Abstract We discuss spontaneous chiral symmetry breaking and the quark bilinear condensate in large-N$_{c}$ quantum chromodynamics (QCD). It is known that the existence of the η′ meson is implied in large-N$_{c}$ QCD, as pointed out by Witten[27] and Veneziano[28]. First, we show that the existence of η′ and the Ward–Takahashi identities implies the existence of Nambu–Goldstone bosons from chiral symmetry breaking SU(N$_{f}$)$_{L}$ × SU(N$_{f}$)$_{R}$ → SU(N$_{f}$)$_{V}$. Second, we show that a QCD inequality implies a non-zero lower bound on the quark bilinear condensate.

Japan

Ryosuke Sato

Chiral symmetry breaking and the quark bilinear condensate in large- Qcd La Rivista del Nuovo Cimento Quarks and strings on a lattice

We study the orientifold projections of the <math><mi>N</mi><mo>=</mo><mn>1</mn></math> superconformal field theories describing D3-branes probing the Pseudo del Pezzo singularities PdP<math><msub><mrow></mrow><mrow><mn>3</mn><mi>b</mi></mrow></msub></math> and PdP<math><msub><mrow></mrow><mrow><mn>3</mn><mi>c</mi></mrow></msub></math>. The PdP<math><msub><mrow></mrow><mrow><mn>3</mn><mi>c</mi></mrow></msub></math> parent theory admits two inequivalent orientifolds. Exploiting a maximization, we find that one of the two has an a-charge smaller than what one would expect from the orientifold projection, which suggests that the theory flows to the fixed point in the infrared. Surprisingly, the value of a coincides with the charge of the unoriented PdP<math><msub><mrow></mrow><mrow><mn>3</mn><mi>b</mi></mrow></msub></math> and we interpret this as the sign of an infrared duality.

Italy

Andrea Antinucci

Salvo Mancani

Fabio Riccioni

Infrared duality in unoriented Pseudo del Pezzo

Motivated by understanding M2-branes, we propose to reformulate partition functions of M2-branes by quantum curves. Especially, we focus on the backgrounds of del Pezzo geometries, which enjoy Weyl group symmetries of exceptional algebras. We construct quantum curves explicitly and turn to the analysis of classical phase space areas and quantum mirror maps. We find that the group structure helps in clarifying previous subtleties, such as the shift of the chemical potential in the area and the identification of the overall factor of the spectral operator in the mirror map. We list the multiplicities characterizing the quantum mirror maps and find that the decoupling relation known for the BPS indices works for the mirror maps. As a result, with the group structure we can present explicitly the statement for the correspondence between spectral theories and topological strings on del Pezzo geometries.

Sanefumi Moriyama

Spectral theories and topological strings on del Pezzo geometries

We investigate the 
					 invariant mass distribution in the 
					 reaction at a center-of-mass energy of 
					 GeV measured by the BESIII collaboration, which concluded that no significant signals were observed for 
					 because of the low statistics. We show, however, that the 
					 invariant mass distribution is compatible with the existence of the 
					 state, appearing as a peak, and a strong cusp structure at the 
					 threshold, resulting from the molecular nature of the 
					 state, which provides a substantial contribution to the reaction. This is consistent with our previous analysis of the 
					 decay measured by the LHCb collaboration. We strongly suggest further measurements of this process with more statistics to clarify the nature of the 
					 and 
					 resonances.
				

China

En Wang

Ju-Jun Xie

Li-Sheng Geng

Spain

Eulogio Oset

The X(4140) and X(4160) resonances in the 
					 reaction Partly supported by the National Natural Science Foundation of China (11735003, 11522539, 11505158, 11475015, 11647601), supported by the Youth Innovation Promotion Association CAS (2016367), Key Research Projects of Henan Higher Education Institutions (20A140027), and the Academic Improvement Project of Zhengzhou University. This work is also partly supported by the Spanish Ministerio de Economia y Competitividad and European FEDER funds under the contract number FIS2014-57026-REDT, FIS2014-51948-C2-1-P, and FIS2014-51948-C2-2-P, the Generalitat Valenciana in the program Prometeo II2014/068, and the proyecto Severo Ochoa del IFIC, SEV-2014-0398.

We revisit a correspondence between toroidal compactifications of M-theory and del Pezzo surfaces, in which rational curves on the del Pezzo are related to <math><mfrac><mn>1</mn><mn>2</mn></mfrac></math>-BPS branes of the corresponding compactification. We argue that curves of higher genus correspond to nongeometric backgrounds of the M-theory compactifications, which are related to exotic branes. In particular, the number of “special directions” of the exotic brane is equal to the genus of the corresponding curve. In addition to predicting three new nongeometric backgrounds, we discuss a relation between addition of curves in the del Pezzo and the brane polarization effect.

United States

Justin Kaidi

Exotic branes from del Pezzo surfaces

The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays and (; or ) are predicted by means of a data-driven approach based on the use of rational approximants applied to and transition form factor experimental data in the space-like region.

