arXiv subjects

Bhag C. Chauhan

Publications and source records attributed to Bhag C. Chauhan.

18 recordsLinked to original sources

arXiv2011

Green's Function Formalism of Holography with Arbitrary Mass, Spin, and Dimensionality

In this work we present a mathematical description of how one can produce and read a thin hologram. We use different kinds of waves, such as scalar, vector (electromagnetic field, Maxwell-Proca fields, acoustic waves, etc.). For reading of the hologram, we use the Green's function formalism. With the help of computer simulations, we investigate the aberrations created by this procedure for the simplest case: 2d-scalar wave case.

physics.optics↗

arXiv2011

Model Independent Constraints on Solar Neutrinos

Using the data from SNO NCD phase, SuperK, Borexino and KamLAND Solar phase, we derive in a model independent way, bounds on the possible components in the solar neutrino flux. We update the limits on the antineutrino ($\barν_x$) flux and sterile ($ν_s$) component and compare them with the previous results obtained using SNO Salt phase data and data from SuperKamiokande experiments. It is affirmed that the upper bound on $\barν_x$ is independent of the $ν_s$ component. We recover the $ν_s$ and $\barν_x$ upper bounds existing in the literature. We also obtain bounds on $f_B$, the SSM normalization factor and the common parameter range for $f_B$ and the $ν_s$ components in the light of latest data. In summary, we update, in a model independent way, the previous results existing in literature in the light of latest solar neutrino data.

hep-ph↗

arXiv2007

Predictions from non trivial Quark-Lepton complementarity

The complementarity between the quark and lepton mixing matrices is shown to provide robust predictions. We obtain these predictions by first showing that the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices, may have a zero (1,3) entry which is favored by experimental data. We obtain that any theoretical model with a vanishing (1,3) entry of V_M that is in agreement with quark data, solar, and atmospheric mixing angle leads to $θ_{13}^{PMNS}=(9{^{+1}_{-2}})^\circ$. This value is consistent with the present 90% CL experimental upper limit. We also investigate the prediction on the lepton phases. We show that the actual evidence, under the only assumption that the correlation matrix V_M product of CKM and PMNS has a zero in the entry (1,3), gives us a prediction for the three CP-violating invariants J, S_1, and S_2. A better determination of the lepton mixing angles will give stronger prediction for the CP-violating invariants in the lepton sector. These will be tested in the next generation experiments. Finally we compute the effect of non diagonal neutrino mass in "l_i -> l_j gamma" in SUSY theories with non trivial Quark-Lepton complementarity and a flavor symmetry. The Quark-Lepton complementarity and the flavor symmetry strongly constrain the theory and we obtain a clear prediction for the contribution to "mu -> e gamma" and the "tau" decays "tau -> e gamma" and "tau -> mu gamma". If the Dirac neutrino Yukawa couplings are degenerate but the low energy neutrino masses are not degenerate, then the lepton decays are related among them by the V_M entries. On the other hand, if the Dirac neutrino Yukawa couplings are hierarchical or the low energy neutrino masses are degenerate, then the prediction for the lepton decays comes from the CKM hierarchy.

hep-ph↗

arXiv2007

Two Gallium data sets, spin flavour precession and KamLAND

We reexamine the possibility of a time modulation of the low energy solar neutrino flux which is suggested by the average decrease of the Ga data in line with our previous arguments. We perform two separate fits to the 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 find a solution with parameters $Δm^2_{21}=8.2\times 10^{-5} eV^2, tan^{2}θ=0.31$ in which the 'high' and the 'low' Ga rates lie far apart and are close to their central values and is of comparable quality to the global best fit, where these rates lie much closer 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 sets, 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.

hep-ph↗

arXiv2007

Quark-lepton complementarity, neutrino and standard model data predict $(θ_{13}^{PMNS}=9^{+1}_{-2})^\circ$

The complementarity between the quark and lepton mixing matrices is shown to provide a robust prediction for the neutrino mixing angle $θ_{13}^{PMNS}$. We obtain this prediction by first showing that the matrix $V_M$, product of the CKM and PMNS mixing matrices, may have a zero (1,3) entry which is favored by experimental data. Hence models with bimaximal or tribimaximal forms of the correlation matrix $V_M$ are quite possible. Any theoretical model with a vanishing (1,3) entry of $V_M$ that is in agreement with quark data, solar, and atmospheric mixing angle leads to $θ_{13}^{PMNS}=(9{^{+1}_{-2}})^\circ$. This value is consistent with the present 90% CL experimental upper limit.

