CERN Accelerating science

TH Articles

Nyeste elementer:
2021-12-03
08:03
Estimating the thermal photon production rate using lattice QCD / Török, Csaba ; Cè, Marco ; Harris, Tim ; Krasniqi, Ardit ; Meyer, Harvey B. ; Toniato, Arianna
We present results for the photon emission rate determined from the transverse channel vector correlator at fixed spatial momentum using two flavors of dynamical Wilson fermions at $T\sim$250 MeV. We estimate the transverse channel spectral function using the continuum extrapolated correlator by applying various fit ansätze with a smooth matching to the NLO perturbative result. [...]
arXiv:2112.00563; CERN-TH-2021-171.- 2021-12-01 - Published in : PoS: LATTICE2021 (2021) , pp. 172 Fulltext: PDF;
In : 38th International Symposium on Lattice Field Theory, Online, 26 - 30 Jul 2021, pp.172

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2021-11-29
04:01
Mounting Evidence for the Violation of Lepton Flavor Universality / Crivellin, Andreas (Zurich U. ; PSI, Villigen ; CERN) ; Hoferichter, Martin (Bern U.)
The Standard Model (SM) of particle physics was finalized in its current form in the mid-1970s, and has been extensively tested and confirmed ever since, with the discovery of the Higgs boson in 2012 being the last missing piece. While no new particles have been directly discovered at the Large Hadron Collider (LHC) at CERN so far, precision observables sensitive to quantum effects of new particles have accumulated intriguing hints for physics beyond the SM. [...]
arXiv:2111.12739; CERN-TH-2021-193; PSI-PR-21-26; ZU-TH 55/21.- 2021-11-24 - 3 p. - Published in : Science 374 (2021) 1051 Fulltext: PDF;

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2021-11-17
06:21
Vacuum correlators at short distances from lattice QCD / Harris, Tim (Edinburgh U.) ; Cè, Marco (CERN) ; Meyer, Harvey B. (U. Mainz, PRISMA ; Mainz U., Inst. Kernphys. ; Darmstadt, GSI) ; Toniato, Arianna (U. Mainz, PRISMA) ; Török, Csaba (U. Mainz, PRISMA)
We propose a method to help control cutoff effects in the short-distance contribution to integrated correlation functions, such as the hadronic vacuum polarization (HVP), using the corresponding screening correlators computed at finite temperature. The strategy is investigated with Wilson fermions at leading order, which reveals a logarithmically-enhanced lattice artifact in the short-distance contribution, whose coefficient is determined at this order. [...]
arXiv:2111.07948; CERN-TH-2021-189.- 2021-11-15 - 9 p. - Published in : PoS: LATTICE2021 (2021) , pp. 572
Fulltext: PDF;
In : 38th International Symposium on Lattice Field Theory, Online, 26 - 30 Jul 2021, pp.572

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2021-10-06
11:30
Logarithmic accuracy of angular-ordered parton showers / Bewick, Gavin (Durham U., IPPP) ; Ferrario Ravasio, Silvia (Durham U., IPPP) ; Richardson, Peter (Durham U., IPPP ; CERN) ; Seymour, Michael H. (Manchester U.)
We study the logarithmic accuracy of angular-ordered parton showers by considering the singular limits of multiple emission matrix elements. This allows us to consider different choices for the evolution variable and propose a new choice which has both the correct logarithmic behaviour and improved performance away from the singular regions. [...]
arXiv:1904.11866; MAN/HEP/2019/003; CERN-TH-2019-047; MCnet-19-08; IPPP/19/30.- 2020-04-03 - 28 p. - Published in : JHEP 2004 (2020) 019 Article from SCOAP3: PDF; Fulltext: PDF;

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2021-09-19
15:48
On the chiral anomaly and the Yang–Mills gradient flow / Lüscher, Martin (CERN ; Bern U. ; U. Bern, AEC)
There are currently two singularity-free universal expressions for the topological susceptibility in QCD, one based on the Yang-Mills gradient flow and the other on density-chain correlation functions. While the latter link the susceptibility to the anomalous chiral Ward identities, the gradient flow permits the emergence of the topological sectors in lattice QCD to be understood. [...]
arXiv:2109.07965; CERN-TH-2021-132.- 2021-12-10 - 9 p. - Published in : Phys. Lett. B 823 (2021) 136725 Fulltext: PDF; Fulltext from publisher: PDF;

