We study light gravitino productions in association with a neutralino at future linear colliders in a scenario in which the lightest SUSY particle is a gravitino and the produced neutralino promptly decays into a photon and a gravitino. Comparing with the multiple goldstino scenario, we show that energy and angular distributions of the photon provide valuable information on the SUSY masses as well as the SUSY breaking.
In supergravity theories with a very light gravitino, the gluino decays dominantly to a gluon and a gravitino. This results in a much larger missing $E_T$ for the multijet final states in hadronic colliders. We use the latest Tevatron data for the multijet final states to set a new absolute lower bound of 3.0 x 10^{-13} GeV for the light gravitino mass.
The spectrum of single-photon events detected in the forward and in the barrel region of a TESLA linear collider detector was studied in order to investigate the production of superlight Gravitino pairs associated with a photon.
We consider theories with spontaneously broken global or local supersymmetry where the pseudo-goldstino or the gravitino is the lightest superparticle (LSP). Assuming that the long-lived next-to-lightest superparticle (NSP) is a charged slepton, we study several supergravity predictions: the NSP lifetime, angular and energy distributions in 3-body NSP decays. The characteristic couplings of the gravitino, or goldstino, can be tested even for very small masses.
We revisit the monophoton plus missing energy signature at $e^+e^-$ colliders in supersymmetric (SUSY) models where the gravitino is very light. There are two possible processes which provide the signal: gravitino pair production and associated gravitino production with a neutralino, leading the monophoton final state via an additional photon radiation and via the neutralino decay, respectively. By using the superspace formalism, we construct a model that allows us to study the parameter space for the both processes. We show that the signal cross section and the photon spectra provide informat…
We consider the production of gravitinos ($\widetilde G$) in association with gluinos ($\tilde g$) or squarks ($\tilde q$) at hadron colliders, including the three main sub-processes: $q \bar q -> \tilde g\widetilde G$, $qg -> \tilde q\widetilde G$, and $gg -> \tilde g\widetilde G$. These channels become enhanced to the point of being observable for sufficiently light gravitino masses ($m_{\widetilde G} < 10^{-4} eV$), as motivated by some supersymmetric explanations of the CDF $eeγγ+ E_{T,miss}$ event. The characteristic signal of such events would be monojets, as opposed to dijets obtained i…
In models with gauge mediated supersymmetry breaking the gravitino is the lightest supersymmetric particle. If R-parity is violated the gravitino decays, but with a half-live far exceeding the age of the universe and thus is, in principle, a candidate for the dark matter. We consider the decays of the next-to-lightest supersymmetric particle, assumed to be the neutralino. We show that in models where the breaking of R-parity is bilinear, the condition that R-parity violation explains correctly the measured neutrino masses fixes the branching ratio of the decay ${\tilde χ}^0_1 \to {\tilde G}γ$ …
In the framework of minimal flavor violation (MFV), we discuss the decay properties of a supersymmetric scalar top (stop) in the presence of a light gravitino. Given a small mass difference between the lighter stop and lightest neutralino and an otherwise sufficiently decoupled spectrum, the stop may be long-lived and thus can provide support to MFV at hadron colliders. For a bino-like lightest neutralino, we apply bounds from searches in the gamma gamma plus missing transverse energy channel (ATLAS with 1 fb^-1 and D0 with 6.3 fb^-1) and give a 5 fb^-1 projection for the ATLAS search.
