We present a comparison of the measured cosmic ray (CR) muon fluxes from two identical portable low‐cost detectors at different geolocations and their sensitivity to space weather events in real ...time. The first detector is installed at Mount Wilson Observatory, CA, USA (geomagnetic cutoff rigidity Rc ∼ 4.88 GV), and the second detector is running on the downtown campus of Georgia State University in Atlanta, GA, USA (Rc ∼ 3.65 GV). The variation of the detected muon fluxes is compared to the changes in the interplanetary solar wind parameters at the L1 Lagrange point and geomagnetic indexes. In particular, we have investigated the muon flux behavior during three major interplanetary shock events and geomagnetic disturbances that occurred during July and August of 2022. To validate the interpretation of the measured muon signals, we compare the muon fluxes to the measurement from the Oulu neutron monitor (NM, Rc ∼ 0.8 GV). The results of this analysis show that the muon detector installed at Mount Wilson Observatory demonstrates a stronger correlation with a high‐latitude NM. Both detectors typically observe a muon flux decrease during the arrival of interplanetary shocks and geomagnetic storms. Interestingly, the decrease could be observed several hours before the onset of the first considered interplanetary shocks at L1 at 2022‐07‐23 02:28:00 UT driven by the high‐speed Coronal Mass Ejection and related geomagnetic storm at 2022‐07‐23 03:59:00 UT. This effort represents an initial step toward establishing a global network of portable low‐cost CR muon detectors for monitoring the sensitivity of muon flux changes to space and terrestrial weather parameters.
Plain Language Summary
A pair of identical, low‐cost, and portable cosmic ray (CR) muon detectors is set up over 3,500 km apart for an exploratory study of monitoring space and terrestrial weather in real time at a global scale. One detector is installed on Mount Wilson, California and the other is in downtown Atlanta, Georgia. To validate the interpretation of the measured muon signals, the muon fluxes are compared to the well‐known neutron flux measurement from the Oulu neutron station in Finland. The results of this analysis show that the CR flux from both muon detectors typically decreases during geomagnetic storm events and that the muon detector installed on Mount Wilson is significantly correlated with the Oulu neutron monitor. Although this is yet an initial effort of building a global network of CR muon detectors for monitoring the space and earth weather in real time, the study provides evidence that muon network detection efficiency can be sufficient for a diagnostic of the major geoeffective space weather events.
Key Points
A global network of portable muon detectors is under development for monitoring the dynamic changes of the space and terrestrial weather
A comparison of the measured cosmic ray (CR) muon fluxes from two identical detectors at different geolocations in real‐time is carried out
A correlation study between the muon data and the neutron measurement at Oulu CR station in Finland is presented in this paper
We present a search for possible spin dependent interactions of the neutron with matter through exchange of spin 1 bosons with axial vector couplings as envisioned in possible extensions of the ...Standard Model. This was sought using a slow neutron polarimeter that passed transversely polarized slow neutrons by unpolarized slabs of material arranged so that interactions would tilt the plane of polarization and develop a component along the neutron momentum. The result for the rotation angle, ϕ′=2.8±4.6(stat.)±4.0(sys.)×10−5 rad/m is consistent with zero. This result improves the upper bounds on the neutron-matter coupling gA2 by about three orders of magnitude for force ranges in the mm– μm regime.
The super Pioneering High Energy Nuclear Interaction eXperiment (sPHENIX) at the Relativistic Heavy Ion Collider will perform high-precision measurements of jets and heavy flavor observables for a ...wide selection of nuclear collision systems, elucidating the microscopic nature of strongly interacting matter ranging from nucleons to the strongly coupled quark-gluon plasma. A prototype of the sPHENIX calorimeter system was tested at the Fermilab Test Beam Facility as experiment T-1044 in the spring of 2016. The electromagnetic calorimeter (EMCal) prototype is composed of scintillating fibers embedded in a mixture of tungsten powder and epoxy. The hadronic calorimeter (HCal) prototype is composed of tilted steel plates alternating with the plastic scintillator. Results of the test beam reveal the energy resolution for electrons in the EMCal is <inline-formula> <tex-math notation="LaTeX">2.8\%\oplus 15.5\%/\sqrt {E} </tex-math></inline-formula> and the energy resolution for hadrons in the combined EMCal plus HCal system is <inline-formula> <tex-math notation="LaTeX">13.5\%\oplus 64.9\%/\sqrt {E} </tex-math></inline-formula>. These results demonstrate that the performance of the proposed calorimeter system satisfies the sPHENIX specifications.
