Sample records for antimuons

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

    CERN Multimedia


    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. Precise Measurement Of Dimuon Production Cross-sections In Muon Neutrino Iron And Anti-muon Neutrino Iron Deep Inelastic Scattering At The Tevatron

    CERN Document Server

    Goncharov, M


    This dissertation presents the measurement of the semi- inclusive cross-sections for nm and n&d1;m -nucleon deep inelastic scattering interactions with two oppositely charged muons in the final state. These events dominantly arise from production of a charm quark during the scattering process. The measurement is obtained from the analysis of 5102 nm induced and 1458 n&d1;m induced events collected with the NuTeV detector exposed to a sign selected beam at the Fermilab Tevatron. A leading-order QCD analysis is used to predict charm production cross-section parameters such as the charm mass mc, strange and anti- strange sea quark probability distribution functions s(x, q2), semi-leptonic charm decay branching ratio Bc, and charm fragmentation function parameter &epsis;. The result is presented as a nearly model-independent dimuon production cross-section table. I also extract cross-section measurements from a re-analysis of 5030 nm induced and 1060 n&d1;m induced events collect...

  3. Neutrino Physics with Accelerator Driven Subcritical Reactors

    CERN Document Server

    Ciuffoli, Emilio; Zhao, Fengyi


    Accelerator driven system (ADS) subcritical nuclear reactors are under development around the world. They will be intense sources of free, 30-50 MeV antimuon decay at rest antimuon neutrinos. These ADS reactor neutrinos can provide a robust test of the LSND anomaly and a precise measurement of the leptonic CP-violating phase delta, including sign(cos(delta)). The first phase of many ADS programs includes the construction of a low energy, high intensity proton or deuteron accelerator, which can yield competitive bounds on sterile neutrinos.

  4. First Measurement of $\

    Energy Technology Data Exchange (ETDEWEB)

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


    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$\

  5. Atmospheric neutrinos as a probe of CPT violation

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Anindya [INFN, Sezione di Roma, Dipartimento di Fisica, Universita La Sapienza, I-00185 Rome (Italy)]. E-mail:; Gandhi, Raj [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India)]. E-mail:; Mehta, Poonam [Department of Physics and Astrophysics, University of Delhi, Delhi 110 019 (India) and Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India)]. E-mail:; Sankar, S. Uma [Department of Physics, IIT, Powai, Mumbai 400 076 (India)]. E-mail:


    We show that atmospheric neutrinos can provide a sensitive and robust probe of CPT violation (CPTV). We perform realistic event-rate calculations and study the variations of the ratio of total muon to antimuon survival rates with L/E and L (L= baseline length, E = neutrino energy) in a detector capable of identifying the muon charge. We demonstrate that measurements of these ratios when coupled with the significant 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 favorably with those possible from a future neutrino factory.

  6. The Energy Spectrum of Atmospheric Neutrinos between 2 and 200 TeV with the AMANDA-II Detector

    Energy Technology Data Exchange (ETDEWEB)

    IceCube Collaboration; Abbasi, R.


    The muon and anti-muon neutrino energy spectrum is determined from 2000-2003 AMANDA telescope data using regularised unfolding. This is the first measurement of atmospheric neutrinos in the energy range 2-200 TeV. The result is compared to different atmospheric neutrino models and it is compatible with the atmospheric neutrinos from pion and kaon decays. No significant contribution from charm hadron decays or extraterrestrial neutrinos is detected. The capabilities to improve the measurement of the neutrino spectrum with the successor experiment IceCube are discussed.

  7. The Muon g-2 Experiment Overview and Status as of June 2016

    CERN Document Server

    Holzbauer, J L


    The Muon g-2 Experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 parts per billion, which is a factor of four improvement over the previous E821 measurement at Brookhaven. The experiment will also extend the search for the electric dipole moment (EDM) of the muon by approximately two orders of magnitude, with a sensitivity down to $10^{-21}$ Both of these measurements are made by combining a precise measurement of the 1.45T storage ring magnetic field with an analysis of the modulation of the decay rate of higher-energy positrons (from anti-muons), recorded by 24 calorimeters and 3 straw tracking detectors. The recent progress in the alignment of the electrostatic quadrapole plates and the trolley rails inside the vacuum chambers, and in establishing the uniform storage ring magnetic field will be described.

