Search

We show how the Higgs boson exchange processes may indicate the occurence of special Higgs boson structures (substructures or peculiar interactions with dark matter) from a possible modification of the s-dependence of their cross section. We illustrate the simplest example with the $\mu^+\mu^-\to f\bar f$ process., Comment: 7 pages, 1 figure

We propose further tests of the occurence of scale dependent heavy particle masses (Z,W,t) and of strong final state interactions by comparing Z longitudinal polarization rates in different kinematical distributions of the $e^+e^-\to Zt\bar t$ and in $e^+e^-\to ZW^+W^-$ processes., Comment: 10 pages, 4 figures

We show that the $ZWW$ production process may give complementary informations about scale dependent heavy particle masses and possible final state interactions as compared to previously studied top quark production processes. We illustrate the $p_Z$ distribution of the rate of longitudinal $Z_L$ component showing its sensitivity to these effects which may arise from heavy particle substructure or a dark matter (DM) environment., Comment: 12 pages, 6 figures

We analyze the $Wt\bar b$ production processes and especially the rate of longitudinal $W$ polarization sensitive to a possible top quark mass scale dependence and to the presence of strong final state $Wt$ interactions for example generated by a dark matter environment. We give illustrations for the three processes $e^+e^-$, gluon-gluon and $\gamma\gamma \to W t\bar b $., Comment: 17 pages, 12 figures

We show what type of effects on the rate of $Z_L$ production in the $\gamma\gamma\to t\bar t Z$ and $gluon~gluon\to t\bar t Z$ processes could be produced by an effective scale dependent top mass or by final state interactions between massive particles for example generated by the presence of dark matter., Comment: 12 pages, 7 figures

We show that the measurement of the $Z$ polarization in the $e^+e^-\to t\bar t Z$ process would allow an interesting determination of the role of the top quark mass. This can be used for testing the possibility of top compositeness or of the occurence of final state interactions related to the mass generation in particular the interaction with dark matter., Comment: 10 pages, 4 figures

We propose deeper tests of the existence of DM interactions between heavy particles in $e^+e^-\to t\bar t, ZZ, W^+W^-$ by looking at the effects on final state polarization. We show that indeed $t$, $W$ and $Z$ polarization are particularly sensitive to the structure of these interactions, to their relation with the origin of the masses and to the quantum numbers of the possibly exchanged dark particles., Comment: 19 pages, 12 figures

We propose further tests of the assumption that the mass of the heavy standard particles ($Z,W,t,...$) arises from a special coupling with dark matter. We look for effects of new interactions due to dark matter exchanges between heavy particles in several $e^+e^-$ and hadronic collision processes., Comment: 20 pages, 12 figures

We assume that the mass of the heavy standard particles ($Z,W,t,...$) arises from a special coupling with dark matter and that this implies a corresponding peculiar connection of these particles to the dark sector. We give examples of possible tests of this assumption in $e^+e^-\to Z+X,~ W^+W^-+X, ~t\bar t+X$ and we mention other possible studies., Comment: 12 pages, 6 figures

Similarly to the previously studied case of inclusive $t\bar t$ production we consider the inclusive $t\bar b$ production in $e^+e^-$, gluon~gluon and photon~photon collisions. We show how it is sensitive to new physics, connected to the charged Goldstone sector and possibly generated by Higgs and/or top quark compositeness., Comment: 12 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1711.02340

We show how the inclusive $t\bar t$ production in $e^+e^-$, gluon~gluon and photon~photon collisions could reveal the presence of new (visible or invisible) particles connected to the Higgs sector and/or to the top quark., Comment: 12 pages, 6 figures

We show that the processes of $\gamma b, Hb, Zb, W^-t$ production in gluon+bottom collision can give interesting informations about possible Higgs boson, top and bottom quark compositeness. We make illustrations of the ratios of new cross sections over standard ones. Specific energy dependences appear for each assumption about $b_L$, $b_R$, $t_L$, $t_R$ compositeness and CSM constraints concerning the Higgs sector., Comment: 18 pages, 13 figures, references added

