Search

Fundamental physical constants are determined from a collection of precision measurements of elementary particles, atoms and molecules. This is usually done under the assumption of the Standard Model~(SM) of particle physics. Allowing for light new physics~(NP) beyond the SM modifies the extraction of fundamental physical constants. Consequently, setting NP bounds using these data, and at the same time assuming the CODATA recommended values for the fundamental physical constants, is not reliable. As we show in this Letter, both SM and NP parameters can be simultaneously determined in a consistent way from a global fit. For light vectors with QED-like couplings, such as the dark photon, we provide a prescription that recovers the degeneracy with the photon in the massless limit, and requires calculations only at leading order in the small new physics couplings. At present, the data show tensions partially related to the proton charge radius determination. We show that these can be alleviated by including contributions from a light scalar with flavor non-universal couplings., Comment: 8+16 pages, 3+7 figures, 5 tables

We show that muonium spectroscopy in the coming years can reach a precision high enough to determine the anomalous magnetic moment of the muon below one part per million (ppm). Such an independent determination of muon g-2, which is not limited by hadronic uncertainties, would certainly shed light on the 2ppm difference currently observed between spin-precession measurements and (R-ratio based) Standard Model predictions. The magnetic dipole interaction between electrons and (anti)muons bound in muonium gives rise to a hyperfine splitting (HFS) of the ground state which is sensitive to the muon anomalous magnetic moment. A direct comparison of the muonium frequency measurements of the HFS at J-PARC and the 1S-2S transition at PSI with theory predictions will allow to extract muon g-2 with high precision. Improving the accuracy of QED calculations of these transitions by about one order of magnitude is also required. Moreover, the good agreement between theory and experiment for the electron g-2 indicates that new physics interactions are unlikely to affect muonium spectroscopy down to the envisaged precision., Comment: matches published version, full supplemental material

We discuss the recent results on the muon anomalous magnetic moment in the context of new physics models with light scalars. We propose a model in which the one-loop contributions to g-2 of a scalar and a pseudoscalar naturally cancel in the massless limit due to the symmetry structure of the model. This model allows to interpolate between two possible interpretations. In the first interpretation, the results provide a strong evidence of the existence of new physics, dominated by the positive contribution of a CP-even scalar. In the second one, supported by the recent lattice result, the data provides a strong upper bound on new physics, specifically in the case of (negative) pseudoscalar contributions. We emphasize that tree-level signatures of the new degrees of freedom of the model are enhanced relative to conventional explanations of the discrepancy. As a result, this model can be tested in the near future with accelerator-based experiments and possibly also at the precision frontier., Comment: 13 pages, 2 figures

We consider models of decaying spin-1 dark matter whose dominant coupling to the standard model sector is through a dark-Higgs Yukawa portal connecting a TeV-scale vector-like lepton to the standard model (right-handed) electron. Below the electron-positron threshold, dark matter has very slow, loop-suppressed decays to photons and (electron) neutrinos, and is stable on cosmological time-scale for sufficiently small gauge coupling values. Its relic abundance is set by in-equilibrium dark lepton decays, through the freeze-in mechanism. We show that this model accommodates the observed dark matter abundance for natural values of its parameters and a dark matter mass in the ~5keV to 1MeV range, while evading constraints from direct detection, indirect detection, stellar cooling and cosmology. We also consider the possibility of a nonzero gauge kinetic mixing with the standard model hypercharge field, which is found to yield a mild impact on the model's phenomenology., Comment: 21p, 3 figures; v2 - added discussion on resonant photon conversion, conclusion unchanged, to be published in JHEP

Atomic spectral lines for different isotopes are shifted, revealing a change in the properties of the nucleus. For spinless nuclei such isotope shifts for two distinct transitions are expected to be linearly related, at least at leading order in a change of the nuclear mass and charge distribution. Looking for a breaking of linearity in so-called King plots was proposed as a novel method to search for physics beyond the standard model. In the light of the recent experimental progress in isotope shift spectroscopy, the sensitivity of these searches will become limited by the determination of the isotope masses and/or by nuclear effects which may induce nonlinearities at an observable level. In this work, we propose two possible generalizations of the traditional King plot that overcome these limitations by including additional isotope shift measurements, thus significantly extending the new physics reach of King plots in a purely spectroscopy-driven approach.

