R. López-Fernández

We present the first public data release of the CALIFA survey. It consists of science-grade optical datacubes for the first 100 of eventually 600 nearby (0.005<z<0.03) galaxies, obtained with the integral-field spectrograph PMAS/PPak mounted on the 3.5m telescope at the Calar Alto observatory. The galaxies in DR1 already cover a wide range of properties in color-magnitude space, morphological type, stellar mass, and gas ionization conditions. This offers the potential to tackle a variety of open questions in galaxy evolution using spatially resolved spectroscopy. Two different spectral setups are available for each galaxy, (i) a low-resolution V500 setup covering the nominal wavelength range 3745-7500A with a spectral resolution of 6.0A (FWHM), and (ii) a medium-resolution V1200 setup covering the nominal wavelength range 3650-4840A with a spectral resolution of 2.3A (FWHM). We present the characteristics and data structure of the CALIFA datasets that should be taken into account for scientific exploitation of the data, in particular the effects of vignetting, bad pixels and spatially correlated noise. The data quality test for all 100 galaxies showed that we reach a median limiting continuum sensitivity of 1.0x10^-18erg/s/cm^2/A/arcsec^2 at 5635A and 2.2x10^-18erg/s/cm^2/A/arcsec^2 at 4500A for the V500 and V1200 setup respectively, which corresponds to limiting r and g band surface brightnesses of 23.6mag/arcsec^2 and 23.4mag/arcsec^2, or an unresolved emission-line flux detection limit of roughly 1x10^-17erg/s/cm^2/arcsec^2 and 0.6x10^-17erg/s/cm^2/arcsec^2, respectively. The median spatial resolution is 3.7", and the absolute spectrophotometric calibration is better than 15% (1sigma). We also describe the available interfaces and tools that allow easy access to this first public CALIFA data.

This paper describes the Second Public Data Release (DR2) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. The data for 200 objects are made public, including the 100 galaxies of the First Public Data Release (DR1). Data were obtained with the integral-field spectrograph PMAS/PPak mounted on the 3.5 m telescope at the Calar Alto observatory. Two different spectral setups are available for each galaxy, (i) a low-resolution V500 setup covering the wavelength range 3745-7500 \AA\ with a spectral resolution of 6.0 \AA\ (FWHM), and (ii) a medium-resolution V1200 setup covering the wavelength range 3650-4840 \AA\ with a spectral resolution of 2.3 \AA\ (FWHM). The sample covers a redshift range between 0.005 and 0.03, with a wide range of properties in the Color-Magnitude diagram, stellar mass, ionization conditions, and morphological types. All released cubes were reduced with the latest pipeline, including improved spectrophotometric calibration, spatial registration and spatial resolution. The spectrophotometric calibration is better than 6% and the median spatial resolution is 2.5". Altogether the second data release contains over 1.5 million spectra. It is available at http://califa.caha.es/DR2.

In a companion paper we have presented many products derived from the application of the spectral synthesis code STARLIGHT to datacubes from the CALIFA survey, including 2D maps of stellar population properties and 1D averages in the temporal and spatial dimensions. Here we evaluate the uncertainties in these products. Uncertainties due to noise and spectral shape calibration errors and to the synthesis method are investigated by means of a suite of simulations based on 1638 CALIFA spectra for NGC 2916, with perturbations amplitudes gauged in terms of the expected errors. A separate study was conducted to assess uncertainties related to the choice of evolutionary synthesis models. We compare results obtained with the Bruzual & Charlot models, a preliminary update of them, and a combination of spectra derived from the Granada and MILES models. About 100k CALIFA spectra are used in this comparison. Noise and shape-related errors at the level expected for CALIFA propagate to 0.10-0.15 dex uncertainties in stellar masses, mean ages and metallicities. Uncertainties in A_V increase from 0.06 mag in the case of random noise to 0.16 mag for shape errors. Higher order products such as SFHs are more uncertain, but still relatively stable. Due to the large number statistics of datacubes, spatial averaging reduces uncertainties while preserving information on the history and structure of stellar populations. Radial profiles of global properties, as well as SFHs averaged over different regions are much more stable than for individual spaxels. Uncertainties related to the choice of base models are larger than those associated with data and method. Differences in mean age, mass and metallicity are ~ 0.15 to 0.25 dex, and 0.1 mag in A_V. Spectral residuals are ~ 1% on average, but with systematic features of up to 4%. The origin of these features is discussed. (Abridged)