We look for possible (partial) compositeness properties of the bottom quark according to the Composite Standard Model (CSM) concept in the same way this was previously done for Higgs boson and top quark. After looking at the direct form factor effects appearing in $e^+e^-\to b\bar b$ we analyze the more complex features of the $e^+e^-, gg, \gamma\gamma \to b\bar b H, b\bar b Z, t\bar b W^-$ processes. We emphasize typical differences appearing between CSM concerving and CSM violating cases. We also mention the possible appearence of an effective bottom mass., Comment: 20 pages, 13 figures

We recall the motivations for the Compositeness Standard Model(CSM) concept, its precise description, the procedures for its applications and the particular constraints that it requires. We present its most spectacular predictions for typical processes observable at present and future colliders. To the previous results we add the treatment of the inclusive processes $e^+e^- \to H,Z,W~or~t+ anything$., Comment: 22 pages with 11 figures

We extend our previous analysis of $t\bar t H, t\bar t Z, t\bar b W$ production in $e^+e^-$ collisions within the CSM (Composite Standard Model) concept of Higgs boson and top quark compositeness to the case of gluon-gluon and photon-photon collisions. We show that remarkable differences may indeed appear between the effects generated by CSM conserving and by CSM violating sets of form factors., Comment: 16 pages, 9 figures

We study the modifications of the amplitudes and cross sections of several processes, especially $e^+e^- \to t\bar t H, t\bar t Z, t\bar b W$, generated by Higgs boson and top quark compositeness, in particular within the CSM concept. We illustrate the observable differences that may appear between various, CSM conserving or CSM violating, compositeness possibilities., Comment: 13 pages, 4 figures

We study the modifications of the $\gamma\gamma\to ZH$ amplitudes and cross sections generated by Higgs and top quark compositeness in particular within the CSM concept. We insist on the particular interest of polarized photon-photon collisions which should allow to identify the origin of the large observable differences between various, CSM conserving or CSM violating, compositeness possibilities., Comment: 16 pages, 8 figures. arXiv admin note: text overlap with arXiv:1702.08853

We study more deeply the sensitivity of the $ZH$ production process in gluon-gluon collisions to the details of a possible Higgs and top quark compositeness. We establish a relation between Higgs and top quark form factors which would keep the basic cancellation appearing in SM and satisfy the concept of CSM. We give illustrations showing the spectacular consequences of various choices preserving or violating this CSM constraint., Comment: 22 pages, 13 figures; references added

In the spirit of the Composite Standard Model (CSM) we look at the effect of $H$, $Z_L$ compositeness on $ZH$ production in gluon-gluon and photon-photon collisions. Because they would perturb the basic cancellations occuring in SM amplitudes, such compositeness effects would lead to spectacular modifications of the energy dependence of the amplitudes and cross sections. We illustrate this fact by introducing $H$, $Z_L$ test form factors and computing the corresponding differential cross section and the fraction of longitudinal $Z_L$ production., Comment: 14 pages, 7 figures

We assume that the Higgs doublet has a composite structure, respecting the main standard model properties, and therefore called Composite Standard Model (CSM), but leading (through Goldstone equivalence) to $Z_L$ and $W_L$ form factors. We illustrate how such a form factor affecting the $ZZ_LH$ coupling will be directly observable in $e^+e^-\to ZH$. We then show the spectacular consequences which would appear in the inclusive processes $e^+e^-\to Z_L+anything $. Such a form factor could also affect the $\gamma W^+_LW^-_L$ and $Z W^+_LW^-_L$ vertices and we show what effects this would generate in $e^+e^-\to W^+W^-$ (especially in $e^+e^-_R\to W^+_LW^-_L$) and in $e^+e^-\to W_L+anything $. We finally mention the $\gamma\gamma\to W^+W^-$ process and several other processes in hadronic collisions which could be similarly affected., Comment: 14 pages, 5 figures