We present a thorough analysis of the sequential freeze-in mechanism for dark matter production in the early universe. In this mechanism the dark matter relic density results from pair annihilation of mediator particles which are themselves produced by thermal collisions of standard model particles. Below some critical value of the mediator coupling to standard model fields, this sequential channel dominates over the usual freeze-in where dark matter is directly produced from thermal collisions, even when the mediator is not in thermal equilibrium. The latter case requires computing the full non-thermal distribution of the mediators, for which finite temperature corrections are particularly important., Comment: 14 pages, 5 figures

In this paper, we implement the Russian standard block cipher Grasshopper on Field-Programmable Gate Array (FPGA). We also study the Correlation Power Analysis attack, which is a special type of side-channel attack proposed by Brier et al. To face this kind of attack, we propose a solution of software countermeasure, and we present the associated implementation of the Grasshopper algorithm. These two implementations are then compared to an AES-256 one. Finally, through the implementation of a CPA attack on an FPGA development board, we show that typical attack models that work on AES fail on Grasshopper implementations., Comment: This article was also presented by Alexander A. Istomin and \'Eric Filiol at RusCrypto 2019

The very high precision of current measurements and theory predictions of spectral lines in few-electron atoms allows to efficiently probe the existence of exotic forces between electrons, neutrons and protons. We investigate the sensitivity to new spin-independent interactions in transition frequencies (and their isotopic shifts) of hydrogen, helium and some helium-like ions. We find that present data probe new regions of the force-carrier couplings to electrons and neutrons around the MeV mass range. We also find that, below few keV, the sensitivity to the electron coupling in precision spectroscopy of helium and positronium is comparable to that of the anomalous magnetic moment of the electron. Finally, we interpret our results in the dark-photon model where a new gauge boson is kinetically mixed with the photon. There, we show that helium transitions, combined with the anomalous magnetic moment of the electron, provide the strongest indirect bound from laboratory experiments above 100keV., Comment: 16 pages, 7 figures

In this Letter we explore the potential of probing new light force-carriers, with spin-independent couplings to the electron and the neutron, using precision isotope shift spectroscopy. We develop a formalism to interpret linear King plots as bounds on new physics with minimal theory inputs. We focus only on bounding the new physics contributions that can be calculated independently of the Standard Model nuclear effects. We apply our method to existing Ca+ data and project its sensitivity to possibly existing new bosons using narrow transitions in other atoms and ions (specifically, Sr and Yb). Future measurements are expected to improve the relative precision by five orders of magnitude, and can potentially lead to an unprecedented sensitivity for bosons within the 10 keV to 10 MeV mass range., Comment: 6 pages, 1 figure

Heavy vector-like quarks coupled to a scalar $S$ will induce a coupling of this scalar to gluons and possibly (if electrically charged) photons. The decay of the heavy quark into $Sq$, with $q$ being a Standard Model quark, provides, if kinematically allowed, new channels for heavy quark searches. Inspired by naturalness considerations, we consider the case of a vector-like partner of the top quark. For illustration, we show that a singlet partner can be searched for at the 13$\,$TeV LHC through its decay into a scalar resonance in the $2\gamma+\ell + X$ final states, especially if the diphoton branching ratio of the scalar $S$ is further enhanced by the contribution of non coloured particles. We then show that conventional heavy quark searches are also sensitive to this new decay mode, when $S$ decays hadronically, by slightly tightening the current selection cuts. Finally, we comment about the possibility of disentangling, by scrutinising appropriate kinematic distributions, heavy quark decays to $St$ from other standard decay modes., Comment: 8 pages, 3 figures and 1 table; v3: typos fixed. Matches published version

