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An alternative to the idea of a metastable electroweak vacuum would be an initial restriction to the pure scalar sector of the Standard Model, but describing spontaneous symmetry breaking consistently with studies indicating that there are two different mass scales in the problem: a mass scale $M_H$ associated with the zero-point energy and a mass scale $m_h$ defined by the quadratic shape of the potential at its minimum. Therefore, differently from perturbation theory where these two mass scales coincide, the Higgs field could exhibit a second resonance with mass $(M_H)^{\rm Theor} = 690\,(30)$ GeV. This stabilises the potential, but the heavy Higgs $H$ would couple to longitudinal $W$s with the same typical strength as the low-mass state with $m_h=125$ GeV and so would still remain a relatively narrow resonance. While interesting signals from LHC experiments were previously pointed out, we have now enlarged our data sample, sharpened the analysis of some final states, and noted correlations between different channels that point directly to such a second resonance. The combined statistical evidence, even if roughly estimated, is thus so large that the observed deviations from the background cannot represent statistical fluctuations., Comment: 14 pages, 7 figures, 4 tables, plain LaTeX

The dominant CMB dipole anisotropy is a Doppler effect due to a particular motion of the solar system with velocity of 370 km/s. Since this derives from peculiar motions and local inhomogeneities, one could meaningfully consider a fundamental frame of rest $\Sigma$ associated with the Universe as a whole. From the group properties of Lorentz transformations, two observers, individually moving within $\Sigma$, would still be connected by the relativistic composition rules. But ultimate implications could be substantial. Physical interpretation is thus traditionally demanded to correlating some dragging of light observed in laboratory with the direct CMB observations. Today the small residuals, from Michelson-Morley to present experiments with optical resonators, are just considered instrumental artifacts. However, if the velocity of light in the interferometers is not the same parameter "c" of Lorentz transformations, nothing would prevent a non-zero dragging. Furthermore, observable effects would be much smaller than classically expected and most likely of irregular nature. We review an alternative reading of experiments which leads to remarkable correlations with the CMB observations. Notably, we explain the irregular $10^{-15}$ fractional frequency shift presently measured with optical resonators operating in vacuum and solid dielectrics. For integration times of about 1 second, and typical Central-Europe latitude, we also predict daily variations of the Allan variance in the range $(5\div12) \cdot 10^{-16}$., Comment: 43 pages, 13 figures, 3 tables

In Veltman's original view, the Standard Model with a large Higgs particle mass of about 1 TeV was the natural completion of non-renormalizable Glashow model. This mass was thus a second threshold for weak interactions, as the W mass was for the non-renormalizable 4-fermion V-A theory. Today, after the observation of the narrow scalar resonance at 125 GeV, Veltman's large-mass idea seems to be ruled out. Yet, this is not necessarily true. Depending on the description of SSB in $\Phi^4$ theory, and by combining analytic calculations and lattice simulations, besides the known particle at 125 GeV, a new resonance of the Higgs field may also show up around 700 GeV. The peculiarity, though, is that this heavier state would couple to longitudinal vector bosons with the same typical strength of the low-mass state and thus represent a relatively narrow resonance. In this way, such hypothetical new resonance would naturally fit with some excess of 4-lepton events observed by ATLAS around 680 GeV. Analogous data from CMS are needed to confirm or disprove this interpretation. Implications of a two-mass structure for radiative corrections are also discussed., Comment: Contribution to Veltman Memorial Volume, to appear in Acta Physica Polonica B, 26 pages, 1 Table, 6 figures

Correlating ether-drift measurements in laboratory and CMB observations in space would confirm the existence of a preferred reference frame. To this end, however, the velocity of light in the interferometers cannot be the same parameter 'c' of Lorentz transformations. Thus, for the earth velocity of 370 km/s, a fundamental 10^(-15) light anisotropy, as presently observed in vacuum and in solid dielectrics, could reveal a 10^(-9) difference in the vacuum refractivity between an ideal freely-falling frame and an apparatus on the earth surface. In this perspective, the stochastic nature of the vacuum could explain the irregular character of the signal and the substantial reduction of its statistical average (10^(-18) or smaller). For the same v=370 km/s the different refractivity, about 10^(-4) and 10^(-5) for air or helium at atmospheric pressure, could also explain the observed anisotropy, respectively about 10^(-10) and 10^(-11). The mechanism enhancing the signal in gaseous matter, but ineffective in solid dielectrics, is naturally identified in a non-local, temperature gradient of a fraction of millikelvin. This is found in all classical experiments and might ultimately reflect the CMB temperature dipole or the fundamental energy flow in a Lorentz-non-invariant vacuum. Clarification requires dedicated experiments and improvements in the data analysis., Comment: 43 pages, 8 figures, 3 tables; version accepted for publication in EPJ Plus

