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

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

An Experimentalist’s theoretical review l “New Physics” in the Sources äTopological Defects äMonopoles “New Physics” in the Cross Section äLow-scale quantum gravity äExtreme proton structure down to x ~10 -8 l Physics of the Neutrino äNeutrino decay äSterile neutrinos äDirac vs. Majorana mass äInstantons äCPT violation äLorentz invariance  Measuring the neutrino mass with the highest energy ’s

Topological Defects l Possible “relic” particles (dubbed X) due to symmetry breaking phase transitions in the early Universe: äMasses at the GUT scale (M X ~10 25 eV). äBy why don’t these decay in sec? - Confine in “topological defects”  stable until destroyed/ annihilate äNO COSMIC ACCELERATOR NEEDED: “top-down” scenario - X  jets  mesons  neutrinos - X  leptons or even all neutrinos

Topological Defects l Some specific models äBhattacharjee, Hill, Schramm PRL 69, 567, (1992) äProtheroe & Stanev PRL 77,3708 (1996) äSigl, Lee, Bhattacharjee, Yoshida PRD 59, (1998) äBarbot, Drees, Halzen, Hooper, PLB 555, 22 (2003) l Basic ideas äWere attractive to circumvent GZK cutoff for UHE cosmic rays. äTopological defects could be monopoles, superconducting cosmic strings, domain walls äGenerally 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 äNeutrino flux vs. energy sensitive to source evolution vs. z of TD’s.

Neutrino Telescopes for Direct Monopole Detection l Monopoles: äDirac: The presence of even one monopole explains electric charge quantization äMonopoles are typically part of GUTs äMasses typically of order GUT scale äbut in some models M mp could even be as low as ~10 14 eV. l Observation of monopoles would be revolutionary for HEP l Parker bound ( cm -2 s -1 sr -1 ) äc.f. UHECR>10 20 eV (~ cm -2 s -1 sr -1 ) äCaveat: if monopoles catalyze proton decay then (lack of) neutron star heating provides extremely strong limit.

Neutrino Telescopes for Direct Monopole Detection Intergalactic magnetic fields sheets (~100 nG over 50 MPc) could accelerate monopoles to energies of ~5£10 24 eV l Light monopoles would be relativistic so are candidates for radio Cherenkov detection l Parker bound ( cm -2 s -1 sr -1 ) äc.f. UHECR>10 20 eV (~ cm -2 s -1 sr -1 ) äother direct MP searches, generally worse than Parker bound l Relativistic monopoles mimic particle with large charge: at least Z~68 äproduce EM showers along path by pair-production, photo-nuclear äcontinuously produces shower along its path  unique signature l WKW estimate F< cm -2 s -1 sr -1 for a km 3 detector for 1 year. äSalSA could do much better: äsensitive for M mp up to eV, far beyond production at accelerators. äFlux limit better than typical searches Wick, Kephart, Weiler, Biermann

Neutrino interactions in SM Early calculation McKay, Ralston, PLB 167, 103 (1986) Most commonly used: Ghandhi et al., Astropart. Phys. 5, 81 (1996): np e e np W /E/E /E 0.36

UHE Neutrino Cross Section and low-scale Quantum Gravity l Probing interactions at high CM  E cm = (2 m p E ) 1/2  150 TeV for E = eV   SM ( +N) ~ £  SM (p +N) Large extra dimension models could enhance cross section äGravity could become strong at E CM =M D äNon-perturbative effects could produce KK-exitations, string excitation, pea- branes, micro-BH above E CM l Astrophysics and laboratory limits still allow än=4, M D > 10 TeV  n¸ 5 M D >1 TeV

Enhancement of UHE Neutrino Cross Section SM Alvarez-Muniz,Feng,Halzen,Han,Hooper PRD65, (2002) Anchordoqui et al., PRD66, (2002)  (cm 2 ) E (eV) SM Sample predictions for M D ~1 TeV, n~6-7: l 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 Anchordoqui,Feng,Goldberg,Shapere, PRD65, (2002)

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

Neutrino Flavor Effects l Critical parameter for neutrino oscillations and decay is proper time, L/E.  Solar neutrinos: 150,000 km/5£10 6 eV = 30 m/eV ä“SalSA” neutrinos from 4 Gpc/10 17 eV = 10 9 m/eV l Standard model: neutrinos change flavor by oscillation   $  (atmos. mixing) tan 2  ~ 1.0 (maximal)   $ e (solar mixing) tan 2  ~ 0.4 l 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 äcase 2: if muons lose energy before they decay  e :  :   0:1:0 becomes  ( ):1:1 depending on solar mixing angle

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

Neutrino Decay’s imprint on Neutrino flavors l Neutrino decay leaves a strong imprint on flavor ratios at Earth äand is sensitive to hierarchy l SalSA opportunity is if GZK are the only neutrinos. Otherwise, lower energy neutrino telescopes (with flavor ID) have better L/E. e :  :  ! (5-6):1:1 e :  :  ! 0:1:1 Beacom,Bell,Hooper,Pakvasa,Weiler, PRL 90, (2003) Recent review: Pakvasa, Phys. Atom. Nucl., 67, 1154 (2004)

 13 and  CP Allows  :  to deviate from 1:1 Measuring CP violation in the neutrino mixing matrix requires U e3 (ie, sin  13 ) to be non-zero. ä|U e3 | known to be <0.04 äcurrently the topic of reactor and accelerator efforts Measuring U e3 via sin  13 through reactor (disappearance) or accelerators (appearance) are the standard techniques.

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

Exotica involving decays l If most massive neutrino  sterile neutrino, get 2:1:1 (if normal hierarchy) äBeacom,Bell,Hooper,Pakvasa,Weiler, PRL 90, (2003). l This flavor analysis assumed CPT conservation. Could get different ratios if CPT were violated äBarenboim & Quigg, PRD 67, (2003). l Dirac vs. Majorana äHelicity effects - Pakvasa, hep-ph/ If Dirac, daughters of “wrong” helicity become sterile -  Dirac: change ratios, Majorana: preserve ratios äPseudo-Dirac neutrinos - Beacom, Bell,Hooper,Learned,Pakvasa,Weiler, PRL 92, (2004) - What if the 3 active states are nearly mass-degenerate with 3 sterile neutrinos? - Can probe <  m 2 < eV 2

Could multi-PeV and greater neutralinos (  0 ) could be the dark matter? l Neutrino telescopes often look for annihilation neutrinos   0 +  0 ! äNeutrino 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 l So, the answer is probably no. Can SalSA Look for Superheavy SUSY annihilation? 00 00 00 Sun or Earth

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

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

Conclusions l Teraton neutrino telescopes can make probe the standard model in unique ways ä~150 TeV center-of-momentum energy  10 8 times longer baseline for decay and oscillations