Probing new physics with atmospheric neutrinos at KM3NeT-ORCA João A. B. Coelho for the KM3NeT Collaboration APC Laboratory [email protected]
• 5.7 Mton detector • Atmospheric neutrinos traverse large KM3Net DOM • 115 lines amounts of dense matter inside the earth. 31x3’’ PMTs • 18 DOMs per line • 31 PMTs per DOM
• 200 200 Matter effects can significantly alter the ̴ neutrino oscillation probabilities. • 1 DOM ~ 3 kton equiv.
m • 1 line ~ 50 kton equiv. • A Mton size detector with good energy
and angle resolution can take advantage of For Comparison: these substantial matter effects to look for • Super-K: 25 kton physics beyond the Standard Model. • NOvA: 10 kton 43 cm • MINOS: 4 kton Sterile Neutrinos Non-Standard Interactions
• Almost all neutrino oscillation data can be well • Matter effects arise from coherent CC forward described by a set of 3 neutrino mass eigenstates scattering of neutrinos on electrons in the coupling to the 3 charged leptons according to the earth’s interior, introducing a flavour imbalance. PMNS matrix. • If additional neutrino-electron interactions exist • Some hints of a 4th neutrino mass eigenstate, with beyond the Standard Model, they may modify very weak coupling to the charged leptons have the neutrino effective propagation Hamiltonian. been found, most notably by the LSND [1] and
MiniBooNE [2] collaborations. • Strong bounds exist on some NSI couplings, e e e • This new, eV scale, mass eigenstate changes the but limits on ee, et and tt are currently effective oscillation Hamiltonian and generates larger than GF [4]. new resonant transition • Atmospheric neutrinos provide effects due to propagation an excellent probe of these NSI, in matter [3]. since strong matter effects are expected to occur at the scale of [1] Phys. Rev. D 64, 112007 (2001) the Fermi interaction. [2] Phys. Rev. Lett. 110, 161801 (2013) [3] JHEP 0712, 014 (2007)
9 9 [4] Rept. Prog. Phys. 76, 044201 (2013) m vertical m spacing Standard Osc. Sterile (3+1) Examples: Examples: Non-Std. Int. Standard Osc.
• E = 24 GeV • E = 5.3 GeV 2 2 • Dm 41 = 0.3 eV 2 • |Ue4| = 0.04 • eet = 0.2 2 • |Um4| = 0.02 • ett = 0.04 2
• |Ut4| = 0.18 • eee = 0
Scan for animations Scan for animations • In ORCA, the dominant effect of adding a eV scale sterile neutrino • ORCA can probe NSI by searching would be the suppression of n to ̴20 m for changes in the oscillation m pattern due to resonant transitions nt oscillation at ~20 GeV. horizontal in both the n and n channels. spacing m e • This effect arises from an interplay of the CC and NC contributions to • The dominant effects would occur the matter potential. in the same energy range used to study the neutrino mass hierarchy, but a different zenith angle • Resonant nm to nt transitions from 100 GeV to the TeV scale also occur. dependence is expected.
• The suppression described above is • strongly dependent on the Ut4 With 1 year of data, ORCA would be sensitive to NSI effects more than an element of the mixing matrix. order of magnitude smaller than their current limits.
• With 1 year of data, ORCA would • NSI can give rise to a very rich 2 be sensitive to |Ut4| values 5x phenomenology and the interplay of smaller than current limits set by the different NSI parameters needs Super-Kamiokande [5]. to be studied carefully.
[5] Phys. Rev. D 91, 052019 (2015) • Constraints from long-baseline experiments will pin down the CAVEATS vacuum oscillation parameters, which is essential for achieving • Sensitivities in this poster are ORCA’s full potential. based on a simplified analysis and do NOT make use of the full KM3NeT-ORCA MC simulation.
• Detector response has been parameterised to approximately match the performance from MC studies performed by the KM3NeT Collaboration [6]. Read the KM3NeT Letter of Intent [6] J. Phys. G: Nucl. Part. Phys. 43, 084001 (2016)