  8. Muon pair creation from positronium in a linearly polarized laser field

    CERN Document Server

    Müller, Carsten; Keitel, Christoph H


    Positronium decay into a muon-antimuon pair by virtue of the interaction with a superintense laser field of linear polarization is considered. The minimum laser intensity required amounts to a few 10^22 W/cm^2 in the near-infrared frequency range. Within the framework of laser-dressed quantum electrodynamics, the total reaction rate is calculated and related to the cross section for field-free electron-positron annihilation into muons. The muons are created with ultrarelativistic energies and emitted under narrow angles along the laser propagation direction. The dynamical properties of the muons are interpreted in terms of a classical simple man's model for the production process. We show that the most promising setup for an experimental investigation of the process employs two counterpropagating laser beams impinging on a positronium target, where the advantage of the coherent electron-positron collisions becomes evident.

  9. Nucleon Decay and Neutrino Properties in a Mass Model based on an SO(10) Grand Unified Theory

    CERN Document Server

    Merten, C


    In this work a mass model based on a SO(10) GUT with a global U(1) familysymmetry is discussed which leads to an asymmetric Nearest NeighbourInteraction structure for the fermionic mass matrices. As a result of theanalysis one gets three solutions of the model which include several largeleft- and right-handed fermion mixings. Those mixings are not observable in theSM where only the CKM quark mixing matrix can be measured, but they havetestable effects on the branching ratios of nucleon decays in theories beyondthe SM. One finds that decay channels with positrons in the final state aresuppressed while channels with antimuons and antineutrinos are enhancedcompared to models with small mixings. The total nucleon lifetimes obtainedshould be observable by future experiments. The SO(10) model also predicts themasses and mixings of the light neutrinos. They are in the right range toexplain the anomalies of solar and atmospheric neutrinos by means ofoscillations, preferring the small angle MSW solution for the solar ...

  10. Backgrounds To Higgs Boson Searches from Asymmetric Internal Conversion

    CERN Document Server

    Gray, Richard C; Park, Michael; Somalwar, Sunil; Thomas, Scott


    A class of potential backgrounds for Higgs boson searches in the W W to di-lepton channel at both the Tevatron and Large Hadron Collider is presented. Backgrounds from W photon production with external conversion of the on-shell photon in detector material to an asymmetric electron-positron pair, with loss of the trailing electron or positron has been treated adequately in Higgs searches. Here we consider analogous backgrounds from the production of a W with an off-shell photon and with the internal conversion of the off-shell photon in vacuum to an asymmetric lepton-anti-lepton pair. While the former process yields almost entirely electrons or positrons, the latter can give electron, positron, muon, and anti-muon backgrounds in roughly equal amounts. We estimate that asymmetric internal conversion backgrounds are comparable to the Higgs boson signal in the standard signal region of phase space. These processes also represent potential backgrounds for new physics searches in same-sign di-lepton channels. Some...

  11. 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 ...

  12. KK-parity non-conservation in UED confronts LHC data

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Avirup [University of Calcutta, Department of Physics, Kolkata (India)


    Kaluza-Klein (KK) parity can be violated in a five-dimensional universal extra-dimensional model with boundary-localised (kinetic or mass) terms (BLTs) at the fixed points of S{sup 1}/Z{sub 2} orbifold. In this framework we study the resonant production of Kaluza-Klein excitations of the neutral electroweak gauge bosons at the LHC and their decay into an electron-positron pair or a muon-antimuon pair. We use the results (for the first time, to our knowledge) given by the LHC experiment to constrain the mass range of the first KK-excitation of the electroweak gauge bosons (B{sup 1} andW{sub 3}{sup 1}). It is interesting to note that the LHC result puts an upper limit on the masses of the n = 1 KK-leptons for positive values of the BLT parameters depending upon the mass of the l{sup +}l{sup -} resonance. (orig.)

  13. 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


    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.


    CERN Document Server

    Yusof, Adib


    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...

