WorldWideScience

Sample records for antimuons

  1. L3: Decay of Z0 to muon-antimuon pair

    CERN Multimedia

    1991-01-01

    This track is an example of real data collected from the L3 detector on the Large Electron-Positron (LEP) collider at CERN, which ran between 1989 and 2000. A Z0 is produced in the electron-positron pair collision and quickly decays into a muon-antimuon pair. The muons pass through the entire detector without being absorbed.

  2. The design of the optimized muon beamline

    CERN Document Server

    Choi, Suyong; Roh, Youn Jung

    2014-01-01

    We designed an optimized antimuon beamline with the simulation using G4beamline and TRANSPORT software packages for Heavy Ion Accelerator Project in South Korea. This research suggests the optimized muon beamline can transport $2.4\\times10^{8}$ antimuons per second to a circle with a radius of 3 cm. In terms of muon rate, this is competitive with world leading muon beam facilities.

  3. First Measurement of $\

    Energy Technology Data Exchange (ETDEWEB)

    Palomino Gallo, Jose Luis [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro (Brazil)

    2012-12-01

    Understanding of the $\\pi^0$ production via anti-neutrino-nucleus charged current interaction in the neutrino energy region of 1-10 GeV is essential for neutrino oscillation experiments. In this thesis, we present a measurement of charged current $\\pi^0$ production from anti-muon neutrinos scattering on a polystyrene scintillator (CH) target in the MINER$\

  4. Extended MSSM Neutralinos as the Source of the PAMELA Positron Excess

    OpenAIRE

    Hooper, Dan; Tait, Tim M. P.

    2009-01-01

    We consider a scenario within the Minimal Supersymmetric Standard Model extended by a singlet chiral superfield, in which neutralino dark matter annihilates to light singlet-like Higgs bosons, which proceed to decay to either electron-positron or muon-antimuon pairs. Unlike neutralino annihilations in the MSSM, this model can provide a good fit to the PAMELA cosmic ray positron fraction excess. Furthermore, the singlet-like scalar Higgs can induce a large Sommerfeld enhancement and provide an...

  5. Comparison of backgrounds in detectors for LHC, NLC and μ+μ- colliders

    International Nuclear Information System (INIS)

    Background levels in detectors at future high-luminosity colliders of three different types - proton-proton, electron-positron, and muon- antimuon - are analyzed. Two sources - debris from the collision points and those from an accelerator tunnel - are studied. It is shown that hadron, electron and muon colliders are similar and very different at the same time with respect to background origin, integrated radiation levels and instantaneous rates of particles in the detectors. 23 refs., 11 figs., 4 tabs

  6. The Production and Discovery of True Muonium in Fixed-Target Experiments

    OpenAIRE

    Banburski, Andrzej; Schuster, Philip

    2012-01-01

    Upcoming fixed-target experiments designed to search for new sub-GeV forces will also have sensitivity to the never before observed True Muonium atom, a bound state of a muon and anti-muon. We describe the production and decay characteristics of True Muonium relevant to these experiments. Importantly, we find that secondary production mechanisms dominate over primary production for the long-lived 2S and 2P states, leading to total yields an order of magnitude larger than naive estimates previ...

  7. Measurement of the Z boson differential cross-section in transverse momentum in the electron-positron channel with the ATLAS detector at LHC.

    OpenAIRE

    Martinez, Homero

    2013-01-01

    This work presents the measurement of the Z boson differential cross section in transverse momentum (ptz), in the electron-positron decay channel, using the ATLAS detector at the LHC. The measurement is done using 4.64 inverse fb of proton-proton collision data, collected in 2011 at a center-of-mass energy of 7 TeV. The result is combined with an independent measurement done in the muon-antimuon decay channel. The measurement is done up to ptz = 800 GeV, and has a typical uncertainty of 0.5 %...

  8. An asymmetry of anti-matter has been observed; Une asymetrie de l'antimatiere a ete observee

    Energy Technology Data Exchange (ETDEWEB)

    Ter Minassian, V.

    2010-08-15

    The purpose of the DZero experiment was to compare the quantity of muon pairs and anti-muon pairs produced either in the decay of B mesons or in the decay of anti B mesons produced in the Tevatron. After 8 years of studies and experimental data acquisition, a difference of 1% has appeared between the decay results of B mesons and of anti-B mesons. This difference is 50 times as high as expected according to the standard model. This stunning result needs confirmation. (A.C.)

  9. The Production and Discovery of True Muonium in Fixed-Target Experiments

    CERN Document Server

    Banburski, Andrzej

    2012-01-01

    Upcoming fixed-target experiments designed to search for new sub-GeV forces will also have sensitivity to the never before observed True Muonium atom, a bound state of a muon and anti-muon. We describe the production and decay characteristics of True Muonium relevant to these experiments. Importantly, we find that secondary production mechanisms dominate over primary production for the long-lived 2S and 2P states, leading to total yields an order of magnitude larger than naive estimates previously suggested. We present yield estimates for True Muonium as a function of energy fraction and decay length, useful for guiding future experimental studies. Discovery and measurement prospects appear very favorable.