We consider the inclusive top quark distributions in $e^+e^-\to t_{L,R}+\rm{anything}$. We analyze the modifications of the basic SM contributions which would result from $t_{R}$ compositeness for example from the presence of form factors in the $t_{R}$ couplings and of an effective top mass $m_t(s)$. We also look at parton like contributions representing additional new particle production related to $t_{R}$ constituents. One observes a large sensitivity of the $t_{R}$ inclusive distribution to these various effects with specific shapes differing from those of the $t_{L}$ distribution and we show that these effects may even be also observable in the unpolarized top case., Comment: 13 pages, 5 figures, references added

We are looking for remarkable differences between predictions of the standard model and those of $t_R$ compositeness (while the $t_L$ remains elementary) in various basic $t\bar t$ production processes, without having to make difficult final polarization analyses. We assume the presence of $q^2$ dependent form factors which first suppress the $t_R$ contributions at high $q^2$, and in addition, may also lead to an effective $q^2$ dependent top mass. We further assume that these effects disappear at low $q^2$ so that there are no anomalous couplings. We show that large specific differences indeed appear in the high energy limits of cross sections and asymmetries in $e^-e^+$, gluon+gluon, $\gamma\gamma$ collisions and other fusion processes and that this should lead to a strategy for analyzing them., Comment: 16 pages, 11 figures, References are added

We study the fusion processes $W^-W^+\to t\bar t$ and $ZZ\to t\bar t$ observable at a future $e^-e^+$ collider and we discuss their sensitivity to an $Htt$ form factor which may be due to compositeness, in particular when the $H$ and the top quark have common constituents. We make an amplitude analysis and illustrate which helicity amplitudes and cross sections for specific final $t\bar t$ polarizations are especially sensitive to this form factor., Comment: 24 pages, 37 figures, version including changes suggested by the Physical Review D publication team

We study the sensitivity of the process $\mu^-\mu^+\to HH$ to the $q^2$-dependence of the $HHH$ form factor, which can reflect the Higgs boson structure, especially in the case of compositeness. We compute the Born and 1 loop SM contribution to this process. We then show how the $\mu^-\mu^+\to HH$ polarized and unpolarized cross sections are modified by the presence of various types of anomalous contributions to the $HHH$ form factor, in particular Higgs constituents in the case of compositeness., Comment: 24 pages, 22 figures, Version to appear to Physical Review D. arXiv admin note: substantial text overlap with arXiv:1510.04102

We show how the $q^2$-dependence of the triple Higgs boson HHH form factor can reveal the presence of various types of new physics contributions, like new particles coupled to the Higgs boson or Higgs boson constituents, without directly observing them. We compare the effect of such new contributions to the one of higher order SM corrections to the point-like HHH coupling, due to triangle, 4-leg and s.e. diagrams. We establish simple analytic expressions describing accurately at high energy these SM corrections, as well as the examples of new physics contributions., Comment: 13 pages, 10 figures

We show that the Higgs boson structure functions observable in the inclusive process $e^-e^+ \to H + {\rm "anything"}$ may reveal the presence of anomalous contributions corresponding to several types of new physics partners, Higgs boson compositeness or invisible (dark) matter. This could be done without making a difficult or even an impossible experimental analysis of the contents of the "anything". We give illustrations showing how the shapes of the various structure functions containing such typical new contributions may differ from the standard prediction and allow their identification., Comment: 19 pages, 36 figures, version accepted in Phys. Rev. D

We study the process $e^-e^+\to \gamma H$, where $H$ represents $H_{SM}$, $h^0$ or $H^0$, which occurs at the one loop level in the standard model (SM) or in the minimal supersymmetric standard model (MSSM). We establish supersimple (sim) high energy expressions for all helicity amplitudes of this process, and we identify their level of accuracy for describing the various polarized and unpolarized observables, and for distinguishing SM from MSSM or another beyond the standard model (BSM). We pay a special attention to transverse electron-positron polarizations and azimuthal dependencies induced by the imaginary parts of the amplitudes, which are relatively important in this process., Comment: 33 pages, 66 figures. Version to appear in Phys. Rev. D