In a supersymmetric large extra dimension scenario, the production of Kaluza-Klein gravitinos accompanied by a photino at e^+ e^- colliders is studied. We assume that a bulk supersymmetry is softly broken on our brane such that the low-energy theory resembles the MSSM. Low energy supersymmetry breaking is further assumed as in GMSB, leading to sub-eV mass shift in each KK mode of the gravitino from the corresponding graviton KK mode. Since the photino decays within a detector due to its sufficiently large inclusive decay rate into a photon and a gravitino, the process e^+ e^- -> photino + grav…
At high temperatures, gravitinos are generated in inelastic scattering processes with particles that are in thermal equilibrium with the hot primordial plasma. We consider the regeneration of gravitinos that starts with completion of reheating after inflation. Following a consistent finite-temperature approach, we provide the complete result for the gravitino production rate to leading order in the gauge couplings. Focusing on gravitino dark matter scenarios we compute the relic density of thermally produced gravitinos. Moreover, we show that a conceivable determination of the gravitino mass a…
We derive Feynman rules for the interactions of a single gravitino with (s)quarks and gluons/gluinos from an effective supergravity Lagrangian in non-derivative form and use them to calculate the hadroproduction cross sections and decay widths of single gravitinos. We confirm the results obtained previously with a derivative Lagrangian as well as those obtained with the non-derivative Lagrangian in the high-energy limit and elaborate on the connection between gauge independence and the presence of quartic vertices. We perform extensive numerical studies of branching ratios, total cross section…
We study the jets plus missing energy signature at the LHC in a scenario where the gravitino is very light and the gluino is the next-to-lightest supersymmetric particle and promptly decays into a gluon and a gravitino. We consider both associated gravitino production with a gluino and gluino pair production. By merging matrix elements with parton showers, we generate inclusive signal and background samples and show how information on the gluino and gravitino masses can be obtained by simple final state observables.
We present a new technique for the calculation of helicity $\pm 1/2$ gravitino production during preheating. It is based on the equivalence between goldstinos and helicity $\pm 1/2$ gravitinos at high energies. The problem is thus reduced to the standard (Majorana) fermion production after inflation. Comparison with the results obtained in the unitary gauge is also presented.
If supersymmetry is spontaneously at a low energy scale then the resulting gravitino would be very light. The interaction strength of the longitudinal components of such a light gravitino to electron-selectron pair then becomes comparable to that of electroweak interactions. Such a light gravitino could modify the cross-section for $e^_L e^_R-->\tilde {e}_L\tilde {e}_R$ from its MSSM value. Precision measurement of this cross-section could therefore be used to probe the low energy SUSY breaking scale.
We study radiative gravitino decay within the framework of R-violating supersymmetry. For trilinear R-violating couplings that involve the third generation of fermions, or for light gravitinos, we find that the radiative loop-decay $\tilde{G} \to γν$ dominates over the tree-level ones for a wide set of parameters. We calculate the gravitino decay width and study its implications for cosmology and collider physics. Slow-decaying gravitinos are good dark matter candidates, for a range of parameters that would also predict observable R-violating signatures in colliders. In general the branching r…
We study decays of the neutral and charged Higgs bosons of the minimal supersymmetric standard model into a very light gravitino and a neutralino or chargino. Present experimental constraints already imply that the lighter scalar Higgs boson can only have a very small branching ratio into this mode. However, if the gravitino mass is below $\sim 0.5$ eV, the heavier neutral and charged Higgs boson decays into a gravitino can be important or even dominant. We discuss the resulting signature for associate production of the heavy CP-even and the CP-odd states at future $e^+ e^-$ colliders, and com…
The axino and the gravitino are extremely weakly interacting candidates for the lightest supersymmetric particle (LSP). We demonstrate that either of them could provide the right amount of cold dark matter. Assuming that a charged slepton is the next-to-lightest supersymmetric particle (NLSP), we discuss how NLSP decays into the axino/gravitino LSP can provide evidence for axino/gravitino dark matter at future colliders. We show that these NLSP decays will allow us to estimate the value of the Peccei-Quinn scale and the axino mass if the axino is the LSP. In the case of the gravitino LSP, we i…
We review our results on the calculation of helicity 1/2 gravitino production during preheating. The method we present is based on the equivalence between goldstinos and longitudinal gravitinos at high energies. The problem is thus reduced to the standard (Majorana) fermion production after inflation. Comparison between helicity 3/2 and 1/2 production and with the results obtained in the unitary gauge is also presented.
