Charles Nelson

Office: S2-408

Phone: 607-777-4317

E-mail: cnelson@binghamton.edu

**Top Quarks:**

The newly discovered top quark, with its high mass (about 200 times that of the proton), allows for probes of new physics beyond the standard model(SM). We exploit the fact that because of this high mass, the top quark decays as a free quark and therefore yields polarization information through its decay products. With several recent graduate and undergraduate students (see below), we are developing model independent tests for CP, T, and (V-A) symmetry violations in, and for the complete Lorentz structure of, the decay top --> W + bottom. These tests are important for determining whether the top quark is indeed simply a more massive quark or, instead, is unusual.

*Higgs Bosons:*

Spin-correlation tests have been developed to probe the CP quantum number of Higgs bosons. In supersymmetric theories there are Higgs bosons with CP even quantum number (as in the SM) and also one with CP odd quantum number. Properties of CP violation effects can also be probed.

We have developed spin-correlation tests of this type with previous graduate students.

*Tau Leptons:*

The tau lepton is about 3,500 times as massive as the electron but it only exists for about 1/3 of a pico-second (10-12 sec). Nevertheless, on-going experiments can still test whether or not the tau is really like the stable electron. The existence of the tau lepton, to go with the muon and the electron, has created an outstanding " e - mu - tau Puzzle ". With several graduate students (see below), we have developed spin-correlation tests which are being used to probe for differences between the tau and the other leptons.

Paraparticles are particles which obey parastatistics which generalize the ordinary Fermi-Dirac and Bose-Einstein statistics (obeyed respectively by electrons and photons). Paraparticles are allowed in local relativistic quantum field theory but have not yet been experimentally discovered. As a major on-going program, we are analyzing the physical and mathematical properties of such theories. We are also constructing tests for the presence of paraparticles in reactions at high energy colliders and in astrophysics / cosmology.

*CP Violation:*

As an outgrowth of the above spin-correlation tests which can probe for non-CKM type leptonic (and top quark) CP violation, we are developing models with simple mechanisms to produce such violations.

*Dynamical Electroweak Symmetry Breaking: *

There is, and will continue to be, a major theoretical and experimental effort to determine whether or not the Higgs-mechanism is due to a fundamental scalar elementary field or, instead, due to a macroscopic f-fbar mechanism a'la the BCS theory in superconductivity.

Spin-correlation tests can be used as a probe for distinguishing possible electroweak symmetry breaking scenarios.

Note: The list below contains references to high energy physics- phenomenology or high energy- theory archives such as hep-ph/xxxxxxx. The best way to access or view the individual articles in the archive is to go to the archive's website and search by my name or the archive number.

"A New Kind of Weak-Coupling in Top- Quark Physics?" , Invited poster at ICHEP08; arXiv:0808.2940[hep-ph] .

"Hanbury-Brown and Twiss intensity correlations of parabosons", with P.R. Shimpi, Physics Letters A364, 104 (2007); math-ph/0610075.

"Use of W- Boson Longitudinal - Transverse Interference in Top Quark Spin- Correlation Functions II", with J.J. Berger and J.R.Wickman; Eur.J.Phy.C46,385 (2006); hep-ph/ 0510348.

"Use of W- Boson Longitudinal - Transverse Interference in Top Quark Spin- Correlation Functions", with E.G. Barbagiovanni, J.J. Berger, E.K. Pueschel, and J.R.Wickman; Eur.J.Phys C45, 121(2006); hep-ph/ 0506240.

"Coherent Production of Pairs of Parabosons of Order 2", with N. Franscino Eur. Phys. J. 39, 109(2005); hep-ph/ 0308089.

"Tests for the Statistics of Pair- Produced New Particles", Proceedings of "V-th Recontres du Vietnam", ed. J.Dumarchez, N.V.Hien and J.T.T.Van Hanoi ( page 461, August 2004); hep-ph/ 0410077.

"On an Intensity - Ratio Equivalence for Two Top Quark Decay Couplings", hep-ph/ 0411072.

“Consequences of a Large Top-Quark Chiral Weak-Moment”, Proceedings of “Les Rencontres de la Valle d’Aoste”, ed. M. Greca, La Thuile, Italy (page 319, March 2003); hep-ph/ 0305036.

“On the Top Quark’s Chiral Weak Moment” hep-ph/ 0304198.

"Three Numerical Puzzles and the Top Quark's Chiral Weak Moment" , Phys. Rev. D65, 074033 (2002); hep-ph/ 010638.

Zachary Waldman , “Majorana Neutrinos in the Jacob- Wick Phase Convention ”, May 2008.

Paresh Shimpi, “Hanbury-Brown and Twiss Intensity Correlations For Parabosons of Arbitrary Order”, Summer 2005.

Nicholas Frascino, “New Parasignatures in the Coherent Production of Pairs of Parabosons of Order 2”, May 2004 .

Nam H. Kim, "Chiral Weak-Moment of the Top Quark," May 2003.

Brijesh Bhayana, "Spin ½, 3/2 Helicity Spinors for Tests for New Physics in Top Quark Processes", May '99.

Thomas McCauley, "Top Quark Decay Tests for CP Violation and Non-(V-A) Couplings", May '97.

Marco Lopes, "Computer Simulation of Top Anti-Top Quark Pair Production", May '97.

Brain Kress, "Tests for CP Violation and Non-(V-A) Couplings in Top Decay", May '97.

Daryl Nazareth, "Second Stage Spin-Correlation Function for Tau Decay in Terms of Semi-Leptonic Parameters", May '96.

Minseob Kim, "Tests for Tau Lepton Couplings", Summer '95.

Robert Joachim, Dustin S. Pardo, Matthew D. Dornfeld, John Franz (in summer, from SUNY Oswego), Joshua B. Julian, Shan Huang, Stephan K. Piotrowski, Matthew T. Barbery, Alessandra Borgia, Jeffrey J. Berger, Patrick R. Gan, Jose Cardoza, David G. Johnston, Joshua R. Wickman, Eric G.Barbagiovanni, Elisa K.Pueschel, L.J. Adler, and Andrew M. Cohen and Zachary Waldman.