Agarwalla, S. K., Conrad, J. M., & Shaevitz, M. H. (2011). Short-baseline neutrino oscillation waves in ultra-large liquid scintillator detectors. J. High Energy Phys., 12(12), 085–24pp.
Abstract: Powerful new multi-kiloton liquid scintillator neutrino detectors, including NOvA and, possibly, LENA, will come on-line within the next decade. When coupled with a modest-power decay-at-rest (DAR) neutrino source at short-baseline, these detectors can decisively address signals for neutrino oscillations at high Delta m(2). Along the greater than 50 m length of the detector, the characteristic oscillation wave will be apparent, providing powerful verification of the oscillation phenomenon. LENA can simultaneously perform (v) over bar (mu) -> (v) over bar (e) appearance and v(e) -> v(e) disappearance searches while NOvA is likely limited to v(e) disappearance. For the appearance channel, a LENA-like detector could test the LSND and MiniBooNE signal regions at > 5 sigma with a fiducial volume of 5 kt and a 10 kW neutrino source. The LENA and NOvA v(e) disappearance sensitivities are complementary to the recent reactor anomaly indicating possible (v) over bar (e) disappearance and would cover this possible oscillation signal at similar to 3 sigma.
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Nishimura, D., Fujita, Y., Fukuda, M., Ganioglu, E., Ichikawa, Y., Kanazawa, M., et al. (2011). Beta and gamma decays of J(pi)=1(+), Al-24m state beta and gamma branching ratios. Eur. Phys. J. A, 47(12), 155–7pp.
Abstract: A beta-gamma spectroscopy of the J(pi) = 1(+), 426 keV isomeric state of Al-24 ( Al-24m) has been carried out by using a Al-24 secondary beam with high purity and high isomeric ratio. From the absolute gamma-ray and beta-particle intensities observed in the decay of the isomeric state, the branching ratio R-B of the isomeric gamma-decay from Al-24m to the J(pi) = 4(+), ground state of Al-24 have been derived. The obtained R-B value of 69.6(7)% is much smaller than the previously accepted value of 82.5(30)%. The precise half-life for the isomer decay, T-1/2(m) = 130.9(13) ms, has been also determined in this experiment. Accordingly, the M3 gamma-decay strength B(M3) of the Al-24m decay becomes smaller and the total beta-decay branching ratio becomes larger. In particular, the beta-decay branching ratio to the ground state of Mg-24 becomes 24.3(9)%, which is 2.4 times larger than the previous value of 10.1(28)%. By combining the branching ratio and the half-life, the Gamow-Teller (GT) transition strength B(GT) of 0.0194(7) is deduced for the GT transition from Al-24m to the J(pi) = 0(+), ground state of Mg-24. This value is in good agreement with the values derived from charge-exchange reactions.
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Leitner, R., Malinsky, M., Roskovec, B., & Zhang, H. (2011). Non-standard antineutrino interactions at Daya Bay. J. High Energy Phys., 12(12), 001–26pp.
Abstract: We study the prospects of pinning down the effects of non-standard antineutrino interactions in the source and in the detector at the Daya Bay neutrino facility. It is well known that if the non-standard interactions in the detection process are of the same type as those in the production, their net effect can be subsumed into a mere shift in the measured value of the leptonic mixing angle theta(13). Relaxing this assumption, the ratio of the antineutrino spectra measured by the Daya Bay far and near detectors is distorted in a characteristic way, and good fits based on the standard oscillation hypothesis are no longer viable. We show that, under certain conditions, three years of Daya Bay running can be sufficient to provide a clear hint of non-standard neutrino physics.
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ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Ferrer, A., et al. (2011). Search for a heavy neutral particle decaying into an electron and a muon using 1 fb(-1) of ATLAS data. Eur. Phys. J. C, 71(12), 1809–17pp.
Abstract: A search is presented for a high mass neutral particle that decays directly to the e(+/-) mu(-/+) final state. The data sample was recorded by the ATLAS detector in root s = 7 TeV pp collisions at the LHC from March to June 2011 and corresponds to an integrated luminosity of 1.07 fb(-1). The data are found to be consistent with the Standard Model background. The high e(+/-) mu(-/+) mass region is used to set 95% confidence level upper limits on the production of two possible new physics processes: tau sneutrinos in an R-parity violating supersymmetric model and Z'-like vector bosons in a lepton flavor violating model.
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ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Ferrer, A., et al. (2011). Search for massive colored scalars in four-jet final states in root s=7 TeV proton-proton collisions with the ATLAS detector. Eur. Phys. J. C, 71(12), 1828–19pp.
Abstract: A search for pair-produced scalar particles decaying to a four-jet final state is presented. The analysis is performed using an integrated luminosity of 34 pb(-1) recorded by the ATLAS detector in 2010. No deviation from the Standard Model is observed. For a scalar mass of 100 GeV (190 GeV) the limit on the scalar gluon pair production cross section at 95% confidence level is 1 nb (0.28 nb). When these results are interpreted as mass limits, scalar-gluons (hyperpions) with masses of 100 to 185 GeV (100 to 155 GeV) are excluded at 95% confidence level with the exception of a mass window of width about 5 GeV (15 GeV) around 140 GeV.
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