A Modified Rishon Model
Patrick S. WaltersAAPT-CPS Spring Meeting 2009Penn State – Mont AltoMarch 27th – 28th 2009
Rishon Theory
First proposed in 1979 by Haim Harari Quarks, leptons, gauge bosons are composite
particles in Rishon Theory. Two fundamental particles, T and V, and
antiparticlesT andV. T is charged -1/3 e, V is neutral. [1]
Haim Harari
Ph.D. in Physics from the Hebrew University of Jerusalem.
In 1967, became the youngest Professor ever to teach at the Weizmann Institute.
Predicted the existence of bottom and top quarks in 1975.
President of the Wiezmann Institute of Science from 1988 to 2001.
In 2001, received the Harnack Medal from the Max Planck Institute [3].
Implications
Electron (TTT), up quark (TTV), down quark (TVV), and neutrino (VVV) are each three-Rishon states.
Additional generations formed by adding TT pairs, i.e. b quark is TVVTTTT.
Photons and gluons are four-Rishon states (TVTV).
W bosons TTTVVV andTTTVVV.
Assumptions
Rishons are bound by an SU(3)H hypercolor mechanism [2].
T is massive, V is massless. T and V have opposite hypercharge (±1/3). 4th generation or higher fermions allowed. No Higgs mechanism is necessary.
Downfalls
No explanation of mass origin. Hypercharge assignments are inconsistent,
and isospin is ambiguous. No certain explanation of attraction between
Rishons. No direct explanation of color forces. Massless photons, gluons, and Z mass are
unexplained.
Proposed Modifications
T P,T P, V N,V N, changing the names and particle/antiparticle assignment slightly.
Assume that we start out with two equally massive non-natural Rishons P′ and N′ which mix at nearly 45 degrees to produce natural Rishons P (massive) and N (nearly massless).
Rishons are attracted strongly to each other, but Rishons and anti-Rishons repel even more strongly, proportional to their masses.
Proposed Modifications
P has positive isospin and hypercharge. P has negative isospin and hypercharge. N has negative isospin and positive
hypercharge. N has positve isospin and negative
hypercharge. Isospin comes in units of 1/6, hypercharge in
units of 1/3, intrinsic spin is ±1/2. SU(3) color charges a, b, and c for Rishons.
Methodology for Rishon Composites
Bag model may be effective for finding masses of composite states, such as quarks, leptons, and bosons.
Since chiral symmetry is broken by the bag contents, and not arbitrarily at the edge of the bag, the earlier problems with bag model may be resolved.
PP attraction is strong enough to cancel out a P mass, the PP repulsion is even stronger.
NN versus PP
NN repulsion is much weaker than PP repulsion, proportional to the much smaller N mass.
NN contributes little mass to a composite state, while PP contributes most of the mass to its composite states.
States with NN pairs will have the same or similar mass to states without it.
Interactions in Modified Model
Rishon interactions come in two types Type 1 (Δg8)2 + (Δg3)2 – ΔI2 = 1/3 Type 2 (Δg8)2 + (Δg3)2 – ΔI2 = 0 Weak nuclear processes proceed via one
Type 1 and two Type 2 processes Strong nuclear processes proceed via two
Type 1 processes
Transitions in Modified Model
P N transitions naturally occur 50% of the time in a 45° mixing scheme.
Natural mixing between quarks occurs for odd numbers of Rishons changing simultaneously in W-mediated processes
3-Rishon processes = 1/23 = 1/8 5-Rishon processes = 1/25 = 1/32 7-Rishon processes = 1/27 = 1/128 Such as t b W+ or s u e-ve
Transitions in Modified Model
Natural mixing between quarks occurs for even numbers of Rishons changing simultaneously in Z-mediated processes
2-Rishon processes = 1/22 = 1/4 4-Rishon processes = 1/24 = 1/16 Such as t c Z or b d uu Fourth-generation composites would instantly
fall apart into three first-generation composites; hence, they do not exist.
Particle Physics Implications
All particle decays and decay ratios can be derived from Rishon Model, and current experimental data may be sufficient to show this.
Quark mixing in the CKM matrix can be derived from Rishon Model.
Neutrino mixing can be derived from Rishon Model.
No new generations of quarks or leptons exist beyond the current three.
Particle Physics Implications
Pure B and W 3 fields in electro-weak model mix due to Rishon mixing to form natural photon and Z fields.
Z is massive and photon massless due to Rishon mixing.
Z branching ratios can be derived from Rishon Model.
Isospin symmetry is completely broken, while hypercharge is always conserved.
Higgs sector may exist, but is not necessary to explain mass.
Cosmological Implications
Natural Abundance; electron plus proton plus neutron plus neutrino.
Natural Abundance gives equal numbers of P and N Rishons.
Natural Abundance gives equal portions of Rishons and anti-Rishons; matter-antimatter symmetry.
1:3:3:1 structure of matter and antimatter; natural repulsion between matter and antimatter.
Testing the Modified Model
Using the quark mixing tables from the modified model, reconstruct the CKM matrix.
Using the modified model, compare the generated Z branching ratios to the experimental Z branching ratios.
Parameters include probabilities ofPP andNN production, P and N exchange.
Using parameters and phase space, compare generated hadronic branching ratios with experimental hadronic branching ratios.
References
[1] H. Harari, Phys. Lett. B86, 83 (1979) [2] H. Harari and N. Seiberg, Phys. Lett. B98, 269
(1981) [3] Wikipedia, http://en.wikipedia.org/wiki/Haim_Harari
(2009)