Simultaneous precision spectroscopy of pp , Be7 , and p

Abstract

We present the simultaneous measurement of the interaction rates R pp , R Be , R pep of pp, 7 Be, and pep solar neutrinos performed with a global fit to the Borexino data in an extended energy range (0.19-2.93) MeV with particular attention to details of the analysis methods. This result was obtained by analyzing 1291.51 days of Borexino Phase-II data, collected after an extensive scintillator purification campaign. Using counts per day ðcpdÞ=100 ton as unit, we find R pp ¼ 134 AE 10ðstatÞ þ6 −10 ðsysÞ, R Be ¼ 48.3 AE 1.1ðstatÞ þ0.4 −0.7 ðsysÞ; and R HZ pep ¼ 2.43 AE 0.36ðstatÞ þ0.15 −0.22 ðsysÞ assuming the interaction rate R CNO of CNO-cycle (Carbon, Nitrogen, Oxigen) solar neutrinos according to the prediction of the high metallicity standard solar model, and R LZ pep ¼ 2.65 AE 0.36ðstatÞ þ0.15 −0.24 ðsysÞ according to that of the low metallicity model. An upper limit R CNO < 8.1 cpd=100 ton (95% C.L.) is obtained by setting in the fit a constraint on the ratio R pp =R pep (47.7 AE 0.8 cpd=100 ton or 47.5 AE 0.8 cpd=100 ton according to the high or low metallicity hypothesis).

Connection between νn→ν¯n¯ reactions and n−Hao1 2020Phys. Rev. D3010View full textAdd to dashboardCite

“…II). The neutrino flavor oscillation has been confirmed and the corresponding ratios of the observed to expected neutrino rates for solar neutrinos in particular have also been given in various cases [67,68,73,79].…”

“…The corresponding fluxes can be predicted by the so-called Standard Solar Model (SSM) [52,55,56] and can be found from Refs. [56][57][58][59][60][61][62][63][64][65][66][67][68]. Numerous experiments [68][69][70][71][72][73][74][75][76][77] have been designed to detect solar neutrinos with various thresholds (see e.g.…”

Discovering true muonium at LHCb

“…Such new forces are motivated by several possible discrepancies with predictions of the SM in other experiments, including measurements of the muon anomalous magnetic moment (g − 2) µ [53], and the proton charge radius problem [54][55][56][57]. However, strong constraints on new physics exist from direct searches [58,59], measurements of (g − 2) µ , neutrino experiments [60][61][62][63][64][65][66], and eµ spectroscopy [67][68][69]. Indeed, these constraints are generally more powerful than the expected sensitivity of LHCb to TM, although some exceptions exist (for example, (g − 2) µ constraints can be alleviated if there are other new particles whose effects partially cancel).…”

Calculated solar-neutrino capture rate for a radiochemical Tl205 -based solar-neutrino detector

“…According to the current Atomic Mass Evaluation [7] the Q-value is given by 50.6 ± 0.5 keV, which is so far the lowest threshold among radiochemical approaches for solar-neutrino detection. This results in a total threshold of about 53 keV for the transition (2). Furthermore, a unique feature of this reaction is the possibility for long-term monitoring of the average solar-neutrino flux and hence the mean solar luminosity over the last 4.31 millions years due to the long half-life 1.73(7) × 10 7 yr of 205 Pb [8].…”

“…To date real-time monitoring of various neutrino chain reactions has been done by the Super-Kamiokande, the Sudbury Neutrino Observatory (SNO), KamLAND, and especially Borexino. Borexino was able to perform a common global fit of all the observed reactions of pp, pep, 7 Be and 8 B in one detector [2].…”