`Ether-drift' experiments have played a crucial role for the origin of relativity. Though, a recent re-analysis shows that those original measurements where light was still propagating in gaseous systems, differently from the modern experiments in vacuum and in solid dielectrics, indicate a small universal anisotropy which is naturally interpreted in terms of a non-local thermal gradient. We argue that this could possibly be the effect, on weakly bound gaseous matter, of the temperature gradient due to the Earth's motion within the Cosmic Background Radiation (CBR). Therefore, a check with modern laser interferometers is needed to reproduce the conditions of those early measurements with today's much greater accuracy. We emphasize that an unambiguous confirmation of our interpretation would have far reaching consequences. For instance, it would also imply that all physical systems on the moving Earth are exposed to a tiny energy flow, an effect that, in principle, could induce forms of self-organization in matter., Comment: 5 pages, 3 figures

According to some authors, gravity might be an emergent phenomenon in a fundamentally flat space-time. In this case the speed of light in the vacuum would not coincide exactly with the basic parameter "c" entering Lorentz transformations and, for an apparatus placed on the Earth's surface, light should exhibit a tiny fractional anisotropy at the level 10^{-15}. We argue that, most probably, this effect is now observed in many room-temperature ether-drift experiments and, in particular, in a very precise cryogenic experiment where this level of signal is about 100 times larger than the designed short-term stability. To fully appreciate what is going on, however, one should consider the vacuum as a true physical medium whose fundamental quantum nature gives rise to the irregular, non-deterministic pattern which characterizes the observed signal., Comment: 13 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1204.6157, arXiv:1106.1277, arXiv:0912.0103

The condensation of elementary quanta and their macroscopic occupation of the same quantum state, say k=0 in some reference frame Sigma, is the essential ingredient of the degenerate vacuum of present-day elementary particle physics. This represents a sort of `quantum ether' which characterizes the physically realized form of relativity and could play the role of preferred reference frame in a modern re-formulation of the Lorentzian approach. In spite of this, the so called `null results' of the classical ether-drift experiments, traditionally interpreted as confirmations of Special Relativity, have so deeply influenced scientific thought as to prevent a critical discussion on the real reasons underlying its alleged supremacy. In this paper, we argue that this traditional null interpretation is far from obvious. In fact, by using Lorentz transformations to connect the Earth's frame to Sigma, the small observed effects point to an average Earth's velocity of about 300 km/s, as in most cosmic motions. A common feature is the irregular behaviour of the data. While this has motivated, so far, their standard interpretation as instrumental artifacts, our new re-analysis of the very accurate Joos experiment gives clear indications for the type of Earth's motion associated with the CMB anisotropy and leaves little space for this traditional interpretation. The new explanation requires instead a view of the vacuum as a stochastic medium, similar to a fluid in a turbulent state of motion, in agreement with basic foundational aspects of both quantum physics and relativity. The overall consistency of this picture with the present experiments with vacuum optical resonators and the need for a new generation of dedicated ether-drift experiments are also emphasized., Comment: 70 pages, 12 figures, 13 tables, version accepted for publication in Eur.Phys.Journ.Plus

Basic foundational aspects of both quantum theory and relativity might induce to represent the physical vacuum as an underlying highly turbulent fluid. By explicit numerical simulations, we show that a form of statistically isotropic and homogeneous vacuum turbulence is entirely consistent with the present ether-drift experiments. In particular, after subtracting known forms of disturbances, the observed stochastic signal requires velocity fluctuations whose absolute scale is well described by the average Earth's motion with respect to the Cosmic Microwave Background. We emphasize that the existence of a genuine stochastic ether drift could be crucial for the emergence of forms of self-organization in matter and thus for the whole approach to complexity., Comment: 25 pages, 5 figures. Accepted for publication in Physica A. arXiv admin note: substantial text overlap with arXiv:1106.1277

We re-consider the idea that quantum fluctuations might reflect the existence of an 'objective randomness', i.e. a basic property of the vacuum state which is independent of any experimental accuracy of the observations or limited knowledge of initial conditions. Besides being responsible for the observed quantum behaviour, this might introduce a weak, residual form of `noise' which is intrinsic to natural phenomena and could be important for the emergence of complexity at higher physical levels. By adopting Stochastic Electro Dynamics as a heuristic model, we are driven to a picture of the vacuum as a form of highly turbulent ether, which is deep-rooted into the basic foundational aspects of both quantum physics and relativity, and to search for experimental tests of this scenario. An analysis of the most precise ether-drift experiments, operating both at room temperature and in the cryogenic regime, shows that, at present, there is some ambiguity in the interpretation of the data. In fact the average amplitude of the signal has precisely the magnitude expected, in a 'Lorentzian' form of relativity, from an underlying stochastic ether and, as such, might not be a spurious instrumental effect. This puzzle, however, should be solved in a next future with the use of new cryogenically cooled optical resonators whose stability should improve by about two orders of magnitude. In these new experimental conditions, the persistence of the present amplitude would represent a clean evidence for the type of random vacuum we are envisaging., Comment: 22 pages, 2 figures; revised version accepted for publication on Chaos, Solitons and Fractals

