Nuclear Theory·nucl-th

Monday·May 30, 2016

8 papers—5 primary·3 cross-listed

06
[Submitted on 27 May 2016] (cross-list from hep-ph)
Search for the sterile neutrino mixing with the ICAL detector at INO
S. P. Behera🇮🇳 · Anushree Ghosh🇨🇱 · Sandhya Choubey🇮🇳 · V. M. Datar🇮🇳 · D. K. Mishra🇮🇳 · A. K. Mohanty🇮🇳
The study has been carried out on the prospects of probing the sterile neutrino mixing with the magnetized Iron CALorimeter (ICAL) at the India-based Neutrino Observatory (INO), using atmospheric neutrinos as a source. The so-called 3~ $+$ ~1 scenario is considered for active-sterile neutrino mixing and lead to projected exclusion curves in the sterile neutrino mass and mixing angle plane. The analysis is performed using the neutrino event generator NUANCE, modified for ICAL, and folded with the detector resolutions obtained by the INO collaboration from a full GEANT4 based detector simulation. A comparison has been made between the results obtained from the analysis considering only the energy and zenith angle of the muon and combined with the hadron energy due to the neutrino induced event. A small improvement has been observed with the addition of the hadron information to the muon. In the analysis we consider neutrinos coming from all zenith angles and the Earth matter effects are also included. The inclusion of events from all zenith angles improves the sensitivity to sterile neutrino mixing by about 35 $%$ over the result obtained using only down-going events. The improvement mainly stems from the impact of Earth matter effects on active-sterile mixing. The expected precision of ICAL on the active-sterile mixing is explored and allowed confidence level (C.L.) contours presented. At the assumed true value of $1 0^{\circ}$ for the sterile mixing angles and marginalization over $Δ m_{41}^{2}$ and the sterile mixing angles, the upper bound at 90\% C.L. (from 2 parameter plots) is around $2 0^{\circ}$ for $θ_{14}$ and $θ_{34}$ , and about $1 2^{\circ}$ for $θ_{24}$ .
Comments:
13 pages, 9 figures, version published in Eur. Phys. J. C
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1605.08607 [pdf]
EPJC(2017)·17 citations
07
[Submitted on 27 May 2016] (cross-list from hep-ph)
Light-by-light scattering in ultraperipheral heavy-ion collisions at the LHC
Antoni Szczurek🇵🇱 · Mariola Klusek-Gawenda🇵🇱 · Piotr Lebiedowicz🇵🇱
We present cross sections for diphoton production in (semi)exclusive $P b P b$ collisions, relevant for the LHC. The calculation is based on equivalent photon approximation in the impact parameter space. The cross sections for elementary elastic scattering $γ γ \to γ γ$ subprocess are calculated including two mechanisms: box diagrams with leptons and quarks in the loops and a mechanism based on vector-meson dominance (VDM-Regge) model with virtual intermediate vector-like excitations of the photons. We get measureable cross sections in $P b P b$ collisions. We present many interesting differential distributions which could be measured by the ALICE, CMS or ATLAS Collaborations at the LHC. We study whether a separation of box and VDM-Regge contributions is possible. We find that the cross section for elastic $γ γ$ scattering could be measured in the heavy-ion collisions for subprocess energies smaller than $W_{γ γ} \approx 15 - 20$ ~GeV.
Comments:
7 pages, 7 figures, invited talk at the "Excited QCD 2016, Costa da Caparica, Portugal, 7-11 March, 2016
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1605.08626 [pdf]
Acta Phys.Polon.Supp.(2016)·0 citations
08
[Submitted on 27 May 2016] (cross-list from hep-ph)
SU(2) higher-order effective quark interactions from polarization
Fábio L. Braghin🇧🇷
Higher order quark effective interactions are found for SU(2) flavor by departing from a non local quark-quark interaction. By integrating out a component of the quark field, the determinant is expanded in chirally symmetric and symmetry breaking effective interactions up to the fifh order in the quark bilinears. The resulting coupling constants are resolved in the leading order of the longwavelength limit and exact numerical ratios between several of these coupling constants are obtained in the large quark mass limit. In this level, chiral invariant interactions only show up in even powers of the quark bilinears, i.e. $O (ψ ˉ ψ)^{2 n}$ ( $n = 1, 2, 3, ..$ ), whereas (explicit) chiral symmetry breaking terms emerge as $O (ψ ˉ ψ)^{n}$ being always proportional to some power of the Lagrangian quark mass.
Comments:
11 pages, revised version, submitted to publication
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1605.08760 [pdf]
PLB(2016)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE

Search for the sterile neutrino mixing with the ICAL detector at INO

Light-by-light scattering in ultraperipheral heavy-ion collisions at the LHC

SU(2) higher-order effective quark interactions from polarization

Affiliations