arXiv subjects

Estia Eichten

Publications and source records attributed to Estia Eichten.

31 records · Page 2Linked to original sources

arXiv2001

Excited Heavy-Light Systems and Hadronic Transitions

A detailed study of orbital and radial excited states in D, Ds, B and B_s systems is performed. The chiral quark model provides the framework for the calculation of pseudoscalar meson (pi, K, ...) hadronic transitions among heavy-light excited and ground states. To calculate the excited states masses and wavefunctions, we must resort to a relativistic quark model. Our model includes the leading order corrections in 1/m_(c,b) (e.g. mixing). Numerical results for masses and light hadronic transition rates are compared to existing experimental data. The effective coupling of the chiral quark model can be determined by comparing with independent results from lattice simulations (g^8_A = 0.53 +-/- 0.11) or fitting to known widths (g^8_A = 0.82 +-/- 0.09).

hep-ph↗

arXiv2000

Hadronic Decays of Excited Heavy Mesons

We studied the hadronic decays of excited states of heavy mesons (D, D_s, B and B_s) to lighter states by emission of pi, eta or K. Wavefunctions and energy levels of these excited states are determined using a Dirac equation for the light quark in the potential generated by the heavy quark (including first order corrections in the heavy quark expansion). Transition amplitudes are computed in the context of the Heavy Chiral Quark Model.

hep-ph↗

arXiv2000

Vacuum Alignment in Technicolor Theories-I. The Technifermion Sector

We have carried out numerical studies of vacuum alignment in technicolor models of electroweak and flavor symmetry breaking. The goal is to understand alignment's implications for strong and weak CP nonconservation in quark interactions. In this first part, we restrict our attention to the technifermion sector of simple models. We find several interesting phenomena, including (1) the possibility that all observable phases in the technifermions' unitary vacuum-alignment matrix are integer multiples of π/N' where N' \le N, the number of technifermion doublets, and (2) the possibility of exceptionally light pseudoGoldstone technipions.

hep-ph↗

arXiv1998

Strong Dynamics at the Muon Collider: Working Group Report

New strong dynamics at the energy scale ~ 1 TeV is an attractive and elegant theoretical ansatz for the origin of electroweak symmetry breaking. We review here the theoretical models for strong dynamics, particularly, technicolor theories and their low energy signatures. We emphasize that the fantastic beam energy resolution (sigma_E/E ~10^{-4}) expected at the first muon collider (sqrt{s} = 100-500 GeV) allows the possibility of resolving some extraordinarily narrow technihadron resonances and, Higgs-like techniscalars produced in the s-channel. Investigating indirect probes for strong dynamics such as search for muon compositeness, we find that the muon colliders provide unparallel reaches. A big muon collider (sqrt{s} =3-4 TeV) would be a remarkable facility to study heavy technicolor particles such as the topcolor Z', to probe the dynamics underlying fermion masses and mixings and to fully explore the strongly interacting electroweak sector.

hep-ph↗

arXiv1998

Narrow Technihadron Production at the First Muon Collider

In modern technicolor models, there exist very narrow spin-zero and spin-one neutral technihadrons---$pi^0_T$, $rho^0_T$ and $omega_T$---with masses of a few 100 GeV. The large coupling of $π^0_T$ to $μ^+μ^-$, the direct coupling of $rho^0_T$ and $omega_T$ to the photon and $Z^0$, and the superb energy resolution of the First Muon Collider may make it possible to resolve these technihadrons and produce them at extraordinarily large rates.

hep-ph↗

arXiv1997

Finding Low-Scale Technicolor at Hadron Colliders

In multiscale and topcolor-assisted models of walking technicolor, relatively light spin-one technihadrons $ρ_T$ and $ω_T$ exist and are expected to decay as $ρ_T \to W π_T, Z π_T$ and $ω_T \to γπ_T$. For $M_{ρ_T} \simeq 200 GeV$ and $M_{π_T} \simeq 100 GeV$, these processes have cross sections in the picobarn range in $\bar p p$ colisions at the Tevatron and about 10 times larger at the Large Hadron Collider. We demonstrate their detectability with simulations appropriate to Run II conditions at the Tevatron.

