Search

Connection of Pauli’s principle with the nontrivial structure of the fermion supertime is shown. When supersymmetry is localized as supergravitation, fields of gravitational and exchange interaction carriers arise. The exchange interaction quantum of free fermions, being a superpartner of graviton (gravitino), is interpreted as a paulino – the particle responsible for the effect of mutual avoidance of identical fermions.

Gravitinos can inherit a non-relativistic dispersion relation while propagating in a background breaking both supersymmetry and Lorentz symmetry spontaneously. This is because the longitudinal mode velocity is controlled by the sound speed in the background. It was pointed out recently by Kolb, Long and McDonough that the production of gravitinos might diverge when this sound speed vanishes. We argue that in the framework of cosmological models with linearly spontaneously broken realised supersymmetry, where the physical fermions are combinations of the vacuum goldstino and the inflatino, the gravitino longitudinal mode has a relativistic dispersion relation and therefore avoids the catastrophic production. We illustrate this in some explicit examples., 16 pages. This v2 matches the published version: one reference added and minor changes in the introduction

By extending a previously proposed conformal gauge mediation model, we construct a gauge-mediated SUSY breaking (GMSB) model where a SUSY-breaking scale, a messenger mass, the $\mu$-parameter and the gravitino mass in a minimal supersymmetric (SUSY) Standard Model (MSSM) are all explained by a single mass scale, a R-symmetry breaking scale. We focus on a low scale SUSY-breaking scenario with the gravitino mass $m_{3/2}=\mathcal{O}(1){\rm eV}$, which is free from the cosmological gravitino problem and relaxes the fine-tuning of the cosmological constant. Both the messenger and SUSY-breaking sectors are subject to a hidden strong dynamics with the conformality above the messenger mass threshold (and hence the name of the model "strongly interacting conformal gauge mediation"). In our model, the Higgs B-term is suppressed and a large $\tan\beta$ is predicted, resulting in the relatively light second CP-even Higgs and the CP-odd Higgs with a sizable production cross section. These Higgs bosons can be tested at future LHC experiments., Comment: 8 pages, 2 figures, 1 table

A keV-scale gravitino arsing from a minimal supersymmetric (SUSY) Standard Model (MSSM) is an interesting possibility since the small scale problems that $\Lambda$CDM model encounters in the modern cosmology could be alleviated with the keV-scale gravitino serving as the warm dark matter (WDM). Such a light gravitino asks for a low scale supersymmetry (SUSY) breaking for which the gauge mediation (GM) is required as a consistent SUSY-breaking mediation mechanism. In this paper, we show upperbounds of the masses of the second CP-even Higgs boson $H$ and the CP-odd Higgs boson $A$, assuming the keV-scale gravitino to be responsible for the current DM relic abundance: the upperbound on the mass of $H/A$ is found to be $\sim 4$ TeV for the gravitino mass of $\mathcal{O}(10$-$100)$ keV. Interestingly, the mass of $H/A$ can be as small as 2-3 TeV and the predicted $\tan\beta$ is as large as 55-60 for the gravitino mass of $\mathcal{O}(10)$ keV. This will be tested in the near future Large Hadron Collider (LHC) experiments., Comment: v2: refs added; version published in JHEP

We construct new models of inflation and spontaneous supersymmetry breaking in de Sitter vacuum, with a single chiral superfield, where inflaton is the superpartner of the goldstino. Our approach is based on hyperbolic K\"ahler geometry, and a gauged (non-axionic) $U(1)_R$ symmetry rotating the chiral scalar field by a phase. The $U(1)_R$ gauge field combines with the angular component of the chiral scalar to form a massive vector, and single-field inflation is driven by the radial part of the scalar. We find that in a certain parameter range they can be approximated by simplest Starobinsky-like (E-model) $\alpha$-attractors, thus predicting $n_s$ and $r$ within $1\sigma$ CMB constraints. Supersymmetry (and $R$-symmetry) is broken at a high scale with the gravitino mass $m_{3/2}\gtrsim 10^{14}$ GeV, and the fermionic sector also includes a heavy spin-$1/2$ field. In all the considered cases the inflaton is the lightest field of the model., Comment: 26 pages, 9 figures, 3 tables. v2: updated version accepted to EPJC

We consider 1/4 BPS black hole solutions of ${\cal N}=2$ gauged supergravity in $AdS_4$. The near horizon geometry is $AdS_2 \times S^2$ and supersymmetry is enhanced. In the first part of the paper we choose a moment map, which allows the embedding of this supergravity solution into a sugra theory with a hypermultiplet. We then perform the s-wave reduction of this theory at the horizon and determine the dilaton multiplet, which couples to both metric and gravitino fluctuations. In the second part we work with Euclidean axial $\mathcal{N}=(2,2)$ JT supergravity and show how to add gauged matter in form of covariantly twisted chiral and anti-chiral multiplets. We demonstrate how to reduce the on-shell action to boundary superspace. We compare both theories and calculate the fourpoint function by integrating out gravitons, gravitini and photons for the s-wave setting and by use of the Super-Schwarzian modes in the JT theory., Comment: 45 pages, v2: references and comments added, minor corrections, version accepted for publication

