Measurement by the STAR experiment at RHIC of the cold nuclear matter (CNM) effects experienced by inclusive J/ψ at mid-rapidity in 0-100% p+Au collisions at sNN = 200 GeV is presented. Such effects ...are quantified utilizing the nuclear modification factor, RpAu, obtained by taking a ratio of J/ψ yield in p+Au collisions to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The differential J/ψ yield in both p+p and p+Au collisions is measured through the dimuon decay channel, taking advantage of the trigger capability provided by the Muon Telescope Detector in the RHIC 2015 run. Consequently, the J/ψRpAu is derived within the transverse momentum (pT) range of 0 to 10 GeV/c. A suppression of approximately 30% is observed for pT<2 GeV/c, while J/ψRpAu becomes compatible with unity for pT greater than 3 GeV/c, indicating the J/ψ yield is minimally affected by the CNM effects at high pT. Comparison to a similar measurement from 0-20% central Au+Au collisions reveals that the observed strong J/ψ suppression above 3 GeV/c is mostly due to the hot medium effects, providing strong evidence for the formation of the quark-gluon plasma in these collisions. Several model calculations show qualitative agreement with the measured J/ψRpAu, while their agreement with the J/ψ yields in p+p and p+Au collisions is worse.
Measurement by the STAR experiment at RHIC of the cold nuclear matter (CNM) effects experienced by inclusive J / ψ at mid-rapidity in 0-100% p+Au collisions at s NN = 200 GeV is presented. Such ...effects are quantified utilizing the nuclear modification factor, R p Au , obtained by taking a ratio of J / ψ yield in p+Au collisions to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The differential J / ψ yield in both p+p and p+Au collisions is measured through the dimuon decay channel, taking advantage of the trigger capability provided by the Muon Telescope Detector in the RHIC 2015 run. Consequently, the J / ψ R p Au is derived within the transverse momentum ( p T ) range of 0 to 10 GeV/c. A suppression of approximately 30% is observed for p T < 2 GeV/c, while J / ψ R p Au becomes compatible with unity for p T greater than 3 GeV/c, indicating the J / ψ yield is minimally affected by the CNM effects at high p T . Comparison to a similar measurement from 0-20% central Au+Au collisions reveals that the observed strong J / ψ suppression above 3 GeV/c is mostly due to the hot medium effects, providing strong evidence for the formation of the quark-gluon plasma in these collisions. Several model calculations show qualitative agreement with the measured J / ψ R p Au , while their agreement with the J / ψ yields in p+p and p+Au collisions is worse.
We present results of a Monte Carlo study of the sensitivity of the planned IceCube detector to predicted fluxes of muon neutrinos at TeV to PeV energies. A complete simulation of the detector and ...data analysis is used to study the detector’s capability to search for muon neutrinos from potential sources such as active galaxies and gamma-ray bursts (GRBs). We study the effective area and the angular resolution of the detector as a function of muon energy and angle of incidence. We present detailed calculations of the sensitivity of the detector to both diffuse and pointlike neutrino fluxes, including an assessment of the sensitivity to neutrinos detected in coincidence with GRB observations. After three years of data taking, IceCube will be able to detect a point-source flux of
E
ν
2×d
N
ν
/d
E
ν
=7×10
−9 cm
−2
s
−1
GeV at a 5
σ significance, or, in the absence of a signal, place a 90% c.l. limit at a level of
E
ν
2×d
N
ν
/d
E
ν
=2×10
−9 cm
−2
s
−1
GeV. A diffuse
E
−2 flux would be detectable at a minimum strength of
E
ν
2×d
N
ν
/d
E
ν
=10
−8 cm
−2
s
−1
sr
−1
GeV. A GRB model following the formulation of Waxman and Bahcall would result in a 5
σ effect after the observation of 200 bursts in coincidence with satellite observations of the gamma rays.
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