3 research outputs found
X(3872): Hadronic Molecules in Effective Field Theory
We consider the implications from the possibility that the recently observed
state X(3872) is a meson-antimeson molecule. We write an effective Lagrangian
consistent with the heavy-quark and chiral symmetries needed to describe
X(3872). We claim that if X(3872) is a molecular bound state of D^*0 and
anti-D^0 mesons, the heavy-quark symmetry requires the existence of the
molecular bound state X_b of B^*0 and anti-B^0 with the mass of 10604 MeV.Comment: 12 pages, 1 figure, 1 table, RevTe
Onset of the Jet Quenching Phenomenon
The aim of this study is to set a baseline for the jet quenching measurements
of the Quark Gluon Plasma (QGP) formed in the large system size Nucleus-Nucleus
(A-A) at top central collisions, via studying simulated small system size,
Nucleon-Nucleon (N-N) collisions. The proton-proton (p-p) collisions were
simulated using PYTHIA, at center of mass energies
and corresponding to the available energies
at the current collider experiments; the Relativistic Heavy Ion Collider
(RHIC), and the Large Hadron Collider (LHC). At both energies, the two-particle
azimuthal correlation functions have been considered, and the yield associated
with the high transverse momentum () particles were extracted at its
near-side () and away-side () at
mid pseudo rapidity (). The ratio between the near-side yields in
the high multiplicity events to these of the low multiplicity events
(), as well as, the ratio of the away-side yields
() were calculated at both energies as a function of the
hadron fractional energy of the high- particle. At both
energies, the values of and were less
than unity, and of trivial dependence on . The values of
are always less than these of at the same
multiplicity and energy, and both quantities show a pattern of systematic
decreases with the multiplicity. Such multiplicity dependence cannot be used
neither to exclude the jet quenching nor to prove it in the high multiplicity
events in p-p collisions, as the suppressions have been found at both sides,
near and away of the high- particle.Comment: 11 pages, 10 figures, comments welcome. This paper supersedes
arXiv:1902.05114 by the same authors because it has been significantly
rewritte