We study the cosmological gravitino production in gauge mediated supersymmetry breaking models, while properly taking into account the existence of the messenger mass scale. It is found that for sizable parameter range of the model the messenger sector contribution leads to more stringent upper bound on the reheat temperature obtained from the condition that the universe should not be overclosed by relic gravitinos. However it turns out that in the limit of relatively low messenger scale and large gravitino mass, the relic gravitino mass density can be smaller than the critical density indepen…
We show that the constraints on GMSB theories from the gravitino cosmology can be significantly relaxed if the messenger-spurion coupling is temperature dependent. We demonstrate this novel mechanism in a scenario in which this coupling depends on the VEV of an extra singlet field $S$ that interacts with the thermalized plasma which can result in a significantly suppressed gravitino production rate. In such a scenario the relic gravitino abundance is determined by the thermal dynamics of the $S$ field and it is easy to fit the observed dark matter abundance evading the stringent constraints on…
Considering gravitino dark matter scenarios, we obtain the full gauge-invariant result for the relic density of thermally produced gravitinos to leading order in the Standard Model gauge couplings. For the temperatures required by thermal leptogenesis, we find gaugino mass bounds which will be probed at future colliders. We show that a conceivable determination of the gravitino mass will allow for a unique test of the viability of thermal leptogenesis in the laboratory.
We review the case of gravitino Dark Matter for stop, neutralino and sneutrino Next-to-Lightest Supersymmetric Particles and discuss prospects to investigate such scenarios at LHC and a Linear Collider.
Using the GAMBIT global fitting framework, we constrain the MSSM with an eV-scale gravitino as the lightest supersymmetric particle, and the six electroweakinos (neutralinos and charginos) as the only other light new states. We combine 15 ATLAS and 12 CMS searches at 13\,TeV, along with a large collection of ATLAS and CMS measurements of Standard Model signatures. This model, which we refer to as the $\tilde G$-EWMSSM, exhibits quite varied collider phenomenology due to its many permitted electroweakino production processes and decay modes. Characteristic $\tilde G$-EWMSSM signal events have t…
Gravitino Dark Matter represents a compelling scenario in Supersymmetry, which brings together a variety of data from cosmology and collider physics. We discuss the constraints obtained from the LHC on supersymmetric models with gravitino dark matter and neutralino NLSP, which is the case most difficult to disentangle at colliders from a neutralino LSP forming DM. The phenomenological SUSY model with 19+1 free parameters is adopted. Results are obtained from broad scans of the phase space of these uncorrelated parameters. The relation between gravitino mass, gluino mass and reheating temperatu…
The axino and the gravitino are well-motivated candidates for the lightest supersymmetric particle (LSP) and also for cold dark matter in the Universe. Assuming that a charged slepton is the next-to-lightest supersymmetric particle (NLSP), we show how the NLSP decays can be used to probe the axino LSP scenario in hadronic axion models as well as the gravitino LSP scenario at the Large Hadron Collider and the International Linear Collider. We show how one can identify experimentally the scenario realized in nature. In the case of the axino LSP, the NLSP decays will allow one to estimate the val…
Present data require a spectral index $n\gsim 0.95$ at something like 1-$σ$ level. If this lower bound survives it will constrain `new' and `modular' inflation models, while raising it to 1.00 would rule out all of these models plus many others. After inflation, gravitinos are created by the oscillating field until the `intermediate' epoch when the Hubble parameter falls below the gravitino mass, or reheating, whichever is earlier. In a wide range of parameter space, these gravitinos are more abundant than those from thermal collisions, leading to stronger cosmological constraints.
Light gravitino productions in association with a neutralino (selectron) in e^+e^- (e^-γ) collisions are restudied in a scenario that the lightest supersymmetric particle is a gravitino and the produced neutralino (selectron) promptly decays into a photon (electron) and a gravitino. We explicitly give the helicity amplitudes for the production processes by using the effective goldstino interaction Lagrangian, and present the cross sections with different collision energies and mass spectra. We also examine selection efficiencies by kinematical cuts and beam polarizations for the signal and bac…
After a period of inflationary expansion, the Universe reheated and reached full thermal equilibrium at the reheating temperature T_R. In this work we point out that, in the context of effective low-energy supersymmetric models, LHC measurements may allow one to determine T_R as a function of the mass of the dark matter particle assumed to be either an axino or a gravitino. An upper bound on their mass may also be derived.
