"Neutrinoless double beta decay" is the correct name for neutrinoless double beta decay

This paper argues against the proposal to rename "neutrinoless double beta decay" as "Majorana double beta decay," asserting that the current terminology is more accurate and that the motivations for the change lack credibility.

The Gist

Imagine the world of particle physics as a giant, high-stakes detective story. For decades, scientists have been hunting for a very specific, ghostly event called "Neutrinoless Double Beta Decay."

Recently, a new voice in the story (a paper by F. Vissani) argued that we are using the wrong name for this crime. They want to rename it "Majorana Double Beta Decay" to give credit to a famous physicist named Ettore Majorana and to make the event sound more like a "creation of matter" rather than just the "absence" of something.

James M. Cline, the author of the paper you provided, is stepping in to say: "Hold on. The current name is actually the best one, and the reasons for changing it don't hold up."

Here is the breakdown of his argument, using simple analogies:

1. The Name Game: Who Deserves the Credit?

The Proposal: The critics say, "Let's call it 'Majorana' because Majorana is the famous guy associated with this idea."
Cline's Rebuttal: "That's like naming a car the 'Ford' when Henry Ford didn't invent the engine; someone else did."

• The Real Inventor: Cline points out that W. H. Furry was actually the first person to realize this specific decay was possible. If we were going to name it after the person who first figured it out, it should be "Furry Double Beta Decay," not Majorana's.
• The Confusion: Majorana did a different, though related, job. He showed that if neutrinos are their own antiparticles (like a mirror image of themselves), it changes the rules of the game. But calling the whole event "Majorana" makes it sound like the ordinary version of the event involves Majorana particles, which is confusing and historically inaccurate.

2. The "Missing" vs. The "Created"

The Proposal: The critics argue that the current name ("Neutrinoless") focuses on what is missing (the neutrinos), which sounds negative. They want a name that focuses on what is created (matter in the lab).
Cline's Rebuttal: "You're trying to sell a lemon by calling it a 'fruit salad'."

• The Analogy: Imagine you are baking a cake.
  • Normal Version: You bake a cake and it comes out with two candles and two wrappers.
  • The Special Version: You bake a cake, and it comes out with just two candles. The wrappers are gone.
• The critics say, "Let's call this the 'Candle Creation Event' because we made candles!"
• Cline says, "No, the most important thing is that the wrappers are missing. That is the magic trick. The fact that we didn't get the wrappers (neutrinos) is the only thing that proves the cake is special. Calling it 'Matter Creation' is just marketing hype. We aren't creating new matter out of thin air; we are just noticing that the usual 'trash' (antineutrinos) didn't show up."

3. The "Sociology of Suspicion"

The Proposal: The critics suggest scientists changed the name because they were embarrassed by false claims of finding this decay in the past. They think the community wanted a "neutral" name to hide their mistakes.
Cline's Rebuttal: "There is no evidence for this conspiracy theory."

• Cline argues that the name "Neutrinoless" wasn't chosen to hide embarrassment. It was chosen because it is the most accurate description of what is happening. In the 1950s, when the name was coined, scientists just cited the papers they had actually read. They weren't trying to play a game of "who gets the credit"; they were just describing the physics.

The Bottom Line

James M. Cline concludes that we should keep the name "Neutrinoless Double Beta Decay."

• It's accurate: It tells you exactly what is missing (the neutrinos), which is the key to the mystery.
• It's honest: It doesn't try to oversell the event as a magical "creation of matter."
• It's fair: Everyone in the physics community already knows that finding this decay proves neutrinos are "Majorana" particles. We don't need to change the name to give Majorana credit; the science speaks for itself.

In short: Don't rename the crime scene just to make it sound more dramatic or to give a specific detective a medal. The current name tells the truth about what is missing, and that is the most important clue of all.

Technical Summary

Based on the provided text, here is a detailed technical summary of the paper "Neutrinoless double beta decay is the correct name for neutrinoless double beta decay" by James M. Cline.

1. Problem Statement

The paper addresses a recent proposal (Ref. [1] by F. Vissani) to rename the particle physics phenomenon currently known as "neutrinoless double beta decay" ($0\nu\beta\beta$) to "Majorana double beta decay."

The proponents of this change argue that:

• The current name is a "semantically bleached neologism" that obscures the physics.
• The term "neutrinoless" focuses on a negative aspect (the absence of neutrinos) and reflects a "sociology of suspicion" stemming from past false claims of detection.
• The new name would properly credit Ettore Majorana and emphasize the "positive" aspect of the phenomenon: the creation of matter in the laboratory.