We revisit a set of dark sector models, motivated by anomalies observed in $B$ decays and the muon anomalous magnetic moment, in the light of a recently reported diphoton excess around 750$\,$GeV. Interpreting the excess as a scalar resonance associated with the symmetry breaking sector of a dark gauge group, we show that a diphoton cross section of few fb can be accomodated, together with anomalies in $R_K$ and $g_\mu-2$ within a minimal dark sector model. The resulting prominent collider signatures are in the form of wide resonant signals into top and muon pair final states below $\sim1\,$TeV. The model further predicts a dark matter candidate, yet with a significantly underabundant relic density, unless produced by an appropriate non-thermal mechanism., Comment: 7 pages, 3 figures

We investigate the potential to probe physics beyond the Standard Model with isotope shift measurements of optical atomic clock transitions. We first derive the reach for generic new physics above the GeV scale at the effective field theory level, as well as estimate the limits on possible new spin-independent forces mediated by sub-GeV states coupled to electrons and neutrons. We also study the weak force and show that isotope shifts could provide strong constraints on the $Z^0$ couplings to valence quarks, which complement precision observables at LEP and atomic parity violation experiments. Finally, motivated by recent experimental hints of a new 750 GeV resonance in diphotons, we also consider the potential to probe its parity-preserving couplings to electrons, quarks and gluons with this method. In particular, combining the diphoton signal with indirect constraints from $g_e-2$ and isotope shifts in Ytterbium allows to probe the resonance coupling to electrons with unprecedented precision., Comment: 6 pages, 2 figures, 2 tables

We propose a novel approach to probe new fundamental interactions using isotope shift spectroscopy in atomic clock transitions. As concrete toy example we focus on the Higgs boson couplings to the building blocks of matter: the electron and the up and down quarks. We show that the attractive Higgs force between nuclei and their bound electrons, that is poorly constrained, might induce effects that are larger than the current experimental sensitivities. More generically, we discuss how new interactions between the electron and the neutrons, mediated via light new degrees of freedom, may lead to measurable non-linearities in a King plot comparison between isotope shifts of two different transitions. Given state-of-the-art accuracy in frequency comparison, isotope shifts have the potential of being measured with sub-Hz accuracy, thus potentially enabling the improvement of current limits on new fundamental interactions. Candidate atomic system for this measurement require two different clock transitions and four zero nuclear spin isotopes. We identify several systems that satisfy this requirement and also briefly discuss existing measurements. We consider the size of the effect related to the Higgs force and the requirements for it to produce an observable signal., Comment: 7 pages, added focus on light higgs-like mediators, electron density at the nucleus improved with effective quantum number, version accepted for publication in PRD

In composite Higgs models (CHMs), electroweak precision data generically push colourless composite vector resonances to a regime where they dominantly decay into pairs of light top partners. This greatly attenuates their traces in canonical collider searches, tailored for narrow resonances promptly decaying into Standard Model final states. By reinterpreting the CMS same-sign dilepton (SS2$\ell$) analysis at the Large Hadron Collider (LHC), originally designed to search for top partners with electric charge $5/3$, we demonstrate its significant coverage over this kinematical regime. We also show the reach of the 13 TeV run of the LHC, with various integrated luminosity options, for a possible upgrade of the SS2$\ell$ search. The top sector of CHMs is found to be more fine-tuned in the presence of colourless composite resonances in the few TeV range., Comment: 9 pages, 5 figures. Minor corrections for publication in JHEP

If weak scale supersymmetry (SUSY) is to somehow explain the radiative stability of the Higgs boson mass, it is likely that non-minimal variants of SUSY models should be considered. Under the assumption that the dark matter of the universe is comprised of neutralinos, recent limits from direct detection experiments as well as dark matter abundance measurements place stringent bounds on the naturalness of minimal supersymmetric models. We show that even non-minimal models introducing moderately decoupled new physics in order to address the Higgs boson mass problem face similar issues, with one interesting exception., Comment: Proceedings of the 18th International Conference From the Planck Scale to the Electroweak Scale, 25-29 May 2015, Ioannina, Greece

