The Quantum Focusing Conjecture (QFC) lies at the foundation of holography and semiclassical gravity. The QFC implies the Bousso bound and the Quantum Null Energy Condition (QNEC). The QFC also ensures the consistency of the quantum extremal surface prescription and bulk reconstruction in AdS/CFT.

United States

Raphael Bousso

Elisa Tabor

Discrete Max-Focusing

Novel methods to reconstruct the slant depth of the maximum of the longitudinal profile ( $$X_{\mathrm{max}}$$  <math> <msub> <mi>X</mi> <mi>max</mi> </msub> </math>  ) of high-energy showers initiated by gamma-rays as well as their energy ( $$E_0$$  <math> <msub> <mi>E</mi> <mn>0</mn> </msub> </math>  ) are presented. The methods were developed for gamma rays with energies ranging from a few hundred GeV to  $$\sim 10$$  <math> <mrow> <mo>∼</mo> <mn>10</mn> </mrow> </math>   TeV. An estimator of  $$X_{\mathrm{max}}$$  <math> <msub> <mi>X</mi> <mi>max</mi> </msub> </math>   is obtained, event-by-event, from its correlation with the distribution of the arrival time of the particles at the ground, or the signal at the ground for lower energies. An estimator of  $$E_0$$  <math> <msub> <mi>E</mi> <mn>0</mn> </msub> </math>   is obtained, event-by-event, using a parametrization that has as inputs the total measured energy at the ground, the amount of energy contained in a region near to the shower core and the estimated  $$X_{\mathrm{max}}$$  <math> <msub> <mi>X</mi> <mi>max</mi> </msub> </math>  . Resolutions about  $$40 \, (20)\,\mathrm{g/cm^2}$$  <math> <mrow> <mn>40</mn> <mspace width="0.166667em"></mspace> <mrow> <mo>(</mo> <mn>20</mn> <mo>)</mo> </mrow> <mspace width="0.166667em"></mspace> <mrow> <mi>g</mi> <mo>/</mo> <msup> <mi>cm</mi> <mn>2</mn> </msup> </mrow> </mrow> </math>   and about  $$30 \, (20)\%$$  <math> <mrow> <mn>30</mn> <mspace width="0.166667em"></mspace> <mo>(</mo> <mn>20</mn> <mo>)</mo> <mo>%</mo> </mrow> </math>   for, respectively,  $$X_{\mathrm{max}}$$  <math> <msub> <mi>X</mi> <mi>max</mi> </msub> </math>   and  $$E_0$$  <math> <msub> <mi>E</mi> <mn>0</mn> </msub> </math>   at  $$1 \, (10) \ \mathrm {TeV}$$  <math> <mrow> <mn>1</mn> <mspace width="0.166667em"></mspace> <mo>(</mo> <mn>10</mn> <mo>)</mo> <mspace width="4pt"></mspace> <mi>TeV</mi> </mrow> </math>   energies are obtained, considering vertical showers. The obtained results are auspicious and can lead to the opening of new physics avenues for large wide field-of-view gamma-ray observatories. The dependence of the resolutions with experimental conditions is discussed.

Portugal

R. Conceição

L. Peres

M. Pimenta

B. Tomé

New methods to reconstruct  $$X_{\mathrm{max}}$$  <math> <msub> <mi>X</mi> <mi>max</mi> </msub> </math>   and the energy of gamma-ray air showers with high accuracy in large wide-field observatories

The determination of the neutrino mass is one of the major challenges in astroparticle physics today. Direct neutrino mass experiments, based solely on the kinematics of $$\upbeta $$ <math><mi>β</mi></math> -decay, provide a largely model-independent probe to the neutrino mass scale. The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to directly measure the effective electron antineutrino mass with a sensitivity of $$0.2\hbox { eV}$$ <math><mrow><mn>0.2</mn><mspace width="0.333333em"></mspace><mtext>eV</mtext></mrow></math>  ($$90\%$$ <math><mrow><mn>90</mn><mo>%</mo></mrow></math>  CL). In this work we report on the first operation of KATRIN with tritium which took place in 2018. During this commissioning phase of the tritium circulation system, excellent agreement of the theoretical prediction with the recorded spectra was found and stable conditions over a time period of 13 days could be established. These results are an essential prerequisite for the subsequent neutrino mass measurements with KATRIN in 2019.