The three-dimensional motion of single colloidal particles close to a plane wall is measured by optical microscopy. In accordance with classical theoretical predictions, we find an asymmetric motion of the particles in the directions parallel and perpendicular to the wall. We also find that, close to the wall, the distribution functions of perpendicular steps are asymmetric, being shorter toward the wall and longer away from it.

Aims. In a companion paper we have presented many products derived from the application of the spectral synthesis code starlight to datacubes from the CALIFA survey, including 2D maps of stellar population properties (such as mean ages, mass, extinction) and 1D averages in the temporal and spatial dimensions. Our goal here is to assess the uncertainties in these products. Methods. Uncertainties associated to noise and spectral shape calibration errors in the data and to the synthesis method are investigated by means of a suite of simulations, perturbing spectra and processing them through our analysis pipelines. The simulations use 1638 CALIFA spectra for NGC 2916, with perturbations amplitudes gauged in terms of the expected errors. A separate study was conducted to assess uncertainties related to the choice of evolutionary synthesis models, the key ingredient in the translation of spectroscopic information to stellar population properties. We compare results obtained with three di erent sets of models: the traditional Bruzual & Charlot models, a preliminary update of them, and a combination of spectra derived from the Granada and MILES models. About 10 5 spectra from over 100 CALIFA galaxies are used in this comparison. Results. Noise and shape-related errors at the level expected for CALIFA propagate to uncertainties of 0.10‐0.15 dex in stellar masses, mean ages and metallicities. Uncertainties in AV increase from 0.06 mag in the case of random noise to 0.16 mag for spectral shape errors. Higher order products such as star formation histories are more uncertain than global properties, but still relatively stable. Due to the large number statistics of datacubes, spatial averaging reduces uncertainties while preserving information on the history and structure of stellar populations. Radial profiles of global properties, as well as star formation histories averaged over di erent regions are much more stable than those obtained for individual spaxels. Uncertainties related to the choice of base models are larger than those associated with data and method. Except for metallicities, which come out very di erent when fits are performed with Bruzual & Charlot models, di erences in mean age, mass and metallicity are of the order of 0.15 to 0.25 dex, and 0.1 mag for AV . Spectral residuals are of order of 1% on average, but with systematic features of up to 4% amplitude. The origin of these features, most of which are present in both in CALIFA and SDSS spectra, is discussed.

En este artículo se identifican tres etapas ocurridas entre 1990 y 2020 en la evolución del sector de telecomunicaciones en México. Estos cambios se concentraron en el marco institucional y su efecto se visibilizó en los proyectos de digitalización respecto a la convergencia de las tecnologías de la información y las comunicaciones. En principio, construimos un marco teórico y lo operamos en un estudio longitudinal que nos permite ilustrar el avance modesto de los programas de digitalización y la transformación digital en México, lo cual tiene eco en los reportes internacionales. Posteriormente, discutimos las contradicciones en la visión de Estado respecto al marco institucional y regulatorio del sector. Esto explica, en gran medida, la falta de avance de los programas de digitalización, lo que sugiere la necesidad de una nueva generación de reformas para impulsar el desarrollo digital desde la esfera del Estado.

Charged particle production in deep-inelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5<Q 2<100 GeV2, and small values of Bjorken-x, 10−4<x<10−2. The analysis is performed in the hadronic centre-of-mass system. The charged particle densities are measured as a function of pseudorapidity (η ∗) and transverse momentum ( $p_{T}^{*}$ ) in the range 0<η ∗<5 and $0<p_{T}^{*} < 10\mbox{~GeV}$ in bins of x and Q 2. The data are compared to predictions from different Monte Carlo generators implementing various options for hadronisation and parton evolutions.