  10. The Leptonic CP Phase from Muon Decay at Rest with Two Detectors

    CERN Document Server

    Ciuffoli, Emilio; Zhang, Xinmin

    2014-01-01

    The DAE$\\delta$ALUS project aims to determine the leptonic CP-violating phase $\\delta$ using the decay at rest (DAR) of antimuons from three cyclotron complexes at various distances from a detector. In all manifestations of this proposal the determination of $\\delta$ is limited by statistics, a limitation augmented by the fact that only a single complex can run at a time. We present an alternative proposal: muon DAR from a single source which runs 100% of the time with two 20 kton liquid scintillator detectors placed at 10 km and 30 km from the source. With a maximum instantaneous current of only 9 mA, $\\delta$ can be determined with a precision of about 40 (30) degrees in 6 (12) years. We note that, while this experiment runs, the pair of detectors may simultaneously be used to determine the neutrino mass hierarchy using reactor neutrinos.

  11. Cross section for muon colliders in the MSSM with complex parameters

    International Nuclear Information System (INIS)

    The idea of a muon collider has already been brought up in the 1960s and 70s by Tinlot, Skrinsky, Neufer etc. However, major technical challenges have to be met in order to collect, accelerate, and collide muons and antimuons, which decay with a lifetime of 2.2μs. At present, the Muon Collider Collaboration carries out the R and D for a muon collider in the US. In Europe, a muon collider is discussed within the ECFA Prospective Study on Muon Colliders. Specific studies are done for O(100) GeV, 0.3 - 0.5 TeV, and multi-TeV machines with luminosities of 1031 to 5 x 1034cm--2s-1. In this paper, we consider the muon collider μ+μ- → q-tildeiq-bar-tildej at the tree level with complex parameters and polarization of μ+, μ- beams. Numerical results are also performed and discussed. (author)

  12. Measurement of the Z boson differential cross-section in transverse momentum in the electron-positron channel with the ATLAS detector at LHC

    CERN Document Server

    Martinez, Homero

    This work presents the measurement of the Z boson differential cross section in transverse momentum (ptz), in the electron-positron decay channel, using the ATLAS detector at the LHC. The measurement is done using 4.64 fb−1 of proton-proton collision data, collected in 2011 at a center-of-mass energy of 7 TeV. The result is combined with an independent measurement done in the muon-antimuon decay channel. The measurement is done up to ptz = 800 GeV, and has a typical uncertainty of 0.5 % for ptz < 60 GeV, rising up to 5 % towards the end of the spectrum. The measurement is compared to theoretical models and Monte Carlo generators predictions.

  13. Atmospheric Neutrinos as a Probe of CPT and Lorentz Violation

    CERN Document Server

    Datta, A; Mehta, P; Sankar, S U; Datta, Anindya; Gandhi, Raj; Mehta, Poonam

    2003-01-01

    We show that atmospheric neutrinos, in conjunction with a (currently planned) large mass magnetized iron calorimeter can provide a sensitive and robust probe of CPT violation (CPTV) and Lorentz violation (LV). We perform realistic eventrate calculations and study the variations of the ratio of total muon to antimuon survival rates with $L/E$, $L$ and $LE$ ($L$ $\\equiv$ baseline length, $E$ $\\equiv$ neutrino energy). We demonstrate that the charge discrimination capability of such a detector when coupled with the broad $L$ and $E$ range which characterizes the atmospheric neutrino spectrum provides a method of both detecting the presence of such violations and putting bounds on them which compare very favourably with those possible from a future neutrino factory.

  14. Measuring charge-odd correlations at lepton-proton and photon-proton collisions

    International Nuclear Information System (INIS)

    The charge-odd correlations (COC) in cross sections of processes of charged particle production are considered. The cases of muonic pair and pion systems π+π-, π+π-π0 are considered in detail for electron-proton or photon-proton collisions in the proton fragmentation region kinematics. COC arise from interference of amplitudes which describe different mechanisms of charged lepton (pion) creation. One of them corresponds to production of particles in the charge-odd state (one virtual photon or vector meson annihilation to this system of particles) and the other corresponds to the charge-even state of produced particles (creation by two photons). COC for muon-antimuon pair creation have a pure QED nature and can be considered as a normalization process. The processes with pion production are sensitive to some characteristics of proton wave functions and, besides, can be used for checking anomalous and normal parts of the effective pionic Lagrangian. The matrix element of three electromagnetic currents can be measured in photon-proton interactions with lepton pair production. For this aim a charge-odd combination of cross sections can be constructed as a conversion of leptonic 3-rank tensor with hadronic ones. These experiments can be considered as an alternative to deep virtual compton scattering

  15. EVENT GENERATION OF STANDARD MODEL HIGGS DECAY TO DIMUON PAIRS USING PYTHIA SOFTWARE

    CERN Document Server

    Yusof, Adib

    2015-01-01

    My project for CERN Summer Student Programme 2015 is on Event Generation of Standard Model Higgs Decay to Dimuon Pairs using Pythia Software. Briefly, Pythia or specifically, Pythia 8.1 is a program for the generation of high-energy Physics events that is able to describe the collisions at any given energies between elementary particles such as Electron, Positron, Proton as well as anti-Proton. It contains theory and models for a number of Physics aspects, including hard and soft interactions, parton distributions, initial-state and final-state parton showers, multiparton interactions, fragmentation and decay. All programming code is to be written in C++ language for this version (the previous version uses FORTRAN) and can be linked to ROOT software for displaying output in form of histogram. For my project, I need to generate events for standard model Higgs Boson into Muon and anti-Muon pairs (H→μ+ μ) to study the expected significance value for this particular process at centre-of-mass energy of 13 TeV...