We study the process $e^-e^+\to ZH$ where $H$ represents the standard model (SM) Higgs particle $H_{SM}$, or the MSSM ones $h^0$ and $H^0$. In each case, we compute the one-loop effects and establish very simple expressions, called supersimple (sim), for the helicity conserving (dominant) and the helicity violating (suppressed) amplitudes. Such expressions, are then used to construct various cross sections and asymmetries, involving polarized or unpolarized beams and Z-polarization measurements. We examine the adequacy of such expressions to distinguish SM or MSSM effects, from other types of BSM (beyond the standard model) contributions., Comment: 38 pages, 57 figures. Paper has already appeared in Phys. Rev. D90, 073007 (2014 . Some misprints in Eqs.(B.17) have been corrected

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C. Please note that version 3 on the archive is the auxiliary version of the Physics of the B Factories book. This uses the notation alpha, beta, gamma for the angles of the Unitarity Triangle. The nominal version uses the notation phi_1, phi_2 and phi_3. Please cite this work as Eur. Phys. J. C74 (2014) 3026., Comment: 928 pages, version 3 (arXiv:1406.6311v3) corresponds to the alpha, beta, gamma version of the book, the other versions use the phi1, phi2, phi3 notation

Studying $e^-e^+\to W^- W^+$ at the 1loop electroweak (EW) order, we derive very accurate and simple expressions for the four Helicity Conserving (HC) amplitudes, which dominate this process at high energies. The calculations are done in both, the SM and MSSM frameworks. Such expressions, called supersimple (sim), nicely emphasize the dynamical contents of each framework. Numerical illustrations are presented, which show the accuracy of this description, and how it can be used for identifying possible additional new physics contributions; like e.g. Anomalous Gauge Couplings (AGC) or a new $Z'$ vector boson exchange. The procedure is useful even if only SM is visible at the future Linear Collider energies., Comment: 24 pages, 22 figures. Somewhat extended version to appear in Phys. Rev. D

According to supersimplicity in MSSM, a renormalization scheme (SRS) may be defined for any high energy 2-to-2 process, to the 1loop EW order; where the helicity conserving (HC) amplitudes, are expressed as a linear combination of just three universal logarithm-involving forms. All other helicity amplitudes vanish asymptotically. Including to these SRS amplitudes the corresponding counter terms, the "supersimple" expressions for the high energy HC amplitudes, renormalized on-shell, are obtained. Previously, this property was noted for a large number of processes that do not involve Yukawa interactions or renormalization group corrections. Here we extend it to $e^-e^+\to t \bar t$, which does involve large Yukawa and renormalization group contributions. We show that the resulting "supersimple" expressions may provide an accurate description, even at energies comparable to the SUSY scale. Such descriptions clearly identify the origin of the important SUSY effects, and they may be used for quickly constraining physics contributions, beyond MSSM., Comment: 26 pages, 15 figures. Paper appeared in Phys. Rev. D. The Journal where Reference 20 has appeared has been added

We consider the Z polarization asymmetry A_Z=(sigma(Z_R)-sigma(Z_L))/(sigma(Z_R)+sigma(Z_L)) in the process of associated bZ production at the LHC. We show that in the Standard Model (SM) this quantity is essentially given by its Born approximation, remaining almost unaffected by QCD scales and parton distribution functions variations as well as by electroweak corrections. The theoretical quantity that appears in A_Z is the same that provides the LEP1 Z -> b bbar forward-backward asymmetry, the only measured observable still in some contradiction with the SM prediction. In this sense, A_Z would provide the possibility of an independent verification of the possible SM discrepancy, which could reach, if consistency with LEP1 measurements is imposed, values of the relative ten percent size., Comment: 10 pages, 5 eps figures

Many extensions of the Standard Model involve two Higgs doublet fields to break the electroweak symmetry, leading to the existence of three neutral and two charged Higgs particles. In particular, this is the case of the Minimal Supersymmetric extension of the Standard Model, the MSSM. A very important parameter is $\tan\beta$ defined as the ratio of the vacuum expectation value of the two Higgs doublets. In this paper we focus on the left-right asymmetry in the production of polarised top quarks in association with charged Higgs bosons at the LHC. This quantity allows for a theoretically clean determination of $\tan\beta$. In the MSSM, the asymmetry remains sensitive to the strong and electroweak radiative corrections and, thus, to the superparticle spectrum. Some possible implications of these results are discussed.