According to several authors, gravity might be a long-wavelength phenomenon emerging in some 'hydrodynamic limit' from the same physical, flat-space vacuum viewed as a form of superfluid medium. In this framework, light might propagate in an effective acoustic geometry and exhibit a tiny anisotropy that could be measurable in the present ether-drift experiments. By accepting this view of the vacuum, one should also consider the possibility of sizeable random fluctuations of the signal that reflect the stochastic nature of the underlying `quantum ether' and could be erroneously interpreted as instrumental noise. To test the present interpretation, we have extracted the mean amplitude of the signal from various experiments with different systematics, operating both at room temperature and in the cryogenic regime. They all give the same consistent value < A > = O (10^{-15}) which is precisely the magnitude expected in an emergent-gravity approach, for an apparatus placed on the Earth's surface. Since physical implications could be substantial, it would be important to obtain more direct checks from the instantaneous raw data and, possibly, with new experimental set-ups operating in gravity-free environments., Comment: 21 pages, 1 table. Version accepted for publication in General Relativity and Gravitation.

In the data of the ether-drift experiments there might be sizable fluctuations superposed on the smooth sinusoidal modulations due to the Earth's rotation and orbital revolution. These fluctuations might reflect the stochastic nature of the underlying "quantum ether" and produce vanishing averages for all vectorial quantities extracted from a naive Fourier analysis of the data. By comparing the typical stability limits of the individual optical resonators with the amplitude of their relative frequency shift, the presently observed signal, rather than being spurious experimental noise, might also express fundamental properties of a physical vacuum similar to a superfluid in a turbulent state of motion. In this sense, the situation might be similar to the discovery of the CMBR that was first interpreted as mere instrumental noise., Comment: 15 pages, 1 Table

It has been argued by several authors that the space-time curvature observed in gravitational fields, and the same idea of forms of physical equivalence different from the Lorentz group, might emerge from the dynamical properties of the physical flat-space vacuum in a suitable hydrodynamic limit. To explore this idea, one could start by representing the physical vacuum as a Bose condensate of elementary quanta and look for vacuum excitations that, on a coarse grained scale, resemble the Newtonian potential. In this way, it is relatively easy to match the weak-field limit of classical General Relativity or of some of its possible variants. The idea that Bose condensates can provide various forms of gravitational dynamics is not new. Here, I want to emphasize some genuine quantum field theoretical aspects that can help to understand i) why infinitesimally weak, 1/r interactions can indeed arise from the same physical vacuum of electroweak and strong interactions and ii) why, on a coarse-grained scale, their dynamical effects can be re-absorbed into an effective curved metric structure., Comment: 30 pages, no figures, accepted by Classical and Quantum Gravity

Long-range 1/r potentials play a fundamental role in physics. Their ultimate origin is usually traced back to the existence of genuine massless particles as photons or gravitons related to fundamental properties of continuum quantum field theories such as gauge invariance. In this Letter, it is argued that, in principle, an asymptotic, infinitesimally weak 1/r potential might also occur in the cutoff version of a simple, one-component spontaneously broken \Phi^4 theory, after taking into account the peculiar nature of the zero-momentum limit of the connected scalar propagator. Physical interpretation, phenomenological implications and proposals for a new generation of lattice simulations are also discussed., Comment: 13 Pages. To appear in Physics Letters B

In principle, by accepting the idea of a non-zero vacuum energy, the physical vacuum of present particle physics might represent a preferred reference frame. By treating this quantum vacuum as a relativistic medium, the non-zero energy-momentum flow expected in a moving frame should effectively behave as a small thermal gradient and could, in principle, induce a measurable anisotropy of the speed of light in a loosely bound system as a gas. We explore the phenomenological implications of this scenario by considering a new class of dedicated ether-drift experiments where arbitrary gaseous media fill the resonating optical cavities. Our predictions cover most experimental set up and should motivate precise experimental tests of these fundamental issues., Comment: Accepted for publication in Eur. Phys. Journ. C

Modern ether-drift experiments in vacuum could in principle detect the tiny refractive index that, in a flat-space picture of gravity, is appropriate for an apparatus placed on the Earth's surface. In this picture, in fact, if there were a preferred reference frame, light on the Earth would exhibit a slight anisotropy with definite quantitative differences from General Relativity. By re-analyzing the data published by two modern experiments with rotating optical resonators, and concentrating on the part of the signal that should be free of spurious systematic effects, we have found evidences that would support the flat-space scenario., Comment: 23 pages, 7 tables, no figures

