1. PHYSICS OF NON-PROMPT TRACKS Jonathan Feng UC Irvine ALCPG 2007, Fermilab 25 October 2007

2. 25 Oct 07Feng 2 OUTLINE Standard Model –Prompt tracks (t decays) –Non-prompt tracks (b decays) –Metastable particles (muons) Beyond the Standard Model –Generically prompt couplings ~ O(1)  m ~ 100 GeV –But there are exceptions, some very well-motivated This talk: an overview of non- prompt (and metastable) examples in 4 categories See also Tom Rizzo’s talk Fine-tunedNatural Coupling Suppressed R p Violating SUSY Decays to Gravitinos Phase Space Suppressed Slepton Decays Wino Decays UED

3. 25 Oct 07Feng 3 COUPLING SUPPRESSED: FINE-TUNED SUSY with R-parity violation –LSP decays –Many possible charge combinations –Coupling strengths unconstrained –Fine-tuned: non-prompt  < 10 -7 u l ̃ d d ̃n d u  d l Slepton  u d m slepton = 200 GeV

4. 25 Oct 07Feng 4 COUPLING SUPPRESSED: NATURAL SUSY  gravitinos Gravitino couplings are superweak, decays to gravitinos highly suppressed Appears naturally in gauge- mediated SUSY breaking Slepton  l G̃ m slepton = 200 GeV G̃ l̃l̃ l t̃t̃ t  

5. 25 Oct 07Feng 5 PHASE SPACE SUPPRESSED: FINE-TUNED New particles may be accidentally highly degenerate –E.g., in SUSY, slepton and neutralinos –Fine-tuned: Non-prompt   m < MeV, lepton is very soft l l̃l̃  Slepton  l  m slepton = 200 GeV

6. PHASE SPACE SUPPRESSED: NATURAL New particles in nearly degenerate multiplets E.g., Winos Appears naturally in anomaly-mediated SUSY breaking Feng, Moroi, Randall, Sstrassler, Su (1999) Chen, Drees, Gunion (1999)  0 ±±  ±,  ±  0,e, ,…

7. 25 Oct 07Feng 7 PHASE SPACE SUPPRESSED: NATURAL Universal Extra Dimensions All KK level 1 states have mass R -1 This is broken by many effects, but the lightest KK states are still highly degenerate loop-level R  = 500 GeV Cheng, Matchev, Schmaltz (2002)

8. PHASE SPACE SUPPRESSED: NATURAL In minimal UED, after all particle and astrophysical constraints, NLKP  LKP is  -   m < 7 GeV  decay length > 10  m Cembranos, Feng, Strigari (2006) B 1 H ±1 f f

9. 25 Oct 07Feng 9 SUMMARY Beyond the SM: many examples of non-prompt, metastable tracks Challenge: trigger, reconstruct, measure lifetimes, even given slow primary, soft secondaries, decay lengths varying from  m to m Representative examples: coupling suppressedphase space suppressed G̃ l̃l̃ l  0 ±±  ±,  ±  0,e,  …