By using a string-inspired modular invariant supergravity, which was proved well to explain WMAP observations appropriately, a mechanism of supersymmetry breaking (SSB) and Gravitino Production just after the end of inflation are investigated. Supersymmetry is broken mainly by F-term of the inflaton superfield and the Goldstino is identified to be inflatino in this model, which fact is shown numerically. By using the canonically normalized and diagonalized scalars, the decay rates of these fields are calculated, for both the $T$ and $Y$ into gravitinos. Non-thermal production of gravitinos is …
The production and the final abundance of gravitino dark matter appear to depend crucially on the restoration of the global U(1) $R$-symmetry of GMSB sectors in a threefold way. An $R$-symmetric phase effectively suppresses the production of goldstinos from scatterings with the supersymmetric Standard Model particles and it generically initiates the goldstino production from the thermalized messenger particles. In addition, the GMSB spurion gets displaced from the zero temperature minimum and under certain conditions it dominates the energy density of the universe producing late entropy. We sh…
We examine the phenomenological consequences of a supersymmetric bulk in the scenario of large extra dimensions. We assume supersymmetry is realized in the bulk and study the interactions of the resulting bulk gravitino Kaluza-Klein (KK) tower of states, with supersymmetry breaking on the brane inducing a light mass for the zero-mode gravitino. We derive the 4-d effective theory, including the couplings of the bulk gravitino KK states to fermions and their scalar superpartners. The virtual exchange of the gravitino KK states in selectron pair production in polarized \epem collisions is then ex…
Supersymmetric (SUSY) standard models in which the lightest SUSY particle (LSP) is an ultralight gravitino (m_{3/2}=O(1) eV) are very attractive, since they are free from the cosmological gravitino problems. If the neutralino is the next lightest SUSY particle (NLSP), it decays into a photon and the gravitino in collider experiments. We propose a simple test for the lightness of gravitino at the LHC.
Light gravitinos, with mass in the eV to MeV range, are well-motivated in particle physics, but their status as dark-matter candidates is muddled by early-Universe uncertainties. We investigate how upcoming data from colliders may clarify this picture. Light gravitinos are produced primarily in the decays of the next-to-lightest supersymmetric particle, resulting in spectacular signals, including di-photons, delayed and non-pointing photons, kinked charged tracks, and heavy metastable charged particles. We find that the Tevatron with 20/fb and the 7 TeV LHC with 1/fb may both see evidence for …
The success of primordial nucleosynthesis imposes stringent bounds on the abundance of gravitational relics. This is particularly true for gravitinos, which - for models with gravitationally mediated supersymmetry breaking - are expected to have a mass below the TeV scale and thus to decay only after nucleosynthesis has concluded. We discuss the nonthermal production of gravitinos in models with several chiral fields, to be able to distinguish the mechanisms of supersymmetry breaking and inflation. Our explicit calculations show that the superpartner of the inflaton can be significantly genera…
We present a new scenario of gravitino dark matter which is compatible with the thermal leptogenesis. We confirm by an explicit calculation in supergravity that the relic abundance of thermally produced gravitino becomes insensitive to the reheating temperature once the temperature of the Universe exceeds the mass scale of the messenger fields. In such a situation, the correct baryon to dark matter ratio can be obtained by thermal leptogenesis when the reheating temperature after inflation is high enough. We demonstrate in a concrete model of gauge mediation that the correct abundance of gravi…
A collider signal with a stable gravitino of ${\cal O}(10)$eV mass at the International Linear Collider (ILC) experiment is investigated. Such a light gravitino is generally predicted in the low-scale gauge mediation scenario of the supersymmetry breaking. We particularly focus on the case that the next lightest supersymmetric particle is stau, which eventually decays into a gravitino and a $τ$-lepton. With such a small gravitino mass, the lifetime of the stau is $10^{-15}$--$10^{-11}$sec, and the produced stau decays before reaching the first layer of the inner detector of the ILC. It is show…
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 gravit…
If the gravitino G is very light and all the other supersymmetric particles are above threshold, supersymmetry may still be found at colliders, by looking at processes with only gravitinos and ordinary particles in the final state. We compute here the cross-section for the process e^+ e^- ==> G G gamma, whose final state can give rise to a distinctive photon plus missing energy signal at present and future e^+ e^- colliders. We describe how the present LEP data can be used to establish a lower bound on the gravitino mass of order 10^{-5} eV. We conclude with a critical discussion of our result…
Braneworld modifications to the Friedmann expansion law can have an important effect on the cosmological evolution of the early universe. In particular, the primordial particle abundances crucially depend on the rate at which the universe expanded at early times. In this article, we study the production of stable and unstable gravitinos, both from thermal creation and from the decay of a heavy scalar, in the Randall-Sundrum II braneworld context. We conclude that, depending on the value of the 5D fundamental Planck mass, some of the usual standard cosmology constraints on the reheating tempera…
The gravitino dark matter with neutralino NLSP hypothesis is investigated in the framework of NMSSM. We have considered both the thermal and non-thermal gravitino production mechanisms, and we have taken into account all the collider and cosmological constraints. The maximum allowed reheating temperature after inflation, as well as the maximum allowed gravitino mass are determined.