hep-ph↗

arXiv2006

Holographic Principle and Quantum Physics

The concept of holography has lured philosophers of science for decades, and is becoming more and more popular on several fronts of science, e. g. in the physics of black holes. In this paper we try to understand things as if the visible universe were a reading of a low-dimensional hologram generated in hyperspace. We performed the whole process of creating and reading the hologram of a point in virtual space by using computer simulations. We claim that the fuzzieness in quantum mechanics, in statistical physics and thermodynamics is due to the fact that we do not see the real image of the object, but a holographic projection of it. We found that the projection of a point particle is a de Broglie-type wave. This indicates that holography could be the origin of the wave nature of a particle. We have also noted that one cannot stabilize the noise (or fuzzieness) in terms of the integration grid-points of the hologram, it means that one needs to give the grid-points a physical significance. So we further claim that the space is quantized, which supports the basic assumption of quantum gravity. Our study in the paper, although it is more qualitative, yet gives a smoking gun hint of a holographic basis of physical reality.

physics.comp-ph↗

arXiv2006

A Tempt To Measure Reality

Despite the extraordinary successes the two great bastions of $20^{th}$ century science (Quantum Theory and General Relativity) are troubled with serious conceptual and mathematical difficulties. As a result, further growth of fundamental science is at stake. Is this the end of science? Optimistic answer is ``NOT''! In this work, it is argued that science must continue its cruise, but with anew strategy -- a thorough recourse into the grass-root level working of science is inevitable. In fact, our conventional scientific methods are based upon ordinary sense perception, which keeps the outer physical universe as a separate entity, that is something quite independent of the observer. Basically, it is the observer -- the knower (human mind) -- which makes perception possible. It makes a person or scientist to recognize or refute the existence of an object or a phenomenon. It is also tempted to evince that working of human mind is epistemically scientific and can, in principle, be completely deciphered. It's inclusion in scientific theories, although tedious, can certainly spark a revolution in our understanding of nature and reality.

physics.pop-ph↗

arXiv2006

$ ^7 Be$ Neutrino Signal Variation in KamLAND

Large Mixing Angle (LMA) neutrino oscillation is the main solution for the long-standing Solar Neutrino Problem (SNP). Whether there is any subdominant effect accompanying the dominant LMA solution can not be ruled out at the moment, but will be settled by the forthcoming data from highly skilled real time experiments targeting essentially the low energy domain of solar neutrinos. Assuming a subdominant effect converting one of the active neutrinos into a sterile partner in the varying solar field with changing sunspot activity, we performed field-profile-independent predictions for $^7 Be$ neutrino signal variation, which might be tested in the KamLAND's future solar neutrino detection program. We found that after a substantial reduction of background and running of KamLAND solar mode through the sunspot maximum period (around 2010 - 2012), when the solar field at the resonance may vary from few $kG$ to $300~kG$, the subdominant time variation effect might be clearly visible (more than $5σ$) for $^7 Be$ neutrinos.

hep-ph↗

arXiv2005

Neutrino Mass Matrices with Vanishing Determinant and $θ_{13}$

We investigate the prospects for scenarios with vanishing determinant neutrino mass matrices and vanishing $θ_{13}$ mixing angle. Normal and inverse mass hierarchies are considered separately. For normal hierarchy it is found that neutrinoless double beta decay cannot be observed by any of the present or next generation experiments. For inverse hierarchy the neutrinoless double beta decay is, on the contrary, accessible to experiments. We also analyse for both hierarchies the case for texture zeros and equalities between mass matrix elements. No texture zeros are found to be possible nor any such equalities, apart from the obvious ones.

hep-ph↗

arXiv2005

Science In Trauma

Quantum theory has been proved as an outstanding mystery in modern science. The predictions of science have turned out to be probabilistic. The principle of determinism has failed. For systems like weather, earthquakes, rolling dices etc... and of course human behavior it has proved impossible, for science, to describe a state of the system accurately for a long time into the future. Moreover, modern cosmology has to rely on philosophical assumptions. It is argued -- by taking into account of the views of learned scientists and philosophers -- that modern science can never explain everything and it is a hard fact to discover the ``Theory Of Everything''. On the other hand, modern scientific technology have damaged our environment and posed serious threats for the future development of science. All these facts and results put a big question-mark (?) on the grass-root level working of science. In fact, all scientific researches are based upon ordinary sense perception, which keeps the outer physical universe as a separate entity, that is something quite independent of the observer. Basically, it is the observer -- the knower -- which makes perception possible. Astonishingly, the knower -- human mind -- is not included in our scientific theories. One should not forget human-being (human mind) is a part of nature and an essential component of our observations, so it's inclusion in scientific theories is must in order to recover modern science from the drastic state of trauma.