We show a new mechanism for baryogenesis where the reheating temperature can be smaller than the electroweak scale. The baryon number symmetry is violated by a dimension nine operator which conserves a baryon parity. A high energy quark from the decay of a heavy particle, $e.g.$ inflaton, modulus or gravitino, undergoes flavor oscillation, and is thermalized due to the scatterings with the ambient thermal plasma. We point out that the baryon asymmetry of our universe can be generated due to the scatterings via the baryon number violating operator. Our scenario can be tested in neutron-antineutron oscillation experiments as well as other terrestrial experiments., Comment: 20pages, 4 figures, published version

Harmonic maps from Riemann surfaces arise from a conformally invariant variational problem. Therefore, on one hand, they are intimately connected with moduli spaces of Riemann surfaces, and on the other hand, because the conformal group is noncompact, constitute a prototype for the formation of singularities, the so-called bubbles, in geometric analysis. In theoretical physics, they arise from the nonlinear $\sigma $ -model of quantum field theory. That model possesses a supersymmetric extension, coupling a harmonic map like field with a nonlinear spinor field. In the physical model, that spinor field is anticommuting. In this contribution, we analyze both a mathematical version with a commuting spinor field and the original supersymmetric version. Moreover, this model gives rise to a further field, a gravitino, that can be seen as the supersymmetric partner of a Riemann surface metric. Altogether, this leads to a beautiful combination of concepts from quantum field theory, structures from Riemannian geometry and Riemann surface theory, and methods of nonlinear geometric analysis.

The braneworld Randall Sundrum II (RSII) model has been introduced to solve the problem related to the inflation standard scenario. The RSII model is based on a modification in the Friedmann equation by addition of the fifth dimension, which corresponds to energy, called the brane tension $\lambda$. After the inflation end, and when the universe enters in the reheating epoch, the effect of this energy $\lambda$ continues. In this context, we use the F-term model due to a simple superpotential with different forms of the Kahler potential to investigate the brane tension influence on the reheating temperature value $ T_{\rm rh}$. Consequently, we found a large value of $ T_{\rm rh}$, which varies in the range $(1-17) \times 10^{14}$ GeV. Also, we have shown that the variation of temperature value $ T_{{\rm rh}}$ depends on the brane tension and on the inflationary potential. Moreover in the F-term with the linear Kahler potential, the inflaton has a nonzero vacuum expectation value. At the end of inflation, this leads to an overproduction of gravitino which causes the destruction of the successful predictions of nucleosynthesis. In this context, we have shown that the increase in temperature is accompanied by the decrease in gravitino abundance. Therefore the solution of the gravitino overproduction.

We present a new consistent truncation of $D=11$ supergravity to $D=4$ $\mathcal{N}=2$ minimal gauged supergravity, on the seven-dimensional internal Riemannian space corresponding to the most general class of $D=11$ solutions with an AdS$_{4}$ factor and $\mathcal{N}=2$ supersymmetry. A truncation ansatz is proposed and its consistency checked at the level of the $D=11$ Bianchi identity, bosonic equations of motion, and supersymmetry variations of the gravitino. The general class includes an $\mathcal{N}=2$ AdS$_{4}$ solution dual to the conformal, low-energy physics phase corresponding to a mass deformation of the M2-brane field theory. A consistent truncation recently constructed on this particular geometry is recovered from our formalism., Comment: v2: Minor change of title, new paragraph in the discussion section and references added. Version to be published in JHEP

We determine the general structure of quantum anomalies for the $R$-multiplet of four dimensional $\mathcal{N}=1$ supersymmetric quantum field theories in the presence of background fields for an arbitrary number of Abelian flavor multiplets. By solving the Wess-Zumino consistency conditions for off-shell new minimal supergravity in four dimensions with an arbitrary number of Abelian vector multiplets, we compute the anomaly in the conservation of the supercurrent to leading non trivial order in the gravitino and vector multiplet fermions. We find that both $R$-symmetry and flavor anomalies necessarily lead to a supersymmetry anomaly, thus generalizing our earlier results to non superconformal theories with Abelian flavor symmetries. The anomaly in the conservation of the supercurrent leads to an anomalous transformation for the supercurrent under rigid supersymmetry on bosonic backgrounds that admit new minimal Killing spinors. The resulting deformation of the supersymmetry algebra has implications for supersymmetric localization computations on such backgrounds., Comment: 34 pages; v2: generalized analysis of flavor supersymmetry anomalies; references added

