Florida and Texas banned them. Airlines, universities, event venues and other businesses are also testing various methods of vaccine verification. The starkly different approaches reflect a wider national and global debate on proof of health in the pandemic era.

“There are a lot of ways it could be done badly,” Jay Stanley of the American Civil Liberties Union told DealBook, but he suggested a “narrow path” to a certification system that could work. The ideal system would be paper-based with a digital supplement, Mr. Stanley argues, so that people who lack access to technology aren’t disadvantaged. Encrypted data would be stored on a decentralized network, protected with a public key for vaccine providers and private keys for users to ensure privacy. Fairness also demands a standardized approach, rather than the current variety of systems, which could result in “a mess for civil liberties, equity and privacy,” he said.

The Biden administration has said it won’t mandate vaccine passports, a point it reiterated this week, but it is working on standards the private sector can adopt. New York partnered with IBM on the state’s opt-in Excelsior Pass, which allows access to restricted activities and venues.

The certificates can raise a slew of social and legal issues, depending on who is asking for proof of vaccination and why, according to the Stanford law professor David Studdert. Government mandates trigger more concerns than opt-in programs, he noted, and companies will have different considerations if they seek certification from customers or workers. Given all the variations, he said, “within reason” the market should decide what works, and officials should avoid both mandates and bans: “Different communities and employers have a different tolerance for risk.”

More on vaccine passports:

Deals

  • A top S.E.C. official warned of “significant and yet undiscovered issues” with SPACs, the latest words of caution from the regulator about blank-check funds. (WSJ)

  • Twitter is said to have held talks to buy Clubhouse for $4 billion, though negotiations aren’t currently active. (Bloomberg)

  • Shares in Deliveroo rose after retail investors were allowed to start trading in the food delivery service. (CNBC)

Politics and policy

  • China is offering tax breaks and other perks to financiers in Hong Kong to keep them from leaving the territory. (NYT)

  • A federal official warned last June that Emergent BioSolutions, the company behind the Johnson & Johnson vaccine mix-up, lacked trained staff and had problems with quality control. (NYT)

Tech

  • Uber and Lyft are “throwing money” at drivers to bring them back to work. (FT)

  • Within weeks, Apple will roll out new privacy notifications for apps, which companies like Facebook have argued would harm their businesses. (Reuters)

  • “No publicly traded company is a family. I fell for the fantasy that it could be.” (NYT Op-Ed)

Best of the rest

  • How the pandemic pummeled the world’s most famous shopping streets. (Quartz)

  • Former employees of Marcus, the consumer lender that is key to Goldman Sachs’s future, reportedly say they were burned out by an ambitious product launch schedule. (Insider)

  • All about muons, the subatomic particles that seem to disobey the known laws of physics. (NYT)

We’d like your feedback! Please email thoughts and suggestions to dealbook@nytimes.com.

View Source

Finding From Particle Research Could Break Known Laws of Physics

Meanwhile, in 2020 a group of 170 experts known as the Muon g-2 Theory Initiative published a new consensus value of the theoretical value of muon’s magnetic moment, based on three years of workshops and calculations using the Standard Model. That answer reinforced the original discrepancy reported by Brookhaven.

Reached by phone on Monday, Aida X. El-Khardra, a physicist at the University of Illinois and a co-chair of the Muon g-2 Theory Initiative, said she did not know the result that Fermilab would be announcing two days later — and she didn’t want to, lest she be tempted to fudge in a lecture scheduled just before the official unveiling on Wednesday.

“I have not had the feeling of sitting on hot coals before,” Dr. El-Khadra said. “We’ve been waiting for this for a long time.”

On the day of the Fermilab announcement another group, using a different technique known as a lattice calculation to compute the muon’s magnetic moment, concluded that there was no discrepancy between the Brookhaven measurement and the Standard Model.

“Yes, we claim that there is no discrepancy between the Standard Model and the Brookhaven result, no new physics,” said Zoltan Fodor of Pennsylvania State University, one of the authors of a report published in Nature on Wednesday.

Dr. El-Khadra, who was familiar with that work, called it an “amazing calculation, but not conclusive.” She noted that the computations involved were horrendously complicated, having to account for all possible ways that a muon could interact with the universe, and requiring thousands of individual sub-calculations and hundreds of hours of supercomputer time.

These lattice calculations, she said, needed to be checked against independent results from other groups to eliminate the possibility of systematic errors. For now, the Theory Initiative’s calculation remains the standard by which the measurements will be compared.

View Source