We show that the recently reported anomalies in $b\to s\mu^+\mu^-$ transitions, as well as the long-standing $g_\mu-2$ discrepancy, can be addressed simultaneously by a new massive abelian gauge boson with loop-induced coupling to muons. Such a scenario typically leads to a stable dark matter candidate with a thermal relic density close to the observed value. Dark matter in our model couples dominantly to leptons, hence signals in direct detection experiments lie well below the current sensitivity. The LHC, in combination with indirect detection searches, can test this scenario through distinctive signatures with muon pairs and missing energy., Comment: 10 pages, 7 figures, 1 table

Weak scale supersymmetry (SUSY) remains a prime explanation for the radiative stability of the Higgs field. A natural account of the Higgs boson mass, however, strongly favors extensions of the Minimal Supersymmetric Standard Model (MSSM). A plausible option is to introduce a new supersymmetric sector coupled to the MSSM Higgs fields, whose associated states resolve the little hierarchy problem between the third generation squark masses and the weak scale. SUSY also accomodates a weakly interacting cold dark matter (DM) candidate in the form of a stable neutralino. In minimal realizations, the thus-far null results of direct DM searches, along with the DM relic abundance constraint, introduce a level of fine-tuning as severe as the one due to the SUSY little hierarchy problem. We analyse the generic implications of new SUSY sectors parametrically heavier than the minimal SUSY spectrum, devised to increase the Higgs boson mass, on this little neutralino DM problem. We focus on the SUSY operator of smallest scaling dimension in an effective field theory description, which modifies the Higgs and DM sectors in a correlated manner. Within this framework, we show that recent null results from the LUX experiment imply a tree-level fine-tuning for gaugino DM which is parametrically at least a few times larger than that of the MSSM. Higgsino DM whose relic abundance is generated through a thermal freeze-out mechanism remains also severely fine-tuned, unless the DM lies below the weak boson pair-production threshold. As in the MSSM, well-tempered gaugino-Higgsino DM is strongly disfavored by present direct detection results., Comment: 41 pages, 8 figures, references added

We study the implications of a large degree of compositeness for the light generation quarks in composite pseudo-Nambu-Goldstone-boson Higgs models. We focus in particular on viable scenarios where the right-handed up-type quarks have a sizable mixing with the strong dynamics. For concreteness we assume the latter to be characterized by an SO(5)/SO(4) symmetry with fermionic resonances in the SO(4) singlet and fourplet representations. Singlet partners dominantly decay to a Higgs boson and jets. As no dedicated searches are currently looking for these final states, singlet partners can still be rather light. Conversely, some fourplet partners dominantly decay to an electroweak gauge boson and a jet, a signature which has been analyzed at the LHC. To constrain the parameter space of this scenario we have reinterpreted various LHC analyses. In the limit of first two generation degeneracy, as in minimal flavor violation or U(2)-symmetric flavor models, fourplet partners need to be relatively heavy, with masses above 1.8 TeV, or the level of compositeness needs to be rather small. The situation is rather different in models that deviate from the first two generation degeneracy paradigm, as the charm parton distribution functions are suppressed relative to the up quark ones. The right-handed charm quark can be composite and its partners being as light as 600 GeV, while the right-handed up quark needs either to be mostly elementary or to have its partners as heavy as 2 TeV. Models with fully composite singlet fermions are also analyzed, leading to similar conclusions. Finally, we consider the case where both the fourplet and the singlet states are present. In this case the bounds could be significantly weaken due to a combination of smaller production rates and the opening of new channels including cascade processes., Comment: 49 pages, 18 figures