physics.pop-ph↗

arXiv2005

Low Energy Solar Neutrinos and Spin Flavour Precession

The possibility that the Gallium data effectively indicates a time modulation of the solar active neutrino flux in possible connection to solar activity is examined on the light of spin flavour precession to sterile neutrinos as a subdominant process in addition to oscillations. We distinguish two sets of Gallium data, relating them to high and low solar activity. Such modulation affects principally the low energy neutrinos ($pp$ and $^7 Be$) so that the effect, if it exists, will become most clear in the forthcoming Borexino and LENS experiments and will provide evidence for a neutrino magnetic moment. Using a model previously developed, we perform two separate fits in relation to low and high activity periods to all solar neutrino data. These fits include the very recent charged current spectrum from the SNO experiment. We also derive the model predictions for Borexino and LENS experiments.

hep-ph↗

arXiv2004

SNO, SuperKamiokande data, antineutrinos and sterile neutrinos

Allowing for antineutrinos ($\barν_x$) and sterile neutrinos ($ν_s$) to accompany LMA oscillations, we derive in a model independent way, upper bounds on their components in the solar flux, using the recent data from SNO and SuperKamiokande. Along with the general case (LMA + $\barν_x$ + $ν_s$) we consider the special cases where only $\barν_x$ or $ν_s$ are present. We obtain an upper bound on $\barν_x$ which is independent of the $ν_s$ component. In the no sterile case we obtain upper and lower bounds on $f_B$, the SSM normalization factor. We also investigate in the general case the common parameter range for $f_B$ and the $\barν_x$, $ν_s$ components and find that the upper bound on $ν_s$ is hardly sensitive to the $\barν_x$ component. In the absence of $\barν_x$ we recover the $ν_s$ upper bound existing in the literature. We finally present a simple $χ^2$ analysis of all four cases considered.

hep-ph↗

arXiv2004

LMA and sterile neutrinos: a case for resonance spin flavour precession?

Open questions remain after the confirmation of LMA as the dominant solution to the solar neutrino deficit. These are the apparent time modulation of the solar neutrino event rates in the Homestake, Gallium and SuperKamiokande experiments, possibly related to solar magnetic activity, the discrepancy between the event rate in the Homestake experiment and its theoretical prediction and the absence of the electron spectrum upturn in SuperKamiokande at energies below 6-8 MeV. We search for a possible understanding of these questions in the context of resonant spin flavour precession to sterile neutrinos, assuming a class of magnetic field profiles anchored in the upper radiation/lower convection zone. We consider the simplest such model beyond the standard 2$ν$ flavour LMA one, with one single magnetic moment transition between active and sterile state and vanishing vacuum mixing. The preferred mass square difference is $Δm^2_{10}=O(10^{-8}eV^2)$. The Ga rate appears to be the most sensitive of all to solar activity. It is also found that a field profile extending within a longer region in the radial direction is favoured over another with a shorter span, and leads to a stronger suppression than in the LMA case of the intermediate energy neutrinos and some of the $^8 B$ ones.

hep-ph↗

arXiv2003

KamLAND and Solar Antineutrino Spectrum

We use the recent KamLAND observations to predict the solar antineutrino spectrum at some confidence limits. We find that a scaling of the antineutrino probability with respect to the magnetic field profile --in the sense that the same probability function can be reproduced by any profile with a suitable peak field value-- can be utilised to obtain a general shape of the solar antineutrino spectrum. This scaling and the upper bound on the solar antineutrino event rate, that can be derived from the data, lead to: 1) an upper bound on the solar antineutrino flux, 2) the prediction of their energy spectrum, as the normalisation of the spectrum can be obtained from the total number of antineutrino events recorded in the experiment. We get $ϕ_{\barν}<3.8\times 10^{-3}ϕ(^8B)$ or $ϕ_{\barν} <5.5\times 10^{-3}ϕ(^8B)$ at 95% CL, assuming Gaussian or Poissonian statistics, respectively. And for 90% CL these become $ϕ_{\barν}<3.4 \times 10^{-3}ϕ(^8B)$ and $ϕ_{\barν}<4.9\times 10^{-3}ϕ(^8B)$. It shows an improvement by a factor of 3-5 with respect to existing bounds. These limits are quite general and independent of the detailed structure of the magnetic field in the solar interior.

