Simultaneous Projectile-Target Excitation in Heavy Ion Collisions

We calculate the lowest-order contribution to the cross section for simultaneous excitation of projectile and target nuclei in relativistic heavy ion collisions. This process is, to leading order, non-classical and adds incoherently to the well-studied semi-classical Weizs\"acker-Williams cross section. While the leading contribution to the cross section is down by only $1/Z_P$ from the semiclassical process, and consequently of potential importance for understanding data from light projectiles, we find that phase space considerations render the cross section utterly negligible.Comment: 9 pages, LA-UR-94-247

Impartial avoidance and achievement games for generating symmetric and alternating groups

We study two impartial games introduced by Anderson and Harary. Both games are played by two players who alternately select previously-unselected elements of a finite group. The first player who builds a generating set from the jointly-selected elements wins the first game. The first player who cannot select an element without building a generating set loses the second game. We determine the nim-numbers, and therefore the outcomes, of these games for symmetric and alternating groups.Comment: 12 pages. 2 tables/figures. This work was conducted during the third author's visit to DIMACS partially enabled through support from the National Science Foundation under grant number #CCF-1445755. Revised in response to comments from refere

Impartial avoidance games for generating finite groups

We study an impartial avoidance game introduced by Anderson and Harary. The game is played by two players who alternately select previously unselected elements of a finite group. The first player who cannot select an element without making the set of jointly-selected elements into a generating set for the group loses the game. We develop criteria on the maximal subgroups that determine the nim-numbers of these games and use our criteria to study our game for several families of groups, including nilpotent, sporadic, and symmetric groups.Comment: 14 pages, 4 figures. Revised in response to comments from refere

Quark Model Calculations Of Symmetry Breaking in Parton Distributions

Using a quark model, we calculate symmetry breaking effects in the valence quark distributions of the nucleon. In particular, we examine the breaking of the quark model SU(4) symmetry by color magnetic effects, and find that color magnetism provides an explanation for deviation of the ratio $d_V(x)/u_V(x)$ from $1/2$. Additionally, we calculate the effect of charge symmetry breaking in the valence quark distributions of the proton and neutron and find, in contrast to other authors, that the effect is too small to be seen experimentally.Comment: 6 Pages, 3 postscript figures compressed using uufile

Color Magnetic Corrections to Quark Model Valence Distributions

We calculate order $\alpha_s$ color magnetic corrections to the valence quark distributions of the proton using the Los Alamos Model Potential wavefunctions. The spin-spin interaction breaks the model SU(4) symmetry, providing a natural mechanism for the difference between the up and down distributions. For a value of $\alpha_s$ sufficient to produce the $N-\Delta$ mass splitting, we find up and down quark distributions in reasonable agreement with experiment.Comment: 25 Pages, LA-UR-93-132

Procedural Justice and the Shadow Docket

This Article critically examines the role of procedural justice in shaping public perceptions of the U.S. Supreme Court’s legitimacy, particularly in light of recent Court actions, including the leak of a major opinion and the increasing, potentially politicized, use of its shadow docket. Drawing from the procedural justice model—which posits that legitimacy is primarily founded on the decision-making processes and principled judgments of the Court—this Article investigates whether the decline in confidence experienced by the Court can be attributed, at least in part, to its shadow docket. Utilizing an experimental survey conducted over three critical time points—coinciding with the leak of the Dobbs v. Jackson Women’s Health Organization decision, its subsequent announcement, and a period of procedural calm—this Article measures the public’s reaction to various procedural scenarios, including the usage of the emergency docket. Results indicate that while the use of the emergency docket doesn’t substantially erode the Court’s diffuse support, it does impact how much respondents approve of how well the Court is doing its job, significantly so when filtered through policy agreement. This Article further finds that the Court’s Dobbs decision strongly influenced perceptions, particularly among those aware of the leak or the opinion, with disagreement causing more pronounced and consistent negative effects than the partial positive effects from agreement. These findings underscore the impact of the Court’s own behaviors on its perceived authority, suggesting that the justices’ actions, particularly their adherence to fair and transparent procedures, can bolster the Court’s legitimacy. As such, this Article highlights the urgent need for the Supreme Court to embrace resolving legal questions via due process in order to reaffirm its critical role in our democracy and regain public trust