The Fermilab Muon $g-2$ experiment is currently preparing for its fourth data-taking period (Run-4). The experiment-wide effort on the analysis of Run-1 data is nearing completion, with the announcement of the first result expected in the coming months. The final goal of the experiment is to determine the muon magnetic anomaly to a precision of 140 ppb. This level of precision will provide indirect evidence of new physics, if the central value agrees with the previously-measured value of the magnetic anomaly. Essential in reducing the systematic uncertainty, through measurements of the muon beam profile, are the in-vacuum straw tracking detectors. A crucial prerequisite in obtaining accurate distributions of the beam profile is the internal alignment of the tracking detectors, which is described in this thesis. As a result of this position calibration, the tracking efficiency has increased by 3%, while the track quality increased by 4%. This thesis also discusses an additional measurement that will be made using the tracking detectors: a search for an electric dipole moment (EDM) of the muon, through the direct detection of an oscillation in the average vertical angle of the electron from the muon decay. An observation of a muon EDM would be evidence of new physics and would provide a new source of CP violation in the charged lepton sector. Essential in measuring the EDM are accurate and precise estimations of potential non-zero radial and longitudinal magnetic fields, which were estimated using the Run-1 data. In addition, a preliminary analysis using the Run-1 data was undertaken to estimate the available precision for the magnetic anomaly measurement using the tracking detectors.
The Mu2e experiment will search for coherent, neutrino-less conversion of muons into electrons in the Coulomb field of an aluminum nucleus with a sensitivity of four orders of magnitude better than previous experiments. The signature of this process is an electron with energy nearly equal to the muon mass. Mu2e relies on a precision (0.1%) measurement of the outgoing electron momentum to separate signal from background. In order to achieve this goal, Mu2e has chosen a very low-mass straw tracker, made of 20,736 5 mm diameter thin-walled (15 $μ$m) Mylar straws, held under tension to avoid the n…
The $g-2$ experiment successfully completed its second data taking period (Run-2) between March and July 2019, with the analysis of Run-1 and Run-2 data currently proceeding. The final goal of the experiment is to determine the muon magnetic anomaly, $a_μ=\frac{g-2}{2}$, to a precision of 140 ppb. Essential to reducing the systematic uncertainty on $a_μ$ through measurements of the muon beam profile are the in-vacuum straw tracking detectors. A crucial prerequisite to obtaining accurate distributions of the beam profile is the internal alignment of the trackers, which is described here, along …
The Muon $g-2$ Experiment at Fermilab uses a gaseous straw tracking detector to make detailed measurements of the stored muon beam profile, which are essential for the experiment to achieve its uncertainty goals. Positrons from muon decays spiral inward and pass through the tracking detector before striking an electromagnetic calorimeter. The tracking detector is therefore located inside the vacuum chamber in a region where the magnetic field is large and non-uniform. As such, the tracking detector must have a low leak rate to maintain a high-quality vacuum, must be non-magnetic so as not to p…
Performance Evaluation of Straw Tubes with Muon Beams at CERN
University of Michigan（密歇根大学）；Tufts University（塔夫茨大学）；Institute of Nuclear Physics, Almaty（阿拉木图核物理研究所）；Joint Institute for Nuclear Research, Dubna（杜布纳联合核研究所）；University of Florida（佛罗里达大学）；CERN（欧洲核子研究组织）；NRC Kurchatov Institute PNPI（库尔恰托夫国家研究中心普列哈诺夫物理技术研究所）
The article considers a prototype module with sensitive dimensions of 2 x 0.5 m2 based on 2 m long straw tubes which preserves its geometrical dimensions up to the pressure of 4 bar independently of the ambient temperature and humidity. The suggested technique provides a possibility of constructing relatively low-cost planar modules by using straw tubes as long as needed for constructing large area detectors at colliders or other field experiments by assembling them in a common coordinate detector with a user-specified acceptance. The distinguishing feature of a detector is its good radiation …
The upcoming Fermilab E989 experiment will measure the muon anomalous magnetic moment $a_μ$ . This measurement is motivated by the previous measurement performed in 2001 by the BNL E821 experiment that reported a 3-4 standard deviation discrepancy between the measured value and the Standard Model prediction. The new measurement at Fermilab aims to improve the precision by a factor of four reducing the total uncertainty from 540 parts per billion (BNL E821) to 140 parts per billion (Fermilab E989). This paper gives the status of the experiment.
