High Energy Neutrino Beams Research Articles

Installation, commissioning, and testing of the HB650 CM at PIP2IT

The Proton Improvement Plan-II (PIP-II) is a major upgrade to the Fermilab accelerator complex, featuring a new 800-MeV Superconducting Radio-Frequency (SRF) linear accelerator (LINAC) powering the accelerator complex to provide the world’s most intense high-energy neutrino beam. This paper describes the conversion of the PIP-II Injector Test Facility (PIP2IT) cryogenic system into a test stand for PIP-II High-Beta 650 MHz (HB650) cryomodules at Fermilab’s Cryomodule Test Facility (CMTF). A description of the associated mechanical, electrical, and controls modifications necessary for testing HB650 cryomodules are provided. The cooldown and warmup requirements, procedures and associated controls logic is described.

Overview and status of the PIP-II cryogenic system

The Proton Improvement Plan-II (PIP-II) is a major upgrade to the Fermilab accelerator complex, featuring a new 800-MeV Superconducting Radio-Frequency (SRF) linear accelerator (Linac) powering the accelerator complex to provide the world’s most intense high-energy neutrino beam. The PIP-II Linac consists of 23 SRF cryomodules operating at 2 K, 5 K, and 40 K temperature levels supplied by a single helium cryoplant providing 2.5 kW of cooling capacity at 2.0 K. The PIP-II cryogenic system consists of two major systems: a helium cryogenic plant and a cryogenic distribution system. The cryogenic plant includes a refrigerator cold box, a warm compressor system, and helium storage, recovery, and purification systems. The cryogenic distribution system includes a distribution box, intermediate transfer line, and a tunnel transfer line consisting of modular bayonet cans which supply and return cryogens to the cryomodules. A turnaround can is located at the end of the Linac to turnaround cryogenic flows. This paper describes the layout, design, and current status of the PIP-II cryogenic system.

Forward neutrino fluxes at the LHC

With the upcoming Run 3 of the LHC, the FASERv and SND@LHC detectors will start a new era of neutrino physics using the far-forward high-energy neutrino beam produced in collisions at ATLAS. This emerging LHC neutrino physics program requires reliable estimates of the LHC's forward neutrino fluxes and their uncertainties. In this paper we provide a new fast-neutrino flux simulation, implemented as a RIVET module, to address this issue. We present the expected energy distributions going through the FASERv and SND@LHC detectors based on various commonly used event generators, analyze the origin of those neutrinos, and present the expected neutrino event rates.

Neutrino beams at ultra high energy proton colliders on the basis of focusing single crystals

The problem of creation of high energy neutrino beams on the basis of modern and future circular proton accelerators with the help of traditional technology seems to be expensive and difficult. In our previous article we proposed a new method for generation of neutrino beams for 6.5 TeV protons at the LHC based on the use of focusing bent single crystals. However, in last years there have been publications devoted to proton colliders with an energy of 50 TeV. This encouraged us to study the possibility of applying of the proposed method to generate neutrino beams at these colliders. In addition, we present some new information for proton energy 6.5 TeV.

Leggett-Garg inequality in the context of three flavor neutrino oscillation

The present work is devoted to the characterization of the Leggett-Garg inequality for three-flavoured neutrino oscillations in presence of both matter and Charge-Conjugation and Parity violating (CP) effects. This study complements and completes the recent one put forward in [17] by relaxing the stationary condition. At variance with the latter case, the LGI contains interference terms which cannot be expressed in terms of experimentally measurable quantities, thus drawing a clear-cut distinction between the two scenarios, as well as highlighting the role of the stationary assumption on such systems. We find that the additional terms are small for high energy neutrino beam compared to the maximum value attained by the Leggett-Garg parameter.

High energy neutrino beam generation based on crystal optics

The problem of creation of high energy neutrino beams on the basis of modern and future circular proton accelerators with the help of traditional technology seems to be expensive and difficult. Because of this, we propose the solution of this problem based on the usage of focusing bent single crystals. In the paper we demonstrate the possibilities of acceptance and focusing of a pion beam with the help of a crystal optical lens system. As an illustration of these features the calculated neutrino fluxes for energy of circulating proton beam equal to 6.5 TeV are presented.

Measurement of the Weinberg angle in neutrino interactions

Neutrino physics with high energy neutrino beams has played a crucial role in establishing the Standard Model of the electroweak interaction, in particular with repeated measurements of increasing precision of the fundamental parameter sin2 θ W which defines the electroweak mixing. This paper relates the history of these measurements, from the discovery of the neutral current interaction in 1973 until the latest high precision measurements in the years 2000. The review discusses in chronological order the important experiments performed at CERN, Fermilab and Brookhaven during the last thirty years of the 20th century.