  16. Search for high-mass resonances decaying to dilepton final states in pp collisions at a center-of-mass energy of 7 TeV with the ATLAS detector

    CERN Document Server

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Å kesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Å sman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste

    2012-01-01

    The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying to an electron-positron pair or a muon-antimuon pair. The search is sensitive to heavy neutral Z' gauge bosons, Randall-Sundrum gravitons, Z* bosons, techni-mesons, Kaluza-Klein Z/gamma bosons, and bosons predicted by Torsion models. Results are presented based on an analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.9/fb in the dielectron channel and 5.0/fb in the dimuon channel. A Z' boson with Standard Model-like couplings is excluded at 95 percent confidence level for masses below 2.22 TeV. A Randall-Sundrum graviton with coupling k/Mbar = 0.1 is excluded at 95 percent confidence level for masses below 2.16 TeV. Limits on the other models are also presented, including Technicolor and Minimal Z' Models.

  17. Measuring C-odd correlations at lepton-proton and photon-proton collisions

    CERN Document Server

    Ahmadov, A I; Kuraev, E A; Zemljanaja, E; Shishkina, T V; Bystritskiy, Yu.M.

    2007-01-01

    We consider the charge-odd correlations (COC) in cross sections of processes of production of charged particles. The cases of a muonic pair and pion systems $\\pi^{+}\\pi^{-},\\pi^{+}\\pi^{-}\\pi^{0}$ are considered in detail for electron-proton or photon-proton collisions in the proton fragmentation region kinematics. COC arise from interference of amplitudes which describe the different mechanisms of charged leptons (pions) creation. One of them corresponds to production of particles in the charge-odd state (one virtual photon or vector meson annihilation to this system of particles) and the other corresponds to the charge-even state of produced particles (creation by two photons). COC for muon-antimuon pair creation have a pure QED nature and can be considered as a normalization process. The processes with pion production are sensitive to some characteristics of proton wave functions and, besides, can be used for checking the anomalous and normal parts of the effective pionic lagrangian. Three electromagnetic c...

  18. Search for Physics beyond the Standard Model with the ATLAS detector and the development of radiation detectors

    CERN Document Server

    Silver, Yiftah

    We are investigating a radiation detector based on plasma display panel technology, the principal component of plasma television displays. This Plasma Panel Sensor (PPS) technology is a variant of micro-pattern gas radiation detectors. Based on the properties of existing plasma display panels, we expect eventually to be able to build a sealed array of plasma discharge gas cells to detect ionizing radiation with fast rise time of less than 10ns and high spatial resolution using a pixel pitch of less than 100 micrometer. In this thesis I shall describe our program of testing plasma display panels as detectors, including simulations, design and the first laboratory and beam studies that demonstrate the detection of cosmic ray muons, beta rays and medium energy protons. The ATLAS detector is used to search for high-mass resonances, in particular heavy neutral gauge bosons (Z') and excited states of Kaluza-Klein γ/Z bosons decaying to an electron-positron pair or a muon-antimuon pair. Results are presented based ...

  19. A possible underground accelerator in the Dresden Felsenkeller

    Energy Technology Data Exchange (ETDEWEB)

    Bemmerer, Daniel [Forschungszentrum Dresden-Rossendorf (FZD), Dresden (Germany); Cowan, Thomas [Forschungszentrum Dresden-Rossendorf (FZD), Dresden (Germany); TU Dresden (Germany); Szuecs, Tamas [Forschungszentrum Dresden-Rossendorf (FZD), Dresden (Germany); Atomki, Debrecen (Hungary); Zuber, Kai [TU Dresden (Germany)

    2011-07-01

    Due to the suppression by the Coulomb barrier, the cross section of astrophysically relevant nuclear reactions is very low at the stellar energy. Therefore it can only be directly measured in a low-background environment. For more than a decade, the LUNA collaboration has pursued this approach with a 0.4 MV accelerator in the Gran Sasso underground laboratory in Italy. It was highly successful in studying nuclear reactions in the Sun and in the Big Bang. However, the energy range of LUNA is not sufficient to address the nuclear reactions of stellar helium burning and the neutron source reactions for the astrophysical s-process. Therefore, in the NuPECC 2010 draft long range plan it is recommended to install one or more higher energy accelerators underground. A dedicated comparison of the background at LUNA (1400 m rock cover) and the Dresden Felsenkeller (45 m) has shown that with an anti-muon veto the background counting rates in a {gamma}-detector differ only by a factor of three. The feasibility of installing a 2-3 MV accelerator for intensive {alpha}-beams in Felsenkeller is discussed.