Tue·Jun 8, 2021Tuesday·June 8, 2021

1. 01*

   Measurement of the transverse polarization of electrons emitted in neutron decay -- nTRV experiment

   K. Bodek🇵🇱 · A. Kozela🇵🇱

   This paper recalls the main achievements of the nTRV experiment which measured two components of the transverse polarization (${\sigma }_{T_1}$, ${\sigma }_{T_2}$) of electrons emitted in the $\beta$-decay of polarized, free neutrons and deduced two correlation coefficients, $R$ and $N$, that are sensitive to physics beyond the Standard Model. The value of time-reversal odd coefficient $R$, 0.004$\pm$0.012$\pm$0.005, significantly improved limits on the relative strength of imaginary scalar coupling constant in the weak interaction. The value obtained for the time-reversal even correlation coefficient $N$, 0.067$\pm$0.011$\pm$0.004, agrees with the Standard Model expectation, providing an important sensitivity test of the electron polarimeter. One of the conclusions of this pioneering experiment was that the transverse electron polarization in the neutron $\beta$-decay is worth more systematic exploring by measurements of yet experimentally not attempted correlation coefficients such as $H$, $L$, $S$, $U$ and $V$. This article presents a brief outlook on that questions.

   nucl-exSciPost Phys.Proc.(2021)·1 citation
2. 02*

   Measurement of the muon flux in the bunker of Monte Soratte with the CRC detector

   Attanasio Candela🇮🇹 · Alfredo Cocco🇮🇹 · Nicola D Ambrosio🇮🇹 · Massimiliano De Deo🇮🇹 · Alessio De Iulis🇮🇹 · Marco D Incecco🇮🇹 · Pablo Garcia Abia🇪🇸 · Carlo Gustavino🇮🇹 · Giuliano Gustavino🇺🇸 · Marcello Messina🇮🇹 · Gregory Paolucci🇮🇹 · Sandra Parlati🇮🇹 · Nicola Rossi🇮🇹

   In the context of the PTOLEMY project, the need for a site with a rather low cosmogenic induced background led us to measure the differential muon flux inside the bunker of Monte Soratte, located about 50~km north of Rome (Italy). The measurement was performed with the Cosmic Ray Cube (CRC), a portable tracking device. The simple operation of the Cosmic Ray Cube was crucial to finalise the measurements, as they were carried out during the COVID-19 lockdown and in a site devoid of scientific equipment. The muon flux measured at the Soratte hypogeum is above two orders of magnitude lower than the flux observed on the surface, suggesting the possible use of the Mt. Soratte bunker for hosting astroparticle physics experiments requiring a low environmental background.

   ↳ physics.ins-dethep-exnucl-exNucl.Instrum.Meth.A(2022)·3 citations
3. 03*

   Lattice QCD Equation of State for Nonvanishing Chemical Potential by Resumming Taylor Expansion

   Sourav Mondal🇮🇳 · Swagato Mukherjee🇺🇸 · Prasad Hegde🇮🇳

   Taylor expansion in powers of baryon chemical potential (${\mu }_B$) is an oft-used method in lattice QCD to compute QCD thermodynamics for ${\mu }_B>0$. Based only upon the few known lowest order Taylor coefficients, it is difficult to discern the range of ${\mu }_B$ where such an expansion around ${\mu }_B=0$ can be trusted. We introduce a resummation scheme for the Taylor expansion of the QCD equation of state in ${\mu }_B$ that is based on the $n$-point correlation functions of the conserved current ($D_n$). The method resums the contributions of the first $N$ correlation function $D_1,\dots ,D_N$ to the Taylor expansion of the QCD partition function to all orders in ${\mu }_B$. We show that the resummed partition function is an approximation to the reweighted partition function at ${\mu }_B\ne 0$. We apply the proposed approach to high-statistics lattice QCD calculations using 2+1 flavors of Highly Improved Staggered Quarks with physical quark masses on $32^3\times 8$ lattices and for temperatures $T\approx 145$-176 MeV. We demonstrate that, as opposed to the Taylor expansion, the resummed version not only leads to improved convergence but also reflects the zeros of the resummed partition function and severity of the sign problem, leading to its eventual breakdown. We also provide a generalization of our scheme to include resummation of powers of temperature and quark masses in addition to ${\mu }_B$, and show that the alternative expansion scheme of [S. Borsányi et al., Phys. Rev. Lett. 126, 232001 (2021).] is a special case of this generalized resummation.

   ↳ hep-lathep-phnucl-exnucl-thPRL(2022)·45 citations
4. 04*

   Systematic study of the Chiral Magnetic Effect with the AVFD model at LHC energies

   Panos Christakoglou🇳🇱 · Shi Qiu🇳🇱 · Joey Staa🇳🇱

   We present a systematic study of the correlators used experimentally to probe the Chiral Magnetic Effect (CME) using the Anomalous Viscous Fluid Dynamics (AVFD) model in Pb--Pb and Xe--Xe collisions at LHC energies. We find a parametrization that describes the dependence of these correlators on the value of the axial current density ($n_5/\mathrm{s}$), which dictates the CME signal, and on the parameter that governs the background in these measurements i.e., the percentage of local charge conservation (LCC) within an event. This allows to deduce the values of $n_5/\mathrm{s}$ and the LCC percentage that provide a quantitative description of the centrality dependence of the experimental measurements. We find that the results in Xe--Xe collisions at $\sqrt{s_{\mathrm{NN}}}=5.44$~TeV are consistent with a background only scenario. On the other hand, the model needs a significant non-zero value of $n_5/\mathrm{s}$ to match the measurements in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$~TeV.

   ↳ nucl-thnucl-exEPJC(2021)·17 citations
5. 05*

   Development of very-thick transparent GEMs with wavelength-shifting capability for noble element TPCs

   M. Kuźniak🇵🇱 · D. González-Díaz🇪🇸 · P. Amedo🇪🇸 · C.D.R. Azevedo🇵🇹 · D.J. Fernández-Posada🇪🇸 · M. Kuźwa🇵🇱 · S. Leardini🇪🇸 · A. Leonhardt🇩🇪 · T. Łęcki🇵🇱 · L. Manzanillas🇩🇪 · D. Muenstermann🇬🇧 · G. Nieradka🇵🇱 and 6 other authors

   A new concept for the simultaneous detection of primary and secondary scintillation in time projection chambers is proposed. Its core element is a type of very-thick GEM structure supplied with transparent electrodes and machined from a polyethylene naphthalate plate, a natural wavelength-shifter. Such a device has good prospects for scalability and, by virtue of its genuine optical properties, it can improve on the light collection efficiency, energy threshold and resolution of conventional micropattern gas detectors. This, together with the intrinsic radiopurity of its constituting elements, offers advantages for noble gas and liquid based time projection chambers, used for dark matter searches and neutrino experiments. Production, optical and electrical characterization, and first measurements performed with the new device are reported.

   ↳ physics.ins-detastro-ph.IMhep-exnucl-exEPJC(2021)·11 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.