For gravitino dark matter with conserved R-parity and mass in the GeV range, very strong constraints from Big Bang Nucleosynthesis exclude the popular NLSP candidates like neutralino and charged sleptons. In this letter we therefore draw attention to the case of a sneutrino NLSP, that is naturally realised in the context of gaugino mediation. We find interesting collider signatures, characterised by soft jets or leptons due to the small sneutrino--stau mass splitting. Moreover, the lightest neutralino can have visible decays into staus, and in some part of the parameter space also into selectr…
Gravitinos and axinos produced in the late decays of other supersymmetric particles are well-motivated dark matter (DM) candidates, whose experimental evidences are very distinctive and different from other standard candidates, as thermal produced neutralinos in similar supersymmetric models. In particular, charged sleptons could appear stable because of the length of its lifetime. The direct production of such particles at both the Large Hadron Collider (LHC) and a future International Linear Collider (ILC) can give not only a clear signature of supersymmetry but also the first non-gravitatio…
By using a No-Scale Supergravity model, which was proved to explain WMAP observations appropriately, a mechanism of supersymmetry breaking and a preheating just after the end of inflation are investigated. Non-thermal production rate of gravitino is estimated as well as supersymmetry breaking mechanism numerically. The supersymmetry breaking is triggered by the inflaton superfield alone and the interchange of supersymmetry breaking fields does not occur in our model. By the instant preheating mechanism, the preheating temperature is calculated through the process where the inflaton decays into…
We analyze the prospects for discovering supersymmetry at the Fermilab Tevatron and CERN LEP colliders in the scenario that the lightest supersymmetric particle is a gravitino of mass < 1 keV. We consider in particular the case that the lightest neutralino has a nearly 100% branching fraction into gravitino + photon within the detector. This implies that supersymmetric events should contain both missing (transverse) energy and two energetic photons. Therefore one can search for supersymmetry simply through inclusive production of superpartners. We consider the exclusion and reach capabilities …
A study is presented illustrating the excellent potential of future International Linear Collider (ILC) experiments to detect metastable staus $\stau$, measure precisely their mass and lifetime, and to determine the mass of the gravitino $\sG$ from the decay $\stau\toτ\sG$, thus providing direct access to the gravitational coupling, respectively Planck scale.
We present the results of a general analysis of the contributions of the supersymmetry-breaking sector to the muon anomalous magnetic moment in models with a superlight gravitino. We find constraints on the model parameters that are comparable and complementary to the ones coming from collider searches, and will become more stringent after the Brookhaven E821 experiment.
In the present work we discuss baryon asymmetry in the non-thermal leptogenesis scenario and gravitino cosmology for an unstable gravitino with inflaton decay. We take into account two production mechanisms for gravitino, namely thermal production and inflaton decay. We wish to show in plots the allowed parameter space so that the BBN constraint and the requirement for the right baryon asymmetry are satisfied at the same time. However our analysis shows that it is impossible to achieve both goals simultaneously.
We investigate how late-time entropy production weakens the Big-Bang Nucleosynthesis (BBN) constraints on the gravitino as lightest superparticle with a charged slepton as next-to-lightest superparticle. We find that with a moderate amount of entropy production, the BBN constraints can be eluded for most of the parameter space relevant for the discovery of the gravitino. This is encouraging for experimental tests of supergravity at LHC and ILC.
