Hadron spectroscopy at RHIC

A description is given of the physics opportunities at RHIC regarding quark-gluon spectroscopy. The basic idea is to isolate with appropriate triggers the subprocesses pomeron + pomeron {yields} hadrons and {gamma}* + {gamma}* {yields} hadrons with the net effective mass of hadrons in the range of 1.0 to 3.0 GeV, in order to study the hadronic states composed of u, d, and s and gluons. The double-pomeron interactions are expected to produce glueballs and hybrids preferentially, while the two-offshell-photon initial states should couple predominantly to quarkonia and multiquark states. A plethora of J{sup PC}-exotic mesons can be produced either directly in both types of interactions or in association with a single recoil photon in the final state. 8 refs., 2 figs

Double-Pomeron and two-photon processes at RHIC

Double-Pomeron processes have been shown to be an important and novel source of hadron production at moderate energies at the ISR. These processes are expected to provide glue-rich hadrons from 1 GeV to 10 GeV or more, encompassing the states consisting of u, d, s and b quarks. The double-pomeron cross sections for central hadroproduction are calculated for p {times} p and Au {times} Au at RHIC. Two-photon production of hadrons in the central region begins to dominate or at least become comparable to the double-Pomeron processes as the Z of the beams increases from p to Au. Since photons couple to charge, these hadroproductions involve mainly quarkonia and multiquark states. Therefore, a comparative study of these processes is expected to provide new insights into the constituents of hadronic matter. The two-photon processes are calculated following the recipe given by Cahn and Jackson. The paper starts out with a thorough discussion of the relevant kinematics, phase space and Regge amplitudes

Hadron spectroscopy and B physics at RHIC

A description is given of the physics opportunities at RHIC regarding quark-gluon spectroscopy. The basic idea is to isolate with appropriate triggers the sub-processes pomeron + pomeron {yields} hadrons and {gamma}{sup *} + {gamma}{sup *} {yields} hadrons with the net effective mass of hadrons in the range of 1.0 to 10.0 GeV, in order to study the hadronic states composed of quarks and gluons. The double-pomeron interactions are expected to produce glueballs and hybrids preferentially, while the two-offshell-photon initial states should couple predominantly to quarkonia and multiquark states. Of particular interest is the possibility of carrying out a CP-violation study in the self-tagging B decays, B{sub d}{sup 0} {yields} K{sup +}{pi}{sup {minus}} and {bar B}{sub d}{sup 0} {yields} K{sup {minus}}{pi}{sup +}. 20 refs., 4 figs

Healing involvement and stressful involvement experienced by psychotherapy trainees: Patterns, correlates and perceived development

Background and Method: The experiences of 454 psychotherapy trainees when providing therapy to patients were surveyed in a multinational sample largely from European countries, as part of the collaborative SPRISTAD study, using established measures of trainees' Healing Involvement (HI) and Stressful Involvement (SI). Results: The results of cross-sectional analyses included the delineation of four differential patterns of therapeutic work involvement showing approximately half the trainees experienced an Effective Practice (high HI, low SI) while the other half experienced either a Challenging Practice (high HI, high SI), a Disengaged Practice (low HI, low SI) or a Distressing Practice (low HI, high SI). Discussion: Strong-to-moderate correlations were found between involvement styles and trainees' individual personal and professional characteristics, and among training programme and workplace situational conditions, and their possible applications to candidate selection and training practices were discussed. A strong association was seen between HI and SI qualities of trainees' therapeutic work and their positive or negative experiences of current professional development. Implications for training and hypotheses for future longitudinal studies were proposed based on the results.</p

Partial-wave analysis of the eta pi+ pi- system produced in the reaction pi-p --> eta pi+ pi- n at 18 GeV/c

A partial-wave analysis of 9082 eta pi+ pi- n events produced in the reaction pi- p --> eta pi+ pi- n at 18.3 GeV/c has been carried out using data from experiment 852 at Brookhaven National Laboratory. The data are dominated by J^{PC} = 0^{-+} partial waves consistent with observation of the eta(1295) and the eta(1440). The mass and width of the eta(1295) were determined to be 1282 +- 5 MeV and 66 +- 13 Mev respectively while the eta(1440) was observed with a mass of 1404 +- 6 MeV and width of 80 +- 21 MeV. Other partial waves of importance include the 1++ and the 1+- waves. Results of the partial wave analysis are combined with results of other experiments to estimate f1(1285) branching fractions. These values are considerably different from current values determined without the aid of amplitude analyses.Comment: 22 pages, 8 figure

Observation of exotic meson production in the reaction π−p→η′π−p \pi^{-} p \to \eta^{\prime} \pi^- p at 18 GeV/c

An amplitude analysis of an exclusive sample of 5765 events from the reaction $\pi^{-} p \to \eta^{\prime} \pi^- p$ at 18 GeV/c is described. The $\eta^{\prime} \pi^-$ production is dominated by natural parity exchange and by three partial waves: those with $J^{PC} = 1^{-+}, 2^{++},$ and $4^{++}$. A mass-dependent analysis of the partial-wave amplitudes indicates the production of the $a_2(1320)$ meson as well as the $a_4(2040)$ meson, observed for the first time decaying to $\eta^{\prime}\pi^-$. The dominant, exotic (non-$q\bar{q})$ $1^{-+}$ partial wave is shown to be resonant with a mass of $1.597 \pm 0.010^{+0.045}_{-0.010}$ GeV/c^2 and a width of $0.340 \pm 0.040 \pm 0.050$ GeV/c^2 . This exotic state, the $\pi_1(1600)$, is produced with a $t$ dependence which is different from that of the $a_2(1320)$ meson, indicating differences between the production mechanisms for the two states.Comment: 5 pages with 4 figure

A partial wave analysis of the π0π0\pi ^0\pi ^0 system produced in π−p\pi ^-p charge exchange collisions

A partial wave analysis of the of the $\pi ^0\pi ^0$ system produced in the charge exchange reaction: $\pi ^-p\to \pi ^0\pi ^0n$ at an incident momentum of $18.3 GeV/c$ is presented as a function of ${\pi ^0\pi ^0}$ invariant mass, $m_{\pi^0\pi^0}$, and momentum transfer squared, $| {t} |$, from the incident $\pi^-$ to the outgoing ${\pi ^0\pi ^0}$ system.Comment: 24 pages total,8 pages text, 14 figures, 1 table. Submitted to Phys Rev

Evidence for Exotic J^{PC}=1^{-+} Meson Production in the Reaction pi- p --> eta pi- p at 18 GeV/c

Details of the analysis of the eta pi- system studied in the reaction pi^{-} p --> eta pi^{-} p at 18 GeV/c are given. Separate analyses for the 2 gamma and pi+ pi- pi0 decay modes of the eta are presented. An amplitude analysis of the data indicates the presence of interference between the a(2)(1320)- and a J^{PC}=1^{-+} wave between 1.2 and 1.6 GeV/c^2. The phase difference between these waves shows phase motion not attributable solely to the a(2)(1320)-. The data can be fitted by interference between the a(2)(1320)- and an exotic 1^{-+} resonance with M = 1370 +-16 +50 -30} MeV/c^2 and Gamma = 385 +- 40 +65 -105 MeV/c^2. Our results are compared with those of other experiments.Comment: 50 pages of text and 34 figure