Crab cavities (CCs) are a key ingredient of the high luminosity Large Hadron Collider (HL-LHC) project for increasing the luminosity of the LHC. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of the order of a few LHC turns and considering the significant stored energy in the HL-LHC beam, CC failures represent a serious threat in regard to LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, the one needed to dump the beam. The simulations assume a quasistationary-state distribution to assess the particles losses for the HL-LHC. These distributions produce beam losses below the safe operation threshold for Gaussian tails, while, for non-Gaussian tails are on the same order of the limit. Additionally, some mitigation strategies are studied for reducing the damage caused by the CC failures.

In this work we investigate the possibility that a simple extension of the Standard Model (SM) can be the dark matter of the universe. We postulate the existence of a scalar field singlet like the Higgs as an extra term in the SM Lagrangian. We find that from the astrophysical point of view a very small mass and self-interaction is more convenient to agree with observations and from particle detectors observations we do not see any essential constrain to this settings. Thus, we conclude that a scalar field singlet with a small mass and self-interaction is a good candidate to be the nature of the dark matter.

We characterize in detail the radial structure of the stellar population properties of 300 galaxies in the nearby universe, observed with integral field spectroscopy in the CALIFA survey. The sample covers a wide range of Hubble types, from spheroidal to spiral galaxies, ranging in stellar masses from $M_\star \sim 10^9$ to $7 \times 10^{11}$ $M_\odot$. We derive the stellar mass surface density ($μ_\star$), light-weighted and mass-weighted ages ($\langle {\rm log}\,age\rangle _L$, $\langle {\rm log}\,age\rangle _M$), and mass-weighted metallicity ($\langle {\rm log}\,Z_\star\rangle _M$), applying the spectral synthesis technique. We study the mean trends with galaxy stellar mass, $M_\star$, and morphology (E, S0, Sa, Sb, Sbc, Sc and Sd). We confirm that more massive galaxies are more compact, older, more metal rich, and less reddened by dust. Additionally, we find that these trends are preserved spatially with the radial distance to the nucleus. Deviations from these relations appear correlated with Hubble type: earlier types are more compact, older, and more metal rich for a given M$_\star$, which evidences that quenching is related to morphology, but not driven by mass.

One of the aims of compulsory education is for students to adequately handle basic maths, owing to its importance in their future professional and personal lives. However, mechanical knowledge of an algorithm may not be sufficient to train future citizens with critical and creative thinking if it is not accompanied by a comprehensive understanding of the concept. In this regard, existing research shows that a high percentage of students in primary education commit errors when they attempt subtraction. However, little is known about whether adults perform the same calculations correctly. In this context, 535 university students completed a questionnaire composed of 20 subtractions. The results showed that only one quarter of respondents performed the subtractions correctly. Analysis of error type showed that the most frequent mistakes corresponded to the systematic errors made by primary-level students. This may indicate that the types of errors committed during early learning persist over time, implying that subtraction may not have been adequately taught. New educational approaches and initiatives are required to encourage the teaching and learning of subtraction in a more reasoned and critical manner during early learning.

This report summarizes the work of the "R-parity violation group" of the French Research Network (GDR) in Supersymmetry, concerning the physics of supersymmetric models without conservation of R-parity at HERA, LEP, Tevatron and LHC and limits on R-parity violating couplings from various processes. The report includes a discussion of the recent searches at the HERA experiment, prospects for new experiments, a review of the existing limits, and also theoretically motivated alternatives to R-parity and a brief discussion on the implications of R-parity violation on the neutrino masses.

Crab cavities (CCs) are a key ingredient of the HighLuminosity Large Hadron Collider (HL-LHC) to ensure head on collisions at the main experiments (ATLAS and CMS) and fully profit from the smaller β ∗ provided by the ATS optics [1]. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of few LHC turns and considering the large energy stored in the HL-LHC beam, CC failures represent a serious risk to the LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similarto,orlongerthan,theoneneededtodumpthebeam. The simulationsassumearealisticsteady-statedistributiontoassess the beam losses for the HL-LHC. Additionally, some strategies are studied in order to reduce the damage caused by the CC failures.

