Heavy fermions from Higgsless models at the LHC

Heavy fermions from Higgsless models at the LHC Baradhwaj Coleppa Michigan State University Pheno ’ 08 Work in Progress R. S. Chivukula, N. D. Christensen, B. Coleppa and E. H. Simmons

Outline n n n Quick review of 3 site model Simple extension of the 3 site model Wave functions and couplings Heavy fermion phenomenology Conclusion 2

Review of 3 site model n n n 3 site model – Captures the essential low energy physics An higgsless theory Spectrum – W’, Z’ and heavy fermionic partners Unitarity violation delayed by W’, Z’ exchanges Electroweak precision constraints – ‘Ideal delocalization’ 3

A simple extension § Lift constraint between and § Motivation – New ‘light’ quarks n n n Separate out top quark mass generation – ‘Top Higgs’ EWSB – still Higgsless! Work in the ‘deconstructed’ picture 4

A ‘Triangle’ moose 5

Gauge spectrum n n n The Lagrangian is given: Kinetic terms of sigma fields Gauge boson masses ‘Top Higgs’ 6

Gauge bosons n W mass matrix n Eigenvalues and eigenvectors: 7

Gauge bosons contd. n Z mass matrix n Eigenvalues and eigenvectors: 8

Fermions n Fermion delocalization 9

Fermion sector n The Lagrangian of the fermion sector is given: n Diagonalizing, we get the masses: 10

Couplings n Fermions are delocalized – ideally Light fermion coupling to SM gauge bosons SM like Off diagonal couplings: n Diagonal couplings: n n 11

Heavy fermions n Light enough to be found at the LHC! Both pair and single production. Decay channels: n Decay controlled by off diagonal coupling. n n 12

pp jj. WZ channel n n Pair production Dominated by gluon fusion for small masses. Can reconstruct the mass fully Include four heavy flavors 13

Choosing the cuts n n Jets are produced at high p. T! distribution – largely central! 14

Cuts and Background n n n Cuts employed: p. T cuts on jets: p. T > 100 Ge. V Rapidity cuts on the jets: Delta R > 0. 5 p. T cuts on leptons and : p. T>15 Ge. V, >15 Ge. V Plot the invariant mass of the j, l, l combination. SM background ~ 0 15

Invariant mass distributions 16

Heavy fermions contd. n Scan the W’, MD parameter space. n Shaded 17

Discovery prospects n Luminosity required for 10 events Cuts: p. T (jets) >100 Ge. V Rapidity: 18

Single production – in progress Cuts: p. T of jet 1> 100 Ge. V. Eta of jet 1: 19

Conclusions n n n Simple extension to 3 site discussed Higgsless – Top Higgs sectors Accommodates heavy fermions light enough to be found at the LHC Masses up to ~1 Te. V can be probed Both single and pair production viable. 20

Back up 1 – Fermion eigenvectors n Fermion mass and eigenvectors. 21