After commenting on the present value of the Higgs particle mass from radiative corrections, we explore the phenomenological implications of an alternative, non-perturbative renormalization of the scalar sector where the mass of the Higgs particle does not represent a measure of observable interactions at the Higgs mass scale. In this approach the Higgs particle could be very heavy, even heavier than 1 TeV, and remain nevertheless a relatively narrow resonance., Comment: 17 pages. Version accepted for publication in Journal of Physics G

It is generally assumed that the physical vacuum of particle physics should be characterized by an energy momentum tensor in such a way to preserve exact Lorentz invariance. On the other hand, if the ground state were characterized by its energy-momentum vector, with zero spatial momentum and a non-zero energy, the vacuum would represent a preferred frame. Since both theoretical approaches have their own good motivations, we propose an experimental test to decide between the two scenarios., Comment: 12 pages, no figures

Modern ether-drift experiments look for a preferred reference frame searching for modulations of the beat note of two optical resonators that might be induced by the Earth's rotation. We present a compact formalism to evaluate the signal for most experiments where two arbitrary gaseous media fill the resonating cavities. Our predictions can provide useful hints to optimize the experimental set up and the data taking., Comment: 7 pages, plain latex

The phenomenon of spontaneous symmetry breaking admits a physical interpretation in terms of the Bose-condensation process of elementary spinless quanta. In a cutoff theory, this leads to a picture of the vacuum as a condensed medium whose excitations might deviate from exact Lorentz covariance in both the ultraviolet and infrared regions. For this reason, the conventional singlet Higgs boson, the shifted field of spontaneous symmetry breaking, rather than being a purely massive field, might possess a gapless branch describing the long-wavelength fluctuations of the scalar condensate. To test this idea, that might have substantial phenomenological implications, I compare with a detailed lattice simulation of the broken phase in the 4D Ising limit of the theory. The results are the following: i) differently from the symmetric phase, the single-particle energy spectrum is not reproduced by the standard massive form ii) for the value of the hopping parameter \kappa=0.076, increasing the lattice size from 20^4 to 32^4, the mass gap is found to decrease from the value 0.392(1) reported by Balog et al. (see Nucl. Phys. B714 (2005) 256) to the value 0.366(5). Both results confirm that, in the infrared region, the standard singlet Higgs cannot be considered as a simple massive field. Several arguments indicate that, approaching the continuum limit of the lattice theory, the observed volume dependence of the mass gap might require larger and larger lattice sizes before to show up., Comment: 29 pages, 16 tables

We consider the Renormalization-Group coupled equations for the effective potential V(\phi) and the field strength Z(\phi) in the spontaneously broken phase as a function of the infrared cutoff momentum k. In the k \to 0 limit, the numerical solution of the coupled equations, while consistent with the expected convexity property of V(\phi), indicates a sharp peaking of Z(\phi) close to the end points of the flatness region that define the physical realization of the broken phase. This might represent further evidence in favor of the non-trivial vacuum field renormalization effect already discovered with variational methods., Comment: 10 pages, 3 Figures, version accepted for publication in Phys. Lett. B

Re-analyzing the data published by the Berlin and Duesseldorf ether-drift experiments, we have found a clean non-zero daily average for the amplitude of the signal. The two experimental values, A_0\sim (10.5 \pm 1.3) 10^{-16} and A_0\sim (12.1\pm 2.2) 10^{-16}$ respectively, are entirely consistent with the theoretical prediction (9.7\pm 3.5) 10^{-16} that is obtained once the Robertson-Mansouri-Sexl anisotropy parameter is expressed in terms of N_{vacuum}, the effective vacuum refractive index that one would get, for an apparatus placed on the Earth's surface, in a flat-space picture of gravity ., Comment: 13 pages, plain latex

Since the end of 80's, the region of sky of galactic coordinates (l\sim 309^o, b\sim 18^o), corresponding to a declination \gamma\sim -44^o and right ascension \alpha\sim 202^o, usually denoted as the "Great Attractor", is known to control the overall galaxy flow in our local Universe. In this sense, this direction might represent a natural candidate to characterize a hypothetical Earth's "absolute motion". Our analysis of the extensive ether-drift observations recently reported by an experimental group in Berlin provides values of \alpha and \gamma that coincide almost exactly with those of the Great Attractor and not with the values \gamma\sim -6^o and \alpha\sim 168^o obtained from a dipole fit to the anisotropy of the CMB. This supports in a new fashion the existence of a discrepancy between the observed motion of the Local Group and the direction obtained from the CMB dipole., Comment: 12 pages, plain Latex

