High precision and -production data and the nuclear glue

Abstract

We use the high statistics E772 data on the nuclear dependence of the production of quarkonia (J /ψ and ϒ) and dimuons at large transverse momentum (p T ) in p-A collisions to get information about the gluonic EMC effect. We find a satisfactory quantitative agreement of the theoretical predictions with the data, although none of the models of the EMC effect we consider could account for the entire data. Nonetheless, our results suggest that these data can now be used for a better determination of the nuclear parton densities. Our conclusions are shown to be insensitive to the hadronization mechanism for the quarkonia.

Z2 monopoles, vortices and the universality of the SU(2) deconfinement transition

“…Therefore it is expected that the adjoint SO(3) coupling (β A ) (see Section 2) will not alter the continuum limit of the mixed SU(2)-SO(3) action. From our work [8,9,10] on the mixed action at non-zero temperatures, we, however, found the following surprising results: [6,7]. The dotted(thick-dashed) lines with hollow(filled) symbols are the second(first) order deconfinement phase transition lines [8,9,10] on N τ =2 (circles) and 4 (squares) lattices.…”

“…In particular, the fundamental-adjoint SU(2) action [6] has been extensively studied [2,3,4,5] in this context due to its rich phase structure, shown in Fig. 1 by solid lines of bulk phase transitions [6,7]. We argued in Ref.…”

More on the SU(2) deconfinement transition in the mixed action

“…The shift, on the other hand, suggests a possible lack of any correlation of the bulk transitions, if any, with the key observation of the change of the order of the deconfinement phase transition. This is so since any possible bulk transition for β A ≤ 1.25 is definitely not [22] and N τ =8 lattices with N σ =12 and 16 respectively. On these lattices the simulations were performed at β A =1.1 and 1.25 to determine the range in which T may lie.…”

“…(1) It may therefore be important to understand and explain the origin of the change in the order of the deconfinement transition even away from the continuum, especially since the results of Ref. [22] suggest a lack of a first order bulk phase transition at β A = 1.25…”

Suppressing monopoles and vortices: a possibly smoother approach to scaling?

“…[6,7]. In fact, simulations on larger symmetric lattices even suggested [10] a lack of a bulk phase transition at that adjoint coupling where a first order deconfinement transition for a lattice of temporal size four was clearly seen.…”