  15. Measurement of the underlying event using track-based event shapes in Z→l{sup +}l{sup -} events with ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Holger


    This thesis describes a measurement of hadron-collider event shapes in proton-proton collisions at a centre of momentum energy of 7 TeV at the Large Hadron Collider (LHC) at CERN (Conseil Europeenne pour la Recherche Nucleaire) located near Geneva (Switzerland). The analysed data (integrated luminosity: 1.1 fb{sup -1}) was recorded in 2011 with the ATLAS-experiment. Events where a Z-boson was produced in the hard sub-process which subsequently decays into an electron-positron or muon-antimuon pair were selected for this analysis. The observables are calculated using all reconstructed tracks of charged particles within the acceptance of the inner detector of ATLAS except those of the leptons of the Z-decay. Thus, this is the first measurement of its kind. The observables were corrected for background processes using data-driven methods. For the correction of so-called ''pile-up'' (multiple overlapping proton-proton collisions) a novel technique was developed and successfully applied. The data was further unfolded to correct for remaining detector effects. The obtained distributions are especially sensitive to the so-called ''Underlying Event'' and can be compared with predictions of Monte-Carlo event-generators directly, i.e. without the necessity of running time-consuming simulations of the ATLAS-detector. Finally, it was tried to improve the predictions of the event generators Pythia8 and Sherpa by finding an optimised setting of relevant model parameters in a technique called ''Tuning''. It became apparent, however, that the underlying Sjoestrand-Zijl model is unable to give a good description of the measured event-shape distributions.

  16. Observations of MilkyWay Dwarf Spheroidal galaxies with the Fermi-LAT detector and

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T.H.; Buson, S.; Caliandro, G.A.; /Naval Research Lab, Wash., D.C. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /SLAC /UC, Santa Cruz /INFN, Pisa /DAPNIA, Saclay /INFN, Trieste /Trieste U. /INFN, Padua /Padua U. /INFN, Perugia /Perugia U. /Bari Polytechnic /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /IASF, Milan /George Mason U. /NASA, Goddard


    -annihilating into muon-antimuon pairs.

  17. Study of low-energy neutrino factory at the Fermilab to DUSEL baseline

    Energy Technology Data Exchange (ETDEWEB)

    Kyberd, Paul; Ellis, Malcolm; /Brunel U.; Bross, Alan; Geer, Steve; /Fermilab; Mena, Olga; /Valencia U., IFIC; Long, Ken; /Imperial Coll., London; Pascoli, Silvia; /Durham U., IPPP; Fernandez Martinez, Enrique; /Munich, Max Planck Inst.; McDonald, Kirk; /Princeton U.; Huber, Patrick; /Virginia Tech.


    the straight sections of the ring. Since the decay of the muon is well understood, the systematic uncertainties associated with a neutrino beam produced in this manner are very small. Beam diagnostics in the decay ring and a specially designed near detector further reduce the systematic uncertainties of the neutrino beam produced at the Neutrino Factory. In addition since the muon (anti-muon) decays produce both muon and anti-electron neutrinos (anti-muon and electron neutrinos), many oscillation channels are accessible from a Neutrino Factory, further extending the reach in the oscillation parameter space. Over the last decade there have been a number of studies [2-5] that have explored the discovery reach of Neutrino Factories in the small mixing angle, {theta}{sub 13}, and its capability to determine the mass hierarchy and determine if CP is violated in leptons through observation of phase parameter, {delta}. The most recent study to be completed [6], the International scoping study of a future Neutrino Factory and super-beam facility (the ISS), studied the physics capabilities of various future neutrino facilities: super-beam, {beta}-Beam and Neutrino Factory and has determined that the Neutrino Factory with an energy of {approx}25 GeV has the best discovery reach for small values of sin{sup 2}2{theta}{sub 13}, reaching an ultimate sensitivity of between 10{sup -5} and 10{sup -4}. However, for larger values of sin{sup 2}2{theta}{sub 13} (> 10{sup -3}), the sensitivity of other experimental approaches is competitive to that of the 25 GeV Neutrino Factory. The wide-band neutrino beam (WBB) produced at Fermilab and directed towards DUSEL [7] is one such competitor. For the case where sin{sup 2}2{theta}{sub 13} (> 10{sup -3}) is large, initial studies have shown that a Low-Energy Neutrino Factory [8-10] with an energy of, for example, 4 GeV, may be both cost-effective and offers exquisite sensitivity. The required baseline for a Low-Energy Neutrino Factory matches