Dipangkar Dutta

Educational Background:

• Ph.D., Northwestern University, 1999
• B. Tech., Indian Institute of Technology, Bombay, 1992

Links

• Curriculum Vitae
• Personal Page

Interests

Nucleon structure, QCD in Nuclei, Violation of Fundamental Symmetries and Precision Tests of the Standard Model.

My research is focused on precision measurement of fundamental properties of nucleons. These studies seek to understand the internal structure of hadrons in terms of the underlying quark and gluon degrees of freedom of Quantum Chromodynamics (QCD). QCD is the fundamental theory of the strong force and it has been tested extremely well in the very high energy regime, i.e., the perturbative QCD (pQCD) regime, but little is known in the non-perturbative regime where ordinary matter exists. One of the important motivations of this area of research is to understand the transition from the nucleon-meson to the quark-gluon degrees of freedom. Most of this research is carried out at Jefferson Lab (JLab) in Newport News where we undertake experiments in search of signatures of QCD in nuclei. In these experiments both polarized and unpolarized observables in exclusive processes are studied in search of signatures of QCD such as color transparency, scaling, hadron helicity conservation and nuclear filtering.

I am also interested in precision tests of fundamental symmetries and the Standard Model. Three of the four fundamental forces in nature (weak, strong and electromagnetic) have been combined (unified) into one mathematically consistent quantum field theory known as the Standard Model (SM). The SM predicts or is consistent with all known aspects of the elementary particles and their interactions over an impressive range of probes and scales. My research program includes two new experiments that aim to challenge the predictions of the SM and look for physics beyond the SM. One of these experiments (The QWeak experiment) proposed for JLab utilizes parity violating electron scattering from the proton to perform a precision measurement of the weak charge of the proton (QPWeak). This experiment will test the SM prediction at the 10sigma level. Any deviation from the SM prediction would be a signal of "New physics", whereas agreement would place new and significant constraints on possible SM extensions. The second experiment is the new search for the neutron electric dipole moment (The nEDM Experiment) which is proposed for the brand new Spallation Neutron Source at Oak Ridge National Lab. The goal of this experiment is a factor of 100 improvement over the current experimental limit. This search for a non-zero value of the neutron EDM is a direct search for violation of the time reversal symmetry (T). Furthermore, this experiment offers an unique opportunity to measure a non-zero value of the neutron EDM, which would imply new sources of CP violation in nature that go beyond the mechanism in the SM. New sources of CP violation have profound implications for understanding the preponderance of matter over antimatter in the universe (Baryon Asymmetry of the Universe).

Selected Publications

 

• J. Seely, C. Crawford, B. Clasie, W. Xu, D. Dutta, and H. Gao, Laser-driven Nuclear-polarized Hydrogen Internal Gas Target, Phys. Rev. A, vol. 73 ( 2006) , pp. 062714 .
• B.~Clasie, C.~Crawford, J.~Seely, W.~Xu, D.~Dutta, H.~Gao, Laser-driven Target of High-density Nuclear-spin Polarized Hydrogen Gas, Phys. Rev. A, vol. 73 ( 2006) , pp. 020703(R).
• K. Kramer et al., The Q^2 Dependence of the Neutron Spin Structure Function g2 at Low Q^2, Phys. Rev. Lett., vol. 95 ( 2005) , pp. 142002 .
• F. Dohrmann et al., Electroproduction of Strangeness on (Lambda)H-3,4 Bound States on Helium, AIP Conf. Proc., vol. 768 ( 2005) , pp. 294 (Proceedings of the 19th European Few-Body Conference on Problems in Physics (EFB 19), Groningen, The Netherlands,.).
• D. J. Hamilton et al., Polarization Transfer in Proton Compton Scattering at High Momentum Transfer, Phys. Rev. Lett., vol. 94 no. 24 ( 2005) , pp. 242001.