sPHENIX is a new experiment under construction for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory which will study the quark-gluon plasma to further the understanding of ...quantum chromodynamics (QCP) matter and interactions. A prototype of the sPHENIX electromagnetic calorimeter (EMCal) was tested at the Fermilab Test Beam Facility in Spring 2018 as experiment T-1044. The EMCal prototype corresponds to a solid angle of <inline-formula> <tex-math notation="LaTeX">\Delta \eta \times \Delta \phi = 0.2 \times 0.2 </tex-math></inline-formula> centered at pseudo-rapidity <inline-formula> <tex-math notation="LaTeX">\eta = 1 </tex-math></inline-formula>. The prototype consists of scintillating fibers embedded in a mix of tungsten powder and epoxy. The fibers project back approximately to the center of the sPHENIX detector, giving 2-D projectivity. The energy response of the EMCal prototype was studied as a function of position and input energy. The energy resolution of the EMCal prototype was obtained after applying a position-dependent energy correction and a beam profile correction. Two separate position-dependent corrections were considered. The EMCal energy resolution was found to be <inline-formula> <tex-math notation="LaTeX">\sigma (E)/\langle E\rangle = 3.5(0.1) \oplus 13.3(0.2)/\sqrt {E} </tex-math></inline-formula> based on the hodoscope position-dependent correction, and <inline-formula> <tex-math notation="LaTeX">\sigma (E)/\langle E\rangle = 3.0(0.1) \oplus 15.4(0.3)/\sqrt {E} </tex-math></inline-formula> based on the cluster position-dependent correction. These energy resolution results meet the requirements of the sPHENIX physics program.
Neutron spin rotation is expected from quark-quark weak interactions in the standard model, which induce weak interactions among nucleons that violate parity. We present the results from an ...experiment searching for the effect of parity violation via the spin rotation of polarized neutrons in a liquid 4He medium. The value for the neutron spin rotation angle per unit length in 4He, d ϕ / d z = + 2.1 ± 8.3 (stat.) - 0.2 + 2.9 (sys.) × 10 - 7 rad/m, is consistent with zero. The result agrees with the best current theoretical estimates of the size of nucleon-nucleon weak amplitudes from other experiments and with the expectations from recent theoretical approaches to weak nucleon-nucleon interactions. In this paper we review the theoretical status of parity violation in the n → + 4He system and discuss details of the data analysis leading to the quoted result. Analysis tools are presented that quantify systematic uncertainties in this measurement and that are expected to be essential for future measurements.
The PHENIX collaboration studies the cold nuclear matter effects by measuring the spectra of various probes over a wide range of transverse momentum and rapidity in d+Au collisions. The lepton decay ...channels of the ϕ meson and heavy flavor make them especially interesting probes since leptons interact only electromagnetically, thus retain information from their production phase. In 2008, the PHENIX collaboration collected ∼60 nb−1 from d+Au collisions at sNN=200 GeV. We report recent PHENIX results of ϕ meson and heavy flavor invariant production spectra and nuclear modification factors from this data set.
Neutron spin rotation measurements Sarsour, M.; Amadio, J.; Anderson, E. ...
EPJ Web of Conferences,
2019, Letnik:
219
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The neutron spin rotation (NSR) collaboration used parity-violating spin rotation of transversely polarized neutrons transmitted through a 0.5 m liquid helium target to constrain weak coupling ...constants between nucleons. While consistent with theoretical expectation, the upper limit set by this measurement on the rotation angle is limited by statistical uncertainties. The NSR collaboration is preparing a new measurement to improve this statistically-limited result by about an order of magnitude. In addition to using the new high-flux NG-C beam at the NIST Center for Neutron Research, the apparatus was upgraded to take advantage of the larger-area and more divergent NG-C beam. Significant improvements are also being made to the cryogenic design. Details of these improvements and readiness of the upgraded apparatus are presented. We also comment on how recent theoretical work combining effective field theory techniques with the 1/
N
c
expansion of QCD along with previous NN weak measurements can be used to make a prediction for
d
ϕ/
dz
in
4
He.
An experiment using the same apparatus with a room-temperature target was carried out at LANSCE to place limits on parity-conserving rotations from possible fifth-force interactions to complement previous studies. We sought this interaction using a slow neutron polarimeter that passed transversely polarized slow neutrons by unpolarized slabs of material arranged so that this interaction would tilt the plane of polarization and develop a component along the neutron momentum. The results of this measurement and its impact on the neutron-matter coupling
g
A
2
from such an interaction are presented. The NSR collaboration is also preparing a new measurement that uses an upgraded version of the room-temperature target to be run on the NG-C beamline; and it is expected to constrain
g
A
2
by at least two additional orders of magnitude for λ
c
between 1 cm and 1 μm.
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