In this work we investigate the possibility that a simple extension of the Standard Model (SM) can be the dark matter of the universe. We postulate the existence of a scalar field singlet like the Higgs as an extra term in the SM Lagrangian. We find that from the astrophysical point of view a very small mass and self-interaction is more convenient to agree with observations and from particle detectors observations we do not see any essential constrain to this settings. Thus, we conclude that a scalar field singlet with a small mass and self-interaction is a good candidate to be the nature of the dark matter.

In a companion paper we have presented many products derived from the application of the spectral synthesis code STARLIGHT to datacubes from the CALIFA survey, including 2D maps of stellar population properties and 1D averages in the temporal and spatial dimensions. Here we evaluate the uncertainties in these products. Uncertainties due to noise and spectral shape calibration errors and to the synthesis method are investigated by means of a suite of simulations based on 1638 CALIFA spectra for NGC 2916, with perturbations amplitudes gauged in terms of the expected errors. A separate study was conducted to assess uncertainties related to the choice of evolutionary synthesis models. We compare results obtained with the Bruzual & Charlot models, a preliminary update of them, and a combination of spectra derived from the Granada and MILES models. About 100k CALIFA spectra are used in this comparison. Noise and shape-related errors at the level expected for CALIFA propagate to 0.10-0.15 dex uncertainties in stellar masses, mean ages and metallicities. Uncertainties in A_V increase from 0.06 mag in the case of random noise to 0.16 mag for shape errors. Higher order products such as SFHs are more uncertain, but still relatively stable. Due to the large number statistics of datacubes, spatial averaging reduces uncertainties while preserving information on the history and structure of stellar populations. Radial profiles of global properties, as well as SFHs averaged over different regions are much more stable than for individual spaxels. Uncertainties related to the choice of base models are larger than those associated with data and method. Differences in mean age, mass and metallicity are ~ 0.15 to 0.25 dex, and 0.1 mag in A_V. Spectral residuals are ~ 1% on average, but with systematic features of up to 4%. The origin of these features is discussed. (Abridged)

Crab cavities (CCs) apply a transverse kick that rotates the bunches so as to have a head-on collision at the interaction point (IP). Such cavities were successfully used to improve the luminosity of KEKB. They are also a key ingredient of the HL-LHC project to increase the luminosity of the LHC. As CCs can rapidly change the particle trajectories, machine protection studies are required to assess the beam losses due to fast CC failures. In this paper, we discuss the effect of rapid voltage or phase changes in a CC for the HL-LHC layout using measured beam distributions from the present LHC.

Do not replace the word “abstract,” but do replace the rest of this text. Text should remain 10‐pt. If you must insert a hard line break, please use Shift+Enter rather than just tapping your “Enter” key. You may want to print this page and refer to it as a style sample before you begin working on your paper. For an experimentalist in high energy physics, the most interesting experiments that one should pursue is often well known. The very rare CP violating decay of the kaon into a pion and two neutrinos (both the charged and neutral modes) is such an experiment. We have recently proposed the charged kaon experiment to Fermilab as proposal P966. We present her a general overview of that proposal. The goal is to obtain of order 1000 events in order to confront the expected theoretical calculations and to search for physics beyond the standard model.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation A. Queijeiro; Radiative Corrections to Asymmetry Parameter in the Ω−→Λ+K− Decay. AIP Conf. Proc. 29 July 2010; 1259 (1): 146–154. https://doi.org/10.1063/1.3479295 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

On November 2009 the Large Hadron Collider produced the first p+p collisions. These, together with the upcoming Pb+Pb data, open up the possibility to answer some of the intriguing questions regarding the Standard Model and likely bring to light new phenomena. In this work I present a short review of the mexican participation in the ALICE experiment, focusing on the detector building and phenemological as well as Monte Carlo simulation work regarding the proton as well as the heavy ion program. I also briefly mention some of the wide spectrum of possible first topics that can be analyzed.