The OPERA experiment

The OPERA experiment was designed to study νμ→ντ oscillations in appearance mode using the CERN to Gran Sasso high energy neutrino beam. From 2008 to 2012, 19505 CNGS neutrino interactions were recorded in the OPERA detector. At the present status of the analysis, 4 ντ candidate events have been observed, establishing the oscillation mechanism in the atmospheric sector with a significance of 4.2 σ. The oscillation analysis will be presented in detail and the candidate events will be described. The final measurement of the atmospheric muon charge ratio in the TeV region will be also reported.

Search for charmed hadrons in the OPERA experiment

The OPERA experiment was designed to study muon neutrino to tau neutrino oscillations in appearance mode, using the CERN to Gran Sasso (CNGS) high energy neutrino beam 730 km far from the source. From 2008 to 2012, CNGS neutrinos interactions were recorded in the OPERA detector, which includes target units made of lead plates alternated with emulsion films and electronic tracker planes. The on-going analysis is aimed at the detection of short-lived particle decays occurring over distances of the order of 1 mm from the neutrino interaction point. It has allowed identifying charmed hadrons together with the tau lepton decay candidates that have established vμ → vτ oscillations with a significance of 4.2 σ. The procedure applied in OPERA to detect short-lived particle decays and its application to the search for charmed hadrons will be discussed here in detail.

Detecting the neutrino magnetic moment at hadron colliders

We consider the model based on the $SU(2{)}_{R}\ifmmode\times\else\texttimes\fi{}SU(2{)}_{L}\ifmmode\times\else\texttimes\fi{}U(1{)}_{B\ensuremath{-}L}$ gauge group with Majorana neutrinos. In this model the transit dipole magnetic moment $({\ensuremath{\mu}}^{\ensuremath{\nu}N}{)}_{if}$ which is associated with the ${N}_{i}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{f}\ensuremath{\gamma}$ transition may be as large as a $\text{few}\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}8}{\ensuremath{\mu}}_{B}$. The possible manifestations of the $({\ensuremath{\mu}}^{\ensuremath{\nu}N}{)}_{if}$ at hadron colliders are investigated. In doing so, we assume that one of the three heavy right-handed neutrinos ${N}_{eR}$ is on the electroweak scale. The process of ${N}_{eR}$ production $p+p\ensuremath{\rightarrow}{W}_{R}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}{N}_{eR}$, with the subsequent ${N}_{eR}$ decay through the channel ${N}_{eR}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{eL}+\ensuremath{\gamma}$, is investigated. Problems caused by selecting the signal from background is examined. It is shown that the process in question is the most perspective one for detecting the $({\ensuremath{\mu}}^{\ensuremath{\nu}N}{)}_{if}$, provided the condition ${m}_{{W}_{R}}<6\text{ }\text{ }\mathrm{TeV}$ is realized. The cross section of ${N}_{\ensuremath{\mu}R}$ production under the collision of a high-energy light neutrino beam with the proton target ${\ensuremath{\nu}}_{\ensuremath{\mu}L}+p\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\rightarrow}{N}_{\ensuremath{\mu}R}+p+X$ is investigated. The produced ${N}_{\ensuremath{\mu}R}$ neutrino is identified through the decay channel ${N}_{\ensuremath{\mu}R}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{\ifmmode\pm\else\textpm\fi{}}+2j$. Detection of both the positive and negative charged muons will point to the Majorana nature of the neutrino. On the other hand, detection of the right-handed polarized muons will be unambiguously indicative of a nonzero value of $({\ensuremath{\mu}}^{\ensuremath{\nu}N}{)}_{if}$.

A method for measuring coherent elastic neutrino-nucleus scattering at a far off-axis high-energy neutrino beam target

We present an experimental method for measuring the process of coherent elastic neutrino-nucleus scattering (CENNS). This method uses a detector situated transverse to a high-energy neutrino beam production target. This detector would be sensitive to the low-energy neutrinos arising from decay-at-rest pions in the target. We discuss the physics motivation for making this measurement and outline the predicted backgrounds and sensitivities using this approach. We report a measurement of neutron backgrounds as found in an off-axis surface location of the Fermilab Booster Neutrino Beam (BNB) target. The results indicate that the Fermilab BNB target is a favorable location for a CENNS experiment.

Beta Beams for Neutrino Production

To use accelerated beta active radioactive ions to produce collimated high energy neutrino beams was proposed by P. Zuchelli in 2002. Since then, several ideas related to how to design Beta Beam facilities have been studied. Design studies of an accelerator complex, based on CERN accelerators, have been supported by research programs within the European Commisison FP6 and FP7 frameworks (EURISOL Design Study and EUROnu). In these studies 6He and 18Ne are used as beta emitters to produce antineutrinos and neutrinos respectively. Alternative isotopes for neutrino beam production, 8Li and 8B, are investigated in the now ongoing study, EUROnu. Due to the higher reaction Q-value of these ions, the resulting neutrino energies are higher. The isotopes we need for neutrino beams have to be produced in large quantities using non conventional methods. Latest research on production of isotopes that are presently considered for Beta Beams will be discussed.The work achieved gives a good ground to propose the Beta Beam, which is based on known technology, for neutrino production. In this status review we concentrate on technical issues related to a possible Beta Beam facility using the CERN infrastructure.