We present a fully model-independent analysis of the extensive observations reported by a recent ether-drift experiment in Berlin. No a priori assumption is made on the nature of a hypothetical preferred frame. We find a remarkable consistency with an Earth's cosmic motion exhibiting an average declination angle |\gamma|\sim 43^o and with values of the RMS anisotropy parameter (1/2-\beta+\delta) that are one order of magnitude larger than the presently quoted ones. This might represent the first modern indication for a preferred frame and for a non-zero anisotropy of the speed of light., Comment: 7 pages, plain Latex

By comparing with the most recent experimental results, we point out the model dependence of the present bounds on the anisotropy of the speed of light. In fact, by replacing the CMB with a class of preferred frames that can better account for the experimental data, one obtains values of the RMS anisotropy parameter (1/2 -beta + delta) that are one order of magnitude larger than the presently quoted ones. The resulting non-zero anisotropy can be understood starting from the observation that the speed of light in the Earth's gravitational field is not the basic parameter c=1 entering Lorentz transformations. In this sense, light can propagate isotropically only in one `preferred' frame., Comment: Plain Latex, 16 pages, 2 tables

Models with extra space-time dimensions produce, tipically, a 4D effective theory whose vacuum is not exactly Lorentz invariant but can be considered a physical medium whose refractive index is determined by the gravitational field. This leads to a version of relativity with a preferred frame and to look for experimental tests with the new generation of ether-drift experiments using rotating cryogenic optical resonators. Considering various types of cosmic motion, we formulate precise predictions for the modulations of the signal induced by the Earth's rotation and its orbital revolution around the Sun. We also compare with recent experimental results that might represent the first modern experimental evidence for a preferred frame., Comment: 15 pages, Latex, no figures

A new ether-drift experiment in D\"usseldorf is currently measuring the relative frequency shift of two cryogenic optical resonators upon active rotations of the apparatus. I point out that the observed fractional amplitude of the sidereal variations of the signal in February, C_sid \sim (11 \pm 2) 10^{-16}, is entirely consistent with the expectations based on Miller's observations in the same epoch of the year. This leads to predict that, with future data collected in August-September, the observed sidereal variations should increase by \sim + 70 %, i.e. up to C_sid \sim (19\pm 2) 10^{-16} retaining the present normalization. This would represent clean experimental evidence for the existence of a preferred frame., Comment: 6 pages, plain Latex, no figures

Lattice data, taken since 1998 near the critical line of a 4D Ising model, have been supporting the large logarithmic rescaling of the scalar condensate predicted in the alternative description of symmetry breaking proposed by Consoli and Stevenson. This conclusion has been challenged in a recent paper by Balog et al. In this paper we respond to the criticism of these authors, recapitulate the theoretical and numerical evidences in favour of the alternative interpretation of `triviality' and reiterate our conclusion: `triviality', by itself, cannot be used to place upper bounds on the Higgs boson mass., Comment: 20 pages, 7 figures

Modern ether-drift experiments look for a preferred frame by measuring the difference \Delta \nu in the relative frequencies of two cavity-stabilized lasers, upon local rotations of the apparatus or under the Earth's rotation. If the small deviations observed in the classical ether-drift experiments were not mere instrumental artifacts, by replacing the high vacuum in the resonating cavities with a dielectric gaseous medium (e.g. air), the typical measured \Delta\nu\sim 1 Hz should increase by orders of magnitude. This prediction is consistent with the characteristic modulation of a few kHz observed in the original experiment with He-Ne masers. However, if such enhancement would not be confirmed by new and more precise data, the existence of a preferred frame can be definitely ruled out., Comment: 15 pages, Latex file

Using two different methods, we have determined the rescaling of the scalar condensate $Z\equiv Z_\phi$ near the critical line of a 4D Ising model. Our lattice data, in agreement with previous numerical indications, support the behavior $Z_\phi\sim \ln ({\Lambda})$, $\Lambda$ being the ultraviolet cutoff. This result is predicted in an alternative description of symmetry breaking where there are no upper bounds on the Higgs boson mass from `triviality'., Comment: 11 pages, 2 figures, 3 tables

