Experimental and Theoretical Mysteries of Mass: A View From A Contrarian Experimenter

Experimental and Theoretical Mysteries of Mass: A View From A Contrarian Experimenter • Martin L. PerlStanford Linear Accelerator Center • martin@slac.stanford.edu • This is the best time for doing physics that I have experienced in my lifetime. We have better technology in particle physics and astronomy. We are more open to new thoughts. • This talk is string theory neutral because my understanding of the theory is at the level • of the first half of Zweiback's “First Course in String Theory “. • References are limited

Supersymmetric particles Dark matter Monopoles Energy reach of colliders Mass reach in astronomy Mass reach of searches in bulk materials Mass of known particles Mass mechanisms Why are the mass ratios so peculiar? Is there a mass scale? Large mass and Planck mass

Masses of the known elementary particles MPlanck 18 10 15 10 12 10 Particle Mass GeV/c2 9 10 6 10 t 3 [1 TeV/c2] 10 W, Z t b c m s 0 [1 GeV/c2] 10 u, d e -3 [1 MeV/c2] 10 -6 10 n1 n2 n3 -9 [1 eV/c2] 10 -12 One n mass could be 0 10 -15 10 Mg < 6×10-26 (see next page}

Aside on photon mass Mg< 6×10-26 GeV/c2 is based on a magnetohydrodynamic study of solar wind, D. D. Ryutov, Plasma Phys. Control Fusion, 39, A73 (1997). I don’t understand the physics. Mg< 7×10-28 GeV/c2 based on a torsion balance method by J. Luo et al. , Phys. Rev. Lett., 90, 081801-1 (2003) but Is disputed by A. S. Goldhaber and M. M. Nieto, Phys. Rev. Lett., 91, 149101-1 (2003). They prefer Mg< 1×10-26 GeV/c2 based on a torsion balance method by J. Lakes , Phys. Rev. Lett., 80, 1826 (1998) Review on photon mass: L-C. Tu, J. Luo, G. T,Gillies, Rept. Prog. Phys., 68, 77 (2005)

Mystery 1 We have multiple models for the physics underlying the Higgs mechanism and other mass mechanisms. Straightforward Higgs mechanism but what is underlying physics? g,W, Z u, d, c, s, t, b e, m , t Higgs mechanism but do not know how to calculate each fermion’s coupling to Higgs. What Is underlying physics?

Usual mechanism is see-saw with initial Higgs mechanism for each neutrino. n1,n2,n3 Kaluza-Klein particles Many mechanisms proposed

Mystery 2 Why are the mass ratios so peculiar? Peculiar mass ratios: me : mm:mt= 1:207:3477 mt / mu~ 8 x 104

Mystery 3 Is there a mass scale? The mass range of the known particles is limited by our technology. We know what zero mass is, but we do not know what is a large mass?

Mystery 4 My problem with the Planck mass. • MPlanck=2.2 x 10-8 kg = 1.2 x 1019 GeV/c2 • My problems: • MPlanck mixes a constant from quantum • mechanics with two classical constants. • The masses of known particles have • nothing to do with their forces. • Does MPlanck have anything to do with • elementary particle masses?

Mystery 4 continued My problem with the Planck mass. EPlanck=2.0 x 109 J = 1.2 x 1019 GeV Perhaps it is better to think of the Planck Energy as the point where quantum mechanics intersects with gravity, and not glibly equate energy with mass.

Mystery 5 Supersymmetry, yes or no? I am optimistic that the question of the existence of supersymmetric particles will be settled by the Large Hadron Collider and the e+e- Linear Collider

Mystery 6 Nature of dark matter Usual assumption is 10<Mdark matter<104 GeV/c2 1. Collider and Direct Searches Courtesy of Blas Cabrera

Mystery 6 continued Nature of dark matter 2. Indirect Searches for Signals from Space Some weak evidence from HEAT balloon measurements for excess of positrons in cosmic rays. Center of sun may be a special source. J. Carr, G. Lamanna, and J. Lavelle, Rep, Prog. Phys. 69, 2475 (2006)

