The Collider Phenomenology of Vectorlike Confinement

Can Kılıç, University of Texas at Austinwork done with: Takemichi Okui (arXiv: 1001.4526, JHEP 1004:128, 2010 ) Takemichi Okui, Raman Sundrum (arXiv: 0906.0577, JHEP 1002:018, 2010)

Steffen Schumann, Minho Son (arXiv: 0810.5542, JHEP 0904:128, 2009)Takemichi Okui, Raman Sundrum (arXiv: 0802.2568, JHEP 0807:038, 2008)

Introduction• The are well into the LHC era.

• We know that there must be new physics.

• Situation very different from previous experiments. No single compelling extension of SM.

• Tension for solutions to hierarchy problem from direct searches and precision data.

What Might Lie Ahead

MPlanck

vNew Physics

• The good (no-tuning):we just haven’t found the magic theory yet.

What Might Lie Ahead

MPlanck

v

New Physics

• The bad (severe fine-tuning)nothing to be seen at LHC except elementary Higgs boson.

What Might Lie Ahead

• The ugly (“meso-tuning”)• Look for low-mass tail

MPlanck

v

New Physics

LHC reach

A Different Angle• Meso-tuning: how to proceed?• We take the absence of low

energy signatures as a hint.• A simple module that can fit into

of bigger picture.• Theoretically generic• Signatures:

– discoverable?– distinguishable?

MPlanck

v

New Physics

LHC reach

Safe Strong Interactions• LHC Phenomenology of BSM physics

dominated by pair production / resonant production: many constraints

• Not all possibilities fully explored.• Strong interactions at TeV scale have been

associated with EW-breaking. Signatures very strongly influenced.

• Can there be safe low energy sector? • Analogy with sub-GeV e+ e- collider. Rich

phenomenology from a minimal theory.

Analogy in a Picture

Low Energy QCD – A Brief Review• Begin by strongest interactions (u,d only)• special because it is light. Guaranteed

by breaking of flavor symmetry.

• ρ special because it is the lightest meson that can be resonantly produced once we add electromagnetism. Decays to .

• ’s and baryons stable

Consequences of adding electromagnetism

(qu = 2/3 , qd = -1/3)• ρ/γ mixing• resonant production• charges• mass difference• Neutral can decay

Low Energy QCD – A Brief Review

• Both up and down number still conserved, charged so far stable, turn on weak interactions.

• Charged can now decay.• Need light particles for charged to

decay, introduce leptons: non-strongly interacting particles.

as well as neutron decay.• Proton still stable.

Low Energy QCD – A Brief Review

Could Lightning Strike Twice?From a simple UV theory to rich IR Physics

• Hypercolor: New fundamental interaction with scale ΛHC.

• “Hyper-pions” lightest. Guaranteed by breaking of flavor symmetry.

• Hyperpions and baryons stable at this point.• Hyper- ρ is the lightest hyper-meson that

can be resonantly produced, decays to 2

Could Lightning Strike Twice?From a simple UV theory to rich IR Physics

• Turn on SM interactions (weak+hypercharge)hyperfermions charged under SM.

• SM breaks many of the flavor numbers, introduce “species” of hyperfermions. (e.g. color triplet)

• Each SM gauge boson can mix with a , resonant production.

• charges (not only electromagnetic)• Radiative masses for• Anomaly of neutral pion decay can decay hyper-pion

with zero species number ( - short)• Species number unbroken. Leads to stable .

Could Lightning Strike Twice?From a simple UV theory to rich IR Physics

• - long stable, SM charged. • Introduce hyper-weak

interactions.• can now decay to a pair

of SM fermions (quark or lepton).

• Hyper-baryons can be stable or they can decay.

Recap

• For each SM gauge boson, there can be a , with mass ~ ΛHC.

• masses from radiative effects / EWSB / hyperquark masses. Produced through SM or through decay.

• either collider-stable or decay to pairs of SMGB

Attractive features

• Precedent• Flavor blind, therefore safe from low energy

searches. You don’t see new physics coming until you produce it directly.

• Dilepton / dijet resonance searches evaded.• Rich phenomenology: A minimal theory naturally

gives rise to an array of distinct collider signatures (multi-photons, CHAMPs, R-hadrons, multijets).

• Few free parameters.

Benchmark I: Without Color

• CHAMP and multi-photon production.• Spectrum: W’,Z’,B’ at ΛHC.

Benchmark I : Mass points

Benchmark I: CHAMP signal• Doubly charged scalar decays promptly to CHAMP, decay products

unobservable• several processes add to “CHAMP production”• Distributions

CHAMPs: Triggering• Production away from

threshold because of spin-1 intermediate state.