This paper will cover the physics and methods behind Fermilab's Muon g-2 Experiment, along with the long-awaited results from Run-1. The experiment was undertaken to resolve the tension between the Standard Model and the previous measurement taken at Brookhaven National Laboratory. The measured value of the muon magnetic anomaly is $a_μ(FNAL)=116592040(54)\times10^{-11}$. This result is in good agreement with Brookhaven's previous measurement. The new world average, $a_μ(Exp)=116592061(41)\times10^{-11}$, shows a difference from the theoretical value of the Standard Model (SM), $a_μ(SM)=116591…
The Muon g-2 Experiment (E989) at Fermilab is seeking to measure the anomalous magnetic moment of muon ($a_μ$) with a precision of 140 parts-per-billion (ppb) and aiming to resolve the discrepancy between the E821 measurement and the Standard Model calculation of $a_μ$. In E989, the muon beam is stored in a ring magnet. The anomalous spin precession frequency $ω_{a}$ is measured by counting decay positrons in 24 calorimeters, and the magnetic field is measured by nuclear magnetic resonance (NMR) probes. Improvements in this experiment with respect to its predecessor and the progress achieved i…
The E989 Muon $g-2$ Experiment at Fermilab aims to measure the muon magnetic anomaly, $a_μ$, to an unprecedented precision of 140 parts per billion (ppb), representing a four-fold improvement over the current best measurement, achieved at Brookhaven National Lab. There stands a greater than 3 standard deviations discrepancy between the Brookhaven measurement of $a_μ$ and the theoretical value predicted using the Standard Model. The Fermilab experiment seeks to either resolve or confirm this discrepancy, which is suggestive of new physics interactions. To achieve the E989 target precision, the …
The Muon g-2 experiment E989 at Fermilab measures the anomalous magnetic moment of the muon $a_μ$ with improved precision compared to the Brookhaven (E821) experiments. The Brookhaven results are in tension with the Standard Model by more than $3σ$. The determination of $a_μ$ requires the measurement of both the muon anomaly frequency, $ω_a$, and the magnetic field, $\mathbf{B}$, that confines muons in a storage ring. The field is monitored by a set of coordinated nuclear magnetic resonance (NMR) measurements. NMR probes at fixed locations above and below the storage region constantly monitor …
There is a long standing discrepancy between the Standard Model prediction for the muon g-2 and the value measured by the Brookhaven E821 Experiment. At present the discrepancy stands at about three standard deviations, with a comparable accuracy between experiment and theory. Two new proposals -- at Fermilab and J-PARC -- plan to improve the experimental uncertainty by a factor of 4, and it is expected that there will be a significant reduction in the uncertainty of the Standard Model prediction. I will review the status of the planned experiment at Fermilab, E989, which will analyse 21 times…
The muon anomalous magnetic moment, $a_μ= (g-2)/2$, is a low-energy observable which can be both measured and computed with very high precision, making it an excellent test of the Standard Model (SM) and a sensitive probe of new physics. Recent efforts improved the precision of both the theoretical prediction and the experimental measurement. On the theory side, the Muon $g-2$ Theory Initiative, an international team of more than 130 physicists, reached in 2020 a consensus on the SM prediction for $a_μ$. On the experimental side, the E989 Muon $g-2$ Collaboration at Fermilab (FNAL) published i…
The intensities and profiles of the muon beam behind the beam dump of the Fermilab test beam area when the facility is running in the "pion" beam mode are measured and summarized in this note. This muon beam with momenta in the range 10 - 50 GeV/c provides an opportunity to perform various measurements in parallel with other users of the test beam area.
We describe the installation, commissioning, and characterization of the new injection kicker system in the Muon $g-2$ Experiment (E989) at Fermilab, which makes a precision measurement of the muon magnetic anomaly. Three Blumlein pulsers drive each of the 1.27-m-long non-ferric kicker magnets, which reside in a storage ring vacuum (SRV) that is subjected to a 1.45 T magnetic field. The new system has been redesigned relative to Muon $g-2$'s predecessor experiment, and we present those details in this manuscript.
