484 results found
Muon beams of low emittance provide the basis for the intense,well-characterised neutrino beams of a neutrino factory and for multi-TeVlepton-antilepton collisions at a muon collider. The international MuonIonization Cooling Experiment (MICE) has demonstrated the principle ofionization cooling, the technique by which it is proposed to reduce thephase-space volume occupied by the muon beam at such facilities. This paperdocuments the performance of the detectors used in MICE to measure themuon-beam parameters, and the physical properties of the liquid hydrogen energyabsorber during running.
El-Neaj YA, Alpigiani C, Amairi-Pyka S, et al., 2020, AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space, EPJ QUANTUM TECHNOLOGY, Vol: 7, ISSN: 2662-4400
The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus (μ–e conversion, μ−N→e−N); a lepton flavor-violating process. The experimental sensitivity goal for this process in the Phase-I experiment is 3.1×10−15, or 90% upper limit of a branching ratio of 7×10−15, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the μ–e conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described.
MICE collaboration, Long KR, 2020, Demonstration of cooling by the Muon Ionization Cooling Experiment, Nature, Vol: 578, Pages: 53-59, ISSN: 0028-0836
The use of accelerated beams of electrons, protons or ions has furthered the development of nearly every scientific discipline. However, high-energy muon beams of equivalent quality have not yet been delivered. Muon beams can be created through the decay of pions produced by the interaction of a proton beam with a target. Such 'tertiary' beams have much lower brightness than those created by accelerating electrons, protons or ions. High-brightness muon beams comparable to those produced by state-of-the-art electron, proton and ion accelerators could facilitate the study of lepton-antilepton collisions at extremely high energies and provide well characterized neutrino beams1-6. Such muon beams could be realized using ionization cooling, which has been proposed to increase muon-beam brightness7,8. Here we report the realization of ionization cooling, which was confirmed by the observation of an increased number of low-amplitude muons after passage of the muon beam through an absorber, as well as an increase in the corresponding phase-space density. The simulated performance of the ionization cooling system is consistent with the measured data, validating designs of the ionization cooling channel in which the cooling process is repeated to produce a substantial cooling effect9-11. The results presented here are an important step towards achieving the muon-beam quality required to search for phenomena at energy scales beyond the reach of the Large Hadron Collider at a facility of equivalent or reduced footprint6.
Collaboration TMICE, Adams D, Adey D, et al., 2019, First particle-by-particle measurement of emittance in the Muon Ionization Cooling Experiment, The European Physical Journal C - Particles and Fields, Vol: 79, Pages: 1-15, ISSN: 1124-1861
The Muon Ionization Cooling Experiment (MICE) collaboration seeks to demonstrate the feasibility of ionization cooling, the technique by which it is proposed to cool the muon beam at a future neutrino factory or muon collider. The emittance is measured from an ensemble of muons assembled from those that pass through the experiment. A pure muon ensemble is selected using a particle-identification system that can reject efficiently both pions and electrons. The position and momentum of each muon are measured using a high-precision scintillating-fibre tracker in a 4 T solenoidal magnetic field. This paper presents the techniques used to reconstruct the phase-space distributions in the upstream tracking detector and reports the first particle-by-particle measurement of the emittance of the MICE Muon Beam as a function of muon-beam momentum.
We report a measurement of the lifetime of the Ω0c baryon using proton-proton collision data at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb experiment. The sample consists of about 1000 Ω−b→Ω0cμ−¯νμX signal decays, where the Ω0c baryon is detected in the pK−K−π+ final state and X represents possible additional undetected particles in the decay. The Ω0c lifetime is measured to be τΩ0c=268±24±10±2 fs, where the uncertainties are statistical, systematic, and from the uncertainty in the D+ lifetime, respectively. This value is nearly four times larger than, and inconsistent with, the current world-average value.