• Acceptance (||<2.5) over 90% for all mass points.

• Time lag to muon system.

CHAMPs: Bounds

CHAMPs: Prospects• Moderate β: TOF, dE/dx, curvature• High- β : Analysis by Adams et al. (arXiv: 0909.3157)

uses the fact that muons are no longer MIPs at these energies. (200 pb-1 at 10 TeV)

CHAMPs: VC Signatures

Can verify • spin-1 s-channel production• resonance

3γ+W: Final States• Production channels: +-,+0 or -0 (no 00, therefore no 4γ)• decays• also 2γ from (WZ)(γγ)(res) / (γZ)(γW) and (γW)(γW)(non-res) –

relevant for GMSB searches.• Since 3γ rate comparable, focus on the easier case.• Should be easy to distinguish from (fermiophobic) Higgs

3γ+W: BG• BG: Taking guidance out of h->γγ searches, we expect irreducible

BG to be O(1) fraction of total BG.• Scale up irreducible BG by x10. (MG γγ+jet(s) / Pythia / PGS)• Signal done with batch mode of CalcHep / Pythia / PGS• hard pT cut to reduce BG

3γ+W: BG• BG: Taking guidance out of h->γγ searches, we expect irreducible

BG to be O(1) fraction of total BG.• Scale up irreducible BG by x10. (MG γγ+jet(s) / Pythia / PGS)• Signal done with batch mode of CalcHep / Pythia / PGS• hard pT cut to reduce BG

3γ+W: BG• BG: Taking guidance out of h->γγ searches, we expect irreducible

BG to be O(1) fraction of total BG.• Scale up irreducible BG by x10. (MG γγ+jet(s) / Pythia / PGS)• Signal done with batch mode of CalcHep / Pythia / PGS• hard pT cut to reduce BG

3γ+W:• Use resonance mass from previous part• Define best W candidate

– for leptonic W, solve for neutrino rapidity, reconstruct scalar– for hadronic W, take pair (pT>20, ΔR<2) with 70GeV<mjj<90GeV

• Reconstruct ECM• Consistency check with CHAMP distribution

Benchmark II: With Color

• R-hadron and multi-jet production• Two resonances, g’ and B’.

Benchmark II: Mass Points

R-hadrons• Large cross section from QCD• Distributions• Effect of gg initial state• Hadronization, comparison to CHAMPs

R-hadrons: Triggering• Very similar kinematics to

CHAMPs, good triggering efficiency.

• Acceptance over 80% for all mass points.

R-hadrons: VC Signatures

• Evidence for g’ resonance• Smaller mass gap• 4 R-hadron production

Multi-jets: Tevatron• Signal dominantly from valence quark initial state,

background from gluons. 2 2 vs. 2 many• 4j with similar pT. Use pT1>120GeV for trigger, • 1fb-1 data, 2fb-1 bg• Cone jets, ΔR=0.7• For mg’=350GeV use pT4>40GeV, Δminv<25GeV• For mg’=600GeV use pT4>90GeV

Multi-jets: LHC• For mg’=750GeV use

pT4>150GeV, Δminv<50GeV (1fb-1 of data)

• For mg’=1.5TeV use pT4>250GeV (10 fb-1 of data)

• <2 for all partons, cone jets, ΔR=0.5

• Straightforward to discover scalar

• Sliding cut• g’ more tricky.

Multi-jets at the LHC: Bounds

Multi-jets: LHC (g’)

• Boldly go where no one has gone before: 8 jets.• Large cross section for g’ pair production.• Self-calibrating search: minv cuts from 4j, pT cuts from hT.• After pT cuts, signal and bg comparable.

Multi-jets: LHC (g’) Analysis• parton level truth – PGS level jet matching• Take 4 hardest jets, 4 more out of next 6.• All pairings, use result of 4j analysis• Plot mass of g’ candidates: signal accumulates• Background sanity check: cannot do 28 unweighted events, do 26 and

shower.• Cross-check with R-hadrons

Conclusions• VC: QCD-like theories with rich phenomenology, safe

from low energy precision tests.• Vector states can be resonantly produced, decay to

naturally light scalars.• Scalars have short-lived and collider stable species.

– Short-lived scalars decay to a pair of SM gauge bosons. – Long lived scalars appear as CHAMPs / R-hadrons.

• Benchmarks– without color: multi-photons, CHAMPs– with color: multi-jets, R-hadrons

• Kinematic reconstruction possible in all final states• Novel signatures: Resonances, 4 R-hadrons• Other possibilities: decay to fermions, cascades, DM

candidates

Backup Slides

Backup Slides

Backup Slides

Anomaly first in shape – then in normalization