Strangeness abundances in p¯-nucleus annihilations

Strange particle abundances in small volumes of hot hadronic gas are determined in the canonical ensemble with exact strangeness and baryon number conservation. Substantial density and baryon number dependence is found. A p¯d experiment is examined and applications to p¯-nucleus annihilations are considered

Metaphor For a Post-White Horizon

This project is a counternarrative, in the tradition of Richard Delgado’s The Rodrigo Chronicles, using critical race theory’s storytelling methodology. We present a discussion between a Black scholar and white scholar sharing their experiences as they explore the relationship between Blackness/whiteness and anti-Blackness/white supremacy. The crux of this counternarrative lies in the intersection between the hopelessness one Black scholar feels toward racial progress in America and the desperation of a white scholar as they process the possibilities for a post-white ontological future within the Western academy in the wake of the January 6th Insurrection. The counter-story integrates Afropessimistic thought with the creativity of Afrofuturism to comment on the uses and abuses of Black labor under the white gaze. The conclusion of the counter-story argues for the need of a post-white futurism that imagines a possible future without whiteness and a future that is also not subsistent upon the foundational abuse and overuse of Black labor. Corresponding author information: Dwayne Kwaysee Wright, J.D., Ph.D., Assistant Professor of Higher Education Administration, The George Washington University, 2136 G Street NW, Room 118, Washington, DC 20052, [email protected], Phone: 347.291.6276 Biographies Dwayne Kwaysee Wright (he/him/his), J.D., Ph.D. is an Assistant Professor of Higher Education and Director of Diversity, Equity, and Inclusion Initiatives at the Graduate School of Education and Human Development which is part of the George Washington University. His research and social activism seek to advance educational opportunity and equity for all students, particularly those historically oppressed and marginalized in American society. Email: [email protected] Dr. Tyler Derreth (he/him/his) is the associate director of SOURCE and faculty in the Department of Health, Behavior, and Society at Johns Hopkins University. His research concentrates on urban community–university partnerships, critical pedagogies, and equitable educational practices. He centers his research agenda on issues of social justice, racism, and identity. Email: [email protected]

Hadronic Ratios and the Number of Projectile Participants. Thermal hadron production in Si-Au collisions

We investigate the dependence of hadronic ratios on the number of projectile participants using a thermal model incorporating exact baryon number and strangeness conservation. A comparison is made with results from $Au-Au$ collisions obtained at the BNL-AGS.Comment: 5 pages LaTeX2e, 4 figures in Postscript forma

The order, shape and critical point for the quark-gluon plasma phase transition

The order, shape and critical point for the phase transition between the hadronic matter and quark-gluon plasma are considered in a thermodynamical consistent approach. The hadronic phase is taken as Van der Waals gas of all the known hadronic mass spectrum particles $m_H\le 2.0$ GeV as well as Hagedorn bubbles which correspond hadronic states with mass spectrum $m_H> 2.0$ GeV. The density of states for Hagedorn bubbles is derived by calculating the microcanonical ensemble for a bag of quarks and gluons with specific internal color-flavor symmetry. The mixed-grand and microcanonical ensembles are derived for massless and massive flavors. We find Hagedorn bubbles are strongly suppressed in the dilute hadronic matter and they appear just below the line of the phase transition. The order of the phase transition depends on Hagedorn bubble's internal color-flavor structure and the volume fluctuation as well. On the other hand, the highly compressed hadronic matter undergoes a smooth phase transition from the gas of known mass spectrum hadrons to another one dominated by Hagedorn bubbles with specific internal color-flavor structure before the phase transition to quark-gluon plasma takes place at last. The phase transition is found a first order for the intermediate and large chemical potentials. The existence of the tri-critical point depends on the modification of the bubble's internal structure specified by a phenomenological parameter $\gamma\propto\mu_B$ in the medium.Comment: 69 pages, 10 figure

Exact Baryon, Strangeness and Charge Conservation in Hadronic Gas Models

Relativistic heavy ion collisions are studied assuming that particles can be described by a hadron gas in thermal and chemical equilibrium. The exact conservation of baryon number, strangeness and charge are explicitly taken into account. For heavy ions the effect arising from the neutron surplus becomes important and leads to a substantial increase in e.g. the $\pi^-/\pi^+$ ratio. A method is developed which is very well suited for the study of small systems.Comment: 5 pages, 5 Postscript figure

Isospin Fluctuations from a Thermally Equilibrated Hadron Gas

Partition functions, multiplicity distributions, and isospin fluctuations are calculated for canonical ensembles in which additive quantum numbers as well as total isospin are strictly conserved. When properly accounting for Bose-Einstein symmetrization, the multiplicity distributions of neutral pions in a pion gas are significantly broader as compared to the non-degenerate case. Inclusion of resonances compensates for this broadening effect. Recursion relations are derived which allow calculation of exact results with modest computer time.Comment: 10 pages, 5 figure

The Legacy of Rolf Hagedorn: Statistical Bootstrap and Ultimate Temperature

In the latter half of the last century, it became evident that there exists an ever increasing number of different states of the so-called elementary particles. The usual reductionist approach to this problem was to search for a simpler infrastructure, culminating in the formulation of the quark model and quantum chromodynamics. In a complementary, completely novel approach, Hagedorn suggested that the mass distribution of the produced particles follows a self-similar composition pattern, predicting an unbounded number of states of increasing mass. He then concluded that such a growth would lead to a limiting temperature for strongly interacting matter. We discuss the conceptual basis for this approach, its relation to critical behavior, and its subsequent applications in different areas of high energy physics.Comment: 25 pages, 5 figures; to appear in R. Hagedorn and J. Rafelski (Ed.), "Melting Hadrons, Boiling Quarks", Springer Verlag 201

Influence of Impact Parameter on Thermal Description of Relativistic Heavy Ion Collisions at GSI/SIS

Attention is drawn to the role played by the size of the system in the thermodynamic analysis of particle yields in relativistic heavy ion collisions at SIS energies. This manifests itself in the non-linear dependence of K+ and K- yields in $AA$ collisions at 1 -- 2 A.GeV on the number of participants. It is shown that this dependence can be quantitatively well described in terms of a thermal model with a canonical strangeness conservation. The measured particle multiplicity ratios (pi+/p, pi-/pi+, d/p, K+/pi+ and K+/K- but not eta/pi0) in central Au-Au and Ni-Ni collisions at 0.8 -- 2.0 A.GeV are also explained in the context of a thermal model with a common freeze-out temperature and chemical potential. Including the concept of collective flow a consistent picture of particle energy distributions is derived with the flow velocity being strongly impact-parameter dependent.Comment: revtex, 20 figure

Antiproton-Nucleus Annihilation

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