPhi(Z,H), Z-boson mass, Z-boson pT, Z-boson eta, Z-decay particle ID, dPhi(l,l) of Z -> ll, pT of Z-decay lepton, Eta of Z-decay lepton, H-boson mass, H-boson pT, H-boson eta, H-decay particle ID, dPhi(x,x) of H -> xx, pT of H-decay b-quark, Eta of H-decay b-quark, pT of H-decay tau-lepton, Eta of H-decay tau-lepton
13	1000	61.0	32.0
13	2000	2.61	65.3
13	3000	0.236	98.5
13	4000	0.0280	132

---

Major updates:
-- KojiTerashi - 02 Nov 2013