Germany

Max Aker

France

Konrad Altenmüller

Marius Arenz

Woo-Jeong Baek

John Barrett

Armen Beglarian

Jan Behrens

Russia

Anatoly Berlev

Uwe Besserer

Klaus Blaum

Fabian Block

Steffen Bobien

Beate Bornschein

Lutz Bornschein

Heiko Bouquet

Tim Brunst

Thomas Caldwell

Suren Chilingaryan

Wonqook Choi

Karol Debowski

Marco Deffert

Martin Descher

Spain

Deseada Díaz Barrero

Peter Doe

Czechia

Otokar Dragoun

Guido Drexlin

Stephan Dyba

Frank Edzards

Klaus Eitel

Enrico Ellinger

Ralph Engel

Sanshiro Enomoto

Dieter Eversheim

Mariia Fedkevych

Arne Felden

Joseph Formaggio

Florian Fränkle

Gregg Franklin

Heinz Frankrone

Fabian Friedel

Dominik Fuchs

Alexander Fulst

Kevin Gauda

Woosik Gil

Ferenc Glück

Steffen Grohmann

Robin Grössle

Rainer Gumbsheimer

Moritz Hackenjos

Volker Hannen

Julius Hartmann

Norman Haußmann

Martin Ha-Minh

Florian Heizmann

Johannes Heizmann

Klaus Helbing

Stephanie Hickford

David Hillesheimer

Dominic Hinz

Thomas Höhn

Bernhard Holzapfel

Siegfried Holzmann

Thibaut Houdy

Mark Howe

Anton Huber

Alexander Jansen

Christian Karl

Jonas Kellerer

Norbert Kernert

Luke Kippenbrock

Manuel Klein

Christoph Köhler

Leonard Köllenberger

Andreas Kopmann

Marc Korzeczek

Alojz Kovalík

Bennet Krasch

Holger Krause

Benedikt Kuffner

Norbert Kunka

Thierry Lasserre

Luisa La Cascio

Ondřej Lebeda

Manuel Lebert

Björn Lehnert

Johann Letnev

Fabian Leven

Thanh-Long Le

Steffen Lichter

Alexey Lokhov

Moritz Machatschek

Emma Malcherek

Martin Mark

Alexander Marsteller

Eric Martin

Fotios Megas

Christin Melzer

Alexander Menshikov

Susanne Mertens

Matthias Meier

First operation of the KATRIN experiment with tritium

The atmospheric depth where the energy deposit profile of secondary particles from extensive air showers (EAS) reaches its maximum, $$X_{\mathrm{max}}$$ <math><msub><mi>X</mi><mi>max</mi></msub></math> , is related to the primary particle mass. The mass composition of the ultra-high energy cosmic rays (UHECRs) can be inferred from measurements of $$X_{\mathrm{max}}$$ <math><msub><mi>X</mi><mi>max</mi></msub></math>  distributions in each energy interval, by fitting these distributions with Monte Carlo (MC) templates for four primary species (p, He, N and Fe). On the basis of simulations, we show that a high abundance of some intermediate elements in the $$X_{\mathrm{max}}$$ <math><msub><mi>X</mi><mi>max</mi></msub></math>  distributions, e.g. Ne or Si, may affect the quality of the fit and also the reconstructed fractions of different species with respect to their true values. We propose a method for finding the “best combination” of elements in each energy interval from a larger set of primaries (p, He, C, N, O, Ne, Si and Fe) which best describes the $$X_{\mathrm{max}}$$ <math><msub><mi>X</mi><mi>max</mi></msub></math>  distributions. Applying this method to the $$X_{\mathrm{max}}$$ <math><msub><mi>X</mi><mi>max</mi></msub></math>  distributions measured by the Pierre Auger Observatory (2014), we found that the “best combination” of elements which best describe the data suggest the presence of Ne or Si in some low energy bins for the EPOS-LHC model.

Romania

Nicusor Arsene

Octavian Sima

UHECRs mass composition from $$X_{\mathrm{max}}$$ <math><msub><mi>X</mi><mi>max</mi></msub></math>  distributions

In the context of massive (bi-)gravity, non-minimal matter couplings have been proposed. These couplings are special in the sense that they are free of the Boulware-Deser ghost below the strong coupling scale and can be used consistently as an effective field theory. Furthermore, they enrich the phenomenology of massive gravity. We consider these couplings in the framework of bimetric gravity and study the cosmological implications for background and linear tensor, vector, and scalar Previous works have investigated special branches of solutions. Here we perform a complete perturbation analysis for the general background equations of motion, completing previous analyses.

Japan

China

Xian Gao

Switzerland

Lavinia Heisenberg

Doubly coupled matter fields in massive bigravitySupported by the Chinese National Youth Thousand Talents Program (71000-41180003), JSPS Grant-in-Aid for Scientific Research (15H02082, 25287054, 26610062), L. H. Acknowledges Financial Support from Dr. Max Rössler, the Walter Haefner Foundation and the ETH Zurich Foundation