123705690
Stringy restrictions on the Scherk-Schwarz mechanism
The authors consider the sigma model describing the propagation of a bosonic string in a manifold of the type M4(X)K obtained by compactification of D=26 spacetime using the Scherk-Schwarz mechanism. The requirement of 2D conformal invariance (at the 1-loop level) of this sigma model is shown to impose rather stringent restrictions on the mass parameters used in the Scherk-Schwarz mechanism. Implications for the background field mass spectrum in the model considered by Scherk and Schwarz (1979) are examined.
121107676
Soft supersymmetry breaking in superstring-based low-energy supergravity
Abstract We study four-dimensional supergravity theories consistent with those symmetries of the underlying ten-dimensionl supergravity (or superstring) theory, which are preserved by string loop effects. On very general grounds, we derive constraints that the Kahler potential of these theories must satisfy, in order that soft supersymmetry breaking terms appear in the low-energy observable sector at tree level.
118589994
A Geometric Approach to Modulus Stabilization
Modulus stabilization, a must for explaining the hierarchy problem in the context of the Randall-Sundrum (RS) scenario, is traditionally achieved through the introduction of an extra field with {\em ad hoc} couplings. We point out that the stabilization can, instead, be achieved in a purely geometrodynamical way, with plausible quantum corrections in the gravity sector playing the key role. The size of the corrections that lead to acceptable phenomenology is also delineated.
119221756
Matter–gravity interaction in a multiply warped braneworld
The role of a bulk graviton in predicting the signature of extra dimensions through collider-based experiments is explored in the context of a multiply warped spacetime. In particular it is shown that in a doubly warped braneworld model, the presence of the sixth dimension, results in enhanced concentration of graviton Kaluza Klein (KK) modes compared to that obtained in the usual 5-dimensional Randall-Sundrum model. Also, the couplings of these massive graviton KK modes with the matter fields on the visible brane turn out to be appreciably larger than that in the corresponding 5dimensional model. The significance of these results are discussed in the context of KK graviton search at the Large Hadron Collider (LHC).
119194203
Neutrino masses, the cosmological constant, and a stable universe in a Randall-Sundrum scenario
The Randall-Sundrum model of warped geometry in a five-dimensional scenario, aimed at explaining the hierarchy between the Planck and electroweak scales, is intrinsically unstable in its minimal form due to negative tension of the visible brane. A proposed solution to the problem yields a negative cosmological constant in four dimensions. We show that this wrong-sign cosmological constant is restricted to small values, therefore requiring less cancellation from hitherto unknown physics, if bulk neutrinos are postulated to explain the observed neutrino mass pattern. Thus neutrino masses, a stable TeV-brane configuration and new physics in the context of the cosmological constant get rather suggestively connected by the same thread.
15739631
Randall-Sundrum with Kalb-Ramond field: return of the hierarchy problem?
We show that when the antisymmetric Kalb–Ramond field is included in the Randall–Sundrum scenario, although the hierarchy problem can be solved, it requires an extreme fine tuning of the Kalb–Ramond field (about 1 part in 1062). We interpret this as the return of the problem in disguise. Further, we show that the Kalb–Ramond field induces a small negative cosmological constant on the visible brane.
39289287
Model of multifragmentation, equation of state, and phase transition
We consider a soluble model of multifragmentation which is similar in spirit to many models which have been used to fit intermediate energy heavy ion collision data. We draw a p-V diagram for the model and compare with a p-V diagram obtained from a mean-field theory. We investigate the question of chemical instability in the multifragmentation model. Phase transitions in the model are discussed.
18967637
Mononuclear caloric curve in a mean field model
A mean field model is used to investigate if a plateau in caloric curve can be reached in mononuclear configuration. In the model the configuration will break up into many pieces as the plateau is approached.
121044914
RENORMALIZATION OF QUANTUM CHROMODYNAMICS
Renormalization of quantum chromodynamics is carried out by means of a momentum-space subtraction scheme, which is computationally simple, provides a well-defined procedure for the determination of renormalization constants, and is equally applicable to light and heavy quarks. We also obtain the renormalization-group parameters, verify the decoupling theorem for heavy quarks, and compute the effective coupling constant and effective quark masses.
117512035
A glimpse of the gluon EMC-effect from J/psi production in pion-nucleus collisions
119767465
Nonlinear Hadron Couplings from Divergence Conditions. III. SU(3) Multiplets