We report on a measurement of the flavor-specific B0s lifetime and of the D−s lifetime using proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to 3.0 fb−1 of integrated luminosity. Approximately 407 000 B0s→D(*)−sμ+νμ decays are partially reconstructed in the K+K−π−μ+ final state. The B0s and D−s natural widths are determined using, as a reference, kinematically similar B0→D(*)−μ+νμ decays reconstructed in the same final state. The resulting differences between widths of B0s and B0 mesons and of D−s and D− mesons are ΔΓ(B)=−0.0115±0.0053(stat)±0.0041(syst) ps−1 and ΔΓ(D)=1.0131±0.0117(stat)±0.0065(syst) ps−1, respectively. Combined with the known B0and D− lifetimes, these yield the flavor-specific B0s lifetime, τfsB0s=1.547±0.013(stat)±0.010(syst)±0.004(τB) ps and the D−s lifetime, τD−s=0.5064±0.0030(stat)±0.0017(syst)±0.0017(τD) ps. The last uncertainties originate from the limited knowledge of the B0 and D− lifetimes. The results improve upon current determinations.
Bogomilov M, Long KR, The MICE collaboration, 2017, Lattice design and expected performance of the Muon Ionization Cooling Experiment demonstration of ionization cooling, Physical Review Accelerators and Beams, Vol: 20, ISSN: 2469-9888
Muon beams of low emittance provide the basis for the intense, well-characterized neutrino beams necessary to elucidate the physics of flavor at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using rf cavities. The combined effect of energy loss and reacceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance.
The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240 MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than ~1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is fπ < 1.4% at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.
Dornan P, 2016, Mu to electron conversion with the COMET experiment, International Workshop on Flavour Changing and Conserving Processes (FCCP), Publisher: E D P SCIENCES, ISSN: 2100-014X
Adams D, Alekou A, Apollonio M, et al., 2015, Electron-muon ranger: performance in the MICE muon beam, Journal of Instrumentation, Vol: 10, ISSN: 1748-0221
Adey D, Agarwalla SK, Ankenbrandt CM, et al., 2014, Light sterile neutrino sensitivity at the nuSTORM facility, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 89, ISSN: 1550-7998
A facility that can deliver beams of electron and muon neutrinos from the decay of a stored muon beam has the potential to unambiguously resolve the issue of the evidence for light sterile neutrinos that arises in short-baseline neutrino oscillation experiments and from estimates of the effective number of neutrino flavors from fits to cosmological data. In this paper, we show that the nuSTORM facility, with stored muons of 3.8 GeV/c ± 10%, will be able to carry out a conclusive muon neutrino appearance search for sterile neutrinos and test the LSND and MiniBooNE experimental signals with 10σ sensitivity, even assuming conservative estimates for the systematic uncertainties. This experiment would add greatly to our knowledge of the contribution of light sterile neutrinos to the number of effective neutrino flavors from the abundance of primordial helium production and from constraints on neutrino energy density from the cosmic microwave background. The appearance search is complemented by a simultaneous muon neutrino disappearance analysis that will facilitate tests of various sterile neutrino models.
Aaij R, Adeva B, Adinolfi M, et al., 2013, Measurement of D-0-(D)over-bar(0) Mixing Parameters and Search for CP Violation Using D-0 -> K+ pi(-) Decays, PHYSICAL REVIEW LETTERS, Vol: 111, ISSN: 0031-9007
Schael S, Barate R, Bruneliere R, et al., 2013, Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP, PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, Vol: 532, Pages: 119-244, ISSN: 0370-1573
Adams D, Collaboration M, Adey D, et al., 2013, Characterisation of the muon beams for the Muon Ionisation Cooling Experiment, EUROPEAN PHYSICAL JOURNAL C, Vol: 73, ISSN: 1434-6044
Bravar U, Bogomilov M, Karadzhov Y, et al., 2013, MICE: the muon ionization cooling experiment. step I: first measurement of emittance with particle physics detectors, Proceedings, Meeting of the Division of the American Physical Society, DPF 2011, Publisher: arXiv, Pages: 1-9
The Muon Ionization Cooling Experiment (MICE) is a strategic R&D project intended to demonstrate the only practical solution to providing high brilliance beams necessary for a neutrino factory or muon collider. MICE is under development at the Rutherford Appleton Laboratory (RAL) in the United Kingdom. It comprises a dedicated beamline to generate a range of input muon emittances and momenta, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance of the incoming beam will be measured in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in Liquid Hydrogen (LH2) absorbers to RF cavity acceleration. A second spectrometer, identical to the first, and a second muon identification system will measure the outgoing emittance. In the 2010 run at RAL the muon beamline and most detectors were fully commissioned and a first measurement of the emittance of the muon beam with particle physics (time-of-flight) detectors was performed. The analysis of these data was recently completed and is discussed in this paper. Future steps for MICE, where beam emittance and emittance reduction (cooling) are to be measured with greater accuracy, are also presented.