In previous work, we have established that for any 2-to-2 process in MSSM, only the helicity conserving (HC) amplitudes survive asymptotically. Studying a large number of such processes, at the 1loop Electroweak (EW) order, it is now found that their high energy HC amplitudes are determined by just three forms: a log-squared function of the ratio of two of the (s,t,u) variables, to which a pi^2 is added; and two Sudakov-like ln- and ln^2-terms accompanied by respective mass-dependent constants. Apart from an additional residual constant, all high energy HC amplitudes, may be expressed as linear combinations of the above three forms, with coefficients being rational functions of the $(s,t,u)$ variables. We call this fact supersimplicity. Applying to the $ug\to dW$ amplitudes, for which the complete 1loop expressions are available, we find that supersimplicity may be a very good approximation at LHC energies, provided the SUSY scale is not too high. SM processes are also discussed, and their differences are explored., Comment: 25 pages, 16 figures. Clarifications added. Version to appear in Acta Physica Polonica B

According to the helicity conservation (HCns) theorem, the sum of the helicities should be conserved, in any 2-to-2 processes in MSSM with R-parity conservation, at high energies; i.e. all amplitudes violating this rule, must vanish asymptotically. The realization of HCns in gluon-fusion to charginos or neutralinos is studied, at the one loop electroweak order (EW), and simple high energy expressions are derived for the non-vanishing helicity conserving (HC) amplitudes. These are very similar to the corresponding expressions for $gg \to W^+W^-, ZZ, \gamma Z, \gamma\gamma $ derived before. Asymptotic relations among observable unpolarized cross sections for many such processes are then obtained, some of which may hold at LHC-type energies., Comment: Extended version to appear in International Journal of Modern Physics A 21 pages

We study how the property of asymptotic helicity conservation (HCns), expected for any 2-to-2 process in the minimal supersymmetric model (MSSM), is realized in the processes $gg \to \gamma\gamma,\gamma Z,ZZ,W^+W^-$, at the 1loop electroweak order and very high energies. The violation of this property for the same process in the standard model (SM), is also shown. This strengthens the claim that HCns is specific to the renormalizable SUSY model, and not generally valid in SM. HCns strongly reduces the number of non-vanishing 2-to-2 amplitudes at asymptotic energies in MSSM. Consequences at LHC and higher energy colliders are identified., Comment: 29 pages, 39 figures, minor corrections Version to appear in International Journal of Modern Physics A

We present the first complete calculation of the one-loop electroweak effect in the process of semi-inclusive bottom-Higgs production at LHC in the MSSM. The size of the electroweak contribution depends on the choice of the final produced neutral Higgs boson, and can be relevant, in some range of the input parameters. A comparison of the one-loop results obtained in two different renormalization schemes is also performed, showing a very good NLO scheme independence. We further comment on two possible, simpler, approximations of the full NLO result, and on their reliabilty.