Motivated by the critical remarks of several authors, we have re-analyzed the classical ether-drift experiments with the conclusion that the small observed deviations should not be neglected. In fact, within the framework of Lorentzian Relativity, they might indicate the existence of a preferred frame relatively to which the Earth is moving with a velocity v_earth\sim 200$ km/s (value projected in the plane of the interferometer). We have checked this idea by comparing with the modern ether-drift experiments, those where the observation of the fringe shifts is replaced by the difference \Delta \nu in the relative frequencies of two cavity-stabilized lasers, upon local rotations of the apparatus or under the Earth's rotation. It turns out that, even in this case, the most recent data are consistent with the same value of the Earth's velocity, once the vacuum within the cavities is considered a physical medium whose refractive index is fixed by General Relativity. We thus propose a sharp experimental test that can definitely resolve the issue. If the small deviations observed in the classical ether-drift experiments were not mere instrumental artifacts, by replacing the high vacuum in the resonating cavities with a dielectric gaseous medium (e.g. air), the typical measured \Delta\nu\sim 1 Hz should increase by orders of magnitude. This expectation is consistent with the characteristic modulation of a few kHz observed in the original experiment with He-Ne masers. However, if such enhancement would not be confirmed by new and more precise data, the existence of a preferred frame can be definitely ruled out., Comment: 25 pages, 2 tables, 2 figures

Historically, the Michelson-Morley experiment has played a crucial role for abandoning the idea of a preferred reference frame, the ether, and for replacing Lorentzian Relativity with Einstein's Special Relativity. However, our re-analysis of the Michelson-Morley original data, consistently with the point of view already expressed by other authors, shows that the experimental observations have been misinterpreted. Namely, the fringe shifts point to a non-zero observable Earth's velocity v_obs = 8.4 +/- 0.5 km/s. Assuming the existence of a preferred reference frame, and using Lorentz transformations to extract the kinematical Earth's velocity that corresponds to this v_obs, we obtain a real velocity, in the plane of the interferometer, v_earth = 201 +/- 12 km/s. This value is in excellent agreement with Miller's calculated value v_earth = 203 +/- 8 km/s and suggests that the magnitude of the fringe shifts is determined by the typical velocity of the Solar System within our galaxy. This conclusion, which is also consistent with the results of all other classical experiments, leads to an alternative interpretation of the Michelson-Morley type of experiments. Contrary to the generally accepted ideas of last century, they provide experimental evidence for the existence of a preferred reference frame. This point of view is also consistent with the most recent data for the anisotropy of the two-way speed of light in the vacuum., Comment: Latex file, 17 pages, 2 tables, 1 figure

The phenomenon of spontaneous symmetry breaking admits a physical interpretation in terms of the Bose-condensation process of elementary spinless quanta. In this picture, the broken-symmetry phase emerges as a real physical medium, endowed with a hierarchical pattern of scales, supporting two types of elementary excitations for k \to 0: a massive energy branch E_a(k) \to M_H, corresponding to the usual Higgs boson field, and a collective gap-less branch E_b(k) \to 0. This is similar to the coexistence of phonons and rotons in superfluid He-4 that, in fact, is usually considered the condensed-matter analog of the Higgs condensate. After previous work dedicated to the properties of the gap-less, phonon branch, in this paper we use quantum hydrodynamics to propose a physical interpretation of the massive branch. On the base of our results, M_H coincides with the energy-gap for vortex formation and a massive Higgs boson is like a roton in superfluid He-4. Within this interpretation of the Higgs particle, there is no "naturalness" problem since M_H remains a naturally intermediate, fixed energy scale, even for an ultimate ultraviolet cutoff Lambda \to \infty., Comment: Latex file, 20 pages, no figures

We have determined the rescaling of the scalar condensate $Z\equiv Z_\phi$ near the critical line of a 4D Ising model. Our lattice data, supporting previous numerical indications, confirm the behaviour $Z_\phi\sim \ln ({\rm cutoff})$. This result is predicted in an alternative description of symmetry breaking where there are no upper bounds on the Higgs boson mass from `triviality'., Comment: 8 pages, 1 figure, 2 tables

The Michelson-Morley experiment was designed to detect the relative motion of the Earth with respect to a preferred reference frame, the ether, by measuring the fringe shifts in an optical interferometer. These shifts, that should have been proportional to the square of the Earth's velocity, were found to be much smaller than expected. As a consequence, that experiment was taken as an evidence that there is no ether and, as such, played a crucial role for deciding between Lorentzian Relativity and Einstein's Special Relativity. However, according to some authors, the observed Earth's velocity was not negligibly small. To provide an independent check, we have re-analyzed the fringe shifts observed in each of the six different sessions of the Michelson-Morley experiment. They are consistent with a non-zero observable Earth's velocity $v_{\rm obs} = 8.4 \pm 0.5 km/s$. Assuming the existence of a preferred reference frame and using Lorentz transformations, this $v_{\rm obs}$ corresponds to a real velocity, in the plane of the interferometer, $v_{\rm earth} = 201 \pm 12 km/s$. This value, which is remarkably consistent with 1932 Miller's cosmic solution, suggests that the magnitude of the fringe shifts is determined by the typical velocity of the solar system within our galaxy. This conclusion is consistent with the results of all classical experiments (Morley-Miller, Illingworth, Joos, Michelson-Pease-Pearson,...) and with the existing data from present-day experiments., Comment: 12 pages, 1 table

