Ultra-High Energy Cosmic Rays from Galactic Supernovae

📝 Abstract

Suppose that even the highest energy cosmic rays (CRs) observed on Earth are protons accelerated in local Milky Way Galaxy sources, with few if any from more distant sources. In this paper we treat the problem that supernovae remnants likely produce protons with energies up to about a PeV, but CRs with 100s of EeV energy are observed. We assume with minimal comment the idea that `new physics’ is at work and we accept that a CR’s collision energy at the Earth exceeds its kinetic energy as it travels through the Galaxy. There is some evidence that the collision energy-kinetic energy difference has been seen at the Tevatron and LHC, but it is small enough to attribute to standard physics. This sets the threshold for energy bifurcation. Based on this threshold and the CR spectrum endpoint, a formula for collision energy as a function of kinetic energy is derived. With the function and the observed CR spectrum we can predict the average spectrum of CR sources. Also we can estimate the collision energies of proton beams as terrestrial particle accelerators advance and produce beams with higher kinetic energies.

💡 Analysis

Suppose that even the highest energy cosmic rays (CRs) observed on Earth are protons accelerated in local Milky Way Galaxy sources, with few if any from more distant sources. In this paper we treat the problem that supernovae remnants likely produce protons with energies up to about a PeV, but CRs with 100s of EeV energy are observed. We assume with minimal comment the idea that `new physics’ is at work and we accept that a CR’s collision energy at the Earth exceeds its kinetic energy as it travels through the Galaxy. There is some evidence that the collision energy-kinetic energy difference has been seen at the Tevatron and LHC, but it is small enough to attribute to standard physics. This sets the threshold for energy bifurcation. Based on this threshold and the CR spectrum endpoint, a formula for collision energy as a function of kinetic energy is derived. With the function and the observed CR spectrum we can predict the average spectrum of CR sources. Also we can estimate the collision energies of proton beams as terrestrial particle accelerators advance and produce beams with higher kinetic energies.

📄 Content

arXiv:0912.3897v2 [astro-ph.HE] 23 Jul 2012 Ultra-High Energy Cosmic Rays from Galactic Supernovae Richard Shurtleff∗ August 23, 2018 Abstract Suppose that even the highest energy cosmic rays (CRs) observed on Earth are protons accelerated in local Milky Way Galaxy sources, with few if any from more distant sources. In this paper we treat the problem that supernovae remnants likely produce protons with energies up to about a PeV, but CRs with 100s of EeV energy are observed. We assume with minimal comment the idea that ‘new physics’ is at work and we accept that a CR’s collision energy at the Earth exceeds its kinetic energy as it travels through the Galaxy. There is some evidence that the collision energy-kinetic energy difference has been seen at the Tevatron and LHC, but it is small enough to attribute to standard physics. This sets the threshold for energy bifurcation. Based on this threshold and the CR spectrum endpoint, a formula for collision energy as a function of kinetic energy is derived. With the function and the observed CR spectrum we can predict the average spectrum of CR sources. Also we can estimate the collision energies of proton beams as terrestrial particle accelerators advance and produce beams with higher kinetic energies. Keywords: Cosmic rays, Supernova remnants, Tevatron, LHC PACS: 96.50.S-, 98.70.Sa , 98.38.Mz, 14.20.Dh ∗affiliation and mailing address: Department of Science, Wentworth Institute of Technology, 550 Hunt- ington Avenue, Boston, MA, USA, ZIP 02115, telephone number: (617) 989-4338, e-mail address: shurtl- effr@wit.edu 1 1 INTRODUCTION 2 1 Introduction If we assume a local origin for cosmic rays, then a cosmic ray (CR) is accelerated in the Galaxy and has a trajectory through the Galaxy. We consider CR protons that are accelerated in supernovae remnants (SNRs). Accel- eration of charges in SNR shockwaves and trajectories in the Galaxy are well researched and continue to be subjects of ongoing investigations. The physics of both acceleration and trajectory accommodate a kinetic energy of at most 1 PeV or so.[1, 2] The most energetic CR protons deposit hundreds of EeVs into the Earth’s atmosphere, so-called ultrahigh energy cosmic rays (UHECRs). We assume that collisions between a CR proton and an atmospheric nucleus involve the same forces that have been studied at lower energies at terrestrial particle accelerators. Thus the UHECRs deposit 100s of EeV, yet are accelerated to at most 1 PeV in SNR shockwaves. With conventional forces for a CR’s collision with an atmospheric nucleus, with conventional forces for its acceleration at an SNR, and with conventional forces for its trajectory in the Galaxy, one remaining possibility is to contemplate the conjecture that a CR proton with a given kinetic energy carries also a collision energy that exceeds its kinetic energy. Protons with 1 PeV kinetic energy are beyond the reach of controlled experiments, so we are free to invoke ‘new physics’; a new relationship is presumed to exist between the collision energy and kinetic energy of protons, both measurable quantities. The two energies are measured differently and so may themselves differ. Kinetic energy depends on mass, timing and displacement, whereas collision energy depends on summing the individual energies of the collision products. The collision energy cannot be measured before the collision and the kinetic energy cannot be measured after. There are ways to make sense of collision energy exceeding kinetic energy. One way uses excited states. In a collision any incident particle in an excited state can deliver its kinetic energy and some or all of its excited state energy. The CR situation suggests that a proton has more internal energy the faster it goes. And that suggests a special frame in which the proton at rest has zero excess internal energy; the special frame is perhaps the cosmic microwave background (CMB) frame. So the ‘new physics’ could explain the extra energy, the collision energy minus the kinetic energy, and explain how that energy depends on speed in the CMB frame. Now turn from speculation to experimental results. Terrestrial particle accelerators produce proton beams with kinetic energies of about 1 TeV or so, with 7 TeV the design maximum for the Large Hadron Collider (LHC). From the LHC and the earlier Tevatron, there have been reports of excessive secondary particle production and unexpectedly high charged particle multiplicities.[3]-[9] These unexpected results could be interpreted as showing proton collision energies exceed kinetic energies. Instead, these small effects are mainly interpreted as modifying and improving accepted 2 DATA 3 theories. Here we disagree and interpret the results as new physics. We take a convenient percent- age, 10% at 1 TeV, as the fractional difference of collision and kinetic energy. This sets the threshold for the onset of collision/kinetic energy bifurcation. In Sec. 2 we discuss some of the available data at the CR spectru

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