We derive the isometry irrep content of squashed seven-sphere compactifications of eleven-dimensional supergravity, i.e., the left-squashed ($LS^7$) with ${\mathcal N}=1$ and right-squashed ($RS^7$) with ${\mathcal N}=0$ supersymmetry, in a manner completely independent of the round sphere. Then we compare this result with the spectrum obtained by Higgsing the round sphere spectrum. This way we discover features of the spectra which makes it possible to argue that the only way the round spectrum can be related by a Higgs mechanism to the one of $LS^7$ is if the singletons are included in the round sphere spectrum. For this to work also in the $RS^7$ case it seems that the gravitino of the $LS^7$ spectrum must be replaced by a fermionic singleton present in the $RS^7$ spectrum., Comment: 24 pages including appendix with 12 figure, v2 minor typos corrected

As the full off-shell theories of supergravity in the important dimensions of eleven and ten dimensions are currently unknown, we introduce a superfield formalism as a foundation and experimental laboratory to explore the possibility that the scalar versions of the higher dimensional supergravitation theory can be constructed.

We discuss $N=2\to N=1$ reduction in four dimensional conformal supergravity. In particular, we keep the off-shell structure of supermultiplets (except hypermultiplets). As we will show, starting with (almost) off-shell conformal supergravity makes the procedure simpler than that from $N=2$ Poincar\'e supergravity, which makes it easier to show the correspondence to the standard $N=1$ conformal supergravity. We find that the $N=1$ superconformal symmetry is simply realized by truncating the gravitino multiplet. We also discuss the consistency with the original $N=2$ system and show the reduced $N=1$ conformal supergravity action., Comment: 23 pages

We compute leading soft theorem for multiple gravitinos (and graviton) in an arbitrary theory of supergravity with an arbitrary number of finite energy particles with arbitrary mass and arbitrary spin by extending Sen's approach \cite{Sen:2017xjn} to fermionic symmetry. Our result is true for any compactification of type II and Heterotic superstring theory. Our result is valid at all orders in perturbation for four and higher spacetime dimensions., version to appear in JHEP

We solve the Wess-Zumino consistency conditions of $\mathcal{N}=1$ off-shell conformal supergravity in four dimensions and determine the general form of the superconformal anomalies for arbitrary $a$ and $c$ anomaly coefficients to leading non trivial order in the gravitino. Besides the well known Weyl and $R$-symmetry anomalies, we compute explicitly the fermionic $\mathcal{Q}$- and $\mathcal{S}$-supersymmetry anomalies. In particular, we show that $\mathcal{Q}$-supersymmetry is anomalous if and only if $R$-symmetry is anomalous. The $\mathcal{Q}$- and $\mathcal{S}$-supersymmetry anomalies give rise to an anomalous supersymmetry transformation for the supercurrent on curved backgrounds admitting Killing spinors, resulting in a deformed rigid supersymmetry algebra. Our results may have implications for supersymmetric localization and supersymmetry phenomenology. Analogous results are expected to hold in dimensions two and six and for other supergravity theories. The present analysis of the Wess-Zumino consistency conditions reproduces the holographic result of arxiv:1703.04299 and generalizes it to arbitrary $a$ and $c$ anomaly coefficients., 13+13 pages; v2: minor corrections and improvements; references added; v3: further minor typos corrected; version published in JHEP

We construct the simplest inflationary α-attractor models in supergravity: it has only one scalar, the inflaton. There is no sinflaton since the inflaton belongs to an orthogonal nilpotent superfield where the sinflaton depends on fermion bilinears. When the local supersymmetry is gauge-fixed, these models have only one single real scalar (the inflaton), a graviton and a massive gravitino. The sinflaton, sgoldstino and inflatino are all absent from the physical spectrum in the unitary gauge. The orthogonality condition leads to the simplest Kähler potential for the inflaton, while preserving the Poincaré disk geometry of α-attractors. The models are particularly simple in the framework of the $$ \overline{D3} $$ D 3 ¯ induced geometric inflation.

Eleven-dimensional supergravity can be formulated in superspaces locally of the form X × Y where X is 4D N = 1 conformal superspace and Y is an arbitrary 7-manifold admitting a G 2-structure. The eleven-dimensional 3-form and the stable 3-form on Y define the lowest component of a gauge superfield on X × Y that is chiral as a superfield on X . This chiral field is part of a tensor hierarchy giving rise to a superspace Chern-Simons action and its real field strength defines a lifting of the Hitchin functional on Y to the G 2 superspace X × Y . These terms are those of lowest order in a superspace Noether expansion in seven N = 1 conformal gravitino superfields Ψ. In this paper, we compute the O(Ψ) action to all orders in the remaining fields. The eleven-dimensional origin of the resulting non-linear structures is parameterized by the choice of a complex spinor on Y encoding the off-shell 4D N = 1 subalgebra of the eleven-dimensional super-Poincaré algebra.