The `triviality' of $\Phi^4_4$ has been traditionally interpreted within perturbation theory where the prediction for the Higgs boson mass depends on the magnitude of the ultraviolet cutoff $\Lambda$. This approach crucially assumes that the vacuum field and its quantum fluctuations rescale in the same way. The results of the present lattice simulation, confirming previous numerical indications, show that this assumption is not true. As a consequence, large values of the Higgs mass $m_H$ can coexist with the limit $\Lambda\to \infty $. As an example, by extrapolating to the Standard Model our results obtained in the Ising limit of the one-component theory, one can obtain a value as large as $m_H=760 \pm 21$ GeV, independently of $\Lambda$., Comment: 3 pages, 2 figures, Lattice2003(higgs)

The recent, precise Michelson-Morley experiment performed by Muller et al. suggests a tiny anisotropy of the speed of light. I propose a quantitative explanation of the observed effect based on the interpretation of gravity as a density fluctuation of the Higgs condensate., Comment: Latex file, 9 pages, no figures

The idea of a `condensed' vacuum state is generally accepted in modern elementary particle physics. We argue that this should motivate a new generation of precise `ether-drift' experiments with present-day technology., Comment: Latex file, 12 pages, no figures

In the `condensed phase' of effective quantum field theories one expects deviations from exact Lorentz invariance at ultralow momenta | k| < delta where the shell 'delta' should only vanish in the strict local limit of the theory when the ultraviolet cutoff 'Lambda' tends to infinity. I explore this idea for the Higgs condensate suggesting that, in this case, the resulting relation connecting 'delta', 'Lambda' and the Fermi scale might provide a simple physical solution of the `hierarchy problem'. In this picture, the Planck scale is not a purely ultraviolet quantity but embodies in its numerical value the peculiar infrared-ultraviolet connection that is realized in the scalar condensate., Comment: Latex file, 45 pages, no figures

The `triviality' of $\Phi^4_4$ has been traditionally interpreted within perturbation theory where the prediction for the Higgs boson mass depends on the magnitude of the ultraviolet cutoff $\Lambda$. This approach crucially assumes that the vacuum field and its quantum fluctuations rescale in the same way. The results of the present lattice simulation, confirming previous numerical indications, show that this assumption is not true. As a consequence, large values of the Higgs mass $m_H$ can coexist with the limit $\Lambda\to \infty $. As an example, by extrapolating to the Standard Model our results obtained in the Ising limit of the one-component theory, one can obtain a value as large as $m_H=760 \pm 21$ GeV, independently of $\Lambda$., Comment: 8 pages, 1 figure, 3 tables (new tables and comments)

Several arguments suggest that an effective curved space-time structure (of the type as in General Relativity) can actually find its dynamical origin in an underlying condensed medium of spinless quanta. For this reason, we exploit the recent idea of density fluctuations in a `Higgs condensate' with the conclusion that such long-wavelength effects might represent the natural dynamical agent of gravity., Comment: 38 pages, Latex file

We point out a basic ambiguity in the $p \to 0$ limit of the connected propagator in a spontaneously broken phase. This may represent an indication that the conventional singlet Higgs boson, rather than being a purely massive field, might have a gap-less branch. This would dominate the energy spectrum for ${\bf{p}} \to 0$ and give rise to a very weak, long-range force. The natural interpretation is in terms of density fluctuations of the `Higgs condensate': in the region of very long wavelengths, infinitely larger than the Fermi scale, it cannot be treated as a purely classical c-number field., Comment: 17 pages, LaTex, small changes and some comments added

Due to the peculiar nature of the underlying medium, density fluctuations in a `Higgs condensate' are predicted to propagate for infinitely long wavelengths with a group velocity $c_s\to \infty $. On the other hand, for any large but finite $c_s$ there is a weak, attractive $1/r$ potential of strength ${{1}\over{c^2_s}}$ and the energy spectrum deviates from the purely massive form $\sqrt{p}^2 + M^2_h}$ at momenta smaller than $\delta\sim {{M_h}\over{c_s}}$. Physically, the length scale $\delta^{-1}$ corresponds to the mean free-path for the elementary constituents in the condensate and would naturally be placed in the millimeter range., Comment: 12 pages, LaTeX

We simulate a four dimensional self-interacting scalar field theory on the lattice at finite temperature. By varying temperature, the system undergoes a phase transition from broken phase to symmetric phase. Our data show that the zero-momentum field renormalization increases by approaching critical temperature. On the other hand, finite-momentum wave-function renormalization remains remarkably constant., Comment: Lattice2001(higgssusy); 3 pages, 2 figures