We show that current Higgs data permit a significantly enhanced Higgs coupling to charm pairs, comparable to the Higgs to bottom pairs coupling in the Standard Model, without resorting to additional new physics sources in Higgs production. With a mild level of the latter current data even allow for the Higgs to charm pairs to be the dominant decay channel. An immediate consequence of such a large charm coupling is a significant reduction of the Higgs signal strengths into the known final states as in particular into bottom pairs. This might reduce the visible vector-boson associated Higgs production rate to a level that could compromise the prospects of ever observing it. We however demonstrate that a significant fraction of this reduced signal can be recovered by jet-flavor-tagging targeted towards charm-flavored jets. Finally we argue that an enhanced Higgs to charm pairs coupling can be obtained in various new physics scenarios in the presence of only a mild accidental cancellation between various contributions., Comment: 8 pages, 3 figures

We propose a new observable designed to probe CP-violating coupling of the Higgs boson to W bosons using associated Higgs production. We define an asymmetry that measures the number of leptons from W decays relative to the plane defined by the beam line and the Higgs boson momentum. The orientation of that plane is determined by the direction of fermions in the initial state, so that in a proton-proton collider it requires rapidity cuts that preferentially select quarks over antiquarks., Comment: 7 pages, 3 figures

We point out that Higgs rates into gauge bosons can be significantly modified in composite pseudo Nambu--Goldstone boson (pNGB) Higgs models if quarks belonging to the first two generation are relatively composite objects as well. Although the lightness of the latter a priori screen them from the electroweak symmetry breaking sector, we show, in an effective two-site description, that their partners can lead to order one shifts in radiative Higgs couplings to gluons and photons. Moreover, due to the pseudo-Goldstone nature of the Higgs boson, the size of these corrections is completely controlled by the degree of compositeness of the individual light quarks. The current measurements of flavor-blind Higgs decay rates at the LHC thus provide an indirect probe of the flavor structure of the framework of pNGB Higgs compositeness., Comment: 28 pages, 9 figures. v2: typo corrected in eq. 22, references added

We present a class of warped extra dimension (composite Higgs) models which conjointly accommodates the t\bar t forward-backward asymmetry observed at the Tevatron and the direct CP asymmetry in singly Cabibbo suppressed D decays first reported by the LHCb collaboration. We argue that both asymmetries, if arising dominantly from new physics beyond the Standard Model, hint for a flavor paradigm within partial compositeness models in which the right-handed quarks of the first two generations are not elementary fields but rather composite objects. We show that this class of models is consistent with current data on flavor and CP violating physics, electroweak precision observables, dijet and top pair resonance searches at hadron colliders. These models have several predictions which will be tested in forthcoming experiments. The CP asymmetry in D decays is induced through an effective operator of the form (\bar u c)_{V+A}(\bar s s)_{V+A} at the charm scale, which implies a larger CP asymmetry in the D^0\to K^+K^- rate relative the D^0\to \pi^+\pi^- channel. This prediction is distinctive from other Standard Model or dipole-based new physics interpretation of the LHCb result. CP violation in D-\bar D mixing as well as an an excess of dijet production of the LHC are also predicted to be observed in a near future. A large top asymmetry originates from the exchange of an axial resonance which dominantly produces left-handed top pairs. As a result a negative contribution to the lepton-based forward-backward asymmetry in t\bar t production, as well as O(10%) forward-backward asymmetry in b\bar b production above m_{b\bar b}\simeq 600GeV at the Tevatron is expected., Comment: 35 pages, 7 figs

We derive generic predictions at hadron colliders from the large forward-backward asymmetry observed at the Tevatron, assuming the latter arises from heavy new physics beyond the Standard Model. We use an effective field theory approach to characterize the associated unknown dynamics. By fitting the Tevatron t \bar t data we derive constraints on the form of the new physics. Furthermore, we show that heavy new physics explaining the Tevatron data generically enhances at high invariant masses both the top pair production cross section and the charge asymmetry at the LHC. This enhancement can be within the sensitivity of the 8 TeV run, such that the 2012 LHC data should be able to exclude a large class of models of heavy new physics or provide hints for its presence. The same new physics implies a contribution to the forward-backward asymmetry in bottom pair production at low invariant masses of order a permil at most., Comment: 11 pages, 6 figures. v2: added remarks on EFT validity range, dijet bounds and UV completions; matches published version