In this note, we discuss the consistency conditions which a discrete $Z_N$ symmetry should satisfy in order that it is not violated by gauge and gravitational instantons. As examples, we enlist all the $Z_N$ ${\cal R}$-symmetries as well as non-${\cal R}$ $Z_N$ symmetries (N=2,3,4) in the minimally supersymmetric standard model (MSSM) that are free from gauge and gravitational anomalies. We show that there exists non-anomalous discrete symmetries that forbid Baryon number violation up to dimension 6 level (in superspace). We also observe that there exists no non-anomalous $Z_3$ ${\cal R}$-symmetry in the MSSM. Furthermore, we point out that in a theory with one Majorana spin 3/2 gravitino, a large class of $Z_4$ ${\cal R}$-symmetries are violated in the presence of Eguchi-Hanson (EH) gravitational instanton. This is also in general true for higher $Z_N$ ${\cal R}$-symmetries. We also notice that in 4 dimensional ${\cal N}=1$ supergravity, the global $U(1)$ ${\cal R}$-symmetry is always violated by the EH instanton irrespective of the matter content of the theory., Comment: Version to appear in JHEP

The regularity of weak solutions of a two-dimensional nonlinear sigma model with coarse gravitino is shown. Here the gravitino is only assumed to be in $$L^p$$ for some $$p>4$$ . The precise regularity results depend on the value of p.

In supersymmetric theories, the gravitino is abundantly produced in the early Universe from thermal scattering, resulting in a strong upper bound on the reheat temperature after inflation. We point out that the gravitino problem may be absent or very mild due to the early dynamics of a supersymmetry breaking field, i.e. a sgoldstino. In models of low scale mediation, the field value of the sgoldstino determines the mediation scale and is in general different in the early Universe from the present one. A large initial field value since the era of the inflationary reheating suppresses the gravitino production significantly. We investigate in detail the cosmological evolution of the sgoldstino and show that the reheat temperature may be much higher than the conventional upper bound, restoring the compatibility with thermal leptogenesis., 23 pages, 3 figures; v2: discussions added and one figure updated, matches version published in JHEP

Presence of the light gravitino as dark matter candidate in a supersymmetric (SUSY) model opens up interesting collider signatures consisting of one or more hard photons together with multiple jets and missing transverse energy from the cascade decay. We investigate such signals at the 13 TeV LHC in presence of compressed SUSY spectra, consistent with the Higgs mass as well as collider and dark matter constraints. We analyse and compare the discovery potential in different benchmark scenarios consisting of both compressed and uncompressed SUSY spectra, considering different levels of compression and intermediate decay modes. Our conclusion is that compressed spectra upto 2.5 TeV are likely to be probed even before the high luminosity run of LHC. Kinematic variables are also suggested, which offer distinction between compressed and uncompressed spectra yielding similar event rates for photons + multi-jets + $E\!\!\!\!/_T$., 32 pages, 7 figures, 4 tables. Published in JHEP, minor modifications in text and few references added

We study the partial breaking of $$ \mathcal{N}=2 $$ global supersymmetry, using a novel formalism that allows for the off-shell nonlinear realization of the broken supersymmetry, extending previous results scattered in the literature. We focus on the Goldstone degrees of freedom of a massive $$ \mathcal{N}=1 $$ gravitino multiplet which are described by deformed $$ \mathcal{N}=2 $$ vector and single-tensor superfields satisfying nilpotent constraints. We derive the corresponding actions and study the interactions of the superfields involved, as well as constraints describing incomplete $$ \mathcal{N}=2 $$ matter multiplets of non-linear supersymmetry (vectors and single-tensors).

The gravitino problem is revisited in the framework of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. Dissipative effects (or bulk viscosity effects) arise owing to the different cooling rates of the fluid components. We show that the effects of the bulk viscosity allow one to avoid the late abundance of gravitinos. In particular, for particular values of the parameters characterizing the cosmological model, the gravitino abundance turns out to be weakly depending on the reheating temperature.

A new scheme for lightest supersymmetric particle (LSP) dark matter is introduced and studied in theories of TeV supersymmetry with a QCD axion, $a$, and a high reheat temperature after inflation, $T_R$. A large overproduction of axinos ($\tilde{a}$) and gravitinos ($\tilde{G}$) from scattering at $T_R$, and from freeze-in at the TeV scale, is diluted by the late decay of a saxion condensate that arises from inflation. The two lightest superpartners are $\tilde{a}$, with mass of order the TeV scale, and $\tilde{G}$ with mass $m_{3/2}$ anywhere between the keV and TeV scales, depending on the mediation scale of supersymmetry breaking. Dark matter contains both warm and cold components: for $\tilde{G}$ LSP the warm component arises from $\tilde{a} \rightarrow \tilde{G}a$, while for $\tilde{a}$ LSP the warm component arises from $\tilde{G} \rightarrow \tilde{a}a$. The free-streaming scale for the warm component is predicted to be of order 1 Mpc (and independent of $m_{3/2}$ in the case of $\tilde{G}$ LSP). $T_R$ can be as high as $10^{16}$ GeV, for any value of $m_{3/2}$, solving the gravitino problem. The PQ symmetry breaking scale $V_{PQ}$ depends on $T_R$ and $m_{3/2}$ and can be anywhere in the range $(10^{10} - 10^{16})$ GeV. Detailed predictions are made for the lifetime of the neutralino LOSP decaying to $\tilde{a}+ h/Z$ and $\tilde{G}+h/Z/\gamma$, which is in the range of $(10^{-1}-10^6)$m over much of parameter space. For an axion misalignment angle of order unity, the axion contribution to dark matter is sub-dominant, except when $V_{PQ}$ approaches $10^{16}$ GeV., Comment: 43 pages, 16 figures

