The Forward Physics Facility at the High-Luminosity LHC

High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe standard model (SM) processes and search for physics beyond the standard model (BSM). In this report, we review the status of the civil engineering plans and the experiments to explore the diverse physics signals that can be uniquely probed in the forward region. FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. We report here on these physics topics, on infrastructure, detector, and simulation studies, and on future directions to realize the FPF's physics potential

Solar neutrino problem and gravitationally induced long-wavelength neutrino oscillation

We have reexamined the possibility of explaining the solar neutrino data through long-wavelength neutrino oscillations induced by a tiny breakdown of the weak equivalence principle of general relativity. We have found that such gravitationally induced oscillations can provide a viable solution to the solar neutrino problem.84184035403

Probing the LSND mass scale and four neutrino scenarios with a neutrino telescope

We show in this Letter that the observation of the angular distribution of upward-going muons and cascade events induced by atmospheric neutrinos at the TeV energy scale, which can be performed by a kilometer-scale neutrino telescope, such as the IceCube detector, can be used to probe a large neutrino mass splitting, \Deltam(2)\ similar to (0.5-2.0) eV(2), implied by the LSND experiment and discriminate among four neutrino mass schemes. This is due to the fact that such a large mass scale can promote non-negligible nu(mu) --> nu(e), nu(tau)/(ν(μ)) over bar --> (ν(e)) over bar,(ν(τ)) over bar conversions at these energies by the MSW effect as well as vacuum oscillation, unlike what is expected if all the neutrino mass splittings are small. (C) 2003 Elsevier Science B.V. All rights reserved.5624173227929

Three flavor long-wavelength vacuum oscillation solution to the solar neutrino problem

We investigate the current status of the long-wavelength vacuum oscillation solution to the solar neutrino problem and to what extent the presence of a third neutrino can affect and modify it. Assuming that the smaller mass squared difference that can induce such oscillations Deltam(12)(2) is in the range 10(-11) - 10(-8) eV(2) and the larger one, Deltam(23)(2) in the range relevant to atmospheric neutrino observations, we analyze the most recent solar neutrino data coming from Homestake, SAGE, GALLEX, GNO, and Super-Kamiokande experiments in the context of three neutrino generations. We include in our vacuum oscillation analysis the Mikheyev-Smirnov-Wolfenstein (MSW) effect in the Sun, which is relevant for some of the parameter space scrutinized. We have also performed, as an extreme exercise, the fit without Homestake data. While we found that the MSW effect basically does not affect the best fitted parameters, it significantly modifies the allowed parameter space for Deltam(12)(2) larger than similar to3 x 10(-10) eV(2), in good agreement with the result obtained by Friedland in the case of two generations. Although the presence of a third neutrino does not essentially improve the quality of the fit, the solar neutrino data alone can give an upper bound on theta (13), which is constrained to be less than similar to 60 degrees at 95% C.L.63

Observation of the Cabibbo-suppressed decay Xi(+)(c) -> pK(-)pi(+)

We report the first observation of the Cabibbo-suppressed charm baryon decay Xi(c)(+) --> pK(-)pi(+) We observe 150 +/- 22 +/- 5 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Sigma(-) beam. The branching fractions of the decay relative to the Cabibbo-favored Xi(c)(+) --> Sigma(+)K(-)pi(+) and Xi(c)(+) --> Xi(-)pi(+)pi(+) are measured to be B(Xi(c)(+) --> pK(-)pi(+))/B(Xi(c)(+) --> Sigma(+)K(-)pi(+)) = 0.22 +/- 0.06 +/- 0.03 and B(Xi(c)(+) --> pK(-)pi(+))/B(Xi(c)(+) --> Xi(-)pi(+)pi(+)) = 0.20 +/- 0.04 +/- 0.02, respectively

The reaction e+ e- ---> gamma gamma (gamma) at Z0 energies

The total and differential cross-sections for the reaction e+e- → γγ(γ) are measured at centre of mass energies around 91 GeV using an integrated luminosity of 4.7 pb-1. The aggreement with QED prediction is good. Consequently there is no evidence for non-standard channels which would have the same experimental signature. The lower limits on the QED cuttoff parameters are Λ+ > 113 GeV and Λ- > 95 GeV. An upper limit on the effective coupling between a possible excited electron and the gamma is derived. At 95% confidence level the branching ratios for Z0 decay into π0γ, ηψ and γγγ are below 1.5 × 10-4, 2.8 × 10-4 and 1.4 × 10-4 respectively.0info:eu-repo/semantics/publishe

A Measurement of sin**2 theta(W) from the charge asymmetry of hadronic events at the Z0 peak

Abstract View references (24)The weak mixing angle has been measured from the charge asymmetry of hadronic events with two different approaches using the DELPHI detector at LEP. Both methods are based on a momentum-weighted charge sum to determine the jet charge in both event hemispheres. In a data sample of 247 300 multihadronic Z0 decays a charge asymmetry of 〈QF〉 - 〈QB〉 = -0.0076±0.0012(stat.)±0.0005(exp. syst.)±0.0014(frag.) and a raw forward-backward asymmetry of Araw FB = -0.0109±0.0020(stat.)±0.0010(exp. syst.)±0.0017(frag.) have been measured. This result corresponds to a value of sinθeff=0.2345±0.0030(exp.)±0.0027(frag.) ,sin2θMS=0.2341±0.0030(exp.)±0. 0027(frag.) and to sin2θW=1-m2 W/m2 Z=0.2299± 0.0030(exp.)±0.0027(frag.)±0.0028(theor.). The experimental error is the quadratic sum of the statistical and the experimental systematic error and the theoretical error originates from a value of mt=130±40 GeV/c2 and a range of mH from 45 GeV/c2 to 1000 GeV/c2.0info:eu-repo/semantics/publishe