arXiv subjects

Poonam Mehta

Publications and source records attributed to Poonam Mehta.

43 records · Page 3Linked to original sources

arXiv2005

Probing the Neutrino Mass Hierarchy via Atmospheric $ν_μ+ \bar ν_μ$ Survival Rates in Megaton Water Cerenkov Detectors

The neutrino mass hierarchy, presently unknown, is a powerful discriminator among various classes of unification theories. We show that the $ν_μ + \barν_μ$ survival rate in atmospheric events can provide a novel method of determining the hierarchy in megaton water Cerenkov detectors. For pathlength and energy ranges relevant to atmospheric neutrinos,this rate obtains significant matter sensitive variations not only from resonant matter effects in $P_{μe}$ but also from those in $P_{μτ}$. We calculate the expected muon event rates in the case of matter oscillations with both natural and inverted hierarchy.We identify the energy and pathlength ranges for which resonant matter effects can lead to observable differences between the above two cases. We also estimate the exposure time required to observe this difference and determine the sign of $Δ_{31}$ in a statistically significant manner.

hep-ph↗

arXiv2004

Large Matter Effects in ${ν_μ\to ν_τ}$ Oscillations

We show that matter effects change the ${\rm {ν_μ\to ν_τ}}$ oscillation probability by as much as 70% for certain ranges of energies and pathlengths. Consequently, the ${\rm {ν_μ\to ν_μ}}$ survival probability also undergoes large changes. A proper understanding of $ν_μ$ survival rates must consider matter effects in $P_{μτ}$ as well as $P_{μe}$. We comment on a) how these matter effects may be observed and the sign of $Δ_{31}$ determined in atmospheric neutrino measurements and at neutrino factories and b) how they lead to heightened sensitivity for small $θ_{13}$.

hep-ph↗

arXiv2004

Atmospheric Neutrinos as a Probe of CPT Violation

We show that atmospheric neutrinos can provide a sensitive and robust probe of CPT violation (CPTV). We perform realistic event-rate calculations and study the variations of the ratio of total muon to antimuon survival rates with $L/E$ and $L$ ($L$ $\equiv$ baseline length, $E$ $\equiv$ neutrino energy) in a detector capable of identifying the muon charge. We demonstrate that measurements of these ratios when coupled with the significant $L$ and $E$ range which characterizes the atmospheric neutrino spectrum provides a method of both detecting the presence of such violations and putting bounds on them which compare very favourably with those possible from a future neutrino factory.

hep-ph↗

arXiv2003

Heavy quark production via leptoquarks at a neutrino factory

The proposed neutrino factory (NF) based on a muon storage ring (MSR) is an ideal place to look for heavy quark production via neutral current (NC) and charged current (CC) interactions. In this article, we address the issue of contribution coming from mediating leptoquarks (LQ) in $ν_μ(\barν_e)-{\rm N}$ interactions leading to the production of $b(\bar b)$ at a MSR and investigate the region where LQ interactions are significant in the near-site experiments.

hep-ph↗

arXiv2002

Leptoquark Signals via $ν$ interactions at Neutrino Factories

The accurate prediction of neutrino beam produced in muon decays and the absence of opposite helicity contamination for a particular neutrino flavour makes a future neutrino factory (NF) based on a muon storage ring (MSR), the ideal place to look for the lepton flavour violating (LFV) effects. In this paper, we address the contribution of mediating LFV leptoquarks (LQ) in $ν(\barν)-{N}$ interactions leading to production of $τ$'s and wrong sign $μ$'s at MSR and investigate the region where LQ interactions are significant in the near-site and short baseline experiments.

hep-ph↗

arXiv2001

Signals of R-parity Violating Supersymmetry at a Muon Storage Ring

Neutrino oscillation signals at muon storage rings (MSR) can be mimicked by Supersymmetric (SUSY) interactions in an R-parity violating scenario. We have investigated the $τ$-appearance signals for both long-baseline and near-site experiments, and concluded that the latter is of great use in distinguishing between oscillation and SUSY effects. On the other hand, SUSY can cause a manifold increase in the event rate for wrong-sign muons at a long-baseline setting, thereby providing us with signatures of new physics.

hep-ph↗

arXiv2001

Signals of R-parity violating supersymmetry in neutrino scattering at muon storage rings

Neutrino oscillation signals at muon storage rings can be faked by supersymmetric (SUSY) interactions in an R-parity violating scenario. We investigate the $τ$-appearance signals for both long-baseline and near-site experiments, and conclude that the latter is of great use in distinguishing between oscillation and SUSY effects. On the other hand, SUSY can cause a manifold increase in the event rate for wrong-sign muons at a long-baseline setting, thereby providing us with signatures of new physics.

hep-ph↗