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Alessandra Lucà

Publications and source records attributed to Alessandra Lucà.

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Beam dynamics corrections to the Run-1 measurement of the muon anomaly $a_μ$ at Fermilab

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 momentum, and the average magnetic field seen by the beam. In an ideal case with muons orbiting in a horizontal plane with a uniform vertical magnetic field, the anomalous precession frequency $ω_a$ is given by the difference between the spin~($s$) and cyclotron~($c$) frequencies, $ω_a = ω_s - ω_c$. The observable $ω_a$ is proportional to $a_μ$. This proceeding presents the beam dynamics systematic corrections that are required to adjust the measured muon precession frequency $ω^{m}_{a}$ to its true physical value $ω_{a}$.

hep-ex

A Panel Prototype for the Mu2e Straw Tube Tracker at Fermilab

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 need for supports within the active volume, and arranged in an approximately 3 m long by 0.7 m radius cylinder, operated in vacuum and a 1 T magnetic field. Groups of 96 straws are assembled into modules, called panels. We present the prototype and the assembly procedure for a Mu2e tracker panel built at Fermilab

physics.ins-det