We construct the Supersymmetric Effective Field Theory of Inflation, that is the most general theory of inflationary fluctuations when time-translations and supersymmetry are spontaneously broken. The non-linear realization of these invariances allows us to define a complete SUGRA multiplet containing the graviton, the gravitino, the Goldstone of time translations and the Goldstino, with no auxiliary fields. Going to a unitary gauge where only the graviton and the gravitino are present, we write the most general Lagrangian built out of the fluctuations of these fields, invariant under time-dependent spatial diffeomorphisms, but softly-breaking time diffeomorphisms and gauged SUSY. With a suitable St\"uckelberg transformation, we introduce the Goldstone boson of time translation and the Goldstino of SUSY. No additional dynamical light field is needed. In the high energy limit, larger than the inflationary Hubble scale for the Goldstino, these fields decouple from the graviton and the gravitino, greatly simplifying the analysis in this regime. We study the phenomenology of this Lagrangian. The Goldstino can have a non-relativistic dispersion relation. Gravitino and Goldstino affect the primordial curvature perturbations at loop level. The UV modes running in the loops generate three-point functions which are degenerate with the ones coming from operators already present in the absence of supersymmetry. Their size is potentially as large as corresponding to $f_{\rm NL}^{\rm equil.,\,orthog.}\sim 1$ or, for particular operators, even $\gg 1$. The non-degenerate contribution from modes of order $H$ is estimated to be very small., Comment: 55 pages, 2 figures

The last 2 years has seen an immense amount of activity and results from the Large Hadron Collider (LHC). Most notable is the discovery of a new particle which may very well be the long sought Higgs boson associated with electroweak symmetry breaking. There have also been many (up to now) unsuccessful searches for new particles associated with supersymmetry. One of the most attractive candidates for dark matter is the lightest supersymmetric particle (LSP). The recent results from the LHC have had a dramatic impact on our expectations for the properties of the LSP. These results can be used to revise expectations for both direct and indirect detection of dark matter.

We revisit the nonthermal gravitino production at the (p)reheating stage after inflation. Particular attention is paid to large field inflation models with a $\mathbb{Z}_2$ symmetry, for which the previous perturbative analysis is inapplicable; and inflation models with a stabilizer superfield, which have not been studied non-perturbatively. It is found that in single-superfield inflation models (without the stabilizer field), nonthermal production of the transverse gravitino can be cosmologically problematic while the abundance of the longitudinal gravitino is small enough. In multi-superfield inflation models (with the stabilizer field), production of the transverse and longitudinal gravitinos is significantly suppressed, and they are cosmologically harmless. We also clarify the relation between the background field method used in the preheating context and the standard perturbative decay method to estimate the gravitino abundance., 47 pages, 3 figures; v3, published version, extended discussions in Section 5 and Appendix B

The Dirac Hamiltonian formalism is applied to a system in (2 + 1)-dimensions consisting of a Dirac field ψ minimally coupled to Chern-Simons U(1) and SO(2, 1) connections, A and ω, respectively. This theory is connected to a supersymmetric Chern-Simons form in which the gravitino has been projected out (unconventional supersymmetry) and, in the case of a flat background, corresponds to the low energy limit of graphene. The separation between first-class and second-class constraints is performed explicitly, and both the field equations and gauge symmetries of the Lagrangian formalism are fully recovered. The degrees of freedom of the theory in generic sectors shows that the propagating states correspond to fermionic modes in the background determined by the geometry of the graphene sheet and the nondynamical electromagnetic field. This is shown for the following canonical sectors: i) a conformally invariant generic description where the spinor field and the dreibein are locally rescaled; ii) a specific configuration for the Dirac fermion consistent with its spin, where Weyl symmetry is exchanged by time reparametrizations; iii) the vacuum sector ψ = 0, which is of interest for perturbation theory. For the latter the analysis is adapted to the case of manifolds with boundary, and the corresponding Dirac brackets together with the centrally extended charge algebra are found. Finally, the SU(2) generalization of the gauge group is briefly treated, yielding analogous conclusions for the degrees of freedom., SCOPUS: ar.j, info:eu-repo/semantics/published