A new measurement of the anomalous magnetic moment of the muon, $a_μ \equiv (g-2)/2$, will be performed at the Fermi National Accelerator Laboratory with data taking beginning in 2017. The most recent measurement, performed at Brookhaven National Laboratory (BNL) and completed in 2001, shows a 3.5 standard deviation discrepancy with the standard model value of $a_μ$. The new measurement will accumulate 21 times the BNL statistics using upgraded magnet, detector, and storage ring systems, enabling a measurement of $a_μ$ to 140 ppb, a factor of 4 improvement in the uncertainty the previous measu…
The Fermi National Accelerator Laboratory (FNAL) Muon $g-2$ Experiment has measured the positive muon magnetic anomaly $a_μ \equiv (g_μ-2)/2$ with a precision of 0.46 parts per million, with data collected during its first physics run in 2018. The experimental result combined with the measurement from the former experiment at Brookhaven National Laboratory increases the tension with the Standard Model expectation to $4.2σ$, thus strengthening evidence for new physics. The magnetic anomaly is determined from the precision measurements of the muon spin precession frequency, relative to the muon …
The Mu2e experiment searches for the neutrino-less muon to electron conversion in the field of a nucleus, which is a charged lepton flavor violating process. The goal of the experiment is to reach a single event sensitivity of 2.8 x 10^{-17}, setting an upper limit on the muon conversion rate at 6.7 x 10^{-17}. This corresponds to a four order of magnitude improvement with respect to the existing limits.
A new measurement of the anomalous magnetic moment of the muon, $a_μ \equiv (g-2)/2$, will be performed at the Fermi National Accelerator Laboratory. The most recent measurement, performed at Brookhaven National Laboratory and completed in 2001, shows a 3.3-3.6 standard deviation discrepancy with the Standard Model predictions for $a_μ$. The new measurement will accumulate 21 times those statistics, measuring $a_μ$ to 140 ppb and reducing the uncertainty by a factor of 4. The data acquisition system for this experiment must have the ability to record deadtime-free records from 700 $μ$s muon sp…
A new experiment at Fermilab will measure the anomalous magnetic moment of the muon with a precision of 140 parts per billion (ppb). This measurement is motivated by the results of the Brookhaven E821 experiment that were first released more than a decade ago, which reached a precision of 540 ppb. As the corresponding Standard Model predictions have been refined, the experimental and theoretical values have persistently differed by about 3 standard deviations. If the Brookhaven result is confirmed at Fermilab with this improved precision, it will constitute definitive evidence for physics beyo…
The Mu2e experiment at Fermilab will search for the charged lepton flavor violating process of neutrino-less $μ\to e$ coherent conversion in the field of an aluminum nucleus. About $7 \cdot 10^{17}$ muons, provided by a dedicated muon beam line in construction at Fermilab, will be stopped in 3 years in the aluminum target. The corresponding single event sensitivity will be $2.5\cdot 10^{-17}$. In this paper a brief overview of the physics explored by the $μ\to e$ conversion is given, followed by a description of the Mu2e experimental apparatus and the expected detector performance.
The Muon $g-2$ experiment, E989, is currently taking data at Fermilab with the aim of reducing the experimental error on the muon anomaly by a factor of four and possibly clarifying the current discrepancy with the theoretical prediction. A central component of this four-fold improvement in precision is the laser calibration system of the calorimeters, which has to monitor the gain variations of the photo-sensors with a 0.04\% precision on the short-term ($\sim 1\,$ms). This is about one order of magnitude better than what has ever been achieved for the calibration of a particle physics calori…
The Fermilab Muon Campus will host the Muon g-2 experiment - a world class experiment dedicated to the search for signals of new physics. Strict demands are placed on beam diagnostics in order to ensure delivery of high quality beams to the storage ring with minimal losses. In this study, we briefly describe the available secondary beam diagnostics for the Fermilab Muon Campus. Then, with the aid of numerical simulations we detail their interaction with the secondary beam. Finally, we compare our results against theoretical findings.
The upcoming muon (g-2) experiment at Fermilab will measure the anomalous magnetic moment of the muon to a relative precision of 140 ppb, 4 times better than the previous experiment at BNL. The new experiment is motivated by the persistent 3-4 standard deviations difference between the experimental value and the Standard Model prediction, and it will have the statistical sensitivity necessary to either refute the claim or confirm it with a confidence level exceeding a discovery threshold. The experiment is under construction and scheduled to start running in early 2017.
