The Collider Phenomenology of Vectorlike Confinement

The Collider Phenomenology of Vectorlike Confinement Can Kılıç, University of Texas at Austin work 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 • The good (no-tuning):we just haven’t found the magic theory yet. MPlanck New Physics v

What Might Lie Ahead MPlanck New Physics • The bad (severe fine-tuning)nothing to be seen at LHC except elementary Higgs boson. v

What Might Lie Ahead • The ugly (“meso-tuning”) • Look for low-mass tail MPlanck New Physics LHC reach v

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 New Physics LHC reach v

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

Low Energy QCD – A Brief Review 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.

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: • 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 28 unweighted events, do 26 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 Anomaly first in shape – then in normalization

The Collider Phenomenology of Vectorlike Confinement