We study the moduli-induced gravitino problem within the framework of the phenomenologically attractive mirage mediations. The huge amount of gravitino generated by the moduli decay can be successfully diluted by introducing an extra light modulus field which does not induce the supersymmetry breaking. Since the lifetime of extra modulus field becomes longer than usually considered modulus field, our proposed mechanism is applied to both the low- and high-scale supersymmetry breaking scenarios. We also point out that such an extra modulus field appears in the flux compactification of type II string theory., Comment: 24 pages, 2 figures

We propose a simple model of split supersymmetry from gauge mediation. This model features gauginos that are parametrically a loop factor lighter than scalars, accommodates a Higgs boson mass of 125 GeV, and incorporates a simple solution to the $\mu-b_\mu$ problem. The gaugino mass suppression can be understood as resulting from collective symmetry breaking. Imposing collider bounds on $\mu$ and requiring viable electroweak symmetry breaking implies small $a$-terms and small $\tan \beta$ -- the stop mass ranges from $10^5$ to $10^8 \mbox{ GeV}$. In contrast with models with anomaly + gravity mediation (which also predict a one-loop loop suppression for gaugino masses), our gauge mediated scenario predicts aligned squark masses and a gravitino LSP. Gluinos, electroweakinos and Higgsinos can be accessible at the LHC and/or future colliders for a wide region of the allowed parameter space., Comment: 16 pages, 1 figure. Journal version, references added

We propose a framework of supersymmetric extensions of the Standard Model that can ameliorate both the SUSY Higgs mass problem and the missing superpartner problem. New vectorlike matter fields couple to the Higgs and provide new loop contributions to its mass. New Yukawa couplings are sizable and large supersymmetry breaking is not needed to lift the Higgs mass. To avoid a Landau pole for the new Yukawa couplings, these fields are charged under a new gauge group, which confines and leads to a Hidden Valley-like phenomenology. The Hidden Valley sector is almost supersymmetric and ordinary sparticles decay to exotic new states which decay back to Standard Model particles and gravitinos with reduced missing energy. We construct a simplified model to simulate this scenario and find a viable parameter space of specific benchmark models which ameliorates both of the major phenomenological problems with supersymmetry., Comment: 29 pages, 8 figures; v2: version accepted for the publication in JHEP

A search for direct pair production of the supersymmetric partner of the top quark, decaying via a scalar tau to a nearly massless gravitino, has been performed using 20 fb(-1) of proton-proton collision data at root s = 8 TeV. The data were collected by the ATLAS experiment at the LHC in 2012. Top squark candidates are searched for in events with either two hadronically decaying tau leptons, one hadronically decaying tau and one light lepton, or two light leptons. No significant excess over the Standard Model expectation is found. Exclusion limits at 95 % confidence level are set as a function of the top squark and scalar tau masses. Depending on the scalar tau mass, ranging from the 87 GeV LEP limit to the top squark mass, lower limits between 490 and 650 GeV are placed on the top squark mass within the model considered.

The canonical quantization for N = 1 supergravity in the context of grav- itational minisuperspace described by Gowdy T 3 and Bianchi class A cosmological models is analyzed in order to search for physical states. There are indeed physical states in the minisuperspace sector of the theory. This fact entails that the non-physical states conjecture has a restricted validity, and in consequence it cannot be considered a general result.

This talk presents some recent work that has been done in inflationary cosmology. First a brief review is given of the inflation scenario and its basic models. After that, one of the main problems in developing inflationary models has been the requirement of a very flat inflation potential. In solving this problem, supersymmetry has played a major role, and the reasons will be discussed and a specific example of the SUSY hybrid model will be examined. Some problems introduced by SUSY such as the η and gravitino problems will then be discussed. Then in a different direction, the quintessential inflation model will be examined as a proposal where a single scalar field plays the role of both the inflaton at early time and the dark energy field later. The final topic covered is developments in understanding dissipation and particle production processes during the inflationary phase.

We evaluate the contribution of chiral fermions in $d=2, 4, 6$, chiral bosons, a chiral gravitino like theory in $d=2$ and chiral gravitinos in $d=6$ to all the leading parity odd transport coefficients at one loop. This is done by using finite temperature field theory to evaluate the relevant Kubo formulae. For chiral fermions and chiral bosons the relation between the parity odd transport coefficient and the microscopic anomalies including gravitational anomalies agree with that found by using the general methods of hydrodynamics and the argument involving the consistency of the Euclidean vacuum. For the gravitino like theory in $d=2$ and chiral gravitinos in $d=6$, we show that relation between the pure gravitational anomaly and parity odd transport breaks down. From the perturbative calculation we clearly identify the terms that contribute to the anomaly polynomial, but not to the transport coefficient for gravitinos. We also develop a simple method for evaluating the angular integrals in the one loop diagrams involved in the Kubo formulae. Finally we show that charge diffusion mode of an ideal 2 dimensional Weyl gas in the presence of a finite chemical potential acquires a speed, which is equal to half the speed of light., Comment: 70 pages, 13 figures, typos corrected, added clarifications and a reference