hep-ph↗

arXiv1996

Electroweak and Flavor Dynamics at Hadron Colliders--I

This is the first of two reports cataloging the principal signatures of electroweak and flavor dynamics at $\pbarp$ and $pp$ colliders. Here, we discuss some of the signatures of dynamical elecroweak and flavor symmetry breaking. The framework for dynamical symmetry breaking we assume is technicolor, with a walking coupling $α_{TC}$, and extended technicolor. The reactions discussed occur mainly at subprocess energies $\sqrt{\hat s} \simle 1 TeV$. They include production of color-singlet and octet technirhos and their decay into pairs of technipions, longitudinal weak bosons, or jets. Technipions, in turn, decay predominantly into heavy fermions. This report will appear in the Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics (Snowmass 96).

hep-ph↗

arXiv1996

Electroweak and Flavor Dynamics at Hadron Colliders--II

This is the second of two reports cataloging the principal signatures of electroweak and flavor dynamics at $\pbarp$ and $pp$ colliders. Here, we complete our overview of technicolor with a discussion of signatures specific to topcolor-assisted technicolor. We also review signatures of flavor dynamics associated with quark and lepton substructure. These occur in excess production rates for dijets and dileptons with high $E_T$ and high invariant mass. An important feature of these processes is that they exhibit fairly central angular and rapidity distributions. This report will appear in the Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics (Snowmass 96).

hep-ph↗

arXiv1996

Low-Scale Technicolor at the Tevatron

In multiscale models of walking technicolor, relatively light color-singlet technipions are produced in $q \ol q$ annihilation in association with longitudinal $W$ and $Z$ bosons and with each other. The technipions decay as $\tpiz \ra b \ol b$ and $\tpip \ra c \ol b$. Their production rates are resonantly enhanced by isovector technirho vector mesons with mass $M_W + M_{\tpi} \simle M_{\tro} \simle 2 M_{\tpi}$. At the Tevatron, these associated production rates are 1--10 picobarns for $M_{\tpi} \simeq 100\,\gev$. Such a low mass technipion requires topcolor-assisted technicolor to suppress the decay $t \ra \tpip b$. Searches for $\tpi\tpi$ production will also be rewarding. Sizable rates are expected if $M_{\tro} \simge 2M_{\tpi} + 10\,\gev$. The isoscalar $ω_T$ is nearly degenerate with $\tro$ and is expected to be produced at roughly the same rate. The $ω_T$ should have the distinctive decay modes $ω_T \ra γ\tpiz$ and $Z \tpiz$.

hep-ph↗

arXiv1995

Natural Topcolor--Assisted Technicolor

We construct a prototype of topcolor--assisted technicolor in which, although both top and bottom quarks acquire some mass from extended technicolor, strong $U(1)$ couplings of technifermions are isospin symmetric and all gauge anomalies vanish. There is a mechanism for mixing between the light and heavy generations and there need be no very light pseudo--Goldstone bosons.

hep-ph↗

arXiv1994

Multiscale Technicolor and Top Production

Pair-production of heavy top quarks at the Tevatron Collider is significantly enhanced by the color--octet technipion, $η_T$, occurring in multiscale models of walking technicolor. We discuss $\bar tt$ rates for $m_t = 170$ GeV and $M_{η_T} = 400-500$ GeV. Multiscale models also have color--octet technirho states in the mass range 200-600 GeV that appear as resonances in dijet production and technipion pair--production.

hep-ph↗

arXiv1993

Masses and Decay Constants of Heavy-Light Mesons Using the Multistate Smearing Technique

We present results for f_B and masses of low-lying heavy-light mesons. Calculations were performed in the quenched approximation using multistate smearing functions generated from a spinless relativistic quark model Hamiltonian. Beta values range from 5.7 to 6.3, and light quark masses corresponding to pion masses as low as 300 MeV are computed at each value. We use the 1P--1S charmonium splitting to set the overall scale.

hep-lat↗

arXiv1992

Properties of Low-Lying Heavy-Light Mesons

We present preliminary results for the B meson decay constant and masses of low-lying heavy-light mesons in the static limit. Calculations were performed on the lattice in the quenched approximation using multistate smearing functions generated from a Hamiltonian for a spinless relativistic quark. The 2S--1S and 1P--1S mass splittings are measured. Using the 1P--1S charmonium splitting to set the overall scale, the ground state decay constant, f_B, is 319 +- 11 (stat) MeV.

hep-ph↗