The Chicagoland Observatory for Underground Particle Physics (COUPP) recently reported first Physics results from an engineering prototype dark matter detector consisting of a 1 liter, room temperature, heavy liquid bubble chamber. These results close the last open window in low mass spin dependent WIMP scattering for a conventional WIMP interpretation of the DAMA annual modulation signal. I will discuss these results and the detector techniques which enabled them.

Abstract

A recently proposed model of non‐linear electrodynamics arising from a gauge invariant spontaneous Lorentz symmetry breaking is reviewed. The potential providing the symmetry breaking is argued to arise from the integration of gauge bosons and fermions in an underlying theory. The invariant subgroups remaining after the symmetry breaking are determined, as well as the dispersion relations and polarization modes of the propagating linear sector or the model. Strong bounds upon the predicted anisotropy of the speed of light are obtained by embedding the model in the electromagnetic sector of the Standard Model Extension and taking advantage of the restrictions in the parameters derived there. Finally, a reasonable estimation of the intergalactic magnetic field is obtained by assuming that the vacuum energy of the model is described by the standard cosmological constant.

Abstract

We present an overview of the calculation of radiative corrections to the Dalitz plot of baryon semileptonic decays with angular correlation between polarized emitted baryons and charged leptons. We discuss both charged and neutral decaying baryons, restricted to the three‐body region of the Dalitz plot. Our analysis is specialized to cover two possible scenarios: The center‐of‐mass frames of the emitted and the decaying baryons. We have accounted for terms up to order (α/π)(q/M1)0, where q is the momentum‐transfer and M1 is the mass of the decaying baryon, and neglected terms of order (α/π)(q/M1)n for n≥1. The expressions displayed are ready to obtain numerical results, suitable for model‐independent experimental analyses.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Alejandro Ayala; Intermediate pT phenomena in relativistic heavy‐ion collisions. AIP Conf. Proc. 29 July 2010; 1259 (1): 85–102. https://doi.org/10.1063/1.3479309 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation R. Martinez, F. Ochoa; Neutral currents production in LHC for 331 models. AIP Conf. Proc. 29 July 2010; 1259 (1): 136–145. https://doi.org/10.1063/1.3479294 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Within the framework of the standard model (SM) of elementary particles and the two Higgs doublet extension to this model (2DHM), we obtained analytical and numerical solutions for the gauge couplings, the vacuum expectation values (VEV) of the Higgs fields, the quark Yukawa couplings and quark masses, the quartic Higgs couplings, and the running Higgs masses, considering the renormalization group equations. The bounds on the SM Higgs running mass have been fixed, and the region of validity of the SM was determined through it, at the one and two loop approximations, using the triviality and stability conditions for the Higgs quartic coupling λH.

The standard Higgs mechanism employed in the Standard Model (SM) for electroweak symmetry breaking, relies on a homogenous Higgs vacuum expectation value (v.e.v.), i.e. a vacuum that does not depend on the position or the time coordinates. However, other non‐homogeneous structures could also be considered, either at long or short distances. For instance, spatial variations of the Higgs v.e.v. on cosmological scales, would induce variations of the fundamental constants, and are severely constrained. Other possibilities, such as a discrete microscopic structure of the Higgs vacuum, or a confined Higgs mechanism associated with a strongly interacting Higgs sector, could be tested and give some light on the electroweak‐scale contributions to the cosmological constant.

We describe a simple experimental setup to measure the rate of arrival of muons at the surface of the Earth by using a single water Cerenkov detector and home‐made electronics. We find a strong anti‐correlation between the muon rates averaged over one‐hour periods and the atmospheric pressure, with a measured correlation coefficient of −0.67% per hPa. After applying this correction we achieve sufficient sensitivity to observe long term (hours) variations in the averaged muon rates which are greater than 2%. Forbush decreases as big as 4% have been observed with muon detectors located at similar magnetic rigidities compared to Morelia, therefore our experimental setup will detect Forbush decreases as soon as the Sun enters into a more active phase.