Rafel Escribano

Sergi Gonzàlez-Solís

A data-driven approach to and single and double Dalitz decaysSupported by the FPI scholarship BES-2012-055371 (S.G-S), the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya under grant 2014 SGR 1450, the Ministerio de Ciencia e Innovación under grant FPA2011-25948, the Ministerio de Economía y Competitividad under grants CICYT-FEDER-FPA 2014-55613-P and SEV-2012-0234, the Spanish Consolider-Ingenio 2010 Program CPAN (CSD2007-00042), and the European Commission under program FP7-INFRASTRUCTURES-2011-1 (283286) S.G-S also Received Support from the CAS President’s International Fellowship Initiative for Young International Scientist (2017PM0031)

We present an explicit expression for the grand potential of the U(N )3 superconformal Chern-Simons theory with the Chern-Simons levels being (k, 0, −k). From the viewpoint of the Newton polygon, it is expected that the grand potential is given by the free energy of the topological string theory on the local D 5 del Pezzo geometry, though the explicit identification was a puzzle for years. We show how the expectation is realized explicitly. As a bonus, we can also study the  <math><msub><mi>ℤ</mi><mn>2</mn></msub></math> $$ {\mathbb{Z}}_2 $$ orbifold of this theory and find the grand potential is now given in terms of the local E 7 del Pezzo geometry.

South Korea

Tomoki Nosaka

Katsuya Yano

Superconformal Chern-Simons theories from del Pezzo geometries

Both scalar fields and (generalized) Chaplygin gases have been widely used separately to characterize the dark sector of the universe. Here we investigate the cosmological background dynamics for a mixture of both these components and quantify the fractional abundances that are admitted by observational data from supernovae of type Ia and from the evolution of the Hubble rate. Moreover, we study how the growth rate of (baryonic) matter perturbations is affected by the dark-sector perturbations.

Chile

Sergio del Campo

Russia

Brazil

Júlio C. Fabris

Ramón Herrera

Winfried Zimdahl

Is the cosmological dark sector better modeled by a generalized Chaplygin gas or by a scalar field?

We report the first results of DarkSide-50, a direct search for dark matter operating in the underground Laboratori Nazionali del Gran Sasso (LNGS) and searching for the rare nuclear recoils possibly induced by weakly interacting massive particles (WIMPs). The dark matter detector is a Liquid Argon Time Projection Chamber with a <math><mo>(</mo><mn>46.4</mn><mo>±</mo><mn>0.7</mn><mo>)</mo><mtext> </mtext><mtext>kg</mtext></math> active mass, operated inside a 30 t organic liquid scintillator neutron veto, which is in turn installed at the center of a 1 kt water Cherenkov veto for the residual flux of cosmic rays. We report here the null results of a dark matter search for a <math><mo>(</mo><mn>1422</mn><mo>±</mo><mn>67</mn><mo>)</mo><mtext> </mtext><mtext>kg</mtext><mspace width="0.2em"></mspace><mtext>d</mtext></math> exposure with an atmospheric argon fill. This is the most sensitive dark matter search performed with an argon target, corresponding to a 90% CL upper limit on the WIMP-nucleon spin-independent cross section of <math><mn>6.1</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>44</mn></mrow></msup><mtext> </mtext><msup><mrow><mtext>cm</mtext></mrow><mrow><mn>2</mn></mrow></msup></math> for a WIMP mass of <math><mn>100</mn><mtext> </mtext><mtext>Gev</mtext><mo>/</mo><msup><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msup></math>.

France

P. Agnes

T. Alexander

A. Alton

K. Arisaka

H.O. Back

B. Baldin

K. Biery

G. Bonfini

M. Bossa

A. Brigatti

J. Brodsky

F. Budano

L. Cadonati

F. Calaprice

N. Canci

A. Candela

H. Cao

M. Cariello

P. Cavalcante

A. Chavarria

A. Chepurnov

A.G. Cocco

L. Crippa

D. D'Angelo

M. D'Incecco

S. Davini

M. De Deo

A. Derbin

A. Devoto

F. Di Eusanio

G. Di Pietro

E. Edkins

A. Empl

A. Fan

G. Fiorillo

JINR

K. Fomenko

G. Forster

D. Franco

F. Gabriele

C. Galbiati

A. Goretti

L. Grandi

M. Gromov

M.Y. Guan

Y. Guardincerri

B. Hackett

K. Herner

E.V. Hungerford

Al. Ianni

An. Ianni

C. Jollet

K. Keeter

C. Kendziora

S. Kidner

Ukraine

V. Kobychev

G. Koh

D. Korablev

G. Korga

A. Kurlej

P.X. Li

B. Loer

P. Lombardi

C. Love

L. Ludhova

S. Luitz

Y.Q. Ma

I. Machulin

A. Mandarano

S. Mari

J. Maricic

L. Marini

C.J. Martoff

A. Meregaglia

E. Meroni

P.D. Meyers

R. Milincic

D. Montanari

A. Monte

M. Montuschi

M.E. Monzani

P. Mosteiro

B. Mount

V. Muratova

P. Musico

A. Nelson

S. Odrowski

M. Okounkova

M. Orsini

F. Ortica

L. Pagani

M. Pallavicini

E. Pantic

L. Papp

S. Parmeggiano

R. Parsells

Poland

K. Pelczar

N. Pelliccia

S. Perasso

A. Pocar

S. Pordes

First results from the DarkSide-50 dark matter experiment at Laboratori Nazionali del Gran Sasso

We use mirror symmetry, quantum geometry and modularity properties of elliptic curves to calculate the refined free energies in the Nekrasov-Shatashvili limit on non-compact toric Calabi-Yau manifolds, based on del Pezzo surfaces. Quantum geometry here is to be understood as a quantum deformed version of rigid special geometry, which has its origin in the quantum mechanical behaviour of branes in the topological string B-model. We will argue that, in the Seiberg-Witten picture, only the Coulomb parameters lead to quantum corrections, while the mass parameters remain uncorrected. In certain cases we will also compute the expansion of the free energies at the orbifold point and the conifold locus. We will compute the quantum corrections order by order on ℏ, by deriving second order differential operators, which act on the classical periods.