165 research outputs found
Exploring Charge and Color Breaking vacuum in Non-Holomorphic MSSM
Non-Holomorphic MSSM (NHSSM) shows various promising features that are not
easily obtained in MSSM. However, the additional Non-Holomorphic (NH) trilinear
interactions that attribute to the interesting phenomenological features, also
modify the effective scalar potential of the model significantly. We derive
analytic constraints involving trilinear parameters and that
exclude global charge and color breaking minima (CCB). Since the analytic
constraints are obtained considering specific directions in the
multi-dimensional field space, we further probe the applicability of these
constraints by exhaustive scan over NH parameter space with two different
regimes of and delineate the nature of metastability by considering
vacuum expectation values for third generation squarks. We adhere to a natural
scenario by fixing Higgsino mass parameter () to a low value and estimate
the allowed ranges of NH trilinear parameters by considering vacuum stability
and observed properties of Higgs as the determining criteria.Comment: 29 pages, 10 figures, Results section elaborated, conclusion
unchanged, published in JHE
Exploring viable vacua of the -symmetric NMSSM
We explore the vacua of the -symmetric Next-to-Minimal Supersymmetric
Standard Model (NMSSM) and their stability by going beyond the simplistic
paradigm that works with a tree-level neutral scalar potential and adheres to
some specific flat directions in the field space. Key effects are demonstrated
by first studying the profiles of this potential under various circumstances of
physical interest via a semi-analytical approach. The results thereof are
compared to the ones obtained from a dedicated package like \veva ~which
further incorporates the thermal effects to the potential. Regions of the
phenomenological NMSSM (pNMSSM) parameter space that render the desired
symmetry breaking (DSB) vacuum absolutely stable, long- or short-lived (in
relation to the age of the Universe) under quantum/thermal tunneling are
delineated. Regions that result in color and charge breaking (CCB) minima are
also presented. It is demonstrated that light singlet scalars along with a
light LSP (lightest supersymmetric particle) having an appreciable singlino
admixture are compatible with a viable DSB vacuum and are much relevant for the
collider experiments.Comment: 52 pages, 19 figures, 4 tables; matches with published versio
Persistent homology of collider observations: when (w)hole matters
Topological invariants have played a fundamental role in the advancement of
theoretical high energy physics. Physicists have used several kinematic
techniques to distinguish new physics predictions from the Standard Model (SM)
of particle physics at Large Hadron Collider (LHC). However, the study of
global topological invariants of the collider signals has not yet attracted
much attention. In this article, we present, a novel approach to study collider
signals using persistent homology. The global topological properties of the
ensemble of events as expressed by measures like persistent entropy, Betti
area, etc. are worth considering in addition to the traditional approach of
using kinematic variables event by event. In this exploratory study, we first
explore the characteristic topological signature of a few SM electroweak
resonant productions. Next, we use the framework to distinguish global
properties of the invisible Higgs decay processes in the SM and a real singlet
extension of the SM featuring stable singlet scalar dark matter.Comment: 7 figures, 5 tables, submitted to PL
Intrinsic geometry of collider events and nearest neighbour based weighted filtration
Collider observations have mainly been studied on an event-by-event basis,
leveraging several kinematic techniques. However, the intrinsic topological
imprints of the ensemble of new physics events can be strikingly different from
the SM background ensemble. Traditional topological data analysis (TDA) is
known for its stability against small perturbations. However, a plethora of
rich information encoded in the clustering of ensembles is often lost due to
the unweighted filtration of simplicial complexes. Taking a singlet extended
model as an example, this work illustrates the rich global properties
associated with the so-called distance-to-measure (DTM) filtration on Alpha
complexes using weights determined from k-nearest neighbours.Comment: 1 table, 7 figure
Numerical Approximation of Nonlinear Stochastic Volterra Integral Equation using Walsh Function
This article proposes an efficient numerical method for solving nonlinear
stochastic Volterra integral equations using the operational matrices of the
Walsh function and the collocation method. In this method, a nonlinear
stochastic Volterra integral equation is reduced to a system of algebraic
equations, which are then solved to obtain an approximation of the solution.
Error analysis has been performed, confirming the effectiveness of the
methodology, which results in a linear order of convergence. Examples were
computed to demonstrate the efficacy and precision of the method.Comment: arXiv admin note: substantial text overlap with arXiv:2305.16678,
arXiv:2305.0082
A natural osmolyte trimethylamine N-oxide promotes assembly and bundling of the bacterial cell division protein, FtsZ and counteracts the denaturing effects of urea
Assembly of FtsZ was completely inhibited by low concentrations of urea and its unfolding occurred in two steps in the presence of urea, with the formation of an intermediate [Santra MK & Panda D (2003) J Biol Chem278, 21336-21343]. In this study, using the fluorescence of 1-anilininonaphthalene-8-sulfonic acid and far-UV circular dichroism spectroscopy, we found that a natural osmolyte, trimethylamine N-oxide (TMAO), counteracted the denaturing effects of urea and guanidium chloride on FtsZ. TMAO also protected assembly and bundling of FtsZ protofilaments from the denaturing effects of urea and guanidium chloride. Furthermore, the standard free energy changes for unfolding of FtsZ were estimated to be 22.5 and 28.4 kJ·mol-1 in the absence and presence of 0.6 m TMAO, respectively. The data are consistent with the view that osmolytes counteract denaturant-induced unfolding of proteins by destabilizing the unfolded states. Interestingly, TMAO was also found to affect the assembly properties of native FtsZ. TMAO increased the light-scattering signal of the FtsZ assembly, increased sedimentable polymer mass, enhanced bundling of FtsZ protofilaments and reduced the GTPase activity of FtsZ. Similar to TMAO, monosodium glutamate, a physiological osmolyte in bacteria, which induces assembly and bundling of FtsZ filaments in vitro[Beuria TK, Krishnakumar SS, Sahar S, Singh N, Gupta K, Meshram M & Panda D (2003) J Biol Chem278, 3735–3741], was also found to counteract the deleterious effects of urea on FtsZ. The results together suggested that physiological osmolytes may regulate assembly and bundling of FtsZ in bacteria and that they may protect the functionality of FtsZ under environmental stress conditions
Adenine nucleotide-dependent regulation of assembly of bacterial tubulin-like FtsZ by a hypermorph of bacterial actin-like FtsA.
Cytokinesis in bacteria depends upon the contractile Z ring, which is composed of dynamic polymers of the tubulin homolog FtsZ as well as other membrane-associated proteins such as FtsA, a homolog of actin that is required for membrane attachment of the Z ring and its subsequent constriction. Here we show that a previously characterized hypermorphic mutant FtsA (FtsA*) partially disassembled FtsZ polymers in vitro. This effect was strictly dependent on ATP or ADP binding to FtsA* and occurred at substoichiometric levels relative to FtsZ, similar to cellular levels. Nucleotide-bound FtsA* did not affect FtsZ GTPase activity or the critical concentration for FtsZ assembly but was able to disassemble preformed FtsZ polymers, suggesting that FtsA* acts on FtsZ polymers. Microscopic examination of the inhibited FtsZ polymers revealed a transition from long, straight polymers and polymer bundles to mainly short, curved protofilaments. These results indicate that a bacterial actin, when activated by adenine nucleotides, can modify the length distribution of bacterial tubulin polymers, analogous to the effects of actin-depolymerizing factor/cofilin on F-actin
CDMA Technology
This paper gives idea about CDMA Technology and its overloading schemes.With the help of matlab codes we simulated and obtained the plot between BER and SNR and also we have shown the effect of increasing the no. of users on the plot
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