On April of 1992 a Mexican group from Cinvestav officially joined the D0 experiment, one of the two experiments in the Tevatron collider at Fermilab. The seed for this experimental group on high energy physics from Cinvestav was planted in Mexico in some measure by Augusto Garcia, to whom this workshop is in memorial. Augusto’s efforts and support to groups dedicated to this area was clear and important. Some of these seeds have given origin to today’s established Mexican groups on experimental high energy physics, one example of this is the Mexican group at D0. I present here a short review of some of the D0 results on which the Mexican group has contributed, emphasizing the last decade, which I have witnessed.

In this work we prove that the transition amplitudes of processes involving the emission of one or more real photons is gauge invariant through terms that are always proportional to the electromagnetic field tensor.

Time in standard quantum mechanics extends from −∞<t<+∞ this is the result of a mathematical theorem (Stone‐von Neumann) for the solutions of the Schrödinger equation for states or of the Heisenberg equation for observables. In reality t does not extend to t→−∞, since according to causality, a quantum state φ+ must be prepared first at a particular time t = t0, before the probability |(ψ−(t),ψ+(t0))|2 for an observable ψ− can be measured in it at t>t0 (Feynman (1948)). In experiments on single Ba+ ions, Dehmelt and others observed this finite preparation time as the ensemble of onset‐times t01, t02,…,t0n of dark periods. How the semigroup time evolution, t0≡0<t<∞ with a beginning of time t0, can suggest the parametrization of the resonance pole position of the Z‐boson at s = sR as sR = (MR−iΓR/2)2 in terms of a mass MR and a width ΓR given by a lifetime τ = ħ/ΓR, is the subject of this contribution dedicated to Augusto García.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Joseph Lach; Accelerators Beyond The Tevatron?. AIP Conference Proceedings 29 July 2010; 1259 (1): 74–82. https://doi.org/10.1063/1.3479308 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

The broad physics potential of e+e− linear colliders was recognized by the high energy physics community right after the end of LEP in 2000. In 2007, the Large Hadron Collider (LHC) now under construction at CERN will obtain its first collisions. The LHC, colliding protons with protons at 14 TeV, will discover a standard model Higgs boson over the full potential mass range, and should be sensitive to new physics into the several TeV range. The program for the Linear Collider (LC) will be set in the context of the discoveries made at the LHC. All the proposals for a Linear Collider will extend the discoveries and provide a wealth of measurements that are essential for giving deeper understanding of their meaning, and pointing the way to further evolution of particle physics in the future. For the mexican groups is the right time to join such an effort.

Measurements of proton structure in deep inelastic scattering in ep interactions are presented. The data were recorded with the H1 and ZEUS detectors at the HERA ep collider in both phases, HERAI (1994–2000) and HERAII (2003–2005). The data were used to extract quark and gluon parton distribution functions (PDFs) and to determine the strong coupling αs.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Ricardo Lopez‐Fernandez; Recent results from the H1 experiment of HERA. AIP Conf. Proc. 25 September 2006; 857 (1): 210–217. https://doi.org/10.1063/1.2359258 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

La symetrie discrete connue sous le nom de r-parite joue un role determinant dans la phenomenologie des extensions supersymetriques du modele standard. Dans le cas ou cette symetrie est brisee, la production simple de particules supersymetriques peut avoir lieu. Au lep la production simple de neutralinos et de charginos via l'echange d'un sneutrino est possible. Ce memoire decrit la recherche inclusive de la production simple de jaugino effectuee avec les donnees prises par le detecteur delphi aux energies du centre de masse de 192, 196, 200 et 202 gev. Les etats finaux etaient classes en trois cas generaux : deux leptons acoplanaires, quatre ou six leptons et multi-leptons multi-jets. Une selection sequentielle a ete appliquee pour chaque etat final et pour les deux couplages possibles ( 1 2 1 et 1 3 1). Aucune evidence de signal n'a ete trouvee, on a donc extrait des limites superieures pour la valeur des constantes de couplages qui brisent la r-parite ( 1 2 1 et 1 3 1). Ces limites sont donnees en fonction de la masse et de la largeur du sneutrino ou en fonction de la masse du sneutrino uniquement. La valeur la plus basse obtenue comme limite pour les couplages se trouve quand la masse du sneutrino est egale a l'energie du centre de masse et cette valeur est environ 0. 015.