<sup>7</sup><i>Be</i>neutrino signal variation in KamLAND

Chauhan, B. C.

doi:10.1088/1126-6708/2006/02/035

Cited by 7 publications

(3 citation statements)

References 22 publications

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“…We start with a brief review of the model presented in ref. [16] whose predictions for Borexino and LENS were analyzed in [13] and for KamLAND in [26]. We also evaluate the event rates in the Chlorine experiment for standard neutrinos (i.e.…”

Section: Resonant Spin Flavour Precession and Solar Modelsmentioning

confidence: 99%

SNO+: predictions from standard solar models and spin flavour precession

Picariello,

Pulido,

Andringa

et al. 2007

Preprint

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Time variability of the solar neutrino flux especially in the low and intermediate energy sector remains an open question and, if it exists, it is likely to be originated from the magnetic moment transition from active to light sterile neutrinos at times of intense solar activity and magnetic field. We examine the prospects for the SNO+ experiment to address this important issue and to distinguish between the two classes of solar models which are currently identified as corresponding to a high (SSM I) and a low (SSM II) heavy element abundance. We also evaluate the predictions from these two models for the Chlorine experiment event rate in the standard LMA and LMA+Resonant Spin Flavour Precession (RSFP) scenarios. It is found that after three years of SNO+ data taking, the pep flux measurement will be able to discriminate between the standard LMA and LMA+RSFP scenarios, independently of which is the correct solar model. If the LMA rate is measured, RSFP with B 0 ∼ 280kG for the resonant ∆m 2 01 can be excluded at more than 4σ. A low rate would signal new physics, excluding all the 90% allowed range of the standard LMA solution at 3σ, and a time variability would be a strong signature of the RSFP model. The CNO fluxes are the ones for which the two SSM predictions exhibit the largest differences, so their measurement at SNO+ will be important to favour one or the other. The distinction will be clearer after LMA or RSFP are confirmed with pep, but still, a CNO measurement at the level of SSM I/LMA will disfavour SSM II at about 3 σ. We conclude that consistency between future pep and CNO flux measurements at SNO+ and Chlorine would either favour an LMA+RSFP scenario or favour SSM II over SSM I.

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Section: Resonant Spin Flavour Precession and Solar Modelsmentioning

confidence: 99%

SNO+: predictions from standard solar models and spin flavour precession

Picariello,

Pulido,

Andringa

et al. 2007

Preprint

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“…No other experiment sees such variations and none is sensitive to low energy neutrinos with the exception of Homestake whose rate contains only 14% of 7 Be. Hence, this fact opens the possibility that low energy neutrinos may undergo a time modulation partially hidden in the gallium data which may be directly connected in some non-obvious way to solar activity [19][20][21]. Hence, also the prime importance of the low energy sector investigation.…”

Section: Introductionmentioning

confidence: 98%

Two gallium data sets, spin flavour precession and KamLAND

Chauhan¹,

Pulido²,

Picariello

2007

J. Phys. G: Nucl. Part. Phys.

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We reexamine the possibility of a time modulation of the low energy solar neutrino flux which is hinted by the average decrease of the Ga data in line with our previous arguments. We perform two separate fits to solar neutrino data, one corresponding to 'high' and the other to 'low' Ga data, associated with low and high solar activity respectively. We therefore consider an alternative to the conventional solar+KamLAND fitting, which allows one to explore the much wider range of the θ 12 angle permitted by the KamLAND fitting alone. We propose a solution with parameters ∆m 2 21 = 8.4 × 10 −5 eV 2 , tan 2 θ = 0.27 in which the 'high' and the 'low' Ga rates lie far apart and are close to their central values, in contrast to the global best fit solution where these rates lie close to each other. This is an indication that the best fit in which all solar and KamLAND data are used is not a good measure of the separation of the two Ga data, as the information from the low energy neutrino modulation is dissimulated in the wealth of data. Furthermore for the parameter set proposed one obtains an equally good fit to the KamLAND energy spectrum and an even better fit than the 'conventional' LMA one for the reactor antineutrino survival probability as measured by KamLAND.

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“…Solar neutrino flux time fluctuations have been studied for several decades, mainly focusing on finding evidence of the solar magnetic cycle and day-night earth effects (e.g., Lisi et al 2004;Sturrock et al 2005;Fogli et al 2005;Chauhan 2006).…”

Section: Introductionmentioning

confidence: 99%

Search for global f-modes and p-modes in the 8B neutrino flux

Lopes

2013

Preprint

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The impact of global acoustic modes on the 8 B neutrino flux time series is computed for the first time. It is shown that the time fluctuations of the 8 B neutrino flux depend on the amplitude of acoustic eigenfunctions in the region where the 8 B neutrino flux is produced: modes with low n (or order) that have eigenfunctions with a relatively large amplitude in the Sun's core, strongly affect the neutrino flux; conversely, modes with high n that have eigenfunctions with a minimal amplitude in the Sun's core have a very small impact on the neutrino flux. It was found that the global modes with a larger impact on the 8 B neutrino flux have a frequency of oscillation in the interval 250 µHz to 500 µHz (or a period in the interval 30 minutes to 70 minutes), such as the f -modes (n = 0) for the low degrees, radial modes of order n ≤ 3, and the dipole mode of order n = 1. Their corresponding neutrino eigenfunctions are very sensitive to the solar inner core and are unaffected by the variability of the external layers of the solar surface. If time variability of neutrinos is observed for these modes, it will lead to new ways of improving the sound speed profile inversion in the central region of the Sun.

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⁷Beneutrino signal variation in KamLAND

Cited by 7 publications

References 22 publications

SNO+: predictions from standard solar models and spin flavour precession

SNO+: predictions from standard solar models and spin flavour precession

Two gallium data sets, spin flavour precession and KamLAND

Search for global f-modes and p-modes in the 8B neutrino flux

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7Beneutrino signal variation in KamLAND

Cited by 7 publications

References 22 publications

SNO+: predictions from standard solar models and spin flavour precession

SNO+: predictions from standard solar models and spin flavour precession

Two gallium data sets, spin flavour precession and KamLAND

Search for global f-modes and p-modes in the 8B neutrino flux

Contact Info

Product

Resources

About

⁷Beneutrino signal variation in KamLAND