The Muon g-2 experiment at Fermilab, with the aim to measure the muon anomalous magnetic moment to an unprecedented level of 140~ppb, has started beam and detector commissioning in Summer 2017. To deal with incoming data projected to be around tens of petabytes, a robust data reconstruction and analysis chain based on Fermilab's \textit{art} event-processing framework is developed. Herein, I report the current status of the framework, together with its novel features such as multi-threaded algorithms for online data quality monitor (DQM) and fast-turnaround operation (nearline). Performance of…
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 muon electric dipole moment (EDM) by approximately two orders of magnitude. 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 the higher-energy positrons from the (anti-)muon decays recorded by 24 calorimeters a…
Starting this summer, Fermilab will host a key experiment dedicated to the search for signals of new physics: The Fermilab Muon g-2 Experiment. Its aim is to precisely measure the anomalous magnetic moment of the muon. In full operation, in order to avoid contamination, the newly born secondary beam is injected into a 505 m long Delivery Ring (DR) wherein it makes several revolutions before being sent to the experiment. Part of the commissioning scenario will execute a running mode wherein the passage from the DR will be skipped. With the aid of numerical simulations, we provide estimates of t…
A new measurement of the anomalous magnetic moment of the muon, $a_μ \equiv (g-2)/2$, will be performed at the Fermi National Accelerator Laboratory with data taking beginning in 2017. The most recent measurement, performed at Brookhaven National Laboratory and completed in 2001, shows a 3.5 standard deviation discrepancy with the standard model prediction of $a_μ$. The new measurement will accumulate 21 times those statistics using upgraded detection and storage ring systems, enabling a measurement of $a_μ$ to 140 ppb, a factor of 4 improvement in the uncertainty the previous measurement. Thi…
Since the discovery of the muon, particle physicists have carried out a series of experiments aimed at measuring flavor violation in charged-lepton interactions. To date, no such violation has been observed. The Mu2e experiment at Fermilab will search for the charged lepton flavor violating process of coherent muon-to-electron conversion in the presence of a nucleus with a sensitivity four orders of magnitude beyond current limits. The experiment will have a single event sensitivity of about $2.5\times10^{-17}$ while limiting the total background to less than 0.5 events. One potential backgrou…
New light, weakly-coupled particles are commonly invoked to address the persistent $\sim 4σ$ anomaly in $(g-2)_μ$ and serve as mediators between dark and visible matter. If such particles couple predominantly to heavier generations and decay invisibly, much of their best-motivated parameter space is inaccessible with existing experimental techniques. In this paper, we present a new fixed-target, missing-momentum search strategy to probe invisibly decaying particles that couple preferentially to muons. In our setup, a relativistic muon beam impinges on a thick active target. The signal consists…
We present details of a high-accuracy absolute scalar magnetometer based on pulsed proton NMR. The $B$-field magnitude is determined from the precession frequency of proton spins in a cylindrical sample of water after accounting for field perturbations from probe materials, sample shape, and other corrections. Features of the design, testing procedures, and corrections necessary for qualification as an absolute scalar magnetometer are described. The device was tested at $B = 1.45$\,T but can be modified for a range exceeding 1--3\,T. The magnetometer was used to calibrate other NMR magnetomete…
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 $10^{-21}$ e.cm. 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…
Graphical Processing Units (GPUs) have recently become a valuable computing tool for the acquisition of data at high rates and for a relatively low cost. The devices work by parallelizing the code into thousands of threads, each executing a simple process, such as identifying pulses from a waveform digitizer. The CUDA programming library can be used to effectively write code to parallelize such tasks on Nvidia GPUs, providing a significant upgrade in performance over CPU based acquisition systems. The muon $g$-$2$ experiment at Fermilab is heavily relying on GPUs to process its data. The data …
I report on the progress of two new muon anomalous magnetic moment experiments, which are in advanced design and construction phases. The goal of Fermilab E989 is to reduce the experimental uncertainty of $a_μ$ from Brookhaven E821 by a factor of 4; that is, $δa_μ\sim 16 \times 10^{-11}$, a relative uncertainty of 140~ppb. The method follows the same magic-momentum storage ring concept used at BNL, and pioneered previously at CERN, but muon beam preparation, storage ring internal hardware, field measuring equipment, and detector and electronics systems are all new or upgraded significantly. In…
The Mu2e experiment aims to test Charge Lepton Flavour Violation to an unprecedented level, enhancing the current sensitivity by four orders of magnitude for the neutrinoless conversion of muons into electrons. A series of graded solenoids convey an intense, pulsed muon beam to an aluminum target. The main detector components are a low mass straw drift tubes tracker, a pure Cesium Iodide calorimeter and an extruded plastic scintillator cosmic ray veto. Requirements, tests on prototypes and status of the production will be discussed.