We summarize the extensive work started in ref.1, according to which total helicity is conserved for any two-to-two process, at sqrt{s} larger than M_{SUSY} and fixed angles, in any SUSY extension of SM. Asymptotically the theorem is exact. But it may also have important implications at lower energies sqrt{s} close to M_{SUSY}. Up to now, these have been investigated to 1loop electroweak (EW) order for the processes ug to d W+, sd_L chi+; as well as the 17 gg to HH', and the 9 gg to VH processes, where H,H' denote Higgs or Goldstone bosons, and V=Z, W., Comment: 4 pages, 2 figures,Talk presented by GJG at the meeting on the "Standard Model and beyond and the Standard Cosmology", held at Corfu (Greece), during August 30 - September 6, 2009

The process of charged Higgs production in association with a top quark at the LHC has been calculated at the complete NLO electroweak level both in a Two Higgs Doublets Model and in the Minimal Supersymmetric Standard Model, assuming a mSUGRA breaking scheme. We have numerically explored the size of the one-loop corrections in two typical supersymmetric scenarios, with particular attention to the tan beta dependence, and we have found that they remain perturbatively small but possibly sizable, reaching a 20% limit for extreme values of tan beta, when the complete set of Feynman diagrams is taken into account., Comment: 22 pages, 5 figures, reference added

We observe that the electroweak one loop correction to the quark+gluon to quark+Higgs amplitude at high energy involves both single and quadratic logarithms of the energy in the SM case but only quadratic logarithms in the MSSM case. We explore the origin of this special SUSY cancellation, both in a diagrammatic way and through the splitting+Parameter Renormalization procedure. We show that it is not an accident but a remarkableand general SUSY property of the renormalized Higgs-fermion-fermion and Higgsino-sfermion-fermion vertices which directly reflects in such processes, for example in $bg\to tH^-$, $bg\to bH^0$, $bg\to bh^0$, $bg\to bA^0$, and through equivalence in $bg\to tW^-_{long}$, $bg\to bZ_{long}$, as well as in $bg\to \tilde{t}\chi^-$, $bg\to\tilde{b}\chi^0$. This simplification of the high energy behaviour (which only leaves quadratic logarithms involving pure gauge couplings without any free parameter) allows to write simple relations among these various processes which constitute genuine tests of the assumed SUSY model., Comment: 23 pqges, 4 eps figures

Within the MSSM and SM frameworks, we analyze the 1loop electroweak (EW) predictions for the helicity amplitudes describing the 17 processes $gg\to HH'$, and the 9 processes $gg\to VH$; where $H,H'$ denote Higgs or Goldstone bosons, while $V= Z, ~W^\pm$. Concentrating on MSSM, we then investigate how the asymptotic helicity conservation (HCns) property of SUSY, affects the amplitudes at the LHC energy range; and what is the corresponding situation in SM, where no HCns theorem exists. HCns is subsequently used to construct many relations among the cross sections of the above MSSM processes, depending only on the angles $\alpha$ and $\beta$. These relations should be asymptotically exact, but with mass-depending deviations appearing, as the energy decreases towards the LHC range. Provided the SUSY scale is not too high, they may remain roughly correct, even at the LHC energy range., Comment: Version to appear in Phys. Rev. D. More references have been added

The process of stop-chargino production at LHC has been calculated in the Minimal Supersymmetric Standard Model at the complete electroweak one-loop level, assuming a mSUGRA symmetry breaking scheme. Several properties of the angular and invariant mass distributions of the basic bottom-gluon to stop-chargino amplitudes have been derived. For a meaningful collection of different benchmark points the overall electroweak one-loop effects are at most of the order of a few percent. At the realistically expected LHC accuracy, the main supersymmetric electroweak features of the process can be therefore essentially derived in this theoretical scheme from the simple Born level expressions., Comment: 27 pages, 10 figures, Hard QED radiation added

We have computed the one-loop electroweak expression of diagonal and non diagonal stop-antistop and sbottom-antisbottom production from initial state gluons at LHC. We have investigated the possibility that the one-loop effects exhibit a dependence on "extra" supersymmetric parameters different from the final squark masses. Our results, given for a choice of twelve SUSY benchmark points in the MSSM with mSUGRA symmetry breaking, show that in some cases a mild dependence might arise, at the percent relative level, of not simple experimental detection., Comment: 44 pages, 23 eps figures