Recently the LHCb collaboration reported evidence for direct CP violation in charm decays. The value is sufficiently large that either substantially enhanced Standard Model contributions or non-Standard Model physics is required to explain it. In the latter case only a limited number of possibilities would be consistent with other existing flavor-changing constraints. We show that warped extra dimensional models that explain the quark spectrum through flavor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the up quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to \gamma\gamma. Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs profile, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs profile approaches the IR brane, implying small dependence on the precise details of the Higgs profile when it is quasi IR localized. We also explain why the calculation of the coefficient of the lowest dimension 5D operator is guaranteed to be finite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b to s\gamma, \epsilon'/\epsilon_K and \mu\ to e\gamma. We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative differences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario., Comment: 14 pages

The CDF collaboration has recently reported a large deviation from the standard model of the t \bar t forward-backward asymmetry in the high invariant mass region. We interpret this measurement as coming from new physics at a heavy scale Lambda, and perform a model-independent analysis up to O(1/Lambda^4). A simple formalism to test and constrain models of new physics is provided. We find that a large asymmetry cannot be accommodated by heavy new physics that does not interfere with the standard model. We show that a smoking gun test for the heavy new physics hypothesis is a significant deviation from the standard model prediction for the t \bar t differential cross section at large invariant mass. At M_{t\bar t}>1 TeV the cross section is predicted to be at least twice that of the SM at the Tevatron, and for M_{t\bar t}>1.5 TeV at least three times larger than the SM at the LHC., Comment: 12 pages, 3 figures. v2: Minor corrections in the text, references added. v3: Extended discussion on QCD NLO corrections, added short discussion on LHC dijet constraints; matches published version

New physics at a high scale Lambda can affect top-related observables at O(1/Lambda^2) via the interference of effective four quark operators with the SM amplitude. The (\bar{u} gamma_mu gamma^5 T^a u)(\bar{t} gamma^mu gamma^5 T^a t) operator modifies the large M_{t\bar{t}} forward-backward asymmetry, and can account for the recent CDF measurement. The (\bar{u} gamma_mu T^a u)(\bar{t} gamma^mu T^a t) operator modifies the differential cross section, but cannot enhance the cross section of ultra-massive boosted jets by more than 60%. The hint for a larger enhancement from a recent CDF measurement may not persist future experimental improvements, or may be a QCD effect that is not accounted for by leading order and matched Monte Carlo tools or naive factorization. If it comes from new physics, it may stem from new light states or an O(1/Lambda^4) new physics effect., Comment: 7 pages, 2 figures and 2 tables. v2: References added. v3: Minor clarifications and modifications; matches published version

Anarchic warped extra dimensional models provide a solution to the hierarchy problem. They can also account for the observed flavor hierarchies, but only at the expense of little hierarchy and CP problems, which naturally require a Kaluza-Klein (KK) scale beyond the LHC reach. We have recently shown that when flavor issues are decoupled, and assumed to be solved by UV physics, the framework's parameter space greatly opens. Given the possibility of a lower KK scale and composite light quarks, this class of flavor triviality models enjoys a rather exceptional phenomenology, which is the focus of this letter. We also revisit the anarchic RS EDM problem, which requires m_{KK} > 8 TeV, and show that it is solved within flavor triviality models. Interestingly, our framework can induce a sizable differential t \bar{t} forward-backward asymmetry, and leads to an excess of massive boosted di-jet events, which may be linked to the recent findings of the CDF collaboration. This feature may be observed by looking at the corresponding planar flow distribution, which is presented here. Finally we point out that the celebrated standard model preference towards a light Higgs is significantly reduced within our framework., Comment: 6 pages, 3 figures. Updated the EDM bound on the anarchic scenario; extended discussion on the KK gluon's width, discovery potential and resulting dijet signal; matches published version