We study a number of $U(1)_X$ models featuring a Dirac fermion dark matter particle. We perform a comprehensive analysis which includes the study of corrections to the muon magnetic moment, dilepton searches with LHC data, as well as direct and indirect dark matter detection constraints. We consider four different coupling structures, namely $U(1)_{B-L}, U(1)_{d-u}, U(1)_{universal}$, and $U(1)_{10+\bar{5}}$, all motivated by compelling extensions to the standard model. We outline the viable and excluded regions of parameter space using a large set of probes. Our key findings are that (i) the combination of direct detection and collider constraints rule out dark matter particle masses lighter than $\sim 1$ TeV, unless rather suppressed Z'-fermion couplings exist, and that (ii) for several of the models under consideration, collider constraints rule out Z' masses up to $\sim 3$ TeV. Lastly, we show that we can accommodate the recent Diboson excess reported by ATLAS collaboration within the $U(1)_{d-u}$ model., Comment: 32 pages, 3 tables, 27 figures. To appear in JHEP

Recent research shows that Hawking radiation (HR) is also possible around the trapping horizon of a wormhole. In this article, we show that the HR of gravitino (spin-$3/2$) particles from the traversable Lorentzian wormholes (TLWH) reveals a negative Hawking temperature (HT). We first introduce the TLWH in the past outer trapping horizon geometry (POTHG). Next, we derive the Rarita-Schwinger equations (RSEs) for that geometry. Then, using both the Hamilton-Jacobi (HJ) ans\"{a}tz and the WKB approximation in the quantum tunneling method, we obtain the probabilities of the emission/absorption modes. Finally, we derive the tunneling rate of the emitted gravitino particles, and succeed to read the HT of the TLWH., Comment: 4 pages, accepted for publication in the Astrophys. Space Sci

If some superpartners were in thermal equilibrium in the early universe, and if the lightest superpartner is a cosmologically stable gravitino, then there is a powerful upper bound on the scale of the superpartner masses. Typically the bound is below tens of TeV, often much lower, and has similar parametrics to the WIMP miracle., Comment: 5 pages, 4 figures

Searches were performed for topologies predicted by gauge-mediated Supersymmetry breaking models (GMSB). All possible lifetimes of the next-to-lightest SUSY particle (NLSP), either the lightest neutralino or slepton, decaying into the lightest SUSY particle, the gravitino, were considered. No evidence for GMSB signatures was found in the OPAL data sample collected at centre-of-mass energies of sqrt{s}=189-209 GeV at LEP. Limits on the product of the production cross-sections and branching fractions are presented for all search topologies. To test the impact of the searches, a complete scan over the parameters of the minimal model of GMSB was performed. NLSP masses below 53.5 GeV/c^2 in the neutralino NLSP scenario, below 87.4 GeV/c^2 in the stau NLSP scenario and below 91.9 GeV/c^2 in the slepton co-NLSP scenario are excluded at 95% confidence level for all NLSP lifetimes. The scan determines constraints on the universal SUSY mass scale Lambda from the direct SUSY particle searches of Lambda > 40,27,21,17,15 TeV/c^2 for messenger indices N=1,2,3,4,5 for all NLSP lifetimes.

A brief overview on the subject of Supersymmetric Quantum Cosmology (SQC) is presented here. Different approaches are described, all of them being inspired by the search of a square root of (quantum) General Relativity. Some new ideas in the form of a list of (still!) open problems and an extensive bibliography are included.

We analyze the predictions of the most general version of the supersymmetric minimal seesaw model with only two right-chiral neutrinos, which are degenerate in masses at the scale of Grand Unification. We apply the renormalization group technique to the running of the masses of the right-chiral neutrinos and the neutrino Yukawa couplings and find that thermal leptogenesis can account for the observed baryon asymmetry of the Universe even with a low reheating temperature, allowing to overcome the gravitino problem.

We consider Dirac leptogenesis in supersymmetric theories where the supersymmetry breaking is transmitted to the observable sector by an anomalous U(1) symmetry. This kind of supersymmetry breaking is known to provide a solution to the μ problem and avoid large CP-violation effects. The asymmetries generated by the decays of heavy leptons do not suffer from wash-out due to the equilibration of left- and right-handed neutrinos thanks to the extreme smallness of the neutrino masses. The model ties up the smallness of the neutrino masses and the out-of-equilibrium nature of the heavy lepton decays with no tension with the overproduction of gravitinos.

The feasibility for mass measurements of supersymmetric particles from minimal gauge mediated models in the ATLAS detector at the large hadron collider is studied using parameterized simulations. The covered models are characterized by having the supersymmetric tau as the only next-to-lightest supersymmetric particle (NLSP). Given independent measurements of the lightest Higgs mass and the NLSP lifetime, a sufficient number of supersymmetric particle mass measurements are performed such that all underlying model parameters are constrained.