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2021-09-17
04:42
Theory Closing Talk / Giudice, Gian F. (CERN)
In this talk I make some remarks about the search for the origin of the electroweak scale..
arXiv:2109.07176; CERN-TH-2021-134.- 2021-11-17 - 8 p. - Published in : 10.22323/1.397.0019 Fulltext: 2109.07176 - PDF; document - PDF;
In : 9th Annual Large Hadron Collider Physics (LHCP 2021), Online, Gb, 7 - 12 Jun 2021, pp.019

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2021-09-07
04:30
Gauge-field production during axion inflation in the gradient expansion formalism / Gorbar, E.V. (Taras Shevchenko U. ; BITP, Kiev) ; Schmitz, K. (CERN) ; Sobol, O.O. (Taras Shevchenko U. ; EPFL, Lausanne, LPPC) ; Vilchinskii, S.I. (Taras Shevchenko U. ; EPFL, Lausanne, LPPC)
We study the explosive production of gauge fields during axion inflation in a novel gradient expansion formalism that describes the time evolution of a set of bilinear electromagnetic functions in position space. Based on this formalism, we are able to simultaneously account for two important effects that have thus far been mostly treated in isolation: (i) the backreaction of the produced gauge fields on the evolution of the inflaton field and (ii) the Schwinger pair production of charged particles in the strong gauge-field background. [...]
arXiv:2109.01651; CERN-TH-2021-128.- 2021-12-02 - 22 p. - Published in : Phys. Rev. D 104 (2021) 123504 Fulltext: 2109.01651 - PDF; PhysRevD.104.123504 - PDF;

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2021-08-07
04:45
Physics Beyond the Standard Model with BlackHawk v2.0 / Arbey, Alexandre (IP2I, Lyon ; CERN ; IUF, Paris) ; Auffinger, Jérémy (IP2I, Lyon)
We present the new version v2.0 of the public code BlackHawk designed to compute the Hawking radiation of black holes, with both primary and hadronized spectra. This new version aims at opening an avenue toward physics beyond the Standard Model (BSM) in Hawking radiation. [...]
arXiv:2108.02737; CERN-TH-2021-117.- 2021 - 14 p. - Published in : Eur. Phys. J. C 81 (2021) 910 Fulltext: PDF; Fulltext from publisher: PDF;

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2021-08-05
09:06
Primordial black holes from Gauss-Bonnet-corrected single field inflation / Kawai, Shinsuke (Sungkyunkwan U.) ; Kim, Jinsu (CERN)
Primordial blackholes formed in the early Universe via gravitational collapse of over-dense regions may contribute a significant amount to the present dark matter relic density. Inflation provides a natural framework for the production mechanism of primordial blackholes. [...]
arXiv:2108.01340; CERN-TH-2021-115.- 2021-10-15 - 9 p. - Published in : Phys. Rev. D 104 (2021) 083545 Fulltext: PDF; Fulltext from publisher: PDF;

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2021-07-31
04:03
First-Generation New Physics in Simplified Models: From Low-Energy Parity Violation to the LHC / Crivellin, Andreas (Zurich U. ; PSI, Villigen ; CERN) ; Hoferichter, Martin (Bern U. ; U. Bern, AEC) ; Kirk, Matthew (Rome U. ; INFN, Rome) ; Manzari, Claudio Andrea (Zurich U. ; PSI, Villigen) ; Schnell, Luc (Paris, LPTHE ; Zurich, ETH ; Ec. Polytech., Palaiseau (main))
New-physics (NP) constraints on first-generation quark-lepton interactions are particularly interesting given the large number of complementary processes and observables that have been measured. Recently, first hints for such NP effects have been observed as an apparent deficit in first-row CKM unitarity, known as the Cabibbo angle anomaly, and the CMS excess in $q\bar q\to e^+e^-$. [...]
arXiv:2107.13569; CERN-TH-2021-112; PSI-21-16; ZU-TH 32/21.- 2021-10-27 - 40 p. - Published in : JHEP 2110 (2021) 221 Fulltext: document - PDF; 2107.13569 - PDF;

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