The NOvA long-baseline neutrino experiment consists of two highly active, finely segmented, liquid scintillator detectors located 14.6 mrad off Fermilab's NuMI beam axis, with a Near Detector located at Fermilab, and a Far Detector located 810 km from the target at Ash River, MI. NO$ν$A released it first preliminary results of the muon neutrino disappearance parameters, measuring $\sin^2(θ_{23}) = 0.51 \pm 0.10$ and or the normal hierarchy $Δm^2_{32} = 2.37^{+0.16}_{-0.15} \times 10^{-3}$ eV$^2$ and for the inverted hierarchy $Δm^2_{32} = -2.40^{+0.14}_{-0.17} \times 10^{-3}$ eV$^2$. This talk…
The Neutrinos at the Main Injector (NuMI) beamline will deliver an intense muon neutrino beam by focusing a beam of mesons into a long evacuated decay volume. We have built 4 arrays of ionization chambers to monitor the neutrino beam direction and quality. The arrays are located at 4 stations downstream of the decay volume, and measure the remnant hadron beam and tertiary muons produced along with neutrinos in meson decays.
The Mu2e Experiment at Fermilab will search for the coherent, neutrinoless conversion of muons into electrons in the field of an aluminium nucleus with an unprecedented sensitivity. Such a charged lepton flavor-violating reaction probes new physics at a scale inaccessible with direct searches at either present or planned high energy colliders. Moreover, the Mu2e experiment both complements and extends the current search for the μ $\to$ eγ decay at MEG and searches for new physics at the LHC. We will present the physics motivation for Mu2e, the experimental setup and the current status of the e…
The MicroBooNE experiment is a liquid argon TPC experiment designed for short-baseline neutrino physics, currently running at Fermilab. Due to its location near the surface, cosmic muons can be a source of backgrounds to many analyses and having a good understanding of the cosmic rays will be very valuable for the experiment. These proceedings describe the physics motivation, setup, and performance of a small external muon counter system, which will provide improved calibration for the liquid argon TPC and better understanding of the cosmogenic background.
The nuSTORM facility has been designed to deliver beams of electron neutrinos and muon neutrinos (and their anti-particles) from the decay of a stored muon beam with a central momentum of 3.8 GeV/c and a momentum acceptance of 10%. The facility is unique in that it will: 1. Allow searches for sterile neutrinos of exquisite sensitivity to be carried out; 2. Serve future long- and short-baseline neutrino-oscillation programs by providing definitive measurements of electron neutrino and muon neutrino scattering cross sections off nuclei with percent-level precision; and 3. Constitutes the crucial…
The magnetic moment is a fundamental property of particles. The measurement of these magnetic moments and the comparison with the values predicted by the standard model of particle physics is a way to test our understanding of the fundamental building blocks of our world. In some cases, such as for the electron, this comparison has resulted in confirmation of the standard model with incredible precision. In contrast, the magnetic moment of the muon has shown a long-standing disagreement in the measured and the predicted value. There is currently a tantalizing three-standard-deviation differenc…
The new muon (g-2) experiment E989 at Fermilab will be equipped with a laser calibration system for all the 1296 channels of the calorimeters. An integrating sphere and an alternative system based on an engineered diffuser have been considered as possible light distributors for the experiment. We present here a detailed comparison of the two based on temporal response, spatial uniformity, transmittance and time stability.