If the gravitino (G) is very light and all the other supersymmetric particles are above threshold, supersymmetry may still be found at colliders, by looking at processes with only gravitinos and ordinary particles in the final state. We compute here the cross-sections for some distinctive signals at hadron colliders: photon plus missing energy, induced by (q antiquark -> G G photon), and jet plus missing energy, induced by (q antiquark -> G G g), (q g -> G G q), and (g g -> G G g). From the present Tevatron data, we estimate the bound m_{3/2} > 2.3 10^-5 eV on the gravitino mass, corresponding…
Effects of the unstable gravitino on the big-bang nucleosynthesis (BBN) and its implications to particle cosmology are discussed. If the gravitino mass is smaller than \sim 20 TeV, lifetime of the gravitino becomes longer than \sim 1sec and its decay may spoil the success of the standard BBN. In order to avoid such a problem, upper bound on the reheating temperature after the inflation is obtained, which may be as low as \sim 10^{5-6} GeV. For a successful baryogenesis with such low reheating temeprature, a consistent scenario based on the large cutoff supergravity (LCSUGRA) hypothesis of supe…
We study the scenario of gravitino DM with a general neutralino NLSP in a model independent way. We consider all neutralino decay channels and compare them with the most recent BBN constraints. We check how those bounds are relaxed for a Higgsino or a Wino NLSP in comparison to the Bino neutralino case and look for possible loopholes in the general MSSM parameter space.We determine constraints on the gravitino and neutralino NLSP mass and comment on the possibility of detecting these scenarios at colliders.
Models of leptogenesis are constrained by the low reheat temperature at the end of reheating associated with the gravitino bound. However a detailed view of reheating, in which the maximum temperature during reheating, $\Tmax$, can be orders of magnitude higher than the reheat temperature, allows for the production of heavy Majorana neutrinos needed for leptogenesis. But then one must also consider the possibility of enhanced gravitino production in such scenarios. In this article we consider gravitino production during reheating, its dependence on $\Tmax$, and its relevance for leptogenesis. …
The gravitino is a promising candidate for cold dark matter. We study cosmological constraints on scenarios in which the gravitino is the lightest supersymmetric particle and a charged slepton the next-to-lightest supersymmetric particle (NLSP). We obtain new results for the hadronic nucleosynthesis bounds by computing the 4-body decay of the NLSP slepton into the gravitino, the associated lepton, and a quark-antiquark pair. The bounds from the observed dark matter density are refined by taking into account gravitinos from both late NLSP decays and thermal scattering in the early Universe. We …
We study resonant gravitino production in the early Universe in the presence of SUSY flat directions whose large VEVs break some but not all gauge symmetries. We find that for a large region of parameter space the gravitino abundance is several orders of magnitude larger than the cosmological upper bound. Since flat directions with large VEVs are generically expected in supersymmetric theories this result further exacerbates the gravitino problem.
Very light gravitinos could be produced at a sizeable rate at colliders and have been searched for in the mono-photon or mono-jet plus missing momentum signature. Strategies for enhancing the signal over background and interpretations of the experimental results are typically obtained within an effective field theory approach where all SUSY particles except the gravitino are heavy and are not produced resonantly. We extend this approach to a simplified model that includes squarks and gluinos in the TeV range. In such a case, the jet(s)-plus-missing-momentum signature can be generated through t…
We study the production of spin 1/2 gravitinos in a thermal Universe. Taking into account supersymmetry breaking due to the finite thermal energy density of the Universe, there is a large enhancement in the cross section of production of these gravitino states. We consider gravitinos with zero temperature masses of 0.1 eV, 1 keV, 100 GeV and 30 TeV as representative of gauge mediated, gravity mediated and anomaly mediated supersymmetry breaking scenarios. We find that the abundance of gravitinos produced in the early Universe is very high for gravitinos of mass 1 keV and 100 GeV. The gravitino…
Flat directions in supersymmetric models can get large vacuum expectation values in the early Universe which leads to a large mass for gauge bosons and gauginos. We point out that this can then result in enhanced gravitino production because the cross-section for the production of the +/- 1/2 helicity states of the gravitino is proportional to the square of the gaugino masses. We consider gravitino production after inflation in such a scenario and find that the abundance in some cases can be much larger than the upper bound on the gravtino abundance from cosmological constraints unless the fla…
We explicitly calculate nonthermal gravitino production during the preheating period in the inflationary Universe. Contrary to earlier investigations, we consider a two--field model to separate the mechanisms of supersymmetry breaking and inflation. We show that the superpartner of the inflaton is significantly generated, while the gravitino production is considerably smaller. Nonthermal production of gravitinos seems thus less worrisome than recently claimed.