We analyze the quark-gluon induced process $u g\to \tilde d\tchi_i^+$, including the one loop electroweak (EW) effects in the minimal supersymmetric model (MSSM). This process is determined by four helicity amplitudes, three of which are violating helicity conservation, and another one which respects it and is logarithmically enhanced at high energy. Combining this $u g\to \tilde d\tchi_i^+$ analysis with a corresponding one for $u g \to d W^+$, we obtain simple approximate relations between the two processes, testing the MSSM structure at the amplitude and the cross section levels. These relations become exact at asymptotic energies and, provided the SUSY scale is not too heavy, they may be approximately correct at LHC energies also. In addition to these, we study the 1loop EW corrections to the inclusive $\tilde d\tchi_i^+$ production at LHC, presenting as examples, the $p_T$ and angular distributions. Comparing these to the corresponding predictions for $W$+jet production derived earlier, provides an accurate test of the supersymmetric assignments., Comment: 19 pages, 10 figures, version to appear in Phys.Rev.D

We have computed the complete one-loop electroweak effects in the MSSM for single top (and single antitop) production in the $t$-channel at hadron colliders, generalizing a previous analysis performed for the dominant $dt$ final state and fully including QED effects. The results are quite similar for all processes. The overall Standard Model one-loop effect is small, of the few percent size. This is due to a compensation of weak and QED contributions that are of opposite sign. The genuine SUSY contribution is generally quite modest in the mSUGRA scenario. The experimental observables would therefore only practically depend, in this framework, on the CKM $Wtb$ coupling., Comment: 25 pages, several eps figures. Update corresponding to published version

This review presents flavour related issues in the production and decays of heavy states at LHC, both from the experimental side and from the theoretical side. We review top quark physics and discuss flavour aspects of several extensions of the Standard Model, such as supersymmetry, little Higgs model or models with extra dimensions. This includes discovery aspects as well as measurement of several properties of these heavy states. We also present public available computational tools related to this topic., Comment: Report of Working Group 1 of the CERN Workshop ``Flavour in the era of the LHC'', Geneva, Switzerland, November 2005 -- March 2007

We write explicit and self-contained asymptotic expressions for the tensorial B, C and D Passarino-Veltman functions. These include quadratic and linear logarithmic terms, as well as subleading constant terms. Only mass-suppressed O(m^2/s) contributions are neglected. We discuss the usefulness of such expressions, particularly for studying one-loop effects in 2-to-2 body processes at high energy., Comment: 25 pages, 9 eps figures

This paper has been withdrawn by the authors because the analysis has been extended in Ref.(arXiv:0804.1252) to the sbottom-antisbottom case., Comment: This paper has been withdrawn

We present a complete 1-loop study of the electroweak corrections to the process $ug\to dW^+$ in MSSM and SM. The occurrence of a number of remarkable properties in the behavior of the helicity amplitudes at high energies is stressed, and the crucial role of the virtual SUSY contributions in establishing them, is emphasized. The approach to asymptopia of these amplitudes is discussed, comparing the effects of the logarithmic and constant contributions to the mass suppressed ones, which are relevant at lower energies. Applying crossing to $ug\to d W^+$, we obtain all subprocesses needed for the 1-loop electroweak corrections to $W^\pm$-production at LHC. The SUSY model dependence of such a production is then studied, and illustrations are given for the transverse $W^{\pm}$ momentum distribution, as well as the angular distribution in the subprocess center of mass., Comment: 21 pages, 12 figures, version to appear in Phys.Rev.D

We compute, in the MSSM framework, the sum of the one-loop electroweak and of the total QED radiation effects for the process $pp \to t W+X$, initiated by the parton process $bg\to tW$. Combining these terms with the existing NLO calculations of SM and SUSY QCD corrections, we analyze the overall one-loop supersymmetric effects on the partial rates of the process, obtained by integrating the differential cross section up to a final variable invariant mass. We conclude that, for some choices of the SUSY parameters and for relatively small final invariant masses, they could reach the relative ten percent level, possibly relevant for a dedicated experimental effort at LHC., Comment: Title changed. Final version published in Eur. Phys. J. C