63,145 research outputs found
The Classical and Quantum Theory of Relativistic p-Branes without Constraints
It is shown that a relativistic (i.e. a Poincar{\' e} invariant) theory of
extended objects (called p-branes) is not necessarily invariant under
reparametrizations of corresponding -dimensional worldsheets (including
worldlines for ). Consequnetly, no constraints among the dynamical
variables are necessary and quantization is straightforward. Additional degrees
of freedom so obtained are given a physical interpretation as being related to
membrane's elastic deformations ("wiggleness"). In particular, such a more
general, unconstrained theory implies as solutions also those p-brane states
that are solutions of the conventional theory of the Dirac-Nambu-Goto type.Comment: 21 page
Mass Terms in Effective Theories of High Density Quark Matter
We study the structure of mass terms in the effective theory for
quasi-particles in QCD at high baryon density. To next-to-leading order in the
expansion we find two types of mass terms, chirality conserving
two-fermion operators and chirality violating four-fermion operators. In the
effective chiral theory for Goldstone modes in the color-flavor-locked (CFL)
phase the former terms correspond to effective chemical potentials, while the
latter lead to Lorentz invariant mass terms. We compute the masses of Goldstone
bosons in the CFL phase, confirming earlier results by Son and Stephanov as
well as Bedaque and Sch\"afer. We show that to leading order in the coupling
constant there is no anti-particle gap contribution to the mass of
Goldstone modes, and that our results are independent of the choice of gauge.Comment: 22 pages, 4 figure
Irreversible Thermodynamics in Multiscale Stochastic Dynamical Systems
This work extends the results of the recently developed theory of a rather
complete thermodynamic formalism for discrete-state, continuous-time Markov
processes with and without detailed balance. We aim at investigating the
question that whether and how the thermodynamic structure is invariant in a
multiscale stochastic system. That is, whether the relations between
thermodynamic functions of state and process variables remain unchanged when
the system is viewed at different time scales and resolutions. Our results show
that the dynamics on a fast time scale contribute an entropic term to the
"internal energy function", , for the slow dynamics. Based on the
conditional free energy , one can then treat the slow dynamics as if
the fast dynamics is nonexistent. Furthermore, we show that the free energy,
which characterizes the spontaneous organization in a system without detailed
balance, is invariant with or without the fast dynamics: The fast dynamics is
assumed to reach stationarity instantaneously on the slow time scale; they have
no effect on the system's free energy. The same can not be said for the entropy
and the internal energy, both of which contain the same contribution from the
fast dynamics. We also investigate the consequences of time-scale separation in
connection to the concepts of quasi-stationaryty and steady-adiabaticity
introduced in the phenomenological steady-state thermodynamics
Molecular states
Motivated by the recent finding of five states by the LHCb
collaboration, and the successful reproduction of three of them in a recent
approach searching for molecular states of meson-baryon with the quantum
numbers of , we extend these ideas and make predictions for the
interaction of meson-baryon in the beauty sector, searching for poles in the
scattering matrix that correspond to physical states. We find several
states: two states with masses 6405~MeV and 6465~MeV for ; two more states with masses 6427~MeV and 6665~MeV for
; and three states between 6500 and 6820~MeV, degenerate with
, stemming from the interaction of
vector-baryon in the beauty sector.Comment: 11 pages, 9 tables; v2: discussion added, version accepted for
publication in NP
Massive quark effects in two flavor color superconductors
The high density effective theory formalism (HDET) is employed to describe
high density QCD with two massive flavors (2SC). The gap equation is derived
and explicitly solved for the gap parameter. The parameters associated to the
pseudo Nambu-Goldstone boson of are evaluated in the limit
and fixed. In particular we find for the velocity of the
NG boson the relation
.Comment: Latex file. 14 pages, 2 figures. Some improvement in the
presentation. 2 references added. Final version to be published in Physics
Letter
Helical motions in the jet of blazar 1156+295
The blazar 1156+295 was observed by VLBA and EVN + MERLIN at 5 GHz in June
1996 and February 1997 respectively. The results show that the jet of the
source has structural oscillations on the milliarcsecond scale and turns
through a large angle to the direction of the arcsecond-scale extension. A
helical jet model can explain most of the observed properties of the radio
structure in 1156+295.Comment: 6 pages, 2 figures, to appear in New Astronomy Reviews (EVN/JIVE
Symposium No. 4, special issue
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