Cline challenges the validity of these arguments, asserting that the proposed name change is historically inaccurate, physically misleading, and unnecessary for crediting Majorana.

2. Methodology

Cline employs a historical and conceptual analysis to refute the arguments for renaming. His methodology involves:

• Historical Fact-Checking: Examining the original literature to determine who first proposed the possibility of the process and who introduced the current terminology.
• Physical Definition Analysis: Comparing the physical mechanisms of standard double beta decay ($2\nu\beta\beta$) and neutrinoless double beta decay ($0\nu\beta\beta$) to determine the most accurate descriptive term.
• Contextual Review: Analyzing the citation practices of early experimentalists (specifically J.A. McCarthy) to understand the origins of the terminology.
• Logical Deconstruction: Critiquing the "matter creation" argument by analyzing the conservation laws and particle content of the decay processes.

3. Key Contributions and Arguments

A. Historical Accuracy and Attribution

• Furry vs. Majorana: Cline clarifies that W.H. Furry (1939), not Ettore Majorana, was the first to recognize the possibility of neutrinoless double beta decay. Majorana's 1937 paper demonstrated that ordinary beta decay theory remains practically unaltered if neutrinos are their own antiparticles (Majorana fermions), but he did not explicitly propose the $0\nu\beta\beta$ process.
• Conclusion on Naming: If the goal were strictly to credit the discoverer of the process, it should be called "Furry double beta decay," not "Majorana double beta decay."
• Terminology Origin: The term "neutrinoless" was introduced by J.A. McCarthy in 1953. Cline argues this was standard practice for the era, where experimentalists cited only directly relevant papers they had read (Furry and Goeppert-Mayer) rather than broader theoretical influencers.

B. Physical Descriptiveness

• Defining Feature: The most critical physical distinction between $2\nu\beta\beta$ and $0\nu\beta\beta$ is the absence of neutrinos in the final state.
• Misleading Implications: Calling it "Majorana double beta decay" creates a misleading mental image where ordinary double beta decay is accompanied by two Majorana neutrinos. The current name accurately describes the observable difference: the lack of neutrino emission.
• Credit is Already Given: Cline argues that renaming is unnecessary because the physics community already universally understands that observing $0\nu\beta\beta$ constitutes evidence for the Majorana nature of neutrinos.

C. Critique of the "Matter Creation" Argument

• Rejection of Hyperbole: Cline dismisses the claim that $0\nu\beta\beta$ represents significant "matter creation."
• Particle Accounting: In $2\nu\beta\beta$, the decay produces two electrons and two antineutrinos. In $0\nu\beta\beta$, it produces two electrons.
• Logical Flaw: Cline argues that since the antineutrinos in $2\nu\beta\beta$ are low-energy and essentially inert/invisible, their absence in $0\nu\beta\beta$ does not constitute a net "creation of matter" in any significant physical sense. He views the "matter creation" narrative as an exaggeration often used to link the phenomenon to leptogenesis.

4. Results

The paper concludes that the proposal to rename the phenomenon is unfounded based on the following findings:

1. Historical Error: The process was not originally called "Majorana double beta decay," nor was Majorana the first to propose it.
2. Descriptive Superiority: "Neutrinoless" is the most accurate descriptor because it highlights the specific experimental signature (missing neutrinos) that distinguishes the process from the standard mode.
3. Unnecessary Change: The link between the observation of the process and the Majorana nature of neutrinos is already well-established in the community; a name change adds no new scientific value.

5. Significance

• Preservation of Scientific Terminology: The paper defends the stability and accuracy of established scientific nomenclature against changes driven by sociological or branding motivations rather than physical necessity.
• Clarification of History: It corrects the historical record regarding the origins of the $0\nu\beta\beta$ concept, ensuring credit is correctly attributed to Furry for the proposal and Majorana for the underlying particle nature.
• Focus on Physics: It reinforces the view that the defining characteristic of the phenomenon is the absence of neutrinos (a test of lepton number violation), rather than a philosophical rebranding of "matter creation."

In summary, Cline argues that the current terminology is scientifically precise, historically grounded, and sufficient for communicating the physics, rendering the proposed change to "Majorana double beta decay" both inaccurate and unnecessary.