High Energy Physics with a Tevatron:

1. High Energy Physics with a Tevatron: Teraton: Probing elementary particles & fields using a 500 km3-sr UHE cosmic neutrino detector David Saltzberg (UCLA) SalSA meeting SLAC Feb 3, 2005

2. The Impact of Cosmic Neutrino Sources on Particle Physics….the first 40 years Every cosmic neutrino source has had major impact on particle physics: Homestake SN1987A Kamiokande Super-K lack of dispersion mass of neutrino state coupling to e <~20 eV 1. weak eigenstates ≠ mass eigenstates 2. mass ≠ 0

3. An Experimentalist’s theoretical review • “New Physics” in the Sources • Topological Defects • Monopoles • “New Physics” in the  Cross Section • Low-scale quantum gravity • Extreme proton structure down to x ~10-8 • Physics of the Neutrino • Neutrino decay • Sterile neutrinos • Dirac vs. Majorana mass • Instantons • CPT violation • Lorentz invariance • Measuring the neutrino mass with the highest energy ’s

4. Topological Defects • Possible “relic” particles (dubbed X) due to symmetry breaking phase transitions in the early Universe: • Masses at the GUT scale (MX~1025 eV). • By why don’t these decay in 10-40 sec? • Confine in “topological defects”  stable until destroyed/ annihilate • NO COSMIC ACCELERATOR NEEDED: “top-down” scenario • X  jets  mesons  neutrinos • X  leptons or even all neutrinos

5. Topological Defects • Some specific models • Bhattacharjee, Hill, Schramm PRL 69, 567, (1992) • Protheroe & Stanev PRL 77,3708 (1996) • Sigl, Lee, Bhattacharjee, Yoshida PRD 59,043504 (1998) • Barbot, Drees, Halzen, Hooper, PLB 555, 22 (2003) • Basic ideas • Were attractive to circumvent GZK cutoff for UHE cosmic rays. • Topological defects could be monopoles, superconducting cosmic strings, domain walls • Generally these models produce hard neutrino spectrum: ~ E-(1-1.5) • “bottom-up” scenarios are more steeply falling: E-2 to E-4 • not ruled out by lower energy telescopes • constrained by MeV—GeV isotropic photon fluxes • Neutrino flux vs. energy sensitive to source evolution vs. z of TD’s.

6. Neutrino Telescopes for Direct Monopole Detection • Monopoles: • Dirac: The presence of even one monopole explains electric charge quantization • Monopoles are typically part of GUTs • Masses typically of order GUT scale • but in some models Mmp could even be as low as ~1014 eV. • Observation of monopoles would be revolutionary for HEP • Parker bound (10-15 cm-2 s-1 sr-1) • c.f. UHECR>1020 eV (~10-21 cm-2 s-1 sr-1) • Caveat: if monopoles catalyze proton decay then (lack of) neutron star heating provides extremely strong limit.

7. Neutrino Telescopes for Direct Monopole Detection Wick, Kephart, Weiler, Biermann • Intergalactic magnetic fields sheets (~100 nG over 50 MPc) could accelerate monopoles to energies of ~5£1024 eV • Light monopoles would be relativistic so are candidates for radio Cherenkov detection • Parker bound (10-15 cm-2 s-1 sr-1) • c.f. UHECR>1020 eV (~10-21 cm-2 s-1 sr-1) • other direct MP searches, generally worse than Parker bound • Relativistic monopoles mimic particle with large charge: at least Z~68 • produce EM showers along path by pair-production, photo-nuclear • continuously produces shower along its path  unique signature • WKW estimate F<10-18 cm-2 s-1 sr-1 for a km3 detector for 1 year. • SalSA could do much better: • sensitive for Mmp up to 1023 eV, far beyond production at accelerators. • Flux limit better than typical searches

8. e n W n p e n n p Neutrino interactions in SM Early calculation McKay, Ralston, PLB 167, 103 (1986) Most commonly used: Ghandhi et al., Astropart. Phys. 5, 81 (1996): /E0.36 /E

9. UHE Neutrino Cross Sectionand low-scale Quantum Gravity • Probing interactions at high CM • Ecm = (2 mp E)1/2 150 TeV for E = 1019 eV • SM(+N) ~ 10-7£SM(p +N) • Large extra dimension models could enhance  cross section • Gravity could become strong at ECM=MD • Non-perturbative effects could produce KK-exitations, string excitation, pea-branes, micro-BH above ECM • Astrophysics and laboratory limits still allow • n=4, MD > 10 TeV • n¸ 5 MD>1 TeV

10. 10-30 (cm2) 10-32 10-34 1017 1019 1021 E (eV) Enhancement of UHE Neutrino Cross Section Sample predictions for MD~1 TeV, n~6-7: Alvarez-Muniz,Feng,Halzen,Han,Hooper PRD65, 124015 (2002) Anchordoqui,Feng,Goldberg,Shapere, PRD65, 103002 (2002) Anchordoqui et al., PRD66, 103002 (2002) SM SM • Caveat: not all energy goes into BH or excitation, and need minimum energy for classical BH formation. • UHE  cross sections could be up to ~100£ Standard Model * would be invisible to UHECR interactions

11. l,  nucleon xp p Less exotic physics with cross section Ghandi, Quigg,Reno,Sarcevic • HERA tests proton structure to x~ 10-4 (only 10-2 at “high” Q2) • UHE  probes proton structure to x ~ 10-8 • Extreme regime: More likely to scatter off of bottom sea than up/down valence. • observables? • Check SM with NC/CC ratio at extremely high Q2