Mystery 7 Where are the monopoles? Many hypothesis about Mmonopole. There used to be interest in so-called GUT Monopole with M~1017GeV/c2, seems to have died off. 1. Colliders • Mmonopole> about 400 GeV/c2 from searches at Tevatron • Abulencia et al., Phys. Rev. Lett., 96 , 201801-1 (2006) ; (direct search for heavy ionization) • G. R. Kalbfleisch et al., Phys. Rev.,D69,052002-1 (2004) : ( search for monopoles in detector parts) • Reviews: • K. A. Milton, Rept. Prog. Phys., 69, 1637 (2008) • M. Fairbairn et al., hep-ph/0611040v2 (Also general • reference for massive stable particles.)

Mystery 7 continued Where are the monopoles? 2. From outer space Macro experiment searched for Mmonopole> 1010 GeV/c2 , found flux < about 10-16 /cm2 s sr M. Ambrosio et al., Eur. Phys. J., C25 , 511 (2002) Extended Parker Bound on monopole flux F<5 x 10-21 (Mmonopole/1017GeV/c2)/cm2 s sr M. J. Lewis, K. Freese, and G. Tarle, Phys. Rev.,D62, 025002 (2000)

Energy reach of colliders with ‘known’ technology VLHC Ecms= 200 TeV 1000 100 LHC CMS energy + - + - e e µ µ 10 in TeV collider collider 1 F. Zimmerman, Int. J. Mod. Phys.A21, 1987 (2006) S. Tazzari and M. Ferrario, Rep. Prog. Phys.66,1045 (2003)

Direct and indirect mass reach of colliders with ‘known’ technology Mass in TeV/c2

We look forward to colliders with advanced technology Require: Large gradients Very small beams Good power efficiency Reasonable cost Advanced technologies: Laser driven plasma wakefield acceleration Beam driven plasma wakefield acceleration Dielectric wakefield acceleration Vacuum laser acceleration

Mystery 8 Mass reach in astronomy Thermal relics from early universe Mass up to ~300 TeV/c2 K. Griest and M. Kamionkowski,Phys. Rev. Lett. 64, 615 (1990) Non-thermal relics produced after inflation Mass up to ~ 1013 TeV/c2 D. J. H. Chung et al., Phys.Rev.D59, 023501(1999)

Mass reach in astronomy Mass reach of searches in bulk materials Mass of known particles Mass mechanisms Why are the mass ratios so peculiar? Is there a mass scale? Large mass and Planck mass Supersymmetric particles Dark matter Monopoles Energy reach of colliders

Mystery 9 Mass reach of searches in bulk matter for stable particles General review: M. L. Perl et al., Int. J. Mod. Phys. A16, 2137 (2001) ________________________________________________ Searches for X+ in water, by looking for HXO in H2O Use electrolysis, ultracentrifuge, etc. to concentrate HXO. Then use mass spectrometer or spectral analysis to look for HXO concentration ratio P. Verkerk et. al. Phys. Rev.Lett. 68, 1116 (1992) T. K. Hemmick et. al. Phys. Rev.D41, 2074 (1990) P. F. Smith et.al. Nucl.Phys. B206, 333 (1982) MHXO MH 0 _____ 2

- Searches for X in Nuclei - X in small Bohr orbit = Z-1, super heavy isotope Nucleus Z Searches in Li, Be, Bo, C, O, F, Na Searches up to MX ~ 105 GeV/c2 No super heavy isotopes found T. K. Hemmick et. al. Phys. Rev.D41, 2074 (1990)

I cannot find a way to search for a massive stable charged particle X in solid material - X has mass MX and charge E Coulomb binding energy ~ 1 eV ~ 10-19 and extends ~10-10m Therefore Coulomb binding force FB~10-9 nt X stays in solid if MX<FB/g ~10-10kg ~1017GeV/c2

Search would extend to even larger MX on an asteroid. I published a method using liquids drops that will not work [Phys. Rev.D57,4441 (1998)]

Experimental and Theoretical Mysteries of Mass: A View From A Contrarian Experimenter