Accelerator systems for the International Design Study of the Neutrino Factory

The Neutrino Factory produces high-energy neutrino beams with a well-defined flavour content and energy spectrum from the decay of intense, high-energy, stored muon beams. The muon storage rings include long straight sections that are directed toward neutrino detectors that are sited several thousand kilometres away. This poster defines the muon-beam requirements and describes the accelerator facility that is required to deliver them. We give a baseline specification for the accelerator facility and describe the accelerator subsystems of which it is comprised. We will briefly present some of the accelerator-physics challenges such a facility presents and alternative designs for some of the subsystems.

Search for νμ → ντ oscillation with the OPERA experiment in the CNGS beam

The OPERA neutrino experiment in the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in direct appearance mode in the νμ → ντ channel, the ντ signature being the identification of the τ-lepton created in its charged current interaction. The hybrid apparatus consists of a large mass emulsion film/lead target complemented by electronic detectors. Placed in the LNGS, it is exposed to the high-energy long-baseline CERN Neutrino beam to Gran Sasso (CNGS) 730 km away from the neutrino source. The observation of a first ντ candidate event was reported in 2010. In this paper, we discuss the result of the analysis of the data taken during the first two years of operation (2008–2009) underlining the major improvements brought to the analysis chain and to the Monte Carlo simulations. The statistical significance of the one event observed so far is then evaluated to 95%.

Physics at CNGS neutrino beam

The CERN Neutrinos to Gran Sasso project (CNGS) is devoted to prove unambiguously the ν μ → ν τ oscillation channel in the atmospheric sector. The high energy and high intensity CNGS muon neutrino beam, generated at CERN, is directed towards the Gran Sasso National Laboratory (LNGS), in Italy, where the ICARUS and OPERA long base-line experiments search for ν τ appearance. In this talk, a review of the status and physics potential of the CNGS program will be presented. A detailed discussion about recent results obtained by the OPERA Collaboration will be given, too.

Beta Beams for Neutrino Production

To use accelerated beta active ions to produce collimated high energy neutrino beams was proposed by P. Zuchelli in 2002 and studies of a suitable accelerator complex, based on CERN accelerators, have been supported by research programs within the European Commisison FP6 and FP7 frameworks (EURISOL Design Study and EUROnu). In these studies 6He and 18Ne are used as beta emitters to produce antineutrinos and neutrinos respectively. Alternative isotopes for neutrino beam production, giving higher neutrino energies, 8Li and 8B, are investigated in the now ongoing study, EUROnu. The isotopes for neutrino beams have to be produced in large quantities using non conventional methods. The work achieved gives a good ground to propose the Beta Beam, for neutrino production. Technical issues related to a Beta Beam facility using the CERN infrastructure are reviewed.

Submarine neutrino communication

We discuss the possibility to use a high energy neutrino beam from a muon storage ring to provide one way communication with a submerged submarine. Neutrino interactions produce muons which can be detected either, directly when they pass through the submarine or by their emission of Cerenkov light in sea water, which, in turn, can be exploited with sensitive photo detectors. Due to the very high neutrino flux from a muon storage ring, it is sufficient to mount either detection system directly onto the hull of the submersible. The achievable data transfer rates compare favorable with existing technologies and do allow for a communication at the usual speed and depth of submarines.

Galactic neutrino communication and SETI

In this talk I summarize some work done over the last few years about how advanced civilizations across the galaxy may be using neutrinos to communicate in a variety of ways and sending signals as well as using high energy neutrino beams to modulate the periods of Cepheid variable stars.

NEUTRINO FLAVOR GONIOMETRY BY HIGH ENERGY ASTROPHYSICAL BEAMS

It is shown how high energy neutrino beams from very distant sources can be utilized to learn about many properties of neutrinos such as lifetimes, mass hierarchy, mixing, minuscule pseudo-Dirac mass splittings and other exotic properties; in addition, the production mechanism of neutrinos in astrophysical sources can also be elucidated.

Search for neutrino oscillations vμ → vτ in CERN → Gran Sasso high-energy neutrino beam (the OPERA experiment)

The main purpose of the OPERA experiment is the direct observation of neutrino oscillations (vμ → vτ) in the vμ beam from the CERN accelerator through the direct detection of τ leptons in nuclear emulsions at the Gran Sasso National Underground Laboratory. Some aspects of the use of the Russian PAVICOM facility for processing and analyzing the data obtained from the OPERA experiment are discussed.