Aaij R, Abellan Beteta C, Adametz A, et al., 2013, First Evidence for the Decay B-s(0) -> mu(+) mu(-), PHYSICAL REVIEW LETTERS, Vol: 110, ISSN: 0031-9007
Aaij R, Abellan Beteta C, Adametz A, et al., 2012, Strong constraints on the rare decays B(s)(0) → μ+ μ- and B0 → μ+ μ-., Phys Rev Lett, Vol: 108
A search for B(s)(0) → μ+ μ- and B0 → μ+ μ decays is performed using 1.0 fb(-1) of pp collision data collected at sqrt[s] = 7 TeV with the LHCb experiment at the Large Hadron Collider. For both decays, the number of observed events is consistent with expectation from background and standard model signal predictions. Upper limits on the branching fractions are determined to be B(B(s)(0) → μ+ μ-) < 4.5(3.8)×10(-9) and B(B0 → μ+ μ-) < 1.0(0.81)×10(-9) at 95% (90%) confidence level.
Aaij R, Abellan Beteta C, Adametz A, et al., 2012, Strong Constraints on the Rare Decays B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-), PHYSICAL REVIEW LETTERS, Vol: 108, ISSN: 0031-9007
Aaij R, Abellan Beteta C, Adeva B, et al., 2012, Search for the rare decays B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-), PHYSICS LETTERS B, Vol: 708, Pages: 55-67, ISSN: 0370-2693
Bogomilov M, others, 2012, The MICE Muon Beam on ISIS and the beam-line instrumentation of the Muon Ionization Cooling Experiment, JINST, Vol: 7, Pages: P05009-P05009
Ellis M, Hobson PR, Kyberd P, et al., 2011, The design, construction and performance of the MICE scintillating fibre trackers, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Vol: 659, Pages: 136-153, ISSN: 0168-9002
Aaij R, Adeva B, Adinolfi M, et al., 2011, Search for the rare decays B-s(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-), PHYSICS LETTERS B, Vol: 699, Pages: 330-340, ISSN: 0370-2693
Aaij R, Adeva B, Adinolfi M, et al., 2011, First observation of (B)over-bar(s)(0) -> D-s2*X+mu(-)(nu)over-bar decays, PHYSICS LETTERS B, Vol: 698, Pages: 14-20, ISSN: 0370-2693
Dornan PJ, 2010, Aims of the workshop, Pages: 1-9
There are challenges and opportunities for the European particle physics community to engage with innovative and exciting developments which could lead to precision measurements in the neutrino sector. These have the potential to yield significant advances in the understanding of CP violation, the flavour riddle and theories beyond the Standard Model. This workshop aims to start the process of a dialogue in Europe so that informed decisions on the appropriate directions to pursue can be made in a few years time.
Aaij R, Beteta CA, Adeva B, et al., 2010, Measurement of sigma (pp -> b(b)over-barX) at root s=7 TeV in the forward region, PHYSICS LETTERS B, Vol: 694, Pages: 209-216, ISSN: 0370-2693
Aaij R, Abellan Beteta C, Adeva B, et al., 2010, Prompt K-S(0) production in pp collisions at root s=0.9 TeV, PHYSICS LETTERS B, Vol: 693, Pages: 69-80, ISSN: 0370-2693
Schael S, Barate R, Bruneliere R, et al., 2010, Search for neutral Higgs bosons decaying into four taus at LEP2, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
Dornan P, 2009, Future neutrino experiments
Precision neutrino physics offers a unique opportunity to investigate phenomena beyond the standard model. The talk reviews both accelerator and non-accelerator experiments to measure neutrino properties, which will take place in the near future and then describes new techniques for long baseline oscillation experiments which could be feasible for precision measurements in the next ten to twenty years. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.
Bandyopadhyay A, Choubey S, Gandhi R, et al., 2009, Physics at a future Neutrino Factory and super-beam facility, REPORTS ON PROGRESS IN PHYSICS, Vol: 72, ISSN: 0034-4885
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