A warped extra-dimensional model, where the Standard Model Yukawa hierarchy is set by UV physics, is shown to have a sweet spot of parameters with improved experimental visibility and possibly naturalness. Upon marginalizing over all the model parameters, a Kaluza-Klein scale of 2.1 TeV can be obtained at 2 sigma (95.4 CL) without conflicting with electroweak precision measurements. Fitting all relevant parameters simultaneously can relax this bound to 1.7 TeV. In this bulk version of the Rattazzi-Zaffaroni shining model, flavor violation is also highly suppressed, yielding a bound of 2.4 TeV. Non-trivial flavor physics at the LHC in the form of flavor gauge bosons is predicted. The model is also characterized by a depletion of the third generation couplings -- as predicted by the general minimal flavor violation framework -- which can be tested via flavor precision measurements. In particular, sizable CP violation in Delta B=2 transitions can be obtained, and there is a natural region where Bs mixing is predicted to be larger than Bd mixing, as favored by recent Tevatron data. Unlike other proposals, the new contributions are not linked to Higgs or any scalar exchange processes., Comment: 44 pages, 6 figures; v2: major revision: author added; title changed; extended statistical analysis; added discussion about fine-tuning and flavor appendix; results slightly changed. v3: minor corrections and clarifications; reference added; matches published version

We study electroweak baryogenesis and electric dipole moments in the presence of the two leading-order, non-renormalizable operators in the Higgs sector of the MSSM. Significant qualitative and quantitative differences from MSSM baryogenesis arise due to the presence of new CP-violating phases and to the relaxation of constraints on the supersymmetric spectrum (in particular, both stops can be light). We find: (1) spontaneous baryogenesis, driven by a change in the phase of the Higgs vevs across the bubble wall, becomes possible; (2) the top and stop CP-violating sources can become effective; (3) baryogenesis is viable in larger parts of parameter space, alleviating the well-known fine-tuning associated with MSSM baryogenesis. Nevertheless, electric dipole moments should be measured if experimental sensitivities are improved by about one order of magnitude., Comment: 33 pages, 6 figures

We study the stability of the Higgs potential in the framework of the effective Lagrangian beyond the MSSM. While the leading nonrenormalizable operators can shift the Higgs boson mass above the experimental bound, they also tend to render the scalar potential unbounded from below. The destabilization is correlated with the Higgs mass increase, so that if quantum corrections are small the problem is severe. We show that a supersymmetric sub-leading correction stabilizes the potential within the domain of validity of the effective theory. Constraints on MSSM parameters as well as on higher dimensional operators are derived, ensuring that our vacuum has a lifetime longer than the present age of the universe. In addition we show that when effective operators are responsible for evading the LEP bound, stability constraints imply an upper bound on the scale of new physics in the few TeV range., Comment: 24 pages, 6 figures

Recent results from PAMELA and ATIC hint that O(TeV) dark matter (DM) is annihilating, in our galactic neighborhood, predominantly to leptons. The annihilation rate is much larger now than during freeze-out, one possible explanation of this is a low-velocity enhancement of the annihilation cross section. In a model independent fashion, we show that in this case the rate of neutrino emission from the Earth, due to DM annihilation, may be greatly enhanced while the rate from the Sun is unaltered. There is potential for IceCube to see these earthborn neutrinos while the same parameter space will be soon covered by direct detection experiments. Combining these near-future data will allow extraction of valuable information about the DM sector dynamics., Comment: 5 pages and 3 figures

These are proceedings for the Les Houches Summer School ``Particle Physics and Cosmology: the Fabric of Spacetime,'' held in Les Houches, France, July 31--August 25, 2006. We summarise the discussions of our working group and outline a procedure for calculating gravity corrections to scalar field potentials, as they might be relevant for inflationary physics. We focus on a specific Randall--Sundrum type braneworld scenario and discuss the relevance of Kaluza--Klein gravitons due to the extra warped dimension., Comment: 5 pages. Extra dimensions working group report, to appear in the proceedings of Les Houches Summer School - Session 86: Particle Physics and Cosmology: The Fabric of Spacetime, Les Houches, France, 31 Jul - 25 Aug 2006