We illustrate why a space-time structure as in General Relativity is not in contradiction with a dynamical origin of gravity from a scalar field. Further, we argue that the recently discovered gap-less mode of the singlet Higgs field represents the most natural dynamical agent of Newtonian gravity., Comment: 12 pages

Quite independently of the Goldstone phenomenon, recent lattice data suggest the existence of gap-less modes in the spontaneously broken phase of a $\lambda \Phi^4$ theory. This result is a direct consequence of the quantum nature of the `Higgs condensate' that cannot be treated as a purely classical c-number field., Comment: 6 pages

Recent lattice results suggest the existence of a gap-less mode of the singlet Higgs field. We present a description of spontaneous symmetry breaking in $\lambda\Phi^4$ theories showing why one is faced with long-wavelength, collective modes of the scalar condensate with $\tilde{E}({\bf{p}}) \to 0$ energy in the ${\bf{p}} \to 0$ limit., Comment: 10 pages

Using lattice simulations of a one-component $(\lambda \Phi^4)_4$ theory, we have measured the energy spectrum $\omega({\mathbf{k}})$ in the broken phase at various lattice sizes. Our data show that the energy-gap $\omega(0)$ is {\it not} the `Higgs mass' $M_h$ but an infrared-sensitive quantity that becomes smaller and smaller by increasing the lattice size and may even vanish in the infinite-volume limit., Comment: 11 pages, 4 figures, 1 table. Revised version with more statistics and other measured quantities

Recent lattice simulations of $(\lambda \Phi^4)_4$ theories in the broken phase show that : a) the shifted field propagator is well reproduced by the simple 2-parameter form ${{Z_{\rm prop}}\over{p^2 + M^2_h}}$ at finite momenta but strongly differs for $p \to 0$ b) the bare zero-momentum two-point function $\Gamma_2(0)= \frac{d^2 V_{\rm eff}}{d \phi^2_B}|_{\phi_B= \pm v_B}$ gives a value of $Z_\phi \equiv {{M^2_h}\over{\Gamma_2(0)}}$ that increases when approaching the continuum limit. This supports theoretical expectations where $v_B$ is related by an infinite re-scaling to the `physical Higgs condensate' $v_R$ defined through $\frac{d^2 V_{\rm eff}}{d \phi^2_R}|_{\phi_R= \pm v_R}=M^2_h$. New lattice data collected around the phase transition confirm this scenario. By denoting $M_{\rm SB} \equiv M_h ={\cal O} (v_R)$ the scale of the broken phase, our results suggest the existence of a `hierarchy' of scales $\Gamma_2(0) \ll M^2_{\rm SB} \ll v^2_B$ that become infinitely far in the continuum limit. This may open unexpected possibilities to reconcile an infinitesimal slope of the effective potential with finite values of $M_h$ and accomodate very different mass scales in the framework of a spontaneously broken theory., Comment: 15 pages, 5 figures

We present a simple semi-perturbative argument in favour of a peculiar infrared behaviour of the (singlet) Higgs propagator. On the basis of `triviality' one expects a continuum limit with a two-point function $\Gamma_2(q) \to (q^2 + M^2_h)$. However, this is not valid in the limit $q \to 0$ where one actually finds a singular behaviour. This is in agreement with both non-perturbative analyses of the effective potential and with lattice computations of the propagator and of the zero-momentum susceptibility in the broken phase. The singular behaviour persists in an O(N) continuous-symmetry theory, the case first pointed out by Symanzik, and supports the existence of an extremely weak $1/r$ potential that does not disappear when coupling the scalar fields to gauge bosons., Comment: 10 pages, LaTeX

The basic idea that gravity can be a long-wavelength effect {\it induced} by the peculiar ground state of an underlying quantum field theory leads to consider the implications of spontaneous symmetry breaking through an elementary scalar field. We point out that Bose-Einstein condensation implies the existence of long-range order and of a gap-less mode of the (singlet) Higgs-field. This gives rise to a $1/r$ potential and couples with infinitesimal strength to the inertial mass of known particles. If this is interpreted as the origin of Newtonian gravity one finds a natural solution of the hierarchy problem. As in any theory incorporating the Equivalence Principle, the classical tests in weak gravitational fields are fulfilled as in general relativity. On the other hand, our picture suggests that Einstein general relativity may represent the weak field approximation of a theory generated from flat space with a sequence of conformal transformations. This explains naturally the absence of a {\it large} cosmological constant from symmetry breaking. Finally, one also predicts new phenomena that have no counterpart in Einstein theory such as typical `fifth force' deviations below the centimeter scale or further modifications at distances $10^{17}$ cm in connection with the Pioneer anomaly and the mass discrepancy in galactic systems., Comment: 31 pages, no figures