[Paper Review] An Interpretation of "Superluminal Neutrino" Compatible with Relativity in the Framework of Standard Model

Noboru Nakanishi|arXiv (Cornell University)|Nov 7, 2011

Particle physics theoretical and experimental studies3 references3 citations

TL;DR

This paper proposes that the OPERA experiment's observation of superluminal neutrinos can be reconciled with relativity by assuming the measured speed of light in vacuum ($c_0$) is slower than the true relativistic speed $c$, due to a medium of dispersed quarks. Using a modified color confinement condition in QCD, the model explains the neutrino speed anomaly without violating relativity or the Standard Model, and remains consistent with SN1987A neutrino observations and other high-energy experiments.

ABSTRACT

According to the measurement of muon-neutrino experiment done by the OPERA collaboration, the speed of high-energy neutrino exceeds that of light in vacuum by 25ppm. Assuming that this result is correct, a possible resolution of the dilemma between it and the validity of relativity is proposed without changing the framework of the Standard Model of elementary particles. The essential idea is based on a possible resolution, proposed previously, of the color confinement problem of quantum chromodynamics.

Motivation & Objective

• To resolve the apparent contradiction between the OPERA experiment’s superluminal neutrino result and the principles of special relativity.
• To maintain the validity of the Standard Model and relativity by reinterpreting the measured speed of light ($c_0$) as lower than the true relativistic speed $c$.
• To explain the anomaly without introducing tachyons or new physics beyond the Standard Model.
• To ensure consistency with cosmological observations, particularly the SN1987A neutrino burst, which constrains neutrino mass and propagation speed.
• To reconcile conflicting experimental results on photon speed, including those from Fermi and HERA, by positing a local medium of dispersed quarks near Earth.

Proposed method

• Introduces an extended color confinement condition in QCD by adding $Q^a|\text{phys}\rangle = 0$ to the standard Kugo-Ojima condition, ensuring all colored states are unphysical.
• Proposes that the cloud of dispersed quarks—composed of charged quarks—acts as a medium that slows light to $c_0 < c$, while neutrinos are unaffected by this medium.
• Assumes that the true speed of light $c$ is the relativistic constant, while $c_0$ is the experimentally measured speed in a quark-rich medium.
• Uses the kinematic relation $v = c \sqrt{1 - (c_0/c)^2}$ to derive neutrino speed from the OPERA result, yielding $v - c_0 \approx 25$ ppm.
• Applies the model to SN1987A by assuming the quark cloud is localized near high-density regions (e.g., Earth and supernovae), so neutrinos travel mostly in true vacuum.
• Demonstrates that the model avoids tachyonic or causal paradoxes by allowing a rest frame for superluminal neutrinos when $c_0 < v < c$.

Experimental results

Research questions

• RQ1 Can the OPERA observation of superluminal neutrinos be reconciled with special relativity without violating the Standard Model?
• RQ2 Is there a physical mechanism that explains why $c_0 < c$ without introducing tachyons or new fundamental particles?
• RQ3 How can the model remain consistent with the SN1987A neutrino observation, which constrains neutrino speed and mass?
• RQ4 Why do high-energy experiments like SLAC and Fermi not contradict the hypothesis of a slower $c_0$?
• RQ5 Can the observed energy dependence of photon speed in some experiments be explained by a local quark cloud medium near Earth?

Key findings

• The OPERA result of $ (v - c_0)/c_0 = 2.48 \pm 0.28 \pm 0.30 \times 10^{-5} $ is compatible with relativity if $c_0 < v < c$, where $c$ is the true speed of light in vacuum.
• The model predicts that the neutrino speed exceeds $c_0$ by 25 ppm, consistent with the OPERA measurement, without violating causality.
• The SN1987A neutrino observation is consistent with the model if the cloud of dispersed quarks is localized near Earth and the supernova, not along the entire path.
• The upper bound on the neutrino mass derived from SN1987A is $m \approx 85$ keV if the cloud were present throughout the path, but this is ruled out by known mass bounds, so the cloud must be localized.
• The model explains the apparent energy dependence of photon speed in HERA data and the lack of such dependence in Fermi observations by attributing the effect to a local medium near Earth.
• The SLAC experiment is consistent with the model because it was conducted in a region where the quark cloud was removed, so $c_0 = c$ in that context, and no contradiction arises.