اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSIM(2) and supergraphs
54
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We construct Feynman rules and Supergraphs in SIM(2) superspace. To test our methods we perform a one-loop calculation of the effective action of the SIM(2) supersymmetric Wess-Zumino model including a term which explicitly breaks Lorentz invariance. The renormalization of the model is also discussed.
قيم البحث
اقرأ أيضاً
In this brief note we give a superspace description of the supersymmetric nonlocal Lorentz noninvariant actions recently proposed by Cohen and Freedman. This leads us to discover similar terms for gauge fields.
Let CMSO denote the counting monadic second order logic of graphs. We give a constructive proof that for some computable function $f$, there is an algorithm $mathfrak{A}$ that takes as input a CMSO sentence $varphi$, a positive integer $t$, and a con
nected graph $G$ of maximum degree at most $Delta$, and determines, in time $f(|varphi|,t)cdot 2^{O(Delta cdot t)}cdot |G|^{O(t)}$, whether $G$ has a supergraph $G$ of treewidth at most $t$ such that $Gmodels varphi$. The algorithmic metatheorem described above sheds new light on certain unresolved questions within the framework of graph completion algorithms. In particular, using this metatheorem, we provide an explicit algorithm that determines, in time $f(d)cdot 2^{O(Delta cdot d)}cdot |G|^{O(d)}$, whether a connected graph of maximum degree $Delta$ has a planar supergraph of diameter at most $d$. Additionally, we show that for each fixed $k$, the problem of determining whether $G$ has an $k$-outerplanar supergraph of diameter at most $d$ is strongly uniformly fixed parameter tractable with respect to the parameter $d$. This result can be generalized in two directions. First, the diameter parameter can be replaced by any contraction-closed effectively CMSO-definable parameter $mathbf{p}$. Examples of such parameters are vertex-cover number, dominating number, and many other contraction-bidimensional parameters. In the second direction, the planarity requirement can be relaxed to bounded genus, and more generally, to bounded local treewidth.
We conjecture that $W$ gravity can be interpreted as the gauge theory of $phi$ diffeomorphisms in the space of dimensionally-reduced $D=2+2$ $SU^*(infty)$ Yang-Mills instantons. These $phi$ diffeomorphisms preserve a volume-three form and are those w
hich furnish the correspondence between the dimensionally-reduced Plebanski equation and the KP equation in $(1+2)$ dimensions. A supersymmetric extension furnishes super-$W$ gravity. The Super-Plebanski equation generates self-dual complexified super gravitational backgrounds (SDSG) in terms of the super-Plebanski second heavenly form. Since the latter equation yields $N=1~D=4~SDSG$ complexified backgrounds associated with the complexified-cotangent space of the Riemannian surface, $(T^*Sigma)^c$, required in the formulation of $SU^*(infty)$ complexified Self-Dual Yang-Mills theory, (SDYM ); it naturally follows that the recently constructed $D=2+2~N=4$ SDSYM theory- as the consistent background of the open $N=2$ superstring- can be embedded into the $N=1~SU^*(infty)$ complexified Self-Dual-Super-Yang-Mills (SDSYM) in $D=3+3$ dimensions. This is achieved after using a generalization of self-duality for $D>4$. We finally comment on the the plausible relationship between the geometry of $N=2$ strings and the moduli of $SU^*(infty)$ complexified SDSYM in $3+3$ dimensions.
A colored heavy particle with sufficiently small width may form non-relativistic bound states when they are produced at the large hadron collider,(LHC), and they can annihilate into a diphoton final state. The invariant mass of the diphoton would be
around twice of the colored particle mass. In this paper, we study if such bound state can be responsible for the 750 GeV diphoton excess reported by ATLAS and CMS. We found that the best-fit signal cross section is obtained for the SU(2)$_L$ singlet colored fermion $X$ with $Y_X=4/3$. Having such an exotic hypercharge, the particle is expected to decay through some higher dimensional operators, consistent with the small width assumption. The decay of $X$ may involve a stable particle $chi$, if both $X$ and $chi$ are odd under some conserved $Z_2$ symmetry. In that case, the particle $X$ suffers from the constraints of jets + missing $E_T$ searches by ATLAS and CMS at 8 TeV and 13 TeV. We found that such a scenario still survives if the mass difference between $X$ and $chi$ is above $sim$ 30 GeV for $m_X sim 375$ GeV. Even assuming pair annihilation of $chi$ is small, the relic density of $chi$ is small enough if the mass difference between $X$ and $chi$ is smaller than $sim$ 40 GeV.
We study N=(0,2) deformed (2,2) two-dimensional sigma models. Such heterotic models were discovered previously on the world sheet of non-Abelian strings supported by certain four-dimensional N=1 theories. We study geometric aspects and holomorphic pr
operties of these models, and derive a number of exact expressions for the beta functions in terms of the anomalous dimensions analogous to the NSVZ beta function in four-dimensional Yang-Mills. Instanton calculus provides a straightforward method for the derivation. The anomalous dimensions are calculated up to two loops implying that one of the beta functions is explicitly known up to three loops. The fixed point in the ratio of the couplings found previously at one loop is not shifted at two loops. We also consider the N=(0,2) supercurrent supermultiplet (the so-called hypercurrent) and its anomalies, as well as the Konishi anomaly. This gives us another method for finding exact $beta$ functions. We prove that despite the chiral nature of the models under consideration quantum loops preserve isometries of the target space.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