These lectures contain an introduction to supersymmetry, a symmetry between bosons and fermions, in high energy and particle physics. The motivation and basic notions of supersymmetry are introduced. The Minimal Supersymmetric Standard Model is considered in greater details. Phenomenological features of the MSSM as well as possible experimental revealing of SUSY are discussed.

We study cosmological constraints in the context of $R$-parity violating MFV SUSY and find it is driven to $\tan(\beta)\approx1$. These constraints are from two sources: first from the requirement that baryon number violation not undo baryogenesis and second that the flux of decay products from gravitino dark matter not exceed that observed by experiments such as PAMELA and Fermi LAT. The latter discussion favors relatively low gravitino masses of a few GeV., Comment: 10 pages, 3 figures

We consider the effects of non-universalities among sfermion generations in models of Pure Gravity Mediation (PGM). In PGM models and in many models with strongly stabilized moduli, the gravitino mass may be O(100) TeV, whereas gaugino masses, generated through anomalies at 1-loop, remain relatively light O(1) TeV. In models with scalar mass universality, input scalar masses are generally very heavy (m_0 \simeq m_{3/2}) resulting in a mass spectrum resembling that in split supersymmetry. However, if one adopts a no-scale or partial no-scale structure for the K\"ahler manifold, sfermion masses may vanish at the tree level. It is usually assumed that the leading order anomaly mediated contribution to scalar masses appears at 2-loops. However, there are at least two possible sources for 1-loop scalar masses. These may arise if Pauli-Villars fields are introduced as messengers of supersymmetry breaking. We consider the consequences of a spectrum in which the scalar masses associated with the third generation are heavy (order m_{3/2}) with 1-loop scalar masses for the first two generations. A similar spectrum is expected to arise in GUT models based on E_7/SO(10) where the first two generations of scalars act as pseudo-Nambu-Goldstone bosons. Explicit breaking of this symmetry by the gauge couplings then generates one-loop masses for the first two generations. In particular, we show that it may be possible to reconcile the g_mu - 2 discrepancy with potentially observable scalars and gauginos at the LHC.

We study a scenario for baryogenesis in modular cosmology and discuss its implications for the moduli stabilization mechanism and the supersymmetry (SUSY) breaking scale. If moduli fields dominate the Universe and decay into the standard model particles through diatonic couplings, the right amount of baryon asymmetry can be generated through CP violating decay of gluino into quark and squark followed by baryon-number violating squark decay. We find that, in the KKLT-type moduli stabilization, at least two non-perturbative terms are required to obtain a sizable CP phase, and that the successful baryogenesis is possible for the soft SUSY breaking mass heavier than O(1) TeV. A part of the parameter space for successful baryogenesis can be probed at the collider experiments, dinucleon decay search experiment, and the measurements of electric dipole moments of neutron and electron. It is also shown that similar baryogenesis works in the case of the gravitino- or the saxion-dominated Universe., 36 pages, 2 figures

Photonic events with large missing energy have been observed in e+e- collisions at a centre-of-mass energy of 189GeV using the OPAL detector at LEP. Results are presented for event topologies consistent with a single photon or with an acoplanar photon pair. Cross-section measurements are performed within the kinematic acceptance of each selection, and the number of light neutrino species is measured. Cross-section results are compared with the expectations from the Standard Model process e+e- to nu nubar + photon(s). No evidence is observed for new physics contributions to these final states. Upper limits are derived on sigma(e+e- to XY).BR(X to Y gamma) and sigma(e+e- to XX).BR**2(X to Y gamma) for the case of stable and invisible Y. These limits apply to single and pair production of excited neutrinos (X=nu*, Y = nu), to neutralino production (X=neutralino_2, Y=neutralino_1) and to supersymmetric models in which X = neutralino_1 and Y = light gravitino. The case of macroscopic decay lengths of particle X is considered for e+e- to XX, X to Y gamma, when M_Y is of order zero. The single-photon results are also used to place upper limits on superlight gravitino pair production as well as graviton-photon production in the context of theories with additional space dimensions.

The goldstino-matter interactions given by the Goldberger-Treiman relations can receive higher dimensional operator corrections of $ O(q^{2}/M^{2})$, where $M$ denotes the mass of the mediators through which SUSY breaking is transmitted. These corrections in the gauge mediated SUSY breaking models arise from loop diagrams, and an explicit calculation of such corrections is presented. It is emphasized that the Goldberger-Treiman vertices are valid only below the mediator scale and at higher energies goldstinos decouple from the MSSM fields. The implication of this fact on gravitino cosmology in GMSB models is mentioned., 9 pages, 4 figures, typos corrected, version to appear in Eur. Phys. J. C