The NO$ν$A experiment is an electron neutrino appearance neutrino oscillation experiment at Fermilab. Electron neutrino events are identified by the electromagnetic (EM) showers induced by electrons in the final state of neutrino interactions. EM showers induced by cosmic muons or rock muons, are abundant in NO$ν$A detectors. We use a Muon-Removal Technique to get pure EM shower samples from cosmic and rock muon data. Those samples can be used to characterize the EM signature and provide valuable checks of the MC simulation, reconstruction, PID algorithms, and calibration across the NO$ν$A det…
The NuMI Off-Axis v Appearance (NOvA) experiment is a long baseline neutrino oscillation experiment using a neutrino source created from the NuMI Beamline at Fermilab. The experiment will study the oscillations of muon neutrinos to electron neutrinos using two functionally identical plastic, liquid scintillator filled detectors placed 14 milliradians off-axis to the NuMI beam. Charged current neutrino interactions will be used to observe the neutrino flavor from identification of the final state lepton. Reconstruction of muon charged particle tracks plays an important role in both the short te…
The ArgoNeuT liquid argon time projection chamber has collected thousands of neutrino and antineutrino events during an extended run period in the NuMI beam-line at Fermilab. This paper focuses on the main aspects of the detector layout and related technical features, including the cryogenic equipment, time projection chamber, read-out electronics, and off-line data treatment. The detector commissioning phase, physics run, and first neutrino event displays are also reported. The characterization of the main working parameters of the detector during data-taking, the ionization electron drift ve…
The MicroBooNE experiment at Fermilab uses liquid argon time projection chamber (LArTPC) technology to study neutrino interactions in argon. A fundamental requirement for LArTPCs is to achieve and maintain a low level of electronegative contaminants in the liquid to minimize the capture of drifting ionization electrons. The attenuation time for the drifting electrons should be long compared to the maximum drift time, so that the signals from particle tracks that generate ionization electrons with long drift paths can be detected efficiently. In this talk we present MicroBooNE measurement of el…
A broken lepton family symmetry can lead to muon decay to a Familon \[μ\to {χ_{Familon}} + e .\] We propose to search for two body muon decay to a Familon in the mass range from 86 to 105 MeV/c$^2$, by observing stopped positive muons. This mass region is the search window blind spot of magnetic spectrometers. The search signal will be a mono-energetic positron peak on top of the standard model muon Michel decay spectrum. The decay positron spectrum will be measured in HPGe detectors surrounded by large volume NaI detectors and a charged particle tracking system used to help reduce false trigg…
The ArgoNeuT collaboration presents measurements of inclusive muon neutrino and antineutrino charged current differential cross sections on argon in the Fermilab NuMI beam operating in the low energy antineutrino mode. The results are reported in terms of outgoing muon angle and momentum at a mean neutrino energy of 9.6 GeV (neutrinos) and 3.6 GeV (antineutrinos), in the range $0^\circ < θ_μ< 36^\circ$ and $0 < p_μ< 25$ GeV/$c$, for both neutrinos and antineutrinos.
The SeaQuest experiment (Fermilab E906) detects pairs of energetic μ+ and μ- produced in 120 GeV/c proton-nucleon interactions in a high rate environment. The trigger system consists of several arrays of scintillator hodoscopes and a set of field-programmable gate array (FPGA) based VMEbus modules. Signals from up to 96 channels of hodoscope are digitized by each FPGA with a 1-ns resolution using the time-to-digital convertor (TDC) firmware. The delay of the TDC output can be adjusted channel-by-channel in 1-ns steps and then re-aligned with the beam RF clock. The hit pattern on the hodoscope …
The Mu2e experiment at Fermilab looks for Charged Lepton Flavor Violation (CLFV) improving by 4 orders of magnitude the current experimental sensitivity for the muon to electron conversion in a muonic atom. A positive signal could not be explained in the framework of the current Standard Model of particle interactions and therefore would be a clear indication of new physics. In 3 years of data taking, Mu2e is expected to observe less than one background event mimicking the electron coming from muon conversion. Achieving such a level of background suppression requires a deep knowledge of the ex…
We describe the design, construction and performance of the upgraded DO muon system for Run II of the Fermilab Tevatron collider. Significant improvements have been made to the major subsystems of the DO muon detector: trigger scintillation counters, tracking detectors, and electronics. The Run II central muon detector has a new scintillation counter system inside the iron toroid and an improved scintillation counter system outside the iron toroid. In the forward region, new scintillation counter and tracking systems have been installed. Extensive shielding has been added in the forward region…
The Muon g-2 Experiment plans to use the Fermilab Recycler Ring for forming the proton bunches that hit its production target. The proposed scheme uses one RF system, 80 kV of 2.5 MHz RF. In order to avoid bunch rotations in a mismatched bucket, the 2.5 MHz is ramped adiabatically from 3 to 80 kV in 90 ms. In this study, the interaction of the primary proton beam with the production target for the Muon g-2 Experiment is numerically examined.
The E989 Muon $g-2$ experiment at Fermilab aims to measure the anomalous magnetic moment, $a^{}_μ$, of the muon with a precision of 140 parts-per-billion. This requires a precise measurement of both the anomalous spin precession frequency, $ω^{}_a$, and the average magnetic field in terms of the shielded proton Larmor frequency, $ω'^{}_p$. The measurement of $ω'^{}_p$ with a total systematic uncertainty of 70 parts-per-billion involves a combination of various NMR probes. There are 378 probes in fixed locations constantly monitoring field drifts. A water-based probe provides the calibration. A…
