The transverse momentum ($p_text{T}$) distribution for inclusive neutral pions in the very forward rapidity region has been measured, with the Large Hadron Collider forward detector (LHCf), in proton--lead collisions at nucleon-nucleon center-of-mass
energies of $sqrt{s_{NN}} = 5.02$TeV at the LHC. The $p_text{T}$ spectra obtained in the rapidity range $-11.0 < y_text{lab} < -8.9$ and $0 < p_text{T} < 0.6$GeV (in the detector reference frame) show a strong suppression of the production of neutral pions after taking into account ultra-peripheral collisions. This leads to a nuclear modification factor value, relative to the interpolated $p_text{T}$ spectra in proton-proton collisions at $sqrt{s} = 5.02$TeV, of about 0.1--0.4. This value is compared with the predictions of several hadronic interaction Monte Carlo simulations.
The inclusive production rate of neutral pions in the rapidity range greater than $y=8.9$ has been measured by the Large Hadron Collider forward (LHCf) experiment during LHC $sqrt{s}=7$,TeV proton-proton collision operation in early 2010. This paper
presents the transverse momentum spectra of the neutral pions. The spectra from two independent LHCf detectors are consistent with each other and serve as a cross check of the data. The transverse momentum spectra are also compared with the predictions of several hadronic interaction models that are often used for high energy particle physics and for modeling ultra-high-energy cosmic-ray showers.
In this paper we study non-standard neutrino interactions as an example of physics beyond the standard model using atmospheric neutrino data collected during the Super-Kamiokande I(1996-2001) and II(2003-2005) periods. We focus on flavor-changing-neu
tral-currents (FCNC), which allow neutrino flavor transitions via neutral current interactions, and effects which violate lepton non-universality (NU) and give rise to different neutral-current interaction-amplitudes for different neutrino flavors. We obtain a limit on the FCNC coupling parameter, varepsilon_{mu tau}, |varepsilon_{mu tau}|<1.1 x 10^{-2} at 90%C.L. and various constraints on other FCNC parameters as a function of the NU coupling, varepsilon_{e e}. We find no evidence of non-standard neutrino interactions in the Super-Kamiokande atmospheric data.