hep-ph↗

arXiv2003

KamLAND, solar antineutrinos and the solar magnetic field

In this work the possibility of detecting solar electron antineutrinos produced by a solar core magnetic field from the KamLAND recent observations is investigated. We find a scaling of the antineutrino probability with respect to the magnetic field profile in the sense that the same probability function can be reproduced by any profile with a suitable peak field value. In this way the solar electron antineutrino spectrum can be unambiguosly predicted. We use this scaling and the negative results indicated by the KamLAND experiment to obtain upper bounds on the solar electron antineutrino flux. We get $ϕ_{\barν}<3.8\times 10^{-3}ϕ(^8B)$ at 95% CL. For 90% CL this becomes $ϕ_{\barν}<3.4\times 10^{-3}ϕ(^8B)$, an improvement by a factor of 3-5 with respect to existing bounds. These limits are independent of the detailed structure of the magnetic field in the solar interior. We also derive upper bounds on the peak field value which are uniquely determined for a fixed solar field profile. In the most efficient antineutrino producing case, we get (95% CL) an upper limit on the product of the neutrino magnetic moment by the solar field $μB< 2.8\times 10^{-19}$ MeV or $B_0 \leq 4.9 \times 10^7 G$ for $μ_ν=10^{-12}μ_B$.

hep-ph↗

arXiv2003

Science: A Solid Whole

However, the observations encompassed by classical physics excludes the observer from the physical reality, yet the deep-down understandung of nature --{\it the quantum theory}-- can not avoid the intrusion of observer into the measurement process. Indeed, the quantum physics experiments have knocked the door of a new paradigm: in which science of consciousness is an important axiom. In the present work, it is argued --by taking into account of the views of learned scientists and philosophers-- that modern science is incomplete and lacking something in the basic understanding of nature \cite{r}. Classical physics has failed to explain the dynamics of the microscopic particles, eventhough modern scientific researches are based upon the prejudice posed by classical physics: keeping the outer physical universe as a separate entity, that is something quite independent of the observer --human mind. One should not forget that human-being is a part of nature and human mind is an essential component of our observations. Basically, it is the observer --the consciousness-- which makes perception possible. The working of human mind must be included in our scientific theories. In fact, human free will is an illusion and nothing in the entire universe (with life) lies outside the domain of science and determinism.

physics.gen-ph↗

arXiv2002

Solar Magnetic Fields Profile: A Natural Consequence of RSFP Scenario

Assuming the solar neutrino deficit is resolved by the resonant interaction of the neutrino magnetic moment with the solar magnetic field --in the framework of Resonant Spin Flavour Precession (RSFP) scenario-- the solar magnetic field profile function has been derived from the scenario in the light of solar neutrino data. An approximate qualitative analysis has been done for vanishing vacuum mixing and it has been found that the profile derived is quite stable in nature. As because on changing the neutrino parameters ($μ_ν, Δ{m^2}$) and the solar neutrino data the profile is just scaled along the axes. In principle, the nature of the profile is strongly dependent on the solar matter density distribution function. The current approach is quite different from the usual one- in which the best field profile is discovered by performing $χ^{2}_{min.}$ calculations using solar neutrino data. Furthermore, the profile derived in the present work --when tested by $χ^{2}_{min.}$ calculations-- was found to be the best suited one, for the solar interior.

hep-ph↗

arXiv2002

Resonance Spin Flavour Precession of Solar Neutrinos After SNO NC Data

We present an analysis of the solar neutrino data assuming the deficit of solar neutrinos to be originated from the interaction of their transition magnetic moments with the solar magnetic field. We perform fits to the rates only and global fits and consider separately the existing data prior to the announcement of the SNO NC results, and present data. Predictions for the Borexino experiment are also derived. The solar field profiles are taken both in the radiation zone and core of the sun, and in the convective zone. The latter are chosen so as to exhibit a rapid increase across the bottom of the convective zone and a moderate decrease towards the surface. Regarding the field profiles in the radiative zone and core, it is found that the data show a preference for those cases in which a strong field rests at the solar centre with a steep decrease thereafter. For these, the quality of the global fits is as good as the one from the best oscillation solutions and the same as for the convective zone profiles examined. It is also found that the $χ^2$ of the fits increases when the most recent data are considered, owing to the smaller errors involved. This in turn provides more precise predictions for Borexino than previous ones, thus resulting in a clearer possible distinction between magnetic moment and the currently favoured oscillation solutions.

hep-ph↗