12. Neutrino Flavor Effects • Critical parameter for neutrino oscillations and decay is proper time, L/E. • Solar neutrinos: 150,000 km/5£106 eV = 30 m/eV • “SalSA” neutrinos from 4 Gpc/1017 eV = 109 m/eV • Standard model: neutrinos change flavor by oscillation • $ (atmos. mixing) tan2 ~ 1.0 (maximal) • $e (solar mixing) tan2 ~ 0.4 • Evolution of ratios • case 1: pion decay at source !! e e (e.g. GZK) e:  :  1:2:0 becomes  1:1:1 regardless of solar mixing angle • case 2: if muons lose energy before they decay e:  :  0:1:0 becomes  (0.5-0.7):1:1 depending on solar mixing angle

13. Neutrino Decay? • In SM, neutrino decays highly suppressed: • low neutrino masses  small phase space in “golden rule” • j!i suppressed by leptonic GIM mechanism • j!i extremely small since  magn. moment is small • SM lifetime far longer than transit time • Beyond SM physics • If there lepton flavor number and lepton number are spontaneously broken symmetries, then the symmetry breaking could correspond to massless goldstone boson, majoron (J) • J couples only to neutrinos • Allows relatively fast decays: ! + J or ! +J • This theory is not currently favored but arguments apply to any decay

14. Neutrino Decay’s imprint onNeutrino flavors Beacom,Bell,Hooper,Pakvasa,Weiler, PRL 90,181301 (2003) Recent review: Pakvasa, Phys. Atom. Nucl., 67, 1154 (2004) • Neutrino decay leaves a strong imprint on flavor ratios at Earth • and is sensitive to hierarchy • SalSA opportunity is if GZK are the only neutrinos. Otherwise, lower energy neutrino telescopes (with flavor ID) have better L/E. e::t! 0:1:1 e::t! (5-6):1:1

15. 13 and CP • Allows : to deviate from 1:1 • Measuring CP violation in the neutrino mixing matrix requires Ue3 (ie, sin 13) to be non-zero. • |Ue3| known to be <0.04 • currently the topic of reactor and accelerator efforts • Measuring Ue3 via sin13 through reactor (disappearance) or accelerators (appearance) are the standard techniques.

16. 13 and CP • IF neutrinos decay, then there is sensitivity to 13 and  CP-violation • (only if it is normal hierarchy) =180 =180 =135 =135 =90 =90 =45 =0 =45 =0 Beacom,Bell,Hooper,Pakvasa,Weiler, PRD 69, 017303 (2004).

17. Exotica involving decays • If most massive neutrinosterile neutrino, get 2:1:1 (if normal hierarchy) • Beacom,Bell,Hooper,Pakvasa,Weiler, PRL 90,181301 (2003). • This flavor analysis assumed CPT conservation. Could get different ratios if CPT were violated • Barenboim & Quigg, PRD 67, 073024 (2003). • Dirac vs. Majorana • Helicity effects • Pakvasa, hep-ph/0305317 • If Dirac, daughters of “wrong” helicity become sterile •  Dirac: change ratios, Majorana: preserve ratios • Pseudo-Dirac neutrinos • Beacom, Bell,Hooper,Learned,Pakvasa,Weiler, PRL 92, 011101 (2004) • What if the 3 active states are nearly mass-degenerate with 3 sterile neutrinos? • Can probe 10-18 < m2 < 10-12 eV2

18. Can SalSA Look for Superheavy SUSY annihilation? • Could multi-PeV and greater neutralinos (0) could be the dark matter? • Neutrino telescopes often look for annihilation neutrinos • 0 + 0! • Neutrino telescopes commonly look for neutrinos coming from the core of Sun or Earth • Unfortunately the  are absorbed in the material on their way out •  get out but with <1 PeV energy • So, the answer is probably no.  0 Sun or Earth 0  0

19. Z Bursts &Relic neutrino mass spectroscopy • A “trick” to circumvent the GZK cutoff (Weiler ’82): If non-degenerate, m~0.04 eV, requires 1023 eV neutrinos  GLUE and FORTE have largely ruled out necessary fluxes • However, mCNB could be as large as 0.3 eV (degenerate masses, constrained by WMAP) Gelmini,Varieschi,Weiler, PRD70, 113005 (2004) Eberle,Ringwald,Song,Weiler, PRD70 023007 (2004) • EUHECR~ 1021 eV Next generation would be sensitive to these. Absorption dip measures  mass

20. Time Domain Neutrino Mass Spectroscopy? • A neutrino is born as a weak eigenstate = a linear superposition mass eigenstates • The proper treatment uses wave-packets for 1, 2, 3 superposition • B. Kayser, PRD 24, 110 (1981) • Packets for m1 m2 m3 so v1 v2 v3 • Originally was interesting for larger mass neutrinos from SN. • Over cosmological distances, packets may “decohere” and arrive at different times • About 50 msec for GRB at z=1. • Is the underlying process fast enough? • Would be the purview of lower energy neutrino telescopes if there are sources. At least for Teraton detectors the GZK neutrinos are expected.

21. Conclusions • Teraton neutrino telescopes can make probe the standard model in unique ways • ~150 TeV center